Hardening

This reverts commit e2b407c6f3.

.github/actions/extract-memory-report/action.yml

@@ -0,0 +1,51 @@
+name: 'Extract Memory Test Report'
+description: 'Extracts and displays memory test report from a container'
+inputs:
+  container-name:
+    description: 'Name of the container to extract logs from'
+    required: true
+  python-version:
+    description: 'Python version for artifact naming'
+    required: true
+  output-dir:
+    description: 'Directory to store output logs'
+    required: false
+    default: 'output-logs'
+
+runs:
+  using: "composite"
+  steps:
+    - name: Create output directory
+      shell: bash
+      run: |
+        mkdir -p ${{ inputs.output-dir }}
+
+    - name: Dump container log
+      shell: bash
+      run: |
+        echo "Disabled for now"
+#        return
+#        docker logs ${{ inputs.container-name }} > ${{ inputs.output-dir }}/${{ inputs.container-name }}-stdout-${{ inputs.python-version }}.txt 2>&1 || echo "Could not get stdout"
+#        docker logs ${{ inputs.container-name }} 2> ${{ inputs.output-dir }}/${{ inputs.container-name }}-stderr-${{ inputs.python-version }}.txt || echo "Could not get stderr"
+
+    - name: Extract and display memory test report
+      shell: bash
+      run: |
+        echo "Disabled for now"
+#        echo "Extracting test-memory.log from container..."
+#        docker cp ${{ inputs.container-name }}:/app/changedetectionio/test-memory.log ${{ inputs.output-dir }}/test-memory-${{ inputs.python-version }}.log || echo "test-memory.log not found in container"
+#
+#        echo "=== Top 10 Highest Peak Memory Tests ==="
+#        if [ -f ${{ inputs.output-dir }}/test-memory-${{ inputs.python-version }}.log ]; then
+#          grep "Peak memory:" ${{ inputs.output-dir }}/test-memory-${{ inputs.python-version }}.log | \
+#            sed 's/.*Peak memory: //' | \
+#            paste -d'|' - <(grep "Peak memory:" ${{ inputs.output-dir }}/test-memory-${{ inputs.python-version }}.log) | \
+#            sort -t'|' -k1 -nr | \
+#            cut -d'|' -f2 | \
+#            head -10
+#          echo ""
+#          echo "=== Full Memory Test Report ==="
+#          cat ${{ inputs.output-dir }}/test-memory-${{ inputs.python-version }}.log
+#        else
+#          echo "No memory log available"
+#        fi

.github/dependabot.yml

@@ -11,6 +11,4 @@ updates:
   - package-ecosystem: pip
     directory: /
     schedule:
-      interval: "daily"
-    allow:
-      - dependency-name: "apprise"
+      interval: "weekly"

.github/test/Dockerfile-alpine

@@ -7,6 +7,8 @@ ENV PYTHONUNBUFFERED=1
 
 COPY requirements.txt /requirements.txt
 
+ARG TARGETPLATFORM
+
 RUN \
  apk add --update --no-cache --virtual=build-dependencies \
     build-base \
@@ -27,7 +29,19 @@ RUN \
     file \
     nodejs \
     poppler-utils \
-    python3 && \
+    python3 \
+    glib \
+    libsm \
+    libxext \
+    libxrender && \
+  case "$TARGETPLATFORM" in \
+    linux/arm/v7|linux/arm/v8) \
+      echo "INFO: Skipping py3-opencv on $TARGETPLATFORM (using pixelmatch fallback)" \
+      ;; \
+    *) \
+      apk add --update --no-cache py3-opencv || echo "WARN: py3-opencv install failed, using pixelmatch fallback" \
+      ;; \
+  esac && \
   echo "**** pip3 install test of changedetection.io ****" && \
   python3 -m venv /lsiopy  && \
   pip install -U pip wheel setuptools && \

.github/workflows/codeql-analysis.yml

@@ -30,11 +30,11 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@v3
+      uses: github/codeql-action/init@v4
       with:
         languages: ${{ matrix.language }}
         # If you wish to specify custom queries, you can do so here or in a config file.
@@ -45,7 +45,7 @@ jobs:
     # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
     # If this step fails, then you should remove it and run the build manually (see below)
     - name: Autobuild
-      uses: github/codeql-action/autobuild@v3
+      uses: github/codeql-action/autobuild@v4
 
     # ℹ️ Command-line programs to run using the OS shell.
     # 📚 https://git.io/JvXDl
@@ -59,4 +59,4 @@ jobs:
     #   make release
 
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v3
+      uses: github/codeql-action/analyze@v4

.github/workflows/containers.yml

@@ -15,6 +15,7 @@ on:
   push:
     branches:
       - master
+      - dev
 
 jobs:
   metadata:
@@ -39,12 +40,20 @@ jobs:
     # Or if we are in a tagged release scenario.
     if: ${{ github.event.workflow_run.conclusion == 'success' }} || ${{ github.event.release.tag_name }} != ''
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up Python 3.11
         uses: actions/setup-python@v6
         with:
           python-version: 3.11
 
+      - name: Cache pip packages
+        uses: actions/cache@v5
+        with:
+          path: ~/.cache/pip
+          key: ${{ runner.os }}-pip-${{ hashFiles('requirements.txt') }}
+          restore-keys: |
+            ${{ runner.os }}-pip-
+
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
@@ -84,10 +93,10 @@ jobs:
           version: latest
           driver-opts: image=moby/buildkit:master
 
-      # master branch -> :dev container tag
+      # dev branch -> :dev container tag
       - name: Build and push :dev
         id: docker_build
-        if: ${{ github.ref }} == "refs/heads/master"
+        if: ${{ github.ref == 'refs/heads/dev' }}
         uses: docker/build-push-action@v6
         with:
           context: ./

.github/workflows/pypi-release.yml

@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: Set up Python
       uses: actions/setup-python@v6
       with:
@@ -21,20 +21,20 @@ jobs:
     - name: Build a binary wheel and a source tarball
       run: python3 -m build
     - name: Store the distribution packages
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       with:
         name: python-package-distributions
         path: dist/
 
 
   test-pypi-package:
-    name: Test the built 📦 package works basically.
+    name: Test the built package works basically.
     runs-on: ubuntu-latest
     needs:
     - build
     steps:
     - name: Download all the dists
-      uses: actions/download-artifact@v5
+      uses: actions/download-artifact@v7
       with:
         name: python-package-distributions
         path: dist/
@@ -42,18 +42,39 @@ jobs:
       uses: actions/setup-python@v6
       with:
         python-version: '3.11'
+
     - name: Test that the basic pip built package runs without error
       run: |
         set -ex
         ls -alR 
         
-        # Find and install the first .whl file
-        find dist -type f -name "*.whl" -exec pip3 install {} \; -quit
+        # Install the first wheel found in dist/
+        WHEEL=$(find dist -type f -name "*.whl" -print -quit)
+        echo Installing $WHEEL
+        python3 -m pip install --upgrade pip
+        python3 -m pip install "$WHEEL"
         changedetection.io -d /tmp -p 10000 &
         
         sleep 3
         curl --retry-connrefused --retry 6 http://127.0.0.1:10000/static/styles/pure-min.css >/dev/null
         curl --retry-connrefused --retry 6 http://127.0.0.1:10000/ >/dev/null
+        
+        # --- API test ---
+        # This also means that the docs/api-spec.yml was shipped and could be read
+        test -f /tmp/url-watches.json
+        API_KEY=$(jq -r '.. | .api_access_token? // empty' /tmp/url-watches.json)
+        echo Test API KEY is $API_KEY
+        curl -X POST "http://127.0.0.1:10000/api/v1/watch" \
+          -H "x-api-key: ${API_KEY}" \
+          -H "Content-Type: application/json" \
+          --show-error --fail \
+          --retry 6 --retry-delay 1 --retry-connrefused \
+          -d '{
+            "url": "https://example.com",
+            "title": "Example Site Monitor",
+            "time_between_check": { "hours": 1 }
+          }'
+          
         killall changedetection.io
 
 
@@ -72,7 +93,7 @@ jobs:
 
     steps:
     - name: Download all the dists
-      uses: actions/download-artifact@v5
+      uses: actions/download-artifact@v7
       with:
         name: python-package-distributions
         path: dist/

.github/workflows/test-container-build.yml

@@ -44,12 +44,20 @@ jobs:
           - platform: linux/arm64
             dockerfile: ./.github/test/Dockerfile-alpine
     steps:
-        - uses: actions/checkout@v5
+        - uses: actions/checkout@v6
         - name: Set up Python 3.11
           uses: actions/setup-python@v6
           with:
             python-version: 3.11
 
+        - name: Cache pip packages
+          uses: actions/cache@v5
+          with:
+            path: ~/.cache/pip
+            key: ${{ runner.os }}-pip-${{ hashFiles('requirements.txt') }}
+            restore-keys: |
+              ${{ runner.os }}-pip-
+
         # Just test that the build works, some libraries won't compile on ARM/rPi etc
         - name: Set up QEMU
           uses: docker/setup-qemu-action@v3

.github/workflows/test-only.yml

@@ -7,7 +7,7 @@ jobs:
   lint-code:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Lint with Ruff
         run: |
           pip install ruff
@@ -21,6 +21,8 @@ jobs:
           python3 -c "from openapi_spec_validator import validate_spec; import yaml; validate_spec(yaml.safe_load(open('docs/api-spec.yaml')))"
 
   test-application-3-10:
+    # Only run on push to master (including PR merges)
+    if: github.event_name == 'push' && github.ref == 'refs/heads/master'
     needs: lint-code
     uses: ./.github/workflows/test-stack-reusable-workflow.yml
     with:
@@ -28,12 +30,15 @@ jobs:
 
 
   test-application-3-11:
+    # Always run
     needs: lint-code
     uses: ./.github/workflows/test-stack-reusable-workflow.yml
     with:
       python-version: '3.11'
 
   test-application-3-12:
+    # Only run on push to master (including PR merges)
+    if: github.event_name == 'push' && github.ref == 'refs/heads/master'
     needs: lint-code
     uses: ./.github/workflows/test-stack-reusable-workflow.yml
     with:
@@ -41,6 +46,8 @@ jobs:
       skip-pypuppeteer: true
 
   test-application-3-13:
+    # Only run on push to master (including PR merges)
+    if: github.event_name == 'push' && github.ref == 'refs/heads/master'
     needs: lint-code
     uses: ./.github/workflows/test-stack-reusable-workflow.yml
     with:

.github/workflows/test-stack-reusable-workflow.yml

@@ -15,138 +15,294 @@ on:
         default: false
 
 jobs:
-  test-application:
+  # Build the Docker image once and share it with all test jobs
+  build:
     runs-on: ubuntu-latest
     env:
       PYTHON_VERSION: ${{ inputs.python-version }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
-      # Mainly just for link/flake8
       - name: Set up Python ${{ env.PYTHON_VERSION }}
         uses: actions/setup-python@v6
         with:
           python-version: ${{ env.PYTHON_VERSION }}
 
+      - name: Cache pip packages
+        uses: actions/cache@v5
+        with:
+          path: ~/.cache/pip
+          key: ${{ runner.os }}-pip-py${{ env.PYTHON_VERSION }}-${{ hashFiles('requirements.txt') }}
+          restore-keys: |
+            ${{ runner.os }}-pip-py${{ env.PYTHON_VERSION }}-
+            ${{ runner.os }}-pip-
+
       - name: Build changedetection.io container for testing under Python ${{ env.PYTHON_VERSION }}
         run: |
           echo "---- Building for Python ${{ env.PYTHON_VERSION }} -----"
-          # Build a changedetection.io container and start testing inside
           docker build --build-arg PYTHON_VERSION=${{ env.PYTHON_VERSION }} --build-arg LOGGER_LEVEL=TRACE -t test-changedetectionio .
-          # Debug info
-          docker run test-changedetectionio  bash -c 'pip list'         
+          docker run test-changedetectionio bash -c 'pip list'
 
       - name: We should be Python ${{ env.PYTHON_VERSION }} ...
-        run: |         
-          docker run test-changedetectionio  bash -c 'python3 --version'
-
-      - name: Spin up ancillary testable services
         run: |
-          
-          docker network create changedet-network
-          
-          # Selenium
-          docker run --network changedet-network -d --hostname selenium  -p 4444:4444 --rm --shm-size="2g"  selenium/standalone-chrome:4
-          
-          # SocketPuppetBrowser + Extra for custom browser test
-          docker run --network changedet-network -d -e "LOG_LEVEL=TRACE" --cap-add=SYS_ADMIN --name sockpuppetbrowser --hostname sockpuppetbrowser --rm -p 3000:3000 dgtlmoon/sockpuppetbrowser:latest                    
-          docker run --network changedet-network -d -e "LOG_LEVEL=TRACE" --cap-add=SYS_ADMIN --name sockpuppetbrowser-custom-url --hostname sockpuppetbrowser-custom-url  -p 3001:3000 --rm dgtlmoon/sockpuppetbrowser:latest
+          docker run test-changedetectionio bash -c 'python3 --version'
 
-      - name: Spin up ancillary SMTP+Echo message test server
+      - name: Save Docker image
         run: |
-          # Debug SMTP server/echo message back server
-          docker run --network changedet-network -d -p 11025:11025 -p 11080:11080  --hostname mailserver test-changedetectionio  bash -c 'pip3 install aiosmtpd && python changedetectionio/tests/smtp/smtp-test-server.py'
-          docker ps
+          docker save test-changedetectionio -o /tmp/test-changedetectionio.tar
 
-      - name: Show docker container state and other debug info
+      - name: Upload Docker image artifact
+        uses: actions/upload-artifact@v6
+        with:
+          name: test-changedetectionio-${{ env.PYTHON_VERSION }}
+          path: /tmp/test-changedetectionio.tar
+          retention-days: 1
+
+  # Unit tests (lightweight, no ancillary services needed)
+  unit-tests:
+    runs-on: ubuntu-latest
+    needs: build
+    timeout-minutes: 10
+    env:
+      PYTHON_VERSION: ${{ inputs.python-version }}
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Download Docker image artifact
+        uses: actions/download-artifact@v7
+        with:
+          name: test-changedetectionio-${{ env.PYTHON_VERSION }}
+          path: /tmp
+
+      - name: Load Docker image
         run: |
-          set -x
-          echo "Running processes in docker..."
-          docker ps
+          docker load -i /tmp/test-changedetectionio.tar
 
       - name: Run Unit Tests
         run: |
-          # Unit tests
-          docker run test-changedetectionio  bash -c 'python3 -m unittest changedetectionio.tests.unit.test_notification_diff'
-          docker run test-changedetectionio  bash -c 'python3 -m unittest changedetectionio.tests.unit.test_watch_model'
-          docker run test-changedetectionio  bash -c 'python3 -m unittest changedetectionio.tests.unit.test_jinja2_security'
-          docker run test-changedetectionio  bash -c 'python3 -m unittest changedetectionio.tests.unit.test_semver'
+          docker run test-changedetectionio bash -c 'python3 -m unittest changedetectionio.tests.unit.test_notification_diff'
+          docker run test-changedetectionio bash -c 'python3 -m unittest changedetectionio.tests.unit.test_watch_model'
+          docker run test-changedetectionio bash -c 'python3 -m unittest changedetectionio.tests.unit.test_jinja2_security'
+          docker run test-changedetectionio bash -c 'python3 -m unittest changedetectionio.tests.unit.test_semver'
 
-      - name: Test built container with Pytest (generally as requests/plaintext fetching)
+  # Basic pytest tests with ancillary services
+  basic-tests:
+    runs-on: ubuntu-latest
+    needs: build
+    timeout-minutes: 25
+    env:
+      PYTHON_VERSION: ${{ inputs.python-version }}
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Download Docker image artifact
+        uses: actions/download-artifact@v7
+        with:
+          name: test-changedetectionio-${{ env.PYTHON_VERSION }}
+          path: /tmp
+
+      - name: Load Docker image
         run: |
-          # All tests
-          echo "run test with pytest"
-          # The default pytest logger_level is TRACE
-          # To change logger_level for pytest(test/conftest.py),
-          # append the docker option. e.g. '-e LOGGER_LEVEL=DEBUG'
-          docker run --name test-cdio-basic-tests --network changedet-network  test-changedetectionio  bash -c 'cd changedetectionio && ./run_basic_tests.sh'
+          docker load -i /tmp/test-changedetectionio.tar
 
-# PLAYWRIGHT/NODE-> CDP
-      - name: Playwright and SocketPuppetBrowser - Specific tests in built container
+      - name: Test built container with Pytest
         run: |
-          # Playwright via Sockpuppetbrowser fetch
-          # tests/visualselector/test_fetch_data.py will do browser steps  
-          docker run --rm -e "FLASK_SERVER_NAME=cdio" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network --hostname=cdio test-changedetectionio  bash -c 'cd changedetectionio;pytest  -vv --capture=tee-sys --showlocals --tb=long --live-server-host=0.0.0.0 --live-server-port=5004 tests/fetchers/test_content.py'
-          docker run --rm -e "FLASK_SERVER_NAME=cdio" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network --hostname=cdio test-changedetectionio  bash -c 'cd changedetectionio;pytest  -vv --capture=tee-sys --showlocals --tb=long --live-server-host=0.0.0.0 --live-server-port=5004 tests/test_errorhandling.py'
-          docker run --rm -e "FLASK_SERVER_NAME=cdio" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network --hostname=cdio test-changedetectionio  bash -c 'cd changedetectionio;pytest  -vv --capture=tee-sys --showlocals --tb=long --live-server-host=0.0.0.0 --live-server-port=5004 tests/visualselector/test_fetch_data.py'
-          docker run --rm -e "FLASK_SERVER_NAME=cdio" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network --hostname=cdio test-changedetectionio  bash -c 'cd changedetectionio;pytest  -vv --capture=tee-sys --showlocals --tb=long --live-server-host=0.0.0.0 --live-server-port=5004 tests/fetchers/test_custom_js_before_content.py'
+          docker network inspect changedet-network >/dev/null 2>&1 || docker network create changedet-network
+          docker run --name test-cdio-basic-tests --network changedet-network test-changedetectionio bash -c 'cd changedetectionio && ./run_basic_tests.sh'
 
+      - name: Extract memory report and logs
+        if: always()
+        uses: ./.github/actions/extract-memory-report
+        with:
+          container-name: test-cdio-basic-tests
+          python-version: ${{ env.PYTHON_VERSION }}
 
-      - name: Playwright and SocketPuppetBrowser - Headers and requests
-        run: |       
-          # Settings headers playwright tests - Call back in from Sockpuppetbrowser, check headers
-          docker run --name "changedet" --hostname changedet --rm -e "FLASK_SERVER_NAME=changedet" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000?dumpio=true" --network changedet-network test-changedetectionio  bash -c 'find .; cd changedetectionio; pytest --live-server-host=0.0.0.0  --live-server-port=5004 tests/test_request.py; pwd;find .'
+      - name: Store test artifacts
+        if: always()
+        uses: actions/upload-artifact@v6
+        with:
+          name: test-cdio-basic-tests-output-py${{ env.PYTHON_VERSION }}
+          path: output-logs
 
-      - name: Playwright and SocketPuppetBrowser - Restock detection
-        run: |                            
-          # restock detection via playwright - added name=changedet here so that playwright and sockpuppetbrowser can connect to it
-          docker run --rm --name "changedet" -e "FLASK_SERVER_NAME=changedet" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network test-changedetectionio  bash -c 'cd changedetectionio;pytest --live-server-port=5004 --live-server-host=0.0.0.0 tests/restock/test_restock.py'
+  # Playwright tests
+  playwright-tests:
+    runs-on: ubuntu-latest
+    needs: build
+    timeout-minutes: 10
+    env:
+      PYTHON_VERSION: ${{ inputs.python-version }}
+    steps:
+      - uses: actions/checkout@v6
 
-# STRAIGHT TO CDP
-      - name: Pyppeteer and SocketPuppetBrowser - Specific tests in built container
-        if: ${{ inputs.skip-pypuppeteer == false }}
+      - name: Download Docker image artifact
+        uses: actions/download-artifact@v7
+        with:
+          name: test-changedetectionio-${{ env.PYTHON_VERSION }}
+          path: /tmp
+
+      - name: Load Docker image
         run: |
-          # Playwright via Sockpuppetbrowser fetch 
-          docker run --rm -e "FLASK_SERVER_NAME=cdio" -e "FAST_PUPPETEER_CHROME_FETCHER=True" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network --hostname=cdio test-changedetectionio  bash -c 'cd changedetectionio;pytest --live-server-host=0.0.0.0 --live-server-port=5004 tests/fetchers/test_content.py'
-          docker run --rm -e "FLASK_SERVER_NAME=cdio" -e "FAST_PUPPETEER_CHROME_FETCHER=True" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network --hostname=cdio test-changedetectionio  bash -c 'cd changedetectionio;pytest --live-server-host=0.0.0.0 --live-server-port=5004 tests/test_errorhandling.py'
-          docker run --rm -e "FLASK_SERVER_NAME=cdio" -e "FAST_PUPPETEER_CHROME_FETCHER=True" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network --hostname=cdio test-changedetectionio  bash -c 'cd changedetectionio;pytest --live-server-host=0.0.0.0 --live-server-port=5004 tests/visualselector/test_fetch_data.py'
-          docker run --rm -e "FLASK_SERVER_NAME=cdio" -e "FAST_PUPPETEER_CHROME_FETCHER=True" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network --hostname=cdio test-changedetectionio  bash -c 'cd changedetectionio;pytest --live-server-host=0.0.0.0 --live-server-port=5004 tests/fetchers/test_custom_js_before_content.py'
+          docker load -i /tmp/test-changedetectionio.tar
 
-      - name: Pyppeteer and SocketPuppetBrowser - Headers and requests checks
-        if: ${{ inputs.skip-pypuppeteer == false }}
+      - name: Spin up ancillary services
         run: |
-          # Settings headers playwright tests - Call back in from Sockpuppetbrowser, check headers
-          docker run --name "changedet" --hostname changedet --rm  -e "FAST_PUPPETEER_CHROME_FETCHER=True" -e "FLASK_SERVER_NAME=changedet" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000?dumpio=true" --network changedet-network test-changedetectionio  bash -c 'cd changedetectionio; pytest --live-server-host=0.0.0.0  --live-server-port=5004 tests/test_request.py'
+          docker network create changedet-network
+          docker run --network changedet-network -d -e "LOG_LEVEL=TRACE" --cap-add=SYS_ADMIN --name sockpuppetbrowser --hostname sockpuppetbrowser --rm -p 3000:3000 dgtlmoon/sockpuppetbrowser:latest
+          docker run --network changedet-network -d -e "LOG_LEVEL=TRACE" --cap-add=SYS_ADMIN --name sockpuppetbrowser-custom-url --hostname sockpuppetbrowser-custom-url -p 3001:3000 --rm dgtlmoon/sockpuppetbrowser:latest
 
-      - name: Pyppeteer and SocketPuppetBrowser - Restock detection
-        if: ${{ inputs.skip-pypuppeteer == false }}
-        run: |                            
-          # restock detection via playwright - added name=changedet here so that playwright and sockpuppetbrowser can connect to it
-          docker run --rm --name "changedet" -e "FLASK_SERVER_NAME=changedet"  -e "FAST_PUPPETEER_CHROME_FETCHER=True"  -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network test-changedetectionio  bash -c 'cd changedetectionio;pytest --live-server-port=5004 --live-server-host=0.0.0.0 tests/restock/test_restock.py'
+      - name: Playwright - Specific tests in built container
+        run: |
+          docker run --rm -e "FLASK_SERVER_NAME=cdio" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network --hostname=cdio test-changedetectionio bash -c 'cd changedetectionio;pytest -vv --capture=tee-sys --showlocals --tb=long --live-server-host=0.0.0.0 --live-server-port=5004 tests/fetchers/test_content.py'
+          docker run --rm -e "FLASK_SERVER_NAME=cdio" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network --hostname=cdio test-changedetectionio bash -c 'cd changedetectionio;pytest -vv --capture=tee-sys --showlocals --tb=long --live-server-host=0.0.0.0 --live-server-port=5004 tests/test_errorhandling.py'
+          docker run --rm -e "FLASK_SERVER_NAME=cdio" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network --hostname=cdio test-changedetectionio bash -c 'cd changedetectionio;pytest -vv --capture=tee-sys --showlocals --tb=long --live-server-host=0.0.0.0 --live-server-port=5004 tests/visualselector/test_fetch_data.py'
+          docker run --rm -e "FLASK_SERVER_NAME=cdio" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network --hostname=cdio test-changedetectionio bash -c 'cd changedetectionio;pytest -vv --capture=tee-sys --showlocals --tb=long --live-server-host=0.0.0.0 --live-server-port=5004 tests/fetchers/test_custom_js_before_content.py'
+
+      - name: Playwright - Headers and requests
+        run: |
+          docker run --name "changedet" --hostname changedet --rm -e "FLASK_SERVER_NAME=changedet" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000?dumpio=true" --network changedet-network test-changedetectionio bash -c 'find .; cd changedetectionio; pytest --live-server-host=0.0.0.0 --live-server-port=5004 tests/test_request.py; pwd;find .'
+
+      - name: Playwright - Restock detection
+        run: |
+          docker run --rm --name "changedet" -e "FLASK_SERVER_NAME=changedet" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network test-changedetectionio bash -c 'cd changedetectionio;pytest --live-server-port=5004 --live-server-host=0.0.0.0 tests/restock/test_restock.py'
+
+  # Pyppeteer tests
+  pyppeteer-tests:
+    runs-on: ubuntu-latest
+    needs: build
+    if: ${{ inputs.skip-pypuppeteer == false }}
+    timeout-minutes: 10
+    env:
+      PYTHON_VERSION: ${{ inputs.python-version }}
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Download Docker image artifact
+        uses: actions/download-artifact@v7
+        with:
+          name: test-changedetectionio-${{ env.PYTHON_VERSION }}
+          path: /tmp
+
+      - name: Load Docker image
+        run: |
+          docker load -i /tmp/test-changedetectionio.tar
+
+      - name: Spin up ancillary services
+        run: |
+          docker network create changedet-network
+          docker run --network changedet-network -d -e "LOG_LEVEL=TRACE" --cap-add=SYS_ADMIN --name sockpuppetbrowser --hostname sockpuppetbrowser --rm -p 3000:3000 dgtlmoon/sockpuppetbrowser:latest
+
+      - name: Pyppeteer - Specific tests in built container
+        run: |
+          docker run --rm -e "FLASK_SERVER_NAME=cdio" -e "FAST_PUPPETEER_CHROME_FETCHER=True" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network --hostname=cdio test-changedetectionio bash -c 'cd changedetectionio;pytest --live-server-host=0.0.0.0 --live-server-port=5004 tests/fetchers/test_content.py'
+          docker run --rm -e "FLASK_SERVER_NAME=cdio" -e "FAST_PUPPETEER_CHROME_FETCHER=True" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network --hostname=cdio test-changedetectionio bash -c 'cd changedetectionio;pytest --live-server-host=0.0.0.0 --live-server-port=5004 tests/test_errorhandling.py'
+          docker run --rm -e "FLASK_SERVER_NAME=cdio" -e "FAST_PUPPETEER_CHROME_FETCHER=True" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network --hostname=cdio test-changedetectionio bash -c 'cd changedetectionio;pytest --live-server-host=0.0.0.0 --live-server-port=5004 tests/visualselector/test_fetch_data.py'
+          docker run --rm -e "FLASK_SERVER_NAME=cdio" -e "FAST_PUPPETEER_CHROME_FETCHER=True" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network --hostname=cdio test-changedetectionio bash -c 'cd changedetectionio;pytest --live-server-host=0.0.0.0 --live-server-port=5004 tests/fetchers/test_custom_js_before_content.py'
+
+      - name: Pyppeteer - Headers and requests checks
+        run: |
+          docker run --name "changedet" --hostname changedet --rm -e "FAST_PUPPETEER_CHROME_FETCHER=True" -e "FLASK_SERVER_NAME=changedet" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000?dumpio=true" --network changedet-network test-changedetectionio bash -c 'cd changedetectionio; pytest --live-server-host=0.0.0.0 --live-server-port=5004 tests/test_request.py'
+
+      - name: Pyppeteer - Restock detection
+        run: |
+          docker run --rm --name "changedet" -e "FLASK_SERVER_NAME=changedet" -e "FAST_PUPPETEER_CHROME_FETCHER=True" -e "PLAYWRIGHT_DRIVER_URL=ws://sockpuppetbrowser:3000" --network changedet-network test-changedetectionio bash -c 'cd changedetectionio;pytest --live-server-port=5004 --live-server-host=0.0.0.0 tests/restock/test_restock.py'
+
+  # Selenium tests
+  selenium-tests:
+    runs-on: ubuntu-latest
+    needs: build
+    timeout-minutes: 10
+    env:
+      PYTHON_VERSION: ${{ inputs.python-version }}
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Download Docker image artifact
+        uses: actions/download-artifact@v7
+        with:
+          name: test-changedetectionio-${{ env.PYTHON_VERSION }}
+          path: /tmp
+
+      - name: Load Docker image
+        run: |
+          docker load -i /tmp/test-changedetectionio.tar
+
+      - name: Spin up ancillary services
+        run: |
+          docker network create changedet-network
+          docker run --network changedet-network -d --hostname selenium -p 4444:4444 --rm --shm-size="2g" selenium/standalone-chrome:4
+          sleep 3
+
+      - name: Specific tests for headers and requests checks with Selenium
+        run: |
+
+          docker run --name "changedet" --hostname changedet --rm -e "FLASK_SERVER_NAME=changedet" -e "WEBDRIVER_URL=http://selenium:4444/wd/hub" --network changedet-network test-changedetectionio bash -c 'cd changedetectionio; pytest --live-server-host=0.0.0.0 --live-server-port=5004 tests/test_request.py'
 
-# SELENIUM
       - name: Specific tests in built container for Selenium
         run: |
-          # Selenium fetch
-          docker run --rm -e "WEBDRIVER_URL=http://selenium:4444/wd/hub" --network changedet-network test-changedetectionio  bash -c 'cd changedetectionio;pytest tests/fetchers/test_content.py && pytest tests/test_errorhandling.py'
+          docker run --rm -e "WEBDRIVER_URL=http://selenium:4444/wd/hub" --network changedet-network test-changedetectionio bash -c 'cd changedetectionio;pytest tests/fetchers/test_content.py && pytest tests/test_errorhandling.py'
 
-      - name: Specific tests in built container for headers and requests checks with Selenium
+
+  # SMTP tests
+  smtp-tests:
+    runs-on: ubuntu-latest
+    needs: build
+    timeout-minutes: 10
+    env:
+      PYTHON_VERSION: ${{ inputs.python-version }}
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Download Docker image artifact
+        uses: actions/download-artifact@v7
+        with:
+          name: test-changedetectionio-${{ env.PYTHON_VERSION }}
+          path: /tmp
+
+      - name: Load Docker image
         run: |
-          docker run --name "changedet" --hostname changedet --rm -e "FLASK_SERVER_NAME=changedet" -e "WEBDRIVER_URL=http://selenium:4444/wd/hub" --network changedet-network test-changedetectionio  bash -c 'cd changedetectionio; pytest --live-server-host=0.0.0.0  --live-server-port=5004 tests/test_request.py'
+          docker load -i /tmp/test-changedetectionio.tar
+
+      - name: Spin up SMTP test server
+        run: |
+          docker network create changedet-network
+          docker run --network changedet-network -d -p 11025:11025 -p 11080:11080 --hostname mailserver test-changedetectionio bash -c 'pip3 install aiosmtpd && python changedetectionio/tests/smtp/smtp-test-server.py'
 
-# OTHER STUFF
       - name: Test SMTP notification mime types
         run: |
-          # SMTP content types - needs the 'Debug SMTP server/echo message back server' container from above
-          # "mailserver" hostname defined above
           docker run --rm --network changedet-network test-changedetectionio bash -c 'cd changedetectionio;pytest tests/smtp/test_notification_smtp.py'
 
-      # @todo Add a test via playwright/puppeteer
-      # squid with auth is tested in run_proxy_tests.sh -> tests/proxy_list/test_select_custom_proxy.py
-      - name: Test proxy squid style interaction
+  # Proxy tests
+  proxy-tests:
+    runs-on: ubuntu-latest
+    needs: build
+    timeout-minutes: 10
+    env:
+      PYTHON_VERSION: ${{ inputs.python-version }}
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Download Docker image artifact
+        uses: actions/download-artifact@v7
+        with:
+          name: test-changedetectionio-${{ env.PYTHON_VERSION }}
+          path: /tmp
+
+      - name: Load Docker image
+        run: |
+          docker load -i /tmp/test-changedetectionio.tar
+
+      - name: Spin up services
+        run: |
+          docker network create changedet-network
+          docker run --network changedet-network -d --hostname selenium -p 4444:4444 --rm --shm-size="2g" selenium/standalone-chrome:4
+          docker run --network changedet-network -d -e "LOG_LEVEL=TRACE" --cap-add=SYS_ADMIN --name sockpuppetbrowser --hostname sockpuppetbrowser --rm -p 3000:3000 dgtlmoon/sockpuppetbrowser:latest
+          docker run --network changedet-network -d -e "LOG_LEVEL=TRACE" --cap-add=SYS_ADMIN --name sockpuppetbrowser-custom-url --hostname sockpuppetbrowser-custom-url -p 3001:3000 --rm dgtlmoon/sockpuppetbrowser:latest
+
+      - name: Test proxy Squid style interaction
         run: |
           cd changedetectionio
           ./run_proxy_tests.sh
+          docker ps
           cd ..
 
       - name: Test proxy SOCKS5 style interaction
@@ -155,28 +311,65 @@ jobs:
           ./run_socks_proxy_tests.sh
           cd ..
 
+  # Custom browser URL tests
+  custom-browser-tests:
+    runs-on: ubuntu-latest
+    needs: build
+    timeout-minutes: 10
+    env:
+      PYTHON_VERSION: ${{ inputs.python-version }}
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Download Docker image artifact
+        uses: actions/download-artifact@v7
+        with:
+          name: test-changedetectionio-${{ env.PYTHON_VERSION }}
+          path: /tmp
+
+      - name: Load Docker image
+        run: |
+          docker load -i /tmp/test-changedetectionio.tar
+
+      - name: Spin up ancillary services
+        run: |
+          docker network create changedet-network
+          docker run --network changedet-network -d -e "LOG_LEVEL=TRACE" --cap-add=SYS_ADMIN --name sockpuppetbrowser --hostname sockpuppetbrowser --rm -p 3000:3000 dgtlmoon/sockpuppetbrowser:latest
+          docker run --network changedet-network -d -e "LOG_LEVEL=TRACE" --cap-add=SYS_ADMIN --name sockpuppetbrowser-custom-url --hostname sockpuppetbrowser-custom-url -p 3001:3000 --rm dgtlmoon/sockpuppetbrowser:latest
+
       - name: Test custom browser URL
         run: |
           cd changedetectionio
           ./run_custom_browser_url_tests.sh
-          cd ..
 
-      - name: Test changedetection.io container starts+runs basically without error
+  # Container startup tests
+  container-tests:
+    runs-on: ubuntu-latest
+    needs: build
+    timeout-minutes: 10
+    env:
+      PYTHON_VERSION: ${{ inputs.python-version }}
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Download Docker image artifact
+        uses: actions/download-artifact@v7
+        with:
+          name: test-changedetectionio-${{ env.PYTHON_VERSION }}
+          path: /tmp
+
+      - name: Load Docker image
         run: |
-          docker run --name test-changedetectionio -p 5556:5000  -d test-changedetectionio
+          docker load -i /tmp/test-changedetectionio.tar
+
+      - name: Test container starts+runs basically without error
+        run: |
+          docker run --name test-changedetectionio -p 5556:5000 -d test-changedetectionio
           sleep 3
-          # Should return 0 (no error) when grep finds it
-          curl --retry-connrefused --retry 6  -s http://localhost:5556 |grep -q checkbox-uuid
-          
-          # and IPv6
-          curl --retry-connrefused --retry 6  -s -g -6 "http://[::1]:5556"|grep -q checkbox-uuid
-
-          # Check whether TRACE log is enabled.
-          # Also, check whether TRACE came from STDOUT
+          curl --retry-connrefused --retry 6 -s http://localhost:5556 |grep -q checkbox-uuid
+          curl --retry-connrefused --retry 6 -s -g -6 "http://[::1]:5556"|grep -q checkbox-uuid
           docker logs test-changedetectionio 2>/dev/null | grep 'TRACE log is enabled' || exit 1
-          # Check whether DEBUG is came from STDOUT
           docker logs test-changedetectionio 2>/dev/null | grep 'DEBUG' || exit 1
-
           docker kill test-changedetectionio
 
       - name: Test HTTPS SSL mode
@@ -184,78 +377,66 @@ jobs:
           openssl req -x509 -newkey rsa:4096 -keyout privkey.pem -out cert.pem -days 365 -nodes -subj "/CN=localhost"
           docker run --name test-changedetectionio-ssl --rm -e SSL_CERT_FILE=cert.pem -e SSL_PRIVKEY_FILE=privkey.pem -p 5000:5000 -v ./cert.pem:/app/cert.pem -v ./privkey.pem:/app/privkey.pem -d test-changedetectionio
           sleep 3
-          # Should return 0 (no error) when grep finds it
-          # -k because its self-signed
           curl --retry-connrefused --retry 6 -k https://localhost:5000 -v|grep -q checkbox-uuid
-      
           docker kill test-changedetectionio-ssl
 
       - name: Test IPv6 Mode
         run: |
-          # IPv6 - :: bind to all interfaces inside container (like 0.0.0.0), ::1 would be localhost only
           docker run --name test-changedetectionio-ipv6 --rm -p 5000:5000 -e LISTEN_HOST=:: -d test-changedetectionio
           sleep 3
-          # Should return 0 (no error) when grep finds it on localhost
           curl --retry-connrefused --retry 6 http://[::1]:5000 -v|grep -q checkbox-uuid
           docker kill test-changedetectionio-ipv6
 
-      - name: Test changedetection.io SIGTERM and SIGINT signal shutdown
+  # Signal tests
+  signal-tests:
+    runs-on: ubuntu-latest
+    needs: build
+    timeout-minutes: 10
+    env:
+      PYTHON_VERSION: ${{ inputs.python-version }}
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Download Docker image artifact
+        uses: actions/download-artifact@v7
+        with:
+          name: test-changedetectionio-${{ env.PYTHON_VERSION }}
+          path: /tmp
+
+      - name: Load Docker image
+        run: |
+          docker load -i /tmp/test-changedetectionio.tar
+
+      - name: Test SIGTERM and SIGINT signal shutdown
         run: |
-          
           echo SIGINT Shutdown request test
           docker run --name sig-test -d test-changedetectionio
           sleep 3
           echo ">>> Sending SIGINT to sig-test container"
           docker kill --signal=SIGINT sig-test
           sleep 3
-          # invert the check (it should be not 0/not running)
           docker ps
-          # check signal catch(STDERR) log. Because of
-          # changedetectionio/__init__.py: logger.add(sys.stderr, level=logger_level)
           docker logs sig-test 2>&1 | grep 'Shutdown: Got Signal - SIGINT' || exit 1
           test -z "`docker ps|grep sig-test`"
-          if [ $? -ne 0 ]
-          then
+          if [ $? -ne 0 ]; then
             echo "Looks like container was running when it shouldnt be"
             docker ps
             exit 1
           fi
-          
-          # @todo - scan the container log to see the right "graceful shutdown" text exists 
           docker rm sig-test
-          
+
           echo SIGTERM Shutdown request test
           docker run --name sig-test -d test-changedetectionio
           sleep 3
           echo ">>> Sending SIGTERM to sig-test container"
           docker kill --signal=SIGTERM sig-test
           sleep 3
-          # invert the check (it should be not 0/not running)
           docker ps
-          # check signal catch(STDERR) log. Because of
-          # changedetectionio/__init__.py: logger.add(sys.stderr, level=logger_level)
           docker logs sig-test 2>&1 | grep 'Shutdown: Got Signal - SIGTERM' || exit 1
           test -z "`docker ps|grep sig-test`"
-          if [ $? -ne 0 ]
-          then
+          if [ $? -ne 0 ]; then
             echo "Looks like container was running when it shouldnt be"
             docker ps
             exit 1
           fi
-          
-          # @todo - scan the container log to see the right "graceful shutdown" text exists           
           docker rm sig-test
-
-      - name: Dump container log
-        if: always()
-        run: |
-          mkdir output-logs
-          docker logs test-cdio-basic-tests > output-logs/test-cdio-basic-tests-stdout-${{ env.PYTHON_VERSION }}.txt
-          docker logs test-cdio-basic-tests 2> output-logs/test-cdio-basic-tests-stderr-${{ env.PYTHON_VERSION }}.txt
-
-      - name: Store everything including test-datastore
-        if: always()
-        uses: actions/upload-artifact@v4
-        with:
-          name: test-cdio-basic-tests-output-py${{ env.PYTHON_VERSION }}
-          path: .

.gitignore

@@ -21,6 +21,7 @@ venv/
 # IDEs
 .idea
 .vscode/settings.json
+*~
 
 # Datastore files
 datastore/

Dockerfile

@@ -34,23 +34,46 @@ ENV OPENSSL_LIB_DIR="/usr/lib/arm-linux-gnueabihf"
 ENV OPENSSL_INCLUDE_DIR="/usr/include/openssl"
 # Additional environment variables for cryptography Rust build
 ENV CRYPTOGRAPHY_DONT_BUILD_RUST=1
-RUN --mount=type=cache,target=/tmp/pip-cache \
-    pip install \
-    --extra-index-url https://www.piwheels.org/simple \
-    --extra-index-url https://pypi.anaconda.org/ARM-software/simple \
-    --cache-dir=/tmp/pip-cache \
-    --target=/dependencies \
-    -r /requirements.txt
+
+RUN --mount=type=cache,id=pip,sharing=locked,target=/tmp/pip-cache \
+  pip install \
+  --prefer-binary \
+  --extra-index-url https://www.piwheels.org/simple \
+  --extra-index-url https://pypi.anaconda.org/ARM-software/simple \
+  --cache-dir=/tmp/pip-cache \
+  --target=/dependencies \
+  -r /requirements.txt
 
 # Playwright is an alternative to Selenium
 # Excluded this package from requirements.txt to prevent arm/v6 and arm/v7 builds from failing
 # https://github.com/dgtlmoon/changedetection.io/pull/1067 also musl/alpine (not supported)
-RUN --mount=type=cache,target=/tmp/pip-cache \
-    pip install \
-    --cache-dir=/tmp/pip-cache \
-    --target=/dependencies \
-    playwright~=1.48.0 \
-    || echo "WARN: Failed to install Playwright. The application can still run, but the Playwright option will be disabled."
+RUN --mount=type=cache,id=pip,sharing=locked,target=/tmp/pip-cache \
+  pip install \
+  --prefer-binary \
+  --cache-dir=/tmp/pip-cache \
+  --target=/dependencies \
+  playwright~=1.56.0 \
+  || echo "WARN: Failed to install Playwright. The application can still run, but the Playwright option will be disabled."
+
+# OpenCV is optional for fast image comparison (pixelmatch is the fallback)
+# Skip on arm/v7 and arm/v8 where builds take weeks - excluded from requirements.txt
+ARG TARGETPLATFORM
+RUN --mount=type=cache,id=pip,sharing=locked,target=/tmp/pip-cache \
+  case "$TARGETPLATFORM" in \
+    linux/arm/v7|linux/arm/v8) \
+      echo "INFO: Skipping OpenCV on $TARGETPLATFORM (build takes too long), using pixelmatch fallback" \
+      ;; \
+    *) \
+      pip install \
+        --prefer-binary \
+        --extra-index-url https://www.piwheels.org/simple \
+        --cache-dir=/tmp/pip-cache \
+        --target=/dependencies \
+        opencv-python-headless>=4.8.0.76 \
+        || echo "WARN: OpenCV install failed, will use pixelmatch fallback" \
+      ;; \
+  esac
+
 
 # Final image stage
 FROM python:${PYTHON_VERSION}-slim-bookworm
@@ -65,6 +88,11 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     # favicon type detection and other uses
     file \
     zlib1g \
+    # OpenCV dependencies for image processing
+    libglib2.0-0 \
+    libsm6 \
+    libxext6 \
+    libxrender-dev \
     && apt-get clean && rm -rf /var/lib/apt/lists/*
 
 
@@ -85,6 +113,9 @@ EXPOSE 5000
 # The actual flask app module
 COPY changedetectionio /app/changedetectionio
 
+# Compile translation files for i18n support
+RUN pybabel compile -d /app/changedetectionio/translations
+
 # Also for OpenAPI validation wrapper - needs the YML
 RUN [ ! -d "/app/docs" ] && mkdir /app/docs
 COPY docs/api-spec.yaml /app/docs/api-spec.yaml

MANIFEST.in

@@ -1,7 +1,9 @@
 recursive-include changedetectionio/api *
+include docs/api-spec.yaml
 recursive-include changedetectionio/blueprint *
 recursive-include changedetectionio/conditions *
 recursive-include changedetectionio/content_fetchers *
+recursive-include changedetectionio/jinja2_custom *
 recursive-include changedetectionio/model *
 recursive-include changedetectionio/notification *
 recursive-include changedetectionio/processors *

README-pip.md

@@ -14,7 +14,7 @@ Ideal for monitoring price changes, content edits, conditional changes and more.
 [<img src="https://raw.githubusercontent.com/dgtlmoon/changedetection.io/master/docs/screenshot.png" style="max-width:100%;" alt="Self-hosted web page change monitoring, list of websites with changes"  title="Self-hosted web page change monitoring, list of websites with changes"  />](https://changedetection.io)
 
 
-[**Don't have time? Try our extremely affordable subscription use our proxies and support!**](https://changedetection.io) 
+[**Don't have time? Try our extremely affordable subscription use our proxies and support!**](https://changedetection.io)
 
 
 
@@ -31,7 +31,7 @@ Available when connected to a <a href="https://github.com/dgtlmoon/changedetecti
 
 ### Perform interactive browser steps
 
-Fill in text boxes, click buttons and more, setup your changedetection scenario. 
+Fill in text boxes, click buttons and more, setup your changedetection scenario.
 
 Using the **Browser Steps** configuration, add basic steps before performing change detection, such as logging into websites, adding a product to a cart, accept cookie logins, entering dates and refining searches.
 
@@ -54,7 +54,7 @@ Requires Playwright to be enabled.
 - Know when your favourite whiskey is on sale, or other special deals are announced before anyone else
 - COVID related news from government websites
 - University/organisation news from their website
-- Detect and monitor changes in JSON API responses 
+- Detect and monitor changes in JSON API responses
 - JSON API monitoring and alerting
 - Changes in legal and other documents
 - Trigger API calls via notifications when text appears on a website
@@ -86,7 +86,7 @@ _Need an actual Chrome runner with Javascript support? We support fetching via W
 
 We [recommend and use Bright Data](https://brightdata.grsm.io/n0r16zf7eivq) global proxy services, Bright Data will match any first deposit up to $100 using our signup link.
 
-[Oxylabs](https://oxylabs.go2cloud.org/SH2d) is also an excellent proxy provider and well worth using, they offer Residental, ISP, Rotating and many other proxy types to suit your project. 
+[Oxylabs](https://oxylabs.go2cloud.org/SH2d) is also an excellent proxy provider and well worth using, they offer Residential, ISP, Rotating and many other proxy types to suit your project.
 
 Please :star: star :star: this project and help it grow! https://github.com/dgtlmoon/changedetection.io/
 
@@ -106,4 +106,3 @@ $ changedetection.io -d /path/to/empty/data/dir -p 5000
 Then visit http://127.0.0.1:5000 , You should now be able to access the UI.
 
 See https://changedetection.io for more information.
-

changedetectionio/PLUGIN_README.md

@@ -64,7 +64,7 @@ def count_words_in_history(watch):
             return 0
             
         latest_key = list(watch.history.keys())[-1]
-        latest_content = watch.get_history_snapshot(latest_key)
+        latest_content = watch.get_history_snapshot(timestamp=latest_key)
         return len(latest_content.split())
     except Exception as e:
         logger.error(f"Error counting words: {str(e)}")

changedetectionio/__init__.py

@@ -1,11 +1,12 @@
 #!/usr/bin/env python3
 
 # Read more https://github.com/dgtlmoon/changedetection.io/wiki
-
-__version__ = '0.50.14'
+# Semver means never use .01, or 00. Should be .1.
+__version__ = '0.51.4'
 
 from changedetectionio.strtobool import strtobool
 from json.decoder import JSONDecodeError
+import logging
 import os
 import getopt
 import platform
@@ -19,6 +20,57 @@ from changedetectionio import store
 from changedetectionio.flask_app import changedetection_app
 from loguru import logger
 
+# ==============================================================================
+# Multiprocessing Configuration - CRITICAL for Thread Safety
+# ==============================================================================
+#
+# PROBLEM: Python 3.12+ warns about fork() with multi-threaded processes:
+#   "This process is multi-threaded, use of fork() may lead to deadlocks"
+#
+# WHY IT'S DANGEROUS:
+#   1. This Flask app has multiple threads (HTTP handlers, workers, SocketIO)
+#   2. fork() copies ONLY the calling thread to the child process
+#   3. BUT fork() also copies all locks/mutexes in their current state
+#   4. If another thread held a lock during fork() → child has locked lock with no owner
+#   5. Result: PERMANENT DEADLOCK if child tries to acquire that lock
+#
+# SOLUTION: Use 'spawn' instead of 'fork'
+#   - spawn starts a fresh Python interpreter (no inherited threads or locks)
+#   - Slower (~200ms vs ~1ms) but safe with multi-threaded parent
+#   - Consistent across all platforms (Windows already uses spawn by default)
+#
+# IMPLEMENTATION:
+#   1. Explicit contexts everywhere (primary protection):
+#      - Watch.py: ctx = multiprocessing.get_context('spawn')
+#      - playwright.py: ctx = multiprocessing.get_context('spawn')
+#      - puppeteer.py: ctx = multiprocessing.get_context('spawn')
+#
+#   2. Global default (defense-in-depth, below):
+#      - Safety net if future code forgets explicit context
+#      - Protects against third-party libraries using Process()
+#      - Costs nothing (explicit contexts always override it)
+#
+# WHY BOTH?
+#   - Explicit contexts: Clear, self-documenting, always works
+#   - Global default: Safety net for forgotten contexts or library code
+#   - If someone writes "Process()" instead of "ctx.Process()", still safe!
+#
+# See: https://docs.python.org/3/library/multiprocessing.html#contexts-and-start-methods
+# ==============================================================================
+
+import multiprocessing
+import sys
+
+# Set spawn as global default (safety net - all our code uses explicit contexts anyway)
+# Skip in tests to avoid breaking pytest-flask's LiveServer fixture (uses unpicklable local functions)
+if 'pytest' not in sys.modules:
+    try:
+        if multiprocessing.get_start_method(allow_none=True) is None:
+            multiprocessing.set_start_method('spawn', force=False)
+            logger.debug("Set multiprocessing default to 'spawn' for thread safety (explicit contexts used everywhere)")
+    except RuntimeError:
+        logger.debug(f"Multiprocessing start method already set: {multiprocessing.get_start_method()}")
+
 # Only global so we can access it in the signal handler
 app = None
 datastore = None
@@ -74,6 +126,12 @@ def main():
 
     datastore_path = None
     do_cleanup = False
+    # Optional URL to watch since start
+    default_url = None
+    # Set a default logger level
+    logger_level = 'DEBUG'
+    include_default_watches = True
+
     host = os.environ.get("LISTEN_HOST", "0.0.0.0").strip()
     port = int(os.environ.get('PORT', 5000))
     ssl_mode = False
@@ -87,15 +145,13 @@ def main():
         datastore_path = os.path.join(os.getcwd(), "../datastore")
 
     try:
-        opts, args = getopt.getopt(sys.argv[1:], "6Ccsd:h:p:l:", "port")
+        opts, args = getopt.getopt(sys.argv[1:], "6Ccsd:h:p:l:u:", "port")
     except getopt.GetoptError:
-        print('backend.py -s SSL enable -h [host] -p [port] -d [datastore path] -l [debug level - TRACE, DEBUG(default), INFO, SUCCESS, WARNING, ERROR, CRITICAL]')
+        print('backend.py -s SSL enable -h [host] -p [port] -d [datastore path] -u [default URL to watch] -l [debug level - TRACE, DEBUG(default), INFO, SUCCESS, WARNING, ERROR, CRITICAL]')
         sys.exit(2)
 
     create_datastore_dir = False
 
-    # Set a default logger level
-    logger_level = 'DEBUG'
     # Set a logger level via shell env variable
     # Used: Dockerfile for CICD
     # To set logger level for pytest, see the app function in tests/conftest.py
@@ -116,6 +172,10 @@ def main():
         if opt == '-d':
             datastore_path = arg
 
+        if opt == '-u':
+            default_url = arg
+            include_default_watches = False
+
         # Cleanup (remove text files that arent in the index)
         if opt == '-c':
             do_cleanup = True
@@ -157,6 +217,11 @@ def main():
               " WARNING, ERROR, CRITICAL")
         sys.exit(2)
 
+    # Disable verbose pyppeteer logging to prevent memory leaks from large CDP messages
+    # Set both parent and child loggers since pyppeteer hardcodes DEBUG level
+    logging.getLogger('pyppeteer.connection').setLevel(logging.WARNING)
+    logging.getLogger('pyppeteer.connection.Connection').setLevel(logging.WARNING)
+
     # isnt there some @thingy to attach to each route to tell it, that this route needs a datastore
     app_config = {'datastore_path': datastore_path}
 
@@ -172,13 +237,20 @@ def main():
             sys.exit(2)
 
     try:
-        datastore = store.ChangeDetectionStore(datastore_path=app_config['datastore_path'], version_tag=__version__)
+        datastore = store.ChangeDetectionStore(datastore_path=app_config['datastore_path'], version_tag=__version__, include_default_watches=include_default_watches)
     except JSONDecodeError as e:
         # Dont' start if the JSON DB looks corrupt
         logger.critical(f"ERROR: JSON DB or Proxy List JSON at '{app_config['datastore_path']}' appears to be corrupt, aborting.")
         logger.critical(str(e))
         return
 
+    # Inject datastore into plugins that need access to settings
+    from changedetectionio.pluggy_interface import inject_datastore_into_plugins
+    inject_datastore_into_plugins(datastore)
+
+    if default_url:
+        datastore.add_watch(url = default_url)
+
     app = changedetection_app(app_config, datastore)
 
     # Get the SocketIO instance from the Flask app (created in flask_app.py)

changedetectionio/api/Import.py

@@ -1,9 +1,22 @@
-import os
 from changedetectionio.strtobool import strtobool
 from flask_restful import abort, Resource
 from flask import request
-import validators
+from functools import wraps
 from . import auth, validate_openapi_request
+from ..validate_url import is_safe_valid_url
+
+
+def default_content_type(content_type='text/plain'):
+    """Decorator to set a default Content-Type header if none is provided."""
+    def decorator(f):
+        @wraps(f)
+        def wrapper(*args, **kwargs):
+            if not request.content_type:
+                # Set default content type in the request environment
+                request.environ['CONTENT_TYPE'] = content_type
+            return f(*args, **kwargs)
+        return wrapper
+    return decorator
 
 
 class Import(Resource):
@@ -12,6 +25,7 @@ class Import(Resource):
         self.datastore = kwargs['datastore']
 
     @auth.check_token
+    @default_content_type('text/plain') #3547 #3542
     @validate_openapi_request('importWatches')
     def post(self):
         """Import a list of watched URLs."""
@@ -35,14 +49,13 @@ class Import(Resource):
 
         urls = request.get_data().decode('utf8').splitlines()
         added = []
-        allow_simplehost = not strtobool(os.getenv('BLOCK_SIMPLEHOSTS', 'False'))
         for url in urls:
             url = url.strip()
             if not len(url):
                 continue
 
             # If hosts that only contain alphanumerics are allowed ("localhost" for example)
-            if not validators.url(url, simple_host=allow_simplehost):
+            if not is_safe_valid_url(url):
                 return f"Invalid or unsupported URL - {url}", 400
 
             if dedupe and self.datastore.url_exists(url):

changedetectionio/api/Watch.py

@@ -1,17 +1,20 @@
 import os
-from changedetectionio.strtobool import strtobool
 
-from flask_expects_json import expects_json
-from changedetectionio import queuedWatchMetaData
-from changedetectionio import worker_handler
-from flask_restful import abort, Resource
-from flask import request, make_response, send_from_directory
-import validators
+from changedetectionio.validate_url import is_safe_valid_url
+
 from . import auth
+from changedetectionio import queuedWatchMetaData, strtobool
+from changedetectionio import worker_handler
+from flask import request, make_response, send_from_directory
+from flask_expects_json import expects_json
+from flask_restful import abort, Resource
+from loguru import logger
 import copy
 
 # Import schemas from __init__.py
 from . import schema, schema_create_watch, schema_update_watch, validate_openapi_request
+from ..notification import valid_notification_formats
+from ..notification.handler import newline_re
 
 
 def validate_time_between_check_required(json_data):
@@ -121,7 +124,64 @@ class Watch(Resource):
         if validation_error:
             return validation_error, 400
 
-        watch.update(request.json)
+        # XSS etc protection
+        if request.json.get('url') and not is_safe_valid_url(request.json.get('url')):
+            return "Invalid URL", 400
+
+        # Handle processor-config-* fields separately (save to JSON, not datastore)
+        from changedetectionio import processors
+        processor_config_data = {}
+        regular_data = {}
+
+        for key, value in request.json.items():
+            if key.startswith('processor_config_'):
+                config_key = key.replace('processor_config_', '')
+                if value:  # Only save non-empty values
+                    processor_config_data[config_key] = value
+            else:
+                regular_data[key] = value
+
+        # Update watch with regular (non-processor-config) fields
+        watch.update(regular_data)
+
+        # Save processor config to JSON file if any config data exists
+        if processor_config_data:
+            try:
+                processor_name = request.json.get('processor', watch.get('processor'))
+                if processor_name:
+                    # Create a processor instance to access config methods
+                    from changedetectionio.processors import difference_detection_processor
+                    processor_instance = difference_detection_processor(self.datastore, uuid)
+                    # Use processor name as filename so each processor keeps its own config
+                    config_filename = f'{processor_name}.json'
+                    processor_instance.update_extra_watch_config(config_filename, processor_config_data)
+                    logger.debug(f"API: Saved processor config to {config_filename}: {processor_config_data}")
+
+                    # Call optional edit_hook if processor has one
+                    try:
+                        import importlib
+                        edit_hook_module_name = f'changedetectionio.processors.{processor_name}.edit_hook'
+
+                        try:
+                            edit_hook = importlib.import_module(edit_hook_module_name)
+                            logger.debug(f"API: Found edit_hook module for {processor_name}")
+
+                            if hasattr(edit_hook, 'on_config_save'):
+                                logger.info(f"API: Calling edit_hook.on_config_save for {processor_name}")
+                                # Call hook and get updated config
+                                updated_config = edit_hook.on_config_save(watch, processor_config_data, self.datastore)
+                                # Save updated config back to file
+                                processor_instance.update_extra_watch_config(config_filename, updated_config)
+                                logger.info(f"API: Edit hook updated config: {updated_config}")
+                            else:
+                                logger.debug(f"API: Edit hook module found but no on_config_save function")
+                        except ModuleNotFoundError:
+                            logger.debug(f"API: No edit_hook module for processor {processor_name} (this is normal)")
+                    except Exception as hook_error:
+                        logger.error(f"API: Edit hook error (non-fatal): {hook_error}", exc_info=True)
+
+            except Exception as e:
+                logger.error(f"API: Failed to save processor config: {e}")
 
         return "OK", 200
 
@@ -171,12 +231,120 @@ class WatchSingleHistory(Resource):
                 response = make_response("No content found", 404)
                 response.mimetype = "text/plain"
         else:
-            content = watch.get_history_snapshot(timestamp)
+            content = watch.get_history_snapshot(timestamp=timestamp)
             response = make_response(content, 200)
             response.mimetype = "text/plain"
 
         return response
 
+class WatchHistoryDiff(Resource):
+    """
+    Generate diff between two historical snapshots.
+
+    Note: This API endpoint currently returns text-based diffs and works best
+    with the text_json_diff processor. Future processor types (like image_diff,
+    restock_diff) may want to implement their own specialized API endpoints
+    for returning processor-specific data (e.g., price charts, image comparisons).
+
+    The web UI diff page (/diff/<uuid>) is processor-aware and delegates rendering
+    to processors/{type}/difference.py::render() for processor-specific visualizations.
+    """
+    def __init__(self, **kwargs):
+        # datastore is a black box dependency
+        self.datastore = kwargs['datastore']
+
+    @auth.check_token
+    @validate_openapi_request('getWatchHistoryDiff')
+    def get(self, uuid, from_timestamp, to_timestamp):
+        """Generate diff between two historical snapshots."""
+        from changedetectionio import diff
+        from changedetectionio.notification.handler import apply_service_tweaks
+
+        watch = self.datastore.data['watching'].get(uuid)
+        if not watch:
+            abort(404, message=f"No watch exists with the UUID of {uuid}")
+
+        if not len(watch.history):
+            abort(404, message=f"Watch found but no history exists for the UUID {uuid}")
+
+        history_keys = list(watch.history.keys())
+
+        # Handle 'latest' keyword for to_timestamp
+        if to_timestamp == 'latest':
+            to_timestamp = history_keys[-1]
+
+        # Handle 'previous' keyword for from_timestamp (second-most-recent)
+        if from_timestamp == 'previous':
+            if len(history_keys) < 2:
+                abort(404, message=f"Not enough history entries. Need at least 2 snapshots for 'previous'")
+            from_timestamp = history_keys[-2]
+
+        # Validate timestamps exist
+        if from_timestamp not in watch.history:
+            abort(404, message=f"From timestamp {from_timestamp} not found in watch history")
+        if to_timestamp not in watch.history:
+            abort(404, message=f"To timestamp {to_timestamp} not found in watch history")
+
+        # Get the format parameter (default to 'text')
+        output_format = request.args.get('format', 'text').lower()
+
+        # Validate format
+        if output_format not in valid_notification_formats.keys():
+            abort(400, message=f"Invalid format. Must be one of: {', '.join(valid_notification_formats.keys())}")
+
+        # Get the word_diff parameter (default to False - line-level mode)
+        word_diff = strtobool(request.args.get('word_diff', 'false'))
+
+        # Get the no_markup parameter (default to False)
+        no_markup = strtobool(request.args.get('no_markup', 'false'))
+
+        # Retrieve snapshot contents
+        from_version_file_contents = watch.get_history_snapshot(from_timestamp)
+        to_version_file_contents = watch.get_history_snapshot(to_timestamp)
+
+        # Get diff preferences (using defaults similar to the existing code)
+        diff_prefs = {
+            'diff_ignoreWhitespace': False,
+            'diff_changesOnly': True
+        }
+
+        # Generate the diff
+        content = diff.render_diff(
+            previous_version_file_contents=from_version_file_contents,
+            newest_version_file_contents=to_version_file_contents,
+            ignore_junk=diff_prefs.get('diff_ignoreWhitespace'),
+            include_equal=not diff_prefs.get('diff_changesOnly'),
+            word_diff=word_diff,
+        )
+
+        # Skip formatting if no_markup is set
+        if no_markup:
+            mimetype = "text/plain"
+        else:
+            # Apply formatting based on the requested format
+            if output_format == 'htmlcolor':
+                from changedetectionio.notification.handler import apply_html_color_to_body
+                content = apply_html_color_to_body(n_body=content)
+                mimetype = "text/html"
+            else:
+                # Apply service tweaks for text/html formats
+                # Pass empty URL and title as they're not used for the placeholder replacement we need
+                _, content, _ = apply_service_tweaks(
+                    url='',
+                    n_body=content,
+                    n_title='',
+                    requested_output_format=output_format
+                )
+                mimetype = "text/html" if output_format == 'html' else "text/plain"
+
+            if 'html' in output_format:
+                content = newline_re.sub('<br>\r\n', content)
+
+        response = make_response(content, 200)
+        response.mimetype = mimetype
+        return response
+
+
 class WatchFavicon(Resource):
     def __init__(self, **kwargs):
         # datastore is a black box dependency
@@ -226,9 +394,7 @@ class CreateWatch(Resource):
         json_data = request.get_json()
         url = json_data['url'].strip()
 
-        # If hosts that only contain alphanumerics are allowed ("localhost" for example)
-        allow_simplehost = not strtobool(os.getenv('BLOCK_SIMPLEHOSTS', 'False'))
-        if not validators.url(url, simple_host=allow_simplehost):
+        if not is_safe_valid_url(url):
             return "Invalid or unsupported URL", 400
 
         if json_data.get('proxy'):

changedetectionio/api/__init__.py

@@ -1,10 +1,7 @@
 import copy
-import yaml
 import functools
 from flask import request, abort
 from loguru import logger
-from openapi_core import OpenAPI
-from openapi_core.contrib.flask import FlaskOpenAPIRequest
 from . import api_schema
 from ..model import watch_base
 
@@ -34,9 +31,17 @@ schema_delete_notification_urls['required'] = ['notification_urls']
 
 @functools.cache
 def get_openapi_spec():
+    """Lazy load OpenAPI spec and dependencies only when validation is needed."""
     import os
+    import yaml  # Lazy import - only loaded when API validation is actually used
+    from openapi_core import OpenAPI  # Lazy import - saves ~10.7 MB on startup
+
     spec_path = os.path.join(os.path.dirname(__file__), '../../docs/api-spec.yaml')
-    with open(spec_path, 'r') as f:
+    if not os.path.exists(spec_path):
+        # Possibly for pip3 packages
+        spec_path = os.path.join(os.path.dirname(__file__), '../docs/api-spec.yaml')
+
+    with open(spec_path, 'r', encoding='utf-8') as f:
         spec_dict = yaml.safe_load(f)
     _openapi_spec = OpenAPI.from_dict(spec_dict)
     return _openapi_spec
@@ -46,14 +51,17 @@ def validate_openapi_request(operation_id):
     def decorator(f):
         @functools.wraps(f)
         def wrapper(*args, **kwargs):
+            from werkzeug.exceptions import BadRequest
             try:
                 # Skip OpenAPI validation for GET requests since they don't have request bodies
                 if request.method.upper() != 'GET':
+                    # Lazy import - only loaded when actually validating a request
+                    from openapi_core.contrib.flask import FlaskOpenAPIRequest
+
                     spec = get_openapi_spec()
                     openapi_request = FlaskOpenAPIRequest(request)
                     result = spec.unmarshal_request(openapi_request)
                     if result.errors:
-                        from werkzeug.exceptions import BadRequest
                         error_details = []
                         for error in result.errors:
                             error_details.append(str(error))
@@ -70,7 +78,7 @@ def validate_openapi_request(operation_id):
     return decorator
 
 # Import all API resources
-from .Watch import Watch, WatchHistory, WatchSingleHistory, CreateWatch, WatchFavicon
+from .Watch import Watch, WatchHistory, WatchSingleHistory, WatchHistoryDiff, CreateWatch, WatchFavicon
 from .Tags import Tags, Tag
 from .Import import Import
 from .SystemInfo import SystemInfo

changedetectionio/api/api_schema.py

@@ -96,7 +96,10 @@ def build_watch_json_schema(d):
                                                            "enum": ["html_requests", "html_webdriver"]
                                                            })
 
-
+    schema['properties']['processor'] = {"anyOf": [
+        {"type": "string", "enum": ["restock_diff", "text_json_diff"]},
+        {"type": "null"}
+    ]}
 
     # All headers must be key/value type dict
     schema['properties']['headers'] = {

changedetectionio/async_update_worker.py

@@ -1,3 +1,5 @@
+from blinker import signal
+
 from .processors.exceptions import ProcessorException
 import changedetectionio.content_fetchers.exceptions as content_fetchers_exceptions
 from changedetectionio.processors.text_json_diff.processor import FilterNotFoundInResponse
@@ -40,13 +42,13 @@ async def async_update_worker(worker_id, q, notification_q, app, datastore):
         try:
             # Use native janus async interface - no threads needed!
             queued_item_data = await asyncio.wait_for(q.async_get(), timeout=1.0)
-            
+
         except asyncio.TimeoutError:
             # No jobs available, continue loop
             continue
         except Exception as e:
             logger.critical(f"CRITICAL: Worker {worker_id} failed to get queue item: {type(e).__name__}: {e}")
-            
+
             # Log queue health for debugging
             try:
                 queue_size = q.qsize()
@@ -54,15 +56,28 @@ async def async_update_worker(worker_id, q, notification_q, app, datastore):
                 logger.critical(f"CRITICAL: Worker {worker_id} queue health - size: {queue_size}, empty: {is_empty}")
             except Exception as health_e:
                 logger.critical(f"CRITICAL: Worker {worker_id} queue health check failed: {health_e}")
-            
+
             await asyncio.sleep(0.1)
             continue
-        
+
         uuid = queued_item_data.item.get('uuid')
-        fetch_start_time = round(time.time())
-        
-        # Mark this UUID as being processed
+
+        # RACE CONDITION FIX: Check if this UUID is already being processed by another worker
         from changedetectionio import worker_handler
+        from changedetectionio.queuedWatchMetaData import PrioritizedItem
+        if worker_handler.is_watch_running(uuid):
+            logger.trace(f"Worker {worker_id} skipping UUID {uuid} - already being processed, re-queuing for later")
+            # Re-queue with MUCH lower priority (higher number = processed later)
+            # This prevents tight loop where high-priority item keeps getting picked immediately
+            deferred_priority = max(1000, queued_item_data.priority * 10)
+            deferred_item = PrioritizedItem(priority=deferred_priority, item=queued_item_data.item)
+            worker_handler.queue_item_async_safe(q, deferred_item, silent=True)
+            await asyncio.sleep(0.1)  # Brief pause to avoid tight loop
+            continue
+
+        fetch_start_time = round(time.time())
+
+        # Mark this UUID as being processed
         worker_handler.set_uuid_processing(uuid, processing=True)
         
         try:
@@ -87,9 +102,8 @@ async def async_update_worker(worker_id, q, notification_q, app, datastore):
                     processor = watch.get('processor', 'text_json_diff')
 
                     # Init a new 'difference_detection_processor'
-                    processor_module_name = f"changedetectionio.processors.{processor}.processor"
                     try:
-                        processor_module = importlib.import_module(processor_module_name)
+                        processor_module = importlib.import_module(f"changedetectionio.processors.{processor}.processor")
                     except ModuleNotFoundError as e:
                         print(f"Processor module '{processor}' not found.")
                         raise e
@@ -97,6 +111,9 @@ async def async_update_worker(worker_id, q, notification_q, app, datastore):
                     update_handler = processor_module.perform_site_check(datastore=datastore,
                                                                          watch_uuid=uuid)
 
+                    update_signal = signal('watch_small_status_comment')
+                    update_signal.send(watch_uuid=uuid, status="Fetching page..")
+
                     # All fetchers are now async, so call directly
                     await update_handler.call_browser()
 
@@ -309,6 +326,7 @@ async def async_update_worker(worker_id, q, notification_q, app, datastore):
                 if not datastore.data['watching'].get(uuid):
                     continue
 
+                logger.debug(f"Processing watch UUID: {uuid} - xpath_data length returned {len(update_handler.xpath_data) if update_handler.xpath_data else 'empty.'}")
                 if process_changedetection_results:
                     try:
                         datastore.update_watch(uuid=uuid, update_obj=update_obj)
@@ -326,7 +344,7 @@ async def async_update_worker(worker_id, q, notification_q, app, datastore):
                                 fetch_start_time += 1
                                 await asyncio.sleep(1)
 
-                            watch.save_history_text(contents=contents,
+                            watch.save_history_blob(contents=contents,
                                                     timestamp=int(fetch_start_time),
                                                     snapshot_id=update_obj.get('previous_md5', 'none'))
 
@@ -334,6 +352,10 @@ async def async_update_worker(worker_id, q, notification_q, app, datastore):
                             if update_handler.fetcher.content or (not update_handler.fetcher.content and empty_pages_are_a_change):
                                 watch.save_last_fetched_html(contents=update_handler.fetcher.content, timestamp=int(fetch_start_time))
 
+                            # Explicitly delete large content variables to free memory IMMEDIATELY after saving
+                            # These are no longer needed after being saved to history
+                            del contents
+
                             # Send notifications on second+ check
                             if watch.history_n >= 2:
                                 logger.info(f"Change detected in UUID {uuid} - {watch['url']}")
@@ -349,12 +371,15 @@ async def async_update_worker(worker_id, q, notification_q, app, datastore):
                 count = watch.get('check_count', 0) + 1
 
                 # Always record page title (used in notifications, and can change even when the content is the same)
-                try:
-                    page_title = html_tools.extract_title(data=update_handler.fetcher.content)
-                    logger.debug(f"UUID: {uuid} Page <title> is '{page_title}'")
-                    datastore.update_watch(uuid=uuid, update_obj={'page_title': page_title})
-                except Exception as e:
-                    logger.warning(f"UUID: {uuid} Exception when extracting <title> - {str(e)}")
+                if update_obj.get('content-type') and 'html' in update_obj.get('content-type'):
+                    try:
+                        page_title = html_tools.extract_title(data=update_handler.fetcher.content)
+                        if page_title:
+                            page_title = page_title.strip()[:2000]
+                            logger.debug(f"UUID: {uuid} Page <title> is '{page_title}'")
+                            datastore.update_watch(uuid=uuid, update_obj={'page_title': page_title})
+                    except Exception as e:
+                        logger.warning(f"UUID: {uuid} Exception when extracting <title> - {str(e)}")
 
                 # Record server header
                 try:
@@ -372,6 +397,12 @@ async def async_update_worker(worker_id, q, notification_q, app, datastore):
                 datastore.update_watch(uuid=uuid, update_obj={'fetch_time': round(time.time() - fetch_start_time, 3),
                                                                'check_count': count})
 
+                # NOW clear fetcher content - after all processing is complete
+                # This is the last point where we need the fetcher data
+                if update_handler and hasattr(update_handler, 'fetcher') and update_handler.fetcher:
+                    update_handler.fetcher.clear_content()
+                    logger.debug(f"Cleared fetcher content for UUID {uuid}")
+
         except Exception as e:
             logger.error(f"Worker {worker_id} unexpected error processing {uuid}: {e}")
             logger.error(f"Worker {worker_id} traceback:", exc_info=True)
@@ -381,6 +412,12 @@ async def async_update_worker(worker_id, q, notification_q, app, datastore):
                 datastore.update_watch(uuid=uuid, update_obj={'last_error': f"Worker error: {str(e)}"})
         
         finally:
+
+            try:
+                await update_handler.fetcher.quit(watch=watch)
+            except Exception as e:
+                logger.error(f"Exception while cleaning/quit after calling browser: {e}")
+
             # Always cleanup - this runs whether there was an exception or not
             if uuid:
                 try:
@@ -392,7 +429,32 @@ async def async_update_worker(worker_id, q, notification_q, app, datastore):
                         #logger.info(f"Worker {worker_id} sending completion signal for UUID {watch['uuid']}")
                         watch_check_update.send(watch_uuid=watch['uuid'])
 
-                    update_handler = None
+                    # Explicitly clean up update_handler and all its references
+                    if update_handler:
+                        # Clear fetcher content using the proper method
+                        if hasattr(update_handler, 'fetcher') and update_handler.fetcher:
+                            update_handler.fetcher.clear_content()
+
+                        # Clear processor references
+                        if hasattr(update_handler, 'content_processor'):
+                            update_handler.content_processor = None
+
+                        update_handler = None
+
+                    # Clear local contents variable if it still exists
+                    if 'contents' in locals():
+                        del contents
+
+                    # Note: We don't set watch = None here because:
+                    # 1. watch is just a local reference to datastore.data['watching'][uuid]
+                    # 2. Setting it to None doesn't affect the datastore
+                    # 3. GC can't collect the object anyway (still referenced by datastore)
+                    # 4. It would just cause confusion
+
+                    # Force garbage collection after cleanup
+                    import gc
+                    gc.collect()
+
                     logger.debug(f"Worker {worker_id} completed watch {uuid} in {time.time()-fetch_start_time:.2f}s")
                 except Exception as cleanup_error:
                     logger.error(f"Worker {worker_id} error during cleanup: {cleanup_error}")

changedetectionio/blueprint/backups/__init__.py

@@ -3,6 +3,7 @@ import glob
 import threading
 
 from flask import Blueprint, render_template, send_from_directory, flash, url_for, redirect, abort
+from flask_babel import gettext
 import os
 
 from changedetectionio.store import ChangeDetectionStore
@@ -82,11 +83,11 @@ def construct_blueprint(datastore: ChangeDetectionStore):
     @backups_blueprint.route("/request-backup", methods=['GET'])
     def request_backup():
         if any(thread.is_alive() for thread in backup_threads):
-            flash("A backup is already running, check back in a few minutes", "error")
+            flash(gettext("A backup is already running, check back in a few minutes"), "error")
             return redirect(url_for('backups.index'))
 
         if len(find_backups()) > int(os.getenv("MAX_NUMBER_BACKUPS", 100)):
-            flash("Maximum number of backups reached, please remove some", "error")
+            flash(gettext("Maximum number of backups reached, please remove some"), "error")
             return redirect(url_for('backups.index'))
 
         # Be sure we're written fresh
@@ -94,7 +95,7 @@ def construct_blueprint(datastore: ChangeDetectionStore):
         zip_thread = threading.Thread(target=create_backup, args=(datastore.datastore_path, datastore.data.get("watching")))
         zip_thread.start()
         backup_threads.append(zip_thread)
-        flash("Backup building in background, check back in a few minutes.")
+        flash(gettext("Backup building in background, check back in a few minutes."))
 
         return redirect(url_for('backups.index'))
 
@@ -157,7 +158,7 @@ def construct_blueprint(datastore: ChangeDetectionStore):
         for backup in backups:
             os.unlink(backup)
 
-        flash("Backups were deleted.")
+        flash(gettext("Backups were deleted."))
 
         return redirect(url_for('backups.index'))
 

changedetectionio/blueprint/backups/templates/overview.html

@@ -3,31 +3,31 @@
     {% from '_helpers.html' import render_simple_field, render_field %}
     <div class="edit-form">
         <div class="box-wrap inner">
-            <h4>Backups</h4>
+            <h4>{{ _('Backups') }}</h4>
             {% if backup_running %}
                 <p>
-                    <strong>A backup is running!</strong>
+                    <strong>{{ _('A backup is running!') }}</strong>
                 </p>
             {% endif %}
             <p>
-                Here you can download and request a new backup, when a backup is completed you will see it listed below.
+                {{ _('Here you can download and request a new backup, when a backup is completed you will see it listed below.') }}
             </p>
             <br>
                 {% if available_backups %}
                     <ul>
                     {% for backup in available_backups %}
-                        <li><a href="{{ url_for('backups.download_backup', filename=backup["filename"]) }}">{{ backup["filename"] }}</a> {{  backup["filesize"] }} Mb</li>
+                        <li><a href="{{ url_for('backups.download_backup', filename=backup["filename"]) }}">{{ backup["filename"] }}</a> {{  backup["filesize"] }} {{ _('Mb') }}</li>
                     {% endfor %}
                     </ul>
                 {% else %}
                     <p>
-                    <strong>No backups found.</strong>
+                    <strong>{{ _('No backups found.') }}</strong>
                     </p>
                 {% endif %}
 
-            <a class="pure-button pure-button-primary" href="{{ url_for('backups.request_backup') }}">Create backup</a>
+            <a class="pure-button pure-button-primary" href="{{ url_for('backups.request_backup') }}">{{ _('Create backup') }}</a>
             {% if available_backups %}
-                <a class="pure-button button-small button-error " href="{{ url_for('backups.remove_backups') }}">Remove backups</a>
+                <a class="pure-button button-small button-error " href="{{ url_for('backups.remove_backups') }}">{{ _('Remove backups') }}</a>
             {% endif %}
         </div>
     </div>

changedetectionio/blueprint/browser_steps/browser_steps.py

@@ -6,7 +6,7 @@ from loguru import logger
 
 from changedetectionio.content_fetchers import SCREENSHOT_MAX_HEIGHT_DEFAULT
 from changedetectionio.content_fetchers.base import manage_user_agent
-from changedetectionio.safe_jinja import render as jinja_render
+from changedetectionio.jinja2_custom import render as jinja_render
 
 
 
@@ -439,7 +439,7 @@ class browsersteps_live_ui(steppable_browser_interface):
             logger.warning("Attempted to get current state after cleanup")
             return (None, None)
 
-        xpath_element_js = importlib.resources.files("changedetectionio.content_fetchers.res").joinpath('xpath_element_scraper.js').read_text()
+        xpath_element_js = importlib.resources.files("changedetectionio.content_fetchers.res").joinpath('xpath_element_scraper.js').read_text(encoding="utf-8")
 
         now = time.time()
         await self.page.wait_for_timeout(1 * 1000)

changedetectionio/blueprint/check_proxies/__init__.py

@@ -33,7 +33,7 @@ def construct_blueprint(datastore: ChangeDetectionStore):
     def long_task(uuid, preferred_proxy):
         import time
         from changedetectionio.content_fetchers import exceptions as content_fetcher_exceptions
-        from changedetectionio.safe_jinja import render as jinja_render
+        from changedetectionio.jinja2_custom import render as jinja_render
 
         status = {'status': '', 'length': 0, 'text': ''}
 

changedetectionio/blueprint/imports/importer.py

@@ -2,6 +2,7 @@ from abc import abstractmethod
 import time
 from wtforms import ValidationError
 from loguru import logger
+from flask_babel import gettext
 
 from changedetectionio.forms import validate_url
 
@@ -41,7 +42,7 @@ class import_url_list(Importer):
         now = time.time()
 
         if (len(urls) > 5000):
-            flash("Importing 5,000 of the first URLs from your list, the rest can be imported again.")
+            flash(gettext("Importing 5,000 of the first URLs from your list, the rest can be imported again."))
 
         for url in urls:
             url = url.strip()
@@ -74,7 +75,7 @@ class import_url_list(Importer):
                 self.remaining_data = []
             self.remaining_data.append(url)
 
-        flash("{} Imported from list in {:.2f}s, {} Skipped.".format(good, time.time() - now, len(self.remaining_data)))
+        flash(gettext("{} Imported from list in {:.2f}s, {} Skipped.").format(good, time.time() - now, len(self.remaining_data)))
 
 
 class import_distill_io_json(Importer):
@@ -94,11 +95,11 @@ class import_distill_io_json(Importer):
         try:
             data = json.loads(data.strip())
         except json.decoder.JSONDecodeError:
-            flash("Unable to read JSON file, was it broken?", 'error')
+            flash(gettext("Unable to read JSON file, was it broken?"), 'error')
             return
 
         if not data.get('data'):
-            flash("JSON structure looks invalid, was it broken?", 'error')
+            flash(gettext("JSON structure looks invalid, was it broken?"), 'error')
             return
 
         for d in data.get('data'):
@@ -135,7 +136,7 @@ class import_distill_io_json(Importer):
                     self.new_uuids.append(new_uuid)
                     good += 1
 
-        flash("{} Imported from Distill.io in {:.2f}s, {} Skipped.".format(len(self.new_uuids), time.time() - now, len(self.remaining_data)))
+        flash(gettext("{} Imported from Distill.io in {:.2f}s, {} Skipped.").format(len(self.new_uuids), time.time() - now, len(self.remaining_data)))
 
 
 class import_xlsx_wachete(Importer):
@@ -156,7 +157,7 @@ class import_xlsx_wachete(Importer):
             wb = load_workbook(data)
         except Exception as e:
             # @todo correct except
-            flash("Unable to read export XLSX file, something wrong with the file?", 'error')
+            flash(gettext("Unable to read export XLSX file, something wrong with the file?"), 'error')
             return
 
         row_id = 2
@@ -196,7 +197,7 @@ class import_xlsx_wachete(Importer):
                         validate_url(data.get('url'))
                     except ValidationError as e:
                         logger.error(f">> Import URL error {data.get('url')} {str(e)}")
-                        flash(f"Error processing row number {row_id}, URL value was incorrect, row was skipped.", 'error')
+                        flash(gettext("Error processing row number {}, URL value was incorrect, row was skipped.").format(row_id), 'error')
                         # Don't bother processing anything else on this row
                         continue
 
@@ -210,12 +211,11 @@ class import_xlsx_wachete(Importer):
                         good += 1
             except Exception as e:
                 logger.error(e)
-                flash(f"Error processing row number {row_id}, check all cell data types are correct, row was skipped.", 'error')
+                flash(gettext("Error processing row number {}, check all cell data types are correct, row was skipped.").format(row_id), 'error')
             else:
                 row_id += 1
 
-        flash(
-            "{} imported from Wachete .xlsx in {:.2f}s".format(len(self.new_uuids), time.time() - now))
+        flash(gettext("{} imported from Wachete .xlsx in {:.2f}s").format(len(self.new_uuids), time.time() - now))
 
 
 class import_xlsx_custom(Importer):
@@ -236,7 +236,7 @@ class import_xlsx_custom(Importer):
             wb = load_workbook(data)
         except Exception as e:
             # @todo correct except
-            flash("Unable to read export XLSX file, something wrong with the file?", 'error')
+            flash(gettext("Unable to read export XLSX file, something wrong with the file?"), 'error')
             return
 
         # @todo cehck atleast 2 rows, same in other method
@@ -265,7 +265,7 @@ class import_xlsx_custom(Importer):
                             validate_url(url)
                         except ValidationError as e:
                             logger.error(f">> Import URL error {url} {str(e)}")
-                            flash(f"Error processing row number {row_i}, URL value was incorrect, row was skipped.", 'error')
+                            flash(gettext("Error processing row number {}, URL value was incorrect, row was skipped.").format(row_i), 'error')
                             # Don't bother processing anything else on this row
                             url = None
                             break
@@ -294,9 +294,8 @@ class import_xlsx_custom(Importer):
                         good += 1
         except Exception as e:
             logger.error(e)
-            flash(f"Error processing row number {row_i}, check all cell data types are correct, row was skipped.", 'error')
+            flash(gettext("Error processing row number {}, check all cell data types are correct, row was skipped.").format(row_i), 'error')
         else:
             row_i += 1
 
-        flash(
-            "{} imported from custom .xlsx in {:.2f}s".format(len(self.new_uuids), time.time() - now))
+        flash(gettext("{} imported from custom .xlsx in {:.2f}s").format(len(self.new_uuids), time.time() - now))

changedetectionio/blueprint/imports/templates/import.html

@@ -6,9 +6,9 @@
 
     <div class="tabs collapsable">
         <ul>
-            <li class="tab" id=""><a href="#url-list">URL List</a></li>
-            <li class="tab"><a href="#distill-io">Distill.io</a></li>
-            <li class="tab"><a href="#xlsx">.XLSX &amp; Wachete</a></li>
+            <li class="tab" id=""><a href="#url-list">{{ _('URL List') }}</a></li>
+            <li class="tab"><a href="#distill-io">{{ _('Distill.io') }}</a></li>
+            <li class="tab"><a href="#xlsx">{{ _('.XLSX & Wachete') }}</a></li>
         </ul>
     </div>
 
@@ -17,11 +17,10 @@
             <input type="hidden" name="csrf_token" value="{{ csrf_token() }}">
             <div class="tab-pane-inner" id="url-list">
                 <div class="pure-control-group">
-                        Enter one URL per line, and optionally add tags for each URL after a space, delineated by comma
-                        (,):
+                        {{ _('Enter one URL per line, and optionally add tags for each URL after a space, delineated by comma (,):') }}
                         <br>
-                        <p><strong>Example:  </strong><code>https://example.com tag1, tag2, last tag</code></p>
-                        URLs which do not pass validation will stay in the textarea.
+                        <p><strong>{{ _('Example:') }}  </strong><code>https://example.com tag1, tag2, last tag</code></p>
+                        {{ _('URLs which do not pass validation will stay in the textarea.') }}
                 </div>
                 {{ render_field(form.processor, class="processor") }}
                 
@@ -42,12 +41,12 @@
 
 
                     <div class="pure-control-group">
-                        Copy and Paste your Distill.io watch 'export' file, this should be a JSON file.<br>
-                        This is <i>experimental</i>, supported fields are <code>name</code>, <code>uri</code>, <code>tags</code>, <code>config:selections</code>, the rest (including <code>schedule</code>) are ignored.
+                        {{ _('Copy and Paste your Distill.io watch \'export\' file, this should be a JSON file.') }}<br>
+                        {{ _('This is') }} <i>{{ _('experimental') }}</i>, {{ _('supported fields are') }} <code>name</code>, <code>uri</code>, <code>tags</code>, <code>config:selections</code>, {{ _('the rest (including') }} <code>schedule</code>) {{ _('are ignored.') }}
                         <br>
                         <p>
-                        How to export? <a href="https://distill.io/docs/web-monitor/how-export-and-import-monitors/">https://distill.io/docs/web-monitor/how-export-and-import-monitors/</a><br>
-                        Be sure to set your default fetcher to Chrome if required.<br>
+                        {{ _('How to export?') }} <a href="https://distill.io/docs/web-monitor/how-export-and-import-monitors/">https://distill.io/docs/web-monitor/how-export-and-import-monitors/</a><br>
+                        {{ _('Be sure to set your default fetcher to Chrome if required.') }}<br>
                         </p>
                     </div>
 
@@ -89,32 +88,32 @@
             </fieldset>
                 <div class="pure-control-group">
                 <span class="pure-form-message-inline">
-                    Table of custom column and data types mapping for the <strong>Custom mapping</strong> File mapping type.
+                    {{ _('Table of custom column and data types mapping for the') }} <strong>{{ _('Custom mapping') }}</strong> {{ _('File mapping type.') }}
                 </span>
                     <table style="border: 1px solid #aaa; padding: 0.5rem; border-radius: 4px;">
                         <tr>
-                            <td><strong>Column #</strong></td>
+                            <td><strong>{{ _('Column #') }}</strong></td>
                             {% for n in range(4) %}
                                 <td><input type="number" name="custom_xlsx[col_{{n}}]" style="width: 4rem;" min="1"></td>
                             {%  endfor %}
                         </tr>
                         <tr>
-                            <td><strong>Type</strong></td>
+                            <td><strong>{{ _('Type') }}</strong></td>
                             {% for n in range(4) %}
                                 <td><select name="custom_xlsx[col_type_{{n}}]">
-                                    <option value="" style="color: #aaa"> -- none --</option>
-                                    <option value="url">URL</option>
-                                    <option value="title">Title</option>
-                                    <option value="include_filters">CSS/xPath filter</option>
-                                    <option value="tag">Group / Tag name(s)</option>
-                                    <option value="interval_minutes">Recheck time (minutes)</option>
+                                    <option value="" style="color: #aaa"> -- {{ _('none') }} --</option>
+                                    <option value="url">{{ _('URL') }}</option>
+                                    <option value="title">{{ _('Title') }}</option>
+                                    <option value="include_filters">{{ _('CSS/xPath filter') }}</option>
+                                    <option value="tag">{{ _('Group / Tag name(s)') }}</option>
+                                    <option value="interval_minutes">{{ _('Recheck time (minutes)') }}</option>
                                 </select></td>
                             {%  endfor %}
                         </tr>
                     </table>
                 </div>
             </div>
-            <button type="submit" class="pure-button pure-input-1-2 pure-button-primary">Import</button>
+            <button type="submit" class="pure-button pure-input-1-2 pure-button-primary">{{ _('Import') }}</button>
         </form>
 
     </div>

changedetectionio/blueprint/rss/__init__.py

@@ -1 +1,27 @@
-RSS_FORMAT_TYPES = [('plaintext', 'Plain text'), ('html', 'HTML Color')]
+from copy import deepcopy
+from loguru import logger
+
+from changedetectionio.model import USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH
+from changedetectionio.notification import valid_notification_formats
+
+RSS_CONTENT_FORMAT_DEFAULT = 'text'
+
+# Some stuff not related
+RSS_FORMAT_TYPES = deepcopy(valid_notification_formats)
+if RSS_FORMAT_TYPES.get('markdown'):
+    del RSS_FORMAT_TYPES['markdown']
+
+if RSS_FORMAT_TYPES.get(USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH):
+    del RSS_FORMAT_TYPES[USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH]
+
+if not RSS_FORMAT_TYPES.get(RSS_CONTENT_FORMAT_DEFAULT):
+    logger.critical(f"RSS_CONTENT_FORMAT_DEFAULT not in the acceptable list {RSS_CONTENT_FORMAT_DEFAULT}")
+
+RSS_TEMPLATE_TYPE_OPTIONS = {'system_default': 'System default', 'notification_body': 'Notification body'}
+
+# @note: We use <pre> because nearly all RSS readers render only HTML (Thunderbird for example cant do just plaintext)
+RSS_TEMPLATE_PLAINTEXT_DEFAULT = "<pre>{{watch_label}} had a change.\n\n{{diff}}\n</pre>"
+
+# @todo add some [edit]/[history]/[goto] etc links
+# @todo need {{watch_edit_link}} + delete + history link token
+RSS_TEMPLATE_HTML_DEFAULT = "<html><body>\n<h4><a href=\"{{watch_url}}\">{{watch_label}}</a></h4>\n<p>{{diff}}</p>\n</body></html>\n"

changedetectionio/blueprint/rss/_util.py

@@ -0,0 +1,156 @@
+"""
+Utility functions for RSS feed generation.
+"""
+
+from changedetectionio.notification.handler import process_notification
+from changedetectionio.notification_service import NotificationContextData, _check_cascading_vars
+from loguru import logger
+import datetime
+import pytz
+import re
+
+
+BAD_CHARS_REGEX = r'[\x00-\x08\x0B\x0C\x0E-\x1F]'
+
+
+def scan_invalid_chars_in_rss(content):
+    """
+    Scan for invalid characters in RSS content.
+    Returns True if invalid characters are found.
+    """
+    for match in re.finditer(BAD_CHARS_REGEX, content):
+        i = match.start()
+        bad_char = content[i]
+        hex_value = f"0x{ord(bad_char):02x}"
+        # Grab context
+        start = max(0, i - 20)
+        end = min(len(content), i + 21)
+        context = content[start:end].replace('\n', '\\n').replace('\r', '\\r')
+        logger.warning(f"Invalid char {hex_value} at pos {i}: ...{context}...")
+        # First match is enough
+        return True
+
+    return False
+
+
+def clean_entry_content(content):
+    """
+    Remove invalid characters from RSS content.
+    """
+    cleaned = re.sub(BAD_CHARS_REGEX, '', content)
+    return cleaned
+
+
+def generate_watch_guid(watch, timestamp):
+    """
+    Generate a unique GUID for a watch RSS entry.
+
+    Args:
+        watch: The watch object
+        timestamp: The timestamp of the specific change this entry represents
+    """
+    return f"{watch['uuid']}/{timestamp}"
+
+
+def validate_rss_token(datastore, request):
+    """
+    Validate the RSS access token from the request.
+
+    Returns:
+        tuple: (is_valid, error_response) where error_response is None if valid
+    """
+    app_rss_token = datastore.data['settings']['application'].get('rss_access_token')
+    rss_url_token = request.args.get('token')
+
+    if rss_url_token != app_rss_token:
+        return False, ("Access denied, bad token", 403)
+
+    return True, None
+
+
+def get_rss_template(datastore, watch, rss_content_format, default_html, default_plaintext):
+    """Get the appropriate template for RSS content."""
+    if datastore.data['settings']['application'].get('rss_template_type') == 'notification_body':
+        return _check_cascading_vars(datastore=datastore, var_name='notification_body', watch=watch)
+
+    override = datastore.data['settings']['application'].get('rss_template_override')
+    if override and override.strip():
+        return override
+    elif 'text' in rss_content_format:
+        return default_plaintext
+    else:
+        return default_html
+
+
+def get_watch_label(datastore, watch):
+    """Get the label for a watch based on settings."""
+    if datastore.data['settings']['application']['ui'].get('use_page_title_in_list') or watch.get('use_page_title_in_list'):
+        return watch.label
+    else:
+        return watch.get('url')
+
+
+def add_watch_categories(fe, watch, datastore):
+    """Add category tags to a feed entry based on watch tags."""
+    for tag_uuid in watch.get('tags', []):
+        tag = datastore.data['settings']['application'].get('tags', {}).get(tag_uuid)
+        if tag and tag.get('title'):
+            fe.category(term=tag.get('title'))
+
+
+def build_notification_context(watch, timestamp_from, timestamp_to, watch_label,
+                               n_body_template, rss_content_format):
+    """Build the notification context object."""
+    return NotificationContextData(initial_data={
+        'notification_urls': ['null://just-sending-a-null-test-for-the-render-in-RSS'],
+        'notification_body': n_body_template,
+        'timestamp_to': timestamp_to,
+        'timestamp_from': timestamp_from,
+        'watch_label': watch_label,
+        'notification_format': rss_content_format
+    })
+
+
+def render_notification(n_object, notification_service, watch, datastore,
+                       date_index_from=None, date_index_to=None):
+    """Process and render the notification content."""
+    kwargs = {'n_object': n_object, 'watch': watch}
+
+    if date_index_from is not None and date_index_to is not None:
+        kwargs['date_index_from'] = date_index_from
+        kwargs['date_index_to'] = date_index_to
+
+    n_object = notification_service.queue_notification_for_watch(**kwargs)
+    n_object['watch_mime_type'] = None
+
+    res = process_notification(n_object=n_object, datastore=datastore)
+    return res[0]
+
+
+def populate_feed_entry(fe, watch, content, guid, timestamp, link=None, title_suffix=None):
+    """Populate a feed entry with content and metadata."""
+    watch_label = watch.get('url')  # Already determined by caller
+
+    # Set link
+    if link:
+        fe.link(link=link)
+
+    # Set title
+    if title_suffix:
+        fe.title(title=f"{watch_label} - {title_suffix}")
+    else:
+        fe.title(title=watch_label)
+
+    # Clean and set content
+    if scan_invalid_chars_in_rss(content):
+        content = clean_entry_content(content)
+    fe.content(content=content, type='CDATA')
+
+    # Set GUID
+    fe.guid(guid, permalink=False)
+
+    # Set pubDate using the timestamp of this specific change
+    dt = datetime.datetime.fromtimestamp(int(timestamp))
+    dt = dt.replace(tzinfo=pytz.UTC)
+    fe.pubDate(dt)
+

changedetectionio/blueprint/rss/blueprint.py

@@ -1,150 +1,26 @@
 
-from changedetectionio.safe_jinja import render as jinja_render
 from changedetectionio.store import ChangeDetectionStore
-from feedgen.feed import FeedGenerator
-from flask import Blueprint, make_response, request, url_for, redirect
-from loguru import logger
-import datetime
-import pytz
-import re
-import time
+from flask import Blueprint
 
-
-BAD_CHARS_REGEX=r'[\x00-\x08\x0B\x0C\x0E-\x1F]'
-
-# Anything that is not text/UTF-8 should be stripped before it breaks feedgen (such as binary data etc)
-def scan_invalid_chars_in_rss(content):
-    for match in re.finditer(BAD_CHARS_REGEX, content):
-        i = match.start()
-        bad_char = content[i]
-        hex_value = f"0x{ord(bad_char):02x}"
-        # Grab context
-        start = max(0, i - 20)
-        end = min(len(content), i + 21)
-        context = content[start:end].replace('\n', '\\n').replace('\r', '\\r')
-        logger.warning(f"Invalid char {hex_value} at pos {i}: ...{context}...")
-        # First match is enough
-        return True
-
-    return False
-
-
-def clean_entry_content(content):
-    cleaned = re.sub(BAD_CHARS_REGEX, '', content)
-    return cleaned
+from . import tag as tag_routes
+from . import main_feed
+from . import single_watch
 
 def construct_blueprint(datastore: ChangeDetectionStore):
+    """
+    Construct and configure the RSS blueprint with all routes.
+
+    Args:
+        datastore: The ChangeDetectionStore instance
+
+    Returns:
+        The configured Flask blueprint
+    """
     rss_blueprint = Blueprint('rss', __name__)
 
-    # Some RSS reader situations ended up with rss/ (forward slash after RSS) due
-    # to some earlier blueprint rerouting work, it should goto feed.
-    @rss_blueprint.route("/", methods=['GET'])
-    def extraslash():
-        return redirect(url_for('rss.feed'))
-
-    # Import the login decorator if needed
-    # from changedetectionio.auth_decorator import login_optionally_required
-    @rss_blueprint.route("", methods=['GET'])
-    def feed():
-        now = time.time()
-        # Always requires token set
-        app_rss_token = datastore.data['settings']['application'].get('rss_access_token')
-        rss_url_token = request.args.get('token')
-        if rss_url_token != app_rss_token:
-            return "Access denied, bad token", 403
-
-        from changedetectionio import diff
-        limit_tag = request.args.get('tag', '').lower().strip()
-        # Be sure limit_tag is a uuid
-        for uuid, tag in datastore.data['settings']['application'].get('tags', {}).items():
-            if limit_tag == tag.get('title', '').lower().strip():
-                limit_tag = uuid
-
-        # Sort by last_changed and add the uuid which is usually the key..
-        sorted_watches = []
-
-        # @todo needs a .itemsWithTag() or something - then we can use that in Jinaj2 and throw this away
-        for uuid, watch in datastore.data['watching'].items():
-            # @todo tag notification_muted skip also (improve Watch model)
-            if datastore.data['settings']['application'].get('rss_hide_muted_watches') and watch.get('notification_muted'):
-                continue
-            if limit_tag and not limit_tag in watch['tags']:
-                continue
-            watch['uuid'] = uuid
-            sorted_watches.append(watch)
-
-        sorted_watches.sort(key=lambda x: x.last_changed, reverse=False)
-
-        fg = FeedGenerator()
-        fg.title('changedetection.io')
-        fg.description('Feed description')
-        fg.link(href='https://changedetection.io')
-
-        html_colour_enable = False
-        if datastore.data['settings']['application'].get('rss_content_format') == 'html':
-            html_colour_enable = True
-
-        for watch in sorted_watches:
-
-            dates = list(watch.history.keys())
-            # Re #521 - Don't bother processing this one if theres less than 2 snapshots, means we never had a change detected.
-            if len(dates) < 2:
-                continue
-
-            if not watch.viewed:
-                # Re #239 - GUID needs to be individual for each event
-                # @todo In the future make this a configurable link back (see work on BASE_URL https://github.com/dgtlmoon/changedetection.io/pull/228)
-                guid = "{}/{}".format(watch['uuid'], watch.last_changed)
-                fe = fg.add_entry()
-
-                # Include a link to the diff page, they will have to login here to see if password protection is enabled.
-                # Description is the page you watch, link takes you to the diff JS UI page
-                # Dict val base_url will get overriden with the env var if it is set.
-                ext_base_url = datastore.data['settings']['application'].get('active_base_url')
-                # @todo fix
-
-                # Because we are called via whatever web server, flask should figure out the right path (
-                diff_link = {'href': url_for('ui.ui_views.diff_history_page', uuid=watch['uuid'], _external=True)}
-
-                fe.link(link=diff_link)
-
-                # Same logic as watch-overview.html
-                if datastore.data['settings']['application']['ui'].get('use_page_title_in_list') or watch.get('use_page_title_in_list'):
-                    watch_label = watch.label
-                else:
-                    watch_label = watch.get('url')
-
-                fe.title(title=watch_label)
-                try:
-
-                    html_diff = diff.render_diff(previous_version_file_contents=watch.get_history_snapshot(dates[-2]),
-                                                 newest_version_file_contents=watch.get_history_snapshot(dates[-1]),
-                                                 include_equal=False,
-                                                 line_feed_sep="<br>",
-                                                 html_colour=html_colour_enable
-                                                 )
-                except FileNotFoundError as e:
-                    html_diff = f"History snapshot file for watch {watch.get('uuid')}@{watch.last_changed} - '{watch.get('title')} not found."
-
-                # @todo Make this configurable and also consider html-colored markup
-                # @todo User could decide if <link> goes to the diff page, or to the watch link
-                rss_template = "<html><body>\n<h4><a href=\"{{watch_url}}\">{{watch_title}}</a></h4>\n<p>{{html_diff}}</p>\n</body></html>\n"
-
-                content = jinja_render(template_str=rss_template, watch_title=watch_label, html_diff=html_diff, watch_url=watch.link)
-
-                # Out of range chars could also break feedgen
-                if scan_invalid_chars_in_rss(content):
-                    content = clean_entry_content(content)
-
-                fe.content(content=content, type='CDATA')
-                fe.guid(guid, permalink=False)
-                dt = datetime.datetime.fromtimestamp(int(watch.newest_history_key))
-                dt = dt.replace(tzinfo=pytz.UTC)
-                fe.pubDate(dt)
-
-        response = make_response(fg.rss_str())
-        response.headers.set('Content-Type', 'application/rss+xml;charset=utf-8')
-        logger.trace(f"RSS generated in {time.time() - now:.3f}s")
-        return response
+    # Register all route modules
+    main_feed.construct_main_feed_routes(rss_blueprint, datastore)
+    single_watch.construct_single_watch_routes(rss_blueprint, datastore)
+    tag_routes.construct_tag_routes(rss_blueprint, datastore)
 
     return rss_blueprint

changedetectionio/blueprint/rss/main_feed.py

@@ -0,0 +1,105 @@
+from flask import make_response, request, url_for, redirect
+
+
+
+def construct_main_feed_routes(rss_blueprint, datastore):
+    """
+    Construct the main RSS feed routes.
+
+    Args:
+        rss_blueprint: The Flask blueprint to add routes to
+        datastore: The ChangeDetectionStore instance
+    """
+
+    # Some RSS reader situations ended up with rss/ (forward slash after RSS) due
+    # to some earlier blueprint rerouting work, it should goto feed.
+    @rss_blueprint.route("/", methods=['GET'])
+    def extraslash():
+        return redirect(url_for('rss.feed'))
+
+    # Import the login decorator if needed
+    # from changedetectionio.auth_decorator import login_optionally_required
+    @rss_blueprint.route("", methods=['GET'])
+    def feed():
+        from feedgen.feed import FeedGenerator
+        from loguru import logger
+        import time
+
+        from . import RSS_TEMPLATE_HTML_DEFAULT, RSS_TEMPLATE_PLAINTEXT_DEFAULT
+        from ._util import (validate_rss_token, generate_watch_guid, get_rss_template,
+                           get_watch_label, build_notification_context, render_notification,
+                           populate_feed_entry, add_watch_categories)
+        from ...notification_service import NotificationService
+
+        now = time.time()
+
+        # Validate token
+        is_valid, error = validate_rss_token(datastore, request)
+        if not is_valid:
+            return error
+
+        rss_content_format = datastore.data['settings']['application'].get('rss_content_format')
+
+        limit_tag = request.args.get('tag', '').lower().strip()
+        # Be sure limit_tag is a uuid
+        for uuid, tag in datastore.data['settings']['application'].get('tags', {}).items():
+            if limit_tag == tag.get('title', '').lower().strip():
+                limit_tag = uuid
+
+        # Sort by last_changed and add the uuid which is usually the key..
+        sorted_watches = []
+
+        # @todo needs a .itemsWithTag() or something - then we can use that in Jinaj2 and throw this away
+        for uuid, watch in datastore.data['watching'].items():
+            # @todo tag notification_muted skip also (improve Watch model)
+            if datastore.data['settings']['application'].get('rss_hide_muted_watches') and watch.get('notification_muted'):
+                continue
+            if limit_tag and not limit_tag in watch['tags']:
+                continue
+            sorted_watches.append(watch)
+
+        sorted_watches.sort(key=lambda x: x.last_changed, reverse=False)
+
+        fg = FeedGenerator()
+        fg.title('changedetection.io')
+        fg.description('Feed description')
+        fg.link(href='https://changedetection.io')
+        notification_service = NotificationService(datastore=datastore, notification_q=False)
+
+        for watch in sorted_watches:
+
+            dates = list(watch.history.keys())
+            # Re #521 - Don't bother processing this one if theres less than 2 snapshots, means we never had a change detected.
+            if len(dates) < 2:
+                continue
+
+            if not watch.viewed:
+                # Re #239 - GUID needs to be individual for each event
+                # @todo In the future make this a configurable link back (see work on BASE_URL https://github.com/dgtlmoon/changedetection.io/pull/228)
+                watch_label = get_watch_label(datastore, watch)
+                timestamp_to = dates[-1]
+                timestamp_from = dates[-2]
+                guid = generate_watch_guid(watch, timestamp_to)
+                # Because we are called via whatever web server, flask should figure out the right path
+                diff_link = {'href': url_for('ui.ui_diff.diff_history_page', uuid=watch['uuid'], _external=True)}
+
+                # Get template and build notification context
+                n_body_template = get_rss_template(datastore, watch, rss_content_format,
+                                                   RSS_TEMPLATE_HTML_DEFAULT, RSS_TEMPLATE_PLAINTEXT_DEFAULT)
+
+                n_object = build_notification_context(watch, timestamp_from, timestamp_to,
+                                                     watch_label, n_body_template, rss_content_format)
+
+                # Render notification
+                res = render_notification(n_object, notification_service, watch, datastore)
+
+                # Create and populate feed entry
+                fe = fg.add_entry()
+                populate_feed_entry(fe, watch, res['body'], guid, timestamp_to, link=diff_link)
+                fe.title(title=watch_label)  # Override title to not include suffix
+                add_watch_categories(fe, watch, datastore)
+
+        response = make_response(fg.rss_str())
+        response.headers.set('Content-Type', 'application/rss+xml;charset=utf-8')
+        logger.trace(f"RSS generated in {time.time() - now:.3f}s")
+        return response

changedetectionio/blueprint/rss/single_watch.py

@@ -0,0 +1,115 @@
+
+
+def construct_single_watch_routes(rss_blueprint, datastore):
+    """
+    Construct RSS feed routes for single watches.
+
+    Args:
+        rss_blueprint: The Flask blueprint to add routes to
+        datastore: The ChangeDetectionStore instance
+    """
+
+    @rss_blueprint.route("/watch/<string:uuid>", methods=['GET'])
+    def rss_single_watch(uuid):
+        import time
+
+        from flask import make_response, request
+        from feedgen.feed import FeedGenerator
+        from loguru import logger
+
+        from . import RSS_TEMPLATE_HTML_DEFAULT, RSS_TEMPLATE_PLAINTEXT_DEFAULT
+        from ._util import (validate_rss_token, get_rss_template, get_watch_label,
+                           build_notification_context, render_notification,
+                           populate_feed_entry, add_watch_categories)
+        from ...notification_service import NotificationService
+
+        """
+        Display the most recent changes for a single watch as RSS feed.
+        Returns RSS XML with multiple entries showing diffs between consecutive snapshots.
+        The number of entries is controlled by the rss_diff_length setting.
+        """
+        now = time.time()
+
+        # Validate token
+        is_valid, error = validate_rss_token(datastore, request)
+        if not is_valid:
+            return error
+
+        rss_content_format = datastore.data['settings']['application'].get('rss_content_format')
+
+        # Get the watch by UUID
+        watch = datastore.data['watching'].get(uuid)
+        if not watch:
+            return f"Watch with UUID {uuid} not found", 404
+
+        # Check if watch has at least 2 history snapshots
+        dates = list(watch.history.keys())
+        if len(dates) < 2:
+            return f"Watch {uuid} does not have enough history snapshots to show changes (need at least 2)", 400
+
+        # Add uuid to watch for proper functioning
+        watch['uuid'] = uuid
+
+        # Get the number of diffs to include (default: 5)
+        rss_diff_length = datastore.data['settings']['application'].get('rss_diff_length', 5)
+
+        # Calculate how many diffs we can actually show (limited by available history)
+        # We need at least 2 snapshots to create 1 diff
+        max_possible_diffs = len(dates) - 1
+        num_diffs = min(rss_diff_length, max_possible_diffs) if rss_diff_length > 0 else max_possible_diffs
+
+        # Create RSS feed
+        fg = FeedGenerator()
+
+        # Set title: use "label (url)" if label differs from url, otherwise just url
+        watch_url = watch.get('url', '')
+        watch_label = get_watch_label(datastore, watch)
+
+        if watch_label != watch_url:
+            feed_title = f'changedetection.io - {watch_label} ({watch_url})'
+        else:
+            feed_title = f'changedetection.io - {watch_url}'
+
+        fg.title(feed_title)
+        fg.description('Changes')
+        fg.link(href='https://changedetection.io')
+
+        # Loop through history and create RSS entries for each diff
+        # Add entries in reverse order because feedgen reverses them
+        # This way, the newest change appears first in the final RSS
+
+        notification_service = NotificationService(datastore=datastore, notification_q=False)
+        for i in range(num_diffs - 1, -1, -1):
+            # Calculate indices for this diff (working backwards from newest)
+            # i=0: compare dates[-2] to dates[-1] (most recent change)
+            # i=1: compare dates[-3] to dates[-2] (previous change)
+            # etc.
+            date_index_to = -(i + 1)
+            date_index_from = -(i + 2)
+            timestamp_to = dates[date_index_to]
+            timestamp_from = dates[date_index_from]
+
+            # Get template and build notification context
+            n_body_template = get_rss_template(datastore, watch, rss_content_format,
+                                               RSS_TEMPLATE_HTML_DEFAULT, RSS_TEMPLATE_PLAINTEXT_DEFAULT)
+
+            n_object = build_notification_context(watch, timestamp_from, timestamp_to,
+                                                 watch_label, n_body_template, rss_content_format)
+
+            # Render notification with date indices
+            res = render_notification(n_object, notification_service, watch, datastore,
+                                     date_index_from, date_index_to)
+
+            # Create and populate feed entry
+            guid = f"{watch['uuid']}/{timestamp_to}"
+            fe = fg.add_entry()
+            title_suffix = f"Change @ {res['original_context']['change_datetime']}"
+            populate_feed_entry(fe, watch, res.get('body', ''), guid, timestamp_to,
+                              link={'href': watch.get('url')}, title_suffix=title_suffix)
+            add_watch_categories(fe, watch, datastore)
+
+        response = make_response(fg.rss_str())
+        response.headers.set('Content-Type', 'application/rss+xml;charset=utf-8')
+        logger.debug(f"RSS Single watch built in {time.time()-now:.2f}s")
+
+        return response

changedetectionio/blueprint/rss/tag.py

@@ -0,0 +1,98 @@
+def construct_tag_routes(rss_blueprint, datastore):
+    """
+    Construct RSS feed routes for tags.
+
+    Args:
+        rss_blueprint: The Flask blueprint to add routes to
+        datastore: The ChangeDetectionStore instance
+    """
+
+    @rss_blueprint.route("/tag/<string:tag_uuid>", methods=['GET'])
+    def rss_tag_feed(tag_uuid):
+
+        from flask import make_response, request, url_for
+        from feedgen.feed import FeedGenerator
+
+        from . import RSS_TEMPLATE_HTML_DEFAULT, RSS_TEMPLATE_PLAINTEXT_DEFAULT
+        from ._util import (validate_rss_token, generate_watch_guid, get_rss_template,
+                           get_watch_label, build_notification_context, render_notification,
+                           populate_feed_entry, add_watch_categories)
+        from ...notification_service import NotificationService
+
+        """
+        Display an RSS feed for all unviewed watches that belong to a specific tag.
+        Returns RSS XML with entries for each unviewed watch with sufficient history.
+        """
+        # Validate token
+        is_valid, error = validate_rss_token(datastore, request)
+        if not is_valid:
+            return error
+
+        rss_content_format = datastore.data['settings']['application'].get('rss_content_format')
+
+        # Verify tag exists
+        tag = datastore.data['settings']['application'].get('tags', {}).get(tag_uuid)
+        if not tag:
+            return f"Tag with UUID {tag_uuid} not found", 404
+
+        tag_title = tag.get('title', 'Unknown Tag')
+
+        # Create RSS feed
+        fg = FeedGenerator()
+        fg.title(f'changedetection.io - {tag_title}')
+        fg.description(f'Changes for watches tagged with {tag_title}')
+        fg.link(href='https://changedetection.io')
+        notification_service = NotificationService(datastore=datastore, notification_q=False)
+        # Find all watches with this tag
+        for uuid, watch in datastore.data['watching'].items():
+            #@todo  This is wrong, it needs to sort by most recently changed and then limit it  datastore.data['watching'].items().sorted(?)
+            # So get all watches in this tag then sort
+
+            # Skip if watch doesn't have this tag
+            if tag_uuid not in watch.get('tags', []):
+                continue
+
+            # Skip muted watches if configured
+            if datastore.data['settings']['application'].get('rss_hide_muted_watches') and watch.get('notification_muted'):
+                continue
+
+            # Check if watch has at least 2 history snapshots
+            dates = list(watch.history.keys())
+            if len(dates) < 2:
+                continue
+
+            # Only include unviewed watches
+            if not watch.viewed:
+                # Add uuid to watch for proper functioning
+                watch['uuid'] = uuid
+
+                # Include a link to the diff page
+                diff_link = {'href': url_for('ui.ui_diff.diff_history_page', uuid=watch['uuid'], _external=True)}
+
+                # Get watch label
+                watch_label = get_watch_label(datastore, watch)
+
+                # Get template and build notification context
+                timestamp_to = dates[-1]
+                timestamp_from = dates[-2]
+
+                # Generate GUID for this entry
+                guid = generate_watch_guid(watch, timestamp_to)
+                n_body_template = get_rss_template(datastore, watch, rss_content_format,
+                                                   RSS_TEMPLATE_HTML_DEFAULT, RSS_TEMPLATE_PLAINTEXT_DEFAULT)
+
+                n_object = build_notification_context(watch, timestamp_from, timestamp_to,
+                                                     watch_label, n_body_template, rss_content_format)
+
+                # Render notification
+                res = render_notification(n_object, notification_service, watch, datastore)
+
+                # Create and populate feed entry
+                fe = fg.add_entry()
+                title_suffix = f"Change @ {res['original_context']['change_datetime']}"
+                populate_feed_entry(fe, watch, res['body'], guid, timestamp_to, link=diff_link, title_suffix=title_suffix)
+                add_watch_categories(fe, watch, datastore)
+
+        response = make_response(fg.rss_str())
+        response.headers.set('Content-Type', 'application/rss+xml;charset=utf-8')
+        return response

changedetectionio/blueprint/settings/__init__.py

@@ -5,6 +5,7 @@ from zoneinfo import ZoneInfo, available_timezones
 import secrets
 import flask_login
 from flask import Blueprint, render_template, request, redirect, url_for, flash
+from flask_babel import gettext
 
 from changedetectionio.store import ChangeDetectionStore
 from changedetectionio.auth_decorator import login_optionally_required
@@ -17,6 +18,12 @@ def construct_blueprint(datastore: ChangeDetectionStore):
     @login_optionally_required
     def settings_page():
         from changedetectionio import forms
+        from changedetectionio.pluggy_interface import (
+            get_plugin_settings_tabs,
+            load_plugin_settings,
+            save_plugin_settings
+        )
+
 
         default = deepcopy(datastore.data['settings'])
         if datastore.proxy_list is not None:
@@ -54,7 +61,7 @@ def construct_blueprint(datastore: ChangeDetectionStore):
                 # SALTED_PASS means the password is "locked" to what we set in the Env var
                 if not os.getenv("SALTED_PASS", False):
                     datastore.remove_password()
-                    flash("Password protection removed.", 'notice')
+                    flash(gettext("Password protection removed."), 'notice')
                     flask_login.logout_user()
                     return redirect(url_for('settings.settings_page'))
 
@@ -88,30 +95,66 @@ def construct_blueprint(datastore: ChangeDetectionStore):
                     )
                     
                     if result['status'] == 'success':
-                        flash(f"Worker count adjusted: {result['message']}", 'notice')
+                        flash(gettext("Worker count adjusted: {}").format(result['message']), 'notice')
                     elif result['status'] == 'not_supported':
-                        flash("Dynamic worker adjustment not supported for sync workers", 'warning')
+                        flash(gettext("Dynamic worker adjustment not supported for sync workers"), 'warning')
                     elif result['status'] == 'error':
-                        flash(f"Error adjusting workers: {result['message']}", 'error')
+                        flash(gettext("Error adjusting workers: {}").format(result['message']), 'error')
 
                 if not os.getenv("SALTED_PASS", False) and len(form.application.form.password.encrypted_password):
                     datastore.data['settings']['application']['password'] = form.application.form.password.encrypted_password
                     datastore.needs_write_urgent = True
-                    flash("Password protection enabled.", 'notice')
+                    flash(gettext("Password protection enabled."), 'notice')
                     flask_login.logout_user()
                     return redirect(url_for('watchlist.index'))
 
                 datastore.needs_write_urgent = True
-                flash("Settings updated.")
+
+                # Also save plugin settings from the same form submission
+                plugin_tabs_list = get_plugin_settings_tabs()
+                for tab in plugin_tabs_list:
+                    plugin_id = tab['plugin_id']
+                    form_class = tab['form_class']
+
+                    # Instantiate plugin form with POST data
+                    plugin_form = form_class(formdata=request.form)
+
+                    # Save plugin settings (validation is optional for plugins)
+                    if plugin_form.data:
+                        save_plugin_settings(datastore.datastore_path, plugin_id, plugin_form.data)
+
+                flash(gettext("Settings updated."))
 
             else:
-                flash("An error occurred, please see below.", "error")
+                flash(gettext("An error occurred, please see below."), "error")
 
         # Convert to ISO 8601 format, all date/time relative events stored as UTC time
         utc_time = datetime.now(ZoneInfo("UTC")).isoformat()
 
+        # Get active plugins
+        from changedetectionio.pluggy_interface import get_active_plugins
+        import sys
+        active_plugins = get_active_plugins()
+        python_version = f"{sys.version_info.major}.{sys.version_info.minor}.{sys.version_info.micro}"
+
+        # Get plugin settings tabs and instantiate forms
+        plugin_tabs = get_plugin_settings_tabs()
+        plugin_forms = {}
+
+        for tab in plugin_tabs:
+            plugin_id = tab['plugin_id']
+            form_class = tab['form_class']
+
+            # Load existing settings
+            settings = load_plugin_settings(datastore.datastore_path, plugin_id)
+
+            # Instantiate the form with existing settings
+            plugin_forms[plugin_id] = form_class(data=settings)
+
         output = render_template("settings.html",
+                                active_plugins=active_plugins,
                                 api_key=datastore.data['settings']['application'].get('api_access_token'),
+                                python_version=python_version,
                                 available_timezones=sorted(available_timezones()),
                                 emailprefix=os.getenv('NOTIFICATION_MAIL_BUTTON_PREFIX', False),
                                 extra_notification_token_placeholder_info=datastore.get_unique_notification_token_placeholders_available(),
@@ -119,8 +162,10 @@ def construct_blueprint(datastore: ChangeDetectionStore):
                                 hide_remove_pass=os.getenv("SALTED_PASS", False),
                                 min_system_recheck_seconds=int(os.getenv('MINIMUM_SECONDS_RECHECK_TIME', 3)),
                                 settings_application=datastore.data['settings']['application'],
-                                timezone_default_config=datastore.data['settings']['application'].get('timezone'),
+                                timezone_default_config=datastore.data['settings']['application'].get('scheduler_timezone_default'),
                                 utc_time=utc_time,
+                                plugin_tabs=plugin_tabs,
+                                plugin_forms=plugin_forms,
                                 )
 
         return output
@@ -131,7 +176,7 @@ def construct_blueprint(datastore: ChangeDetectionStore):
         secret = secrets.token_hex(16)
         datastore.data['settings']['application']['api_access_token'] = secret
         datastore.needs_write_urgent = True
-        flash("API Key was regenerated.")
+        flash(gettext("API Key was regenerated."))
         return redirect(url_for('settings.settings_page')+'#api')
         
     @settings_blueprint.route("/notification-logs", methods=['GET'])

changedetectionio/blueprint/settings/templates/notification-log.html

@@ -4,7 +4,7 @@
 <div class="edit-form">
      <div class="inner">
 
-         <h4 style="margin-top: 0px;">Notification debug log</h4>
+         <h4 style="margin-top: 0px;">{{ _('Notification debug log') }}</h4>
                 <div id="notification-error-log">
                 <ul style="font-size: 80%; margin:0px; padding: 0 0 0 7px">
                 {% for log in logs|reverse %}

changedetectionio/blueprint/settings/templates/settings.html

@@ -1,8 +1,8 @@
 {% extends 'base.html' %}
 
 {% block content %}
-{% from '_helpers.html' import render_field, render_checkbox_field, render_button, render_time_schedule_form, render_ternary_field %}
-{% from '_common_fields.html' import render_common_settings_form %}
+{% from '_helpers.html' import render_field, render_checkbox_field, render_button, render_time_schedule_form, render_ternary_field, render_fieldlist_with_inline_errors %}
+{% from '_common_fields.html' import render_common_settings_form, show_token_placeholders %}
 <script>
     const notification_base_url="{{url_for('ui.ui_notification.ajax_callback_send_notification_test', mode="global-settings")}}";
 {% if emailprefix %}
@@ -18,14 +18,21 @@
 <div class="edit-form">
     <div class="tabs collapsable">
         <ul>
-            <li class="tab" id=""><a href="#general">General</a></li>
-            <li class="tab"><a href="#notifications">Notifications</a></li>
-            <li class="tab"><a href="#fetching">Fetching</a></li>
-            <li class="tab"><a href="#filters">Global Filters</a></li>
-            <li class="tab"><a href="#ui-options">UI Options</a></li>
-            <li class="tab"><a href="#api">API</a></li>
-            <li class="tab"><a href="#timedate">Time &amp Date</a></li>
-            <li class="tab"><a href="#proxies">CAPTCHA &amp; Proxies</a></li>
+            <li class="tab" id=""><a href="#general">{{ _('General') }}</a></li>
+            <li class="tab"><a href="#notifications">{{ _('Notifications') }}</a></li>
+            <li class="tab"><a href="#fetching">{{ _('Fetching') }}</a></li>
+            <li class="tab"><a href="#filters">{{ _('Global Filters') }}</a></li>
+            <li class="tab"><a href="#ui-options">{{ _('UI Options') }}</a></li>
+            <li class="tab"><a href="#api">{{ _('API') }}</a></li>
+            <li class="tab"><a href="#rss">{{ _('RSS') }}</a></li>
+            <li class="tab"><a href="#timedate">{{ _('Time & Date') }}</a></li>
+            <li class="tab"><a href="#proxies">{{ _('CAPTCHA & Proxies') }}</a></li>
+            {% if plugin_tabs %}
+                {% for tab in plugin_tabs %}
+            <li class="tab"><a href="#plugin-{{ tab.plugin_id }}">{{ tab.tab_label }}</a></li>
+                {% endfor %}
+            {% endif %}
+            <li class="tab"><a href="#info">{{ _('Info') }}</a></li>
         </ul>
     </div>
     <div class="box-wrap inner">
@@ -35,18 +42,15 @@
                 <fieldset>
                     <div class="pure-control-group">
                         {{ render_field(form.requests.form.time_between_check, class="time-check-widget") }}
-                        <span class="pure-form-message-inline">Default recheck time for all watches, current system minimum is <i>{{min_system_recheck_seconds}}</i> seconds (<a href="https://github.com/dgtlmoon/changedetection.io/wiki/Misc-system-settings#enviroment-variables">more info</a>).</span>
+
+                        <span class="pure-form-message-inline">{{ _('Default recheck time for all watches, current system minimum is') }} <i>{{min_system_recheck_seconds}}</i> {{ _('seconds') }} (<a href="https://github.com/dgtlmoon/changedetection.io/wiki/Misc-system-settings#enviroment-variables">{{ _('more info') }}</a>).</span>
                             <div id="time-between-check-schedule">
-                                <!-- Start Time and End Time -->
+                                <!-- Start Time and End Time {{ timezone_default_config }} -->
                                 <div id="limit-between-time">
-                                    {{ render_time_schedule_form(form.requests, available_timezones, timezone_default_config) }}
+                                   {{ render_time_schedule_form(form.requests, available_timezones, timezone_default_config) }}
                                 </div>
                         </div>
                     </div>
-                    <div class="pure-control-group">
-                        {{ render_field(form.requests.form.jitter_seconds, class="jitter_seconds") }}
-                        <span class="pure-form-message-inline">Example - 3 seconds random jitter could trigger up to 3 seconds earlier or up to 3 seconds later</span>
-                    </div>
                     <div class="pure-control-group">
                         {{ render_field(form.application.form.filter_failure_notification_threshold_attempts, class="filter_failure_notification_threshold_attempts") }}
                         <span class="pure-form-message-inline">After this many consecutive times that the CSS/xPath filter is missing, send a notification
@@ -69,28 +73,13 @@
 
                     <div class="pure-control-group">
                         {{ render_checkbox_field(form.application.form.shared_diff_access, class="shared_diff_access") }}
-                        <span class="pure-form-message-inline">Allow access to view watch diff page when password is enabled (Good for sharing the diff page)
+                        <span class="pure-form-message-inline">Allow access to the watch change history page when password is enabled (Good for sharing the diff page)
                         </span>
                     </div>
-                    <div class="pure-control-group">
-                        {{ render_checkbox_field(form.application.form.rss_hide_muted_watches) }}
-                    </div>
-                    <div class="pure-control-group">
-                        {{ render_field(form.application.form.rss_content_format) }}
-                        <span class="pure-form-message-inline">Love RSS? Does your reader support HTML? Set it here</span>
-                    </div>
                     <div class="pure-control-group">
                         {{ render_checkbox_field(form.application.form.empty_pages_are_a_change) }}
                         <span class="pure-form-message-inline">When a request returns no content, or the HTML does not contain any text, is this considered a change?</span>
                     </div>
-                {% if form.requests.proxy %}
-                    <div class="pure-control-group inline-radio">
-                        {{ render_field(form.requests.form.proxy, class="fetch-backend-proxy") }}
-                        <span class="pure-form-message-inline">
-                        Choose a default proxy for all watches
-                        </span>
-                    </div>
-                {% endif %}
                 </fieldset>
             </div>
 
@@ -133,6 +122,14 @@
                     <span class="pure-form-message-inline">Number of concurrent workers to process watches. More workers = faster processing but higher memory usage.<br>
                     Currently running: <strong>{{ worker_info.count }}</strong> operational {{ worker_info.type }} workers{% if worker_info.active_workers > 0 %} ({{ worker_info.active_workers }} actively processing){% endif %}.</span>
                 </div>
+                <div class="pure-control-group">
+                    {{ render_field(form.requests.form.jitter_seconds, class="jitter_seconds") }}
+                    <span class="pure-form-message-inline">Example - 3 seconds random jitter could trigger up to 3 seconds earlier or up to 3 seconds later</span>
+                </div>
+                <div class="pure-control-group">
+                    {{ render_field(form.requests.form.timeout) }}
+                    <span class="pure-form-message-inline">For regular plain requests (not chrome based), maximum number of seconds until timeout, 1-999.<br>
+                </div>
                 <div class="pure-control-group inline-radio">
                     {{ render_field(form.requests.form.default_ua) }}
                     <span class="pure-form-message-inline">
@@ -228,7 +225,37 @@ nav
                     </p>
                 </div>
             </div>
-            <div class="tab-pane-inner" id="timedate">
+            <div class="tab-pane-inner" id="rss">
+                <div class="pure-control-group">
+                    {{ render_checkbox_field(form.application.form.rss_hide_muted_watches) }}
+                </div>
+                <div class="pure-control-group">
+                    {{ render_field(form.application.form.rss_diff_length) }}
+                    <span class="pure-form-message-inline">Maximum number of history snapshots to include in the watch specific RSS feed.</span>
+                </div>
+                <div class="pure-control-group">
+                    {{ render_checkbox_field(form.application.form.rss_reader_mode) }}
+                    <span class="pure-form-message-inline">For watching other RSS feeds - When watching RSS/Atom feeds, convert them into clean text for better change detection.</span>
+                </div>
+                <div class="pure-control-group grey-form-border">
+                    <div class="pure-control-group">
+                        {{ render_field(form.application.form.rss_content_format) }}
+                        <span class="pure-form-message-inline">Does your reader support HTML? Set it here</span>
+                    </div>
+                    <div class="pure-control-group">
+                        {{ render_field(form.application.form.rss_template_type) }}
+                        <span class="pure-form-message-inline">'System default' for the same template for all items, or re-use your "Notification Body" as the template.</span>
+                    </div>
+                    <div>
+                       {{ render_field(form.application.form.rss_template_override) }}
+                        {{ show_token_placeholders(extra_notification_token_placeholder_info=extra_notification_token_placeholder_info, suffix="-rss") }}
+                    </div>
+                </div>
+                <br>
+
+
+            </div>
+                <div class="tab-pane-inner" id="timedate">
                 <div class="pure-control-group">
                     Ensure the settings below are correct, they are used to manage the time schedule for checking your web page watches.
                 </div>
@@ -236,11 +263,9 @@ nav
                     <p><strong>UTC Time &amp Date from Server:</strong> <span id="utc-time" >{{ utc_time }}</span></p>
                     <p><strong>Local Time &amp Date in Browser:</strong> <span class="local-time" data-utc="{{ utc_time }}"></span></p>
                     <p>
-                       {{ render_field(form.application.form.timezone) }}
+                       {{ render_field(form.application.form.scheduler_timezone_default) }}
                         <datalist id="timezones" style="display: none;">
-                            {% for tz_name in available_timezones %}
-                                <option value="{{ tz_name }}">{{ tz_name }}</option>
-                            {% endfor %}
+                            {%- for timezone in available_timezones -%}<option value="{{ timezone }}">{{ timezone }}</option>{%- endfor -%}
                         </datalist>
                     </p>
                 </div>
@@ -314,23 +339,71 @@ nav
                <p><strong>Tip</strong>: "Residential" and "Mobile" proxy type can be more successfull than "Data Center" for blocked websites.
 
                 <div class="pure-control-group" id="extra-proxies-setting">
-                {{ render_field(form.requests.form.extra_proxies) }}
+                {{ render_fieldlist_with_inline_errors(form.requests.form.extra_proxies) }}
                 <span class="pure-form-message-inline">"Name" will be used for selecting the proxy in the Watch Edit settings</span><br>
                 <span class="pure-form-message-inline">SOCKS5 proxies with authentication are only supported with 'plain requests' fetcher, for other fetchers you should whitelist the IP access instead</span>
+                {% if form.requests.proxy %}
+                <div>
+                <br>
+                    <div class="inline-radio">
+                        {{ render_field(form.requests.form.proxy, class="fetch-backend-proxy") }}
+                        <span class="pure-form-message-inline">Choose a default proxy for all watches</span>
+                    </div>
+                </div>
+                {% endif %}
                 </div>
                 <div class="pure-control-group" id="extra-browsers-setting">
                     <p>
                     <span class="pure-form-message-inline"><i>Extra Browsers</i> can be attached to further defeat CAPTCHA's on websites that are particularly hard to scrape.</span><br>
                     <span class="pure-form-message-inline">Simply paste the connection address into the box, <a href="https://changedetection.io/tutorial/using-bright-datas-scraping-browser-pass-captchas-and-other-protection-when-monitoring">More instructions and examples here</a> </span>
                     </p>
-                    {{ render_field(form.requests.form.extra_browsers) }}
+                    {{ render_fieldlist_with_inline_errors(form.requests.form.extra_browsers) }}
                 </div>
             </div>
+            {% if plugin_tabs %}
+                {% for tab in plugin_tabs %}
+            <div class="tab-pane-inner" id="plugin-{{ tab.plugin_id }}">
+                {% set plugin_form = plugin_forms[tab.plugin_id] %}
+                {% if tab.template_path %}
+                    {# Plugin provides custom template - include it directly (no separate form) #}
+                    {% include tab.template_path with context %}
+                {% else %}
+                    {# Default form rendering - fields only, no submit button #}
+                    <fieldset>
+                        {% for field in plugin_form %}
+                            {% if field.type != 'CSRFToken' and field.type != 'SubmitField' %}
+                        <div class="pure-control-group">
+                                {% if field.type == 'BooleanField' %}
+                            {{ render_checkbox_field(field) }}
+                                {% else %}
+                            {{ render_field(field) }}
+                                {% endif %}
+                        </div>
+                            {% endif %}
+                        {% endfor %}
+                    </fieldset>
+                {% endif %}
+            </div>
+                {% endfor %}
+            {% endif %}
+            <div class="tab-pane-inner" id="info">
+                <p><strong>{{ _('Python version:') }}</strong> {{ python_version }}</p>
+                <p><strong>{{ _('Plugins active:') }}</strong></p>
+                {% if active_plugins %}
+                <ul>
+                    {% for plugin in active_plugins %}
+                    <li><strong>{{ plugin.name }}</strong> - {{ plugin.description }}</li>
+                    {% endfor %}
+                </ul>
+                {% else %}
+                <p>{{ _('No plugins active') }}</p>
+                {% endif %}
+            </div>
             <div id="actions">
                 <div class="pure-control-group">
                     {{ render_button(form.save_button) }}
-                    <a href="{{url_for('watchlist.index')}}" class="pure-button button-cancel">Back</a>
-                    <a href="{{url_for('ui.clear_all_history')}}" class="pure-button button-error">Clear Snapshot History</a>
+                    <a href="{{url_for('watchlist.index')}}" class="pure-button button-cancel">{{ _('Back') }}</a>
+                    <a href="{{url_for('ui.clear_all_history')}}" class="pure-button button-error">{{ _('Clear Snapshot History') }}</a>
                 </div>
             </div>
         </form>

changedetectionio/blueprint/tags/__init__.py

@@ -1,5 +1,5 @@
 from flask import Blueprint, request, render_template, flash, url_for, redirect
-
+from flask_babel import gettext
 
 from changedetectionio.store import ChangeDetectionStore
 from changedetectionio.flask_app import login_optionally_required
@@ -21,9 +21,10 @@ def construct_blueprint(datastore: ChangeDetectionStore):
         tag_count = Counter(tag for watch in datastore.data['watching'].values() if watch.get('tags') for tag in watch['tags'])
 
         output = render_template("groups-overview.html",
+                                 app_rss_token=datastore.data['settings']['application'].get('rss_access_token'),
                                  available_tags=sorted_tags,
                                  form=add_form,
-                                 tag_count=tag_count
+                                 tag_count=tag_count,
                                  )
 
         return output
@@ -42,11 +43,11 @@ def construct_blueprint(datastore: ChangeDetectionStore):
         title = request.form.get('name').strip()
 
         if datastore.tag_exists_by_name(title):
-            flash(f'The tag "{title}" already exists', "error")
+            flash(gettext('The tag "{}" already exists').format(title), "error")
             return redirect(url_for('tags.tags_overview_page'))
 
         datastore.add_tag(title)
-        flash("Tag added")
+        flash(gettext("Tag added"))
 
 
         return redirect(url_for('tags.tags_overview_page'))
@@ -71,7 +72,7 @@ def construct_blueprint(datastore: ChangeDetectionStore):
                 removed += 1
                 watch['tags'].remove(uuid)
 
-        flash(f"Tag deleted and removed from {removed} watches")
+        flash(gettext("Tag deleted and removed from {} watches").format(removed))
         return redirect(url_for('tags.tags_overview_page'))
 
     @tags_blueprint.route("/unlink/<string:uuid>", methods=['GET'])
@@ -83,7 +84,7 @@ def construct_blueprint(datastore: ChangeDetectionStore):
                 unlinked += 1
                 watch['tags'].remove(uuid)
 
-        flash(f"Tag unlinked removed from {unlinked} watches")
+        flash(gettext("Tag unlinked removed from {} watches").format(unlinked))
         return redirect(url_for('tags.tags_overview_page'))
 
     @tags_blueprint.route("/delete_all", methods=['GET'])
@@ -93,7 +94,7 @@ def construct_blueprint(datastore: ChangeDetectionStore):
             watch['tags'] = []
         datastore.data['settings']['application']['tags'] = {}
 
-        flash(f"All tags deleted")
+        flash(gettext("All tags deleted"))
         return redirect(url_for('tags.tags_overview_page'))
 
     @tags_blueprint.route("/edit/<string:uuid>", methods=['GET'])
@@ -105,7 +106,7 @@ def construct_blueprint(datastore: ChangeDetectionStore):
 
         default = datastore.data['settings']['application']['tags'].get(uuid)
         if not default:
-            flash("Tag not found", "error")
+            flash(gettext("Tag not found"), "error")
             return redirect(url_for('watchlist.index'))
 
         form = group_restock_settings_form(
@@ -149,9 +150,9 @@ def construct_blueprint(datastore: ChangeDetectionStore):
             included_content = template.render(**template_args)
 
         output = render_template("edit-tag.html",
-                                 settings_application=datastore.data['settings']['application'],
-                                 extra_tab_content=form.extra_tab_content() if form.extra_tab_content() else None,
                                  extra_form_content=included_content,
+                                 extra_tab_content=form.extra_tab_content() if form.extra_tab_content() else None,
+                                 settings_application=datastore.data['settings']['application'],
                                  **template_args
                                  )
 
@@ -180,7 +181,7 @@ def construct_blueprint(datastore: ChangeDetectionStore):
         datastore.data['settings']['application']['tags'][uuid].update(form.data)
         datastore.data['settings']['application']['tags'][uuid]['processor'] = 'restock_diff'
         datastore.needs_write_urgent = True
-        flash("Updated")
+        flash(gettext("Updated"))
 
         return redirect(url_for('tags.tags_overview_page'))
 

changedetectionio/blueprint/tags/templates/edit-tag.html

@@ -24,12 +24,12 @@
 
     <div class="tabs collapsable">
         <ul>
-            <li class="tab" id=""><a href="#general">General</a></li>
-            <li class="tab"><a href="#filters-and-triggers">Filters &amp; Triggers</a></li>
+            <li class="tab" id=""><a href="#general">{{ _('General') }}</a></li>
+            <li class="tab"><a href="#filters-and-triggers">{{ _('Filters & Triggers') }}</a></li>
             {% if extra_tab_content %}
             <li class="tab"><a href="#extras_tab">{{ extra_tab_content }}</a></li>
             {% endif %}
-            <li class="tab"><a href="#notifications">Notifications</a></li>
+            <li class="tab"><a href="#notifications">{{ _('Notifications') }}</a></li>
         </ul>
     </div>
 
@@ -47,10 +47,10 @@
             </div>
 
             <div class="tab-pane-inner" id="filters-and-triggers">
-                <p>These settings are <strong><i>added</i></strong> to any existing watch configurations.</p>
+                <p>{{ _('These settings are') }} <strong><i>{{ _('added') }}</i></strong> {{ _('to any existing watch configurations.') }}</p>
                 {% include "edit/include_subtract.html" %}
                 <div class="text-filtering border-fieldset">
-                    <h3>Text filtering</h3>
+                    <h3>{{ _('Text filtering') }}</h3>
                     {% include "edit/text-options.html" %}
                 </div>
             </div>
@@ -70,18 +70,18 @@
                     <div class="pure-control-group inline-radio">
                       {{ render_checkbox_field(form.notification_screenshot) }}
                         <span class="pure-form-message-inline">
-                            <strong>Use with caution!</strong> This will easily fill up your email storage quota or flood other storages.
+                            <strong>{{ _('Use with caution!') }}</strong> {{ _('This will easily fill up your email storage quota or flood other storages.') }}
                         </span>
                     </div>
                     {% endif %}
                     <div class="field-group" id="notification-field-group">
                         {% if has_default_notification_urls %}
                         <div class="inline-warning">
-                            <img class="inline-warning-icon" src="{{url_for('static_content', group='images', filename='notice.svg')}}" alt="Look out!" title="Lookout!" >
-                            There are <a href="{{ url_for('settings.settings_page')}}#notifications">system-wide notification URLs enabled</a>, this form will override notification settings for this watch only &dash; an empty Notification URL list here will still send notifications.
+                            <img class="inline-warning-icon" src="{{url_for('static_content', group='images', filename='notice.svg')}}" alt="{{ _('Look out!') }}" title="{{ _('Lookout!') }}" >
+                            {{ _('There are') }} <a href="{{ url_for('settings.settings_page')}}#notifications">{{ _('system-wide notification URLs enabled') }}</a>, {{ _('this form will override notification settings for this watch only') }} &dash; {{ _('an empty Notification URL list here will still send notifications.') }}
                         </div>
                         {% endif %}
-                        <a href="#notifications" id="notification-setting-reset-to-default" class="pure-button button-xsmall" style="right: 20px; top: 20px; position: absolute; background-color: #5f42dd; border-radius: 4px; font-size: 70%; color: #fff">Use system defaults</a>
+                        <a href="#notifications" id="notification-setting-reset-to-default" class="pure-button button-xsmall" style="right: 20px; top: 20px; position: absolute; background-color: #5f42dd; border-radius: 4px; font-size: 70%; color: #fff">{{ _('Use system defaults') }}</a>
 
                         {{ render_common_settings_form(form, emailprefix, settings_application, extra_notification_token_placeholder_info) }}
                     </div>

changedetectionio/blueprint/tags/templates/groups-overview.html

@@ -2,22 +2,23 @@
 {% block content %}
 {% from '_helpers.html' import render_simple_field, render_field %}
 <script src="{{url_for('static_content', group='js', filename='jquery-3.6.0.min.js')}}"></script>
+<script src="{{url_for('static_content', group='js', filename='modal.js')}}"></script>
 
 <div class="box">
     <form class="pure-form" action="{{ url_for('tags.form_tag_add') }}" method="POST" id="new-watch-form">
         <input type="hidden" name="csrf_token" value="{{ csrf_token() }}" >
         <fieldset>
-            <legend>Add a new organisational tag</legend>
+            <legend>{{ _('Add a new organisational tag') }}</legend>
             <div id="watch-add-wrapper-zone">
                 <div>
-                    {{ render_simple_field(form.name, placeholder="Watch group / tag") }}
+                    {{ render_simple_field(form.name, placeholder=_("Watch group / tag")) }}
                 </div>
                 <div>
-                    {{ render_simple_field(form.save_button, title="Save" ) }}
+                    {{ render_simple_field(form.save_button, title=_("Save") ) }}
                 </div>
             </div>
             <br>
-            <div style="color: #fff;">Groups allows you to manage filters and notifications for multiple watches under a single organisational tag.</div>
+            <div style="color: #fff;">{{ _('Groups allows you to manage filters and notifications for multiple watches under a single organisational tag.') }}</div>
         </fieldset>
     </form>
     <!-- @todo maybe some overview matrix, 'tick' with which has notification, filter rules etc -->
@@ -27,8 +28,8 @@
             <thead>
             <tr>
                 <th></th>
-                <th># Watches</th>
-                <th>Tag / Label name</th>
+                <th>{{ _('# Watches') }}</th>
+                <th>{{ _('Tag / Label name') }}</th>
                 <th></th>
             </tr>
             </thead>
@@ -38,7 +39,7 @@
             --->
             {% if not available_tags|length %}
             <tr>
-                <td colspan="3">No website organisational tags/groups configured</td>
+                <td colspan="3">{{ _('No website organisational tags/groups configured') }}</td>
             </tr>
             {% endif %}
             {% for uuid, tag in available_tags  %}
@@ -49,9 +50,24 @@
                 <td>{{ "{:,}".format(tag_count[uuid]) if uuid in tag_count else 0 }}</td>
                 <td class="title-col inline"> <a href="{{url_for('watchlist.index', tag=uuid) }}">{{ tag.title }}</a></td>
                 <td>
-                    <a class="pure-button pure-button-primary" href="{{ url_for('tags.form_tag_edit', uuid=uuid) }}">Edit</a>&nbsp;
-                    <a class="pure-button pure-button-primary" href="{{ url_for('tags.delete', uuid=uuid) }}" title="Deletes and removes tag">Delete</a>
-                    <a class="pure-button pure-button-primary" href="{{ url_for('tags.unlink', uuid=uuid) }}" title="Keep the tag but unlink any watches">Unlink</a>
+                    <a class="pure-button pure-button-primary" href="{{ url_for('tags.form_tag_edit', uuid=uuid) }}">{{ _('Edit') }}</a>&nbsp;
+                    <a class="pure-button button-error"
+                       href="{{ url_for('tags.delete', uuid=uuid) }}"
+                       data-requires-confirm
+                       data-confirm-type="danger"
+                       data-confirm-title="{{ _('Delete Group?') }}"
+                       data-confirm-message="{{ _('<p>Are you sure you want to delete group <strong>%(title)s</strong>?</p><p>This action cannot be undone.</p>', title=tag.title) }}"
+                       data-confirm-button="{{ _('Delete') }}"
+                       title="{{ _('Deletes and removes tag') }}">{{ _('Delete') }}</a>
+                    <a class="pure-button button-warning"
+                       href="{{ url_for('tags.unlink', uuid=uuid) }}"
+                       data-requires-confirm
+                       data-confirm-type="warning"
+                       data-confirm-title="{{ _('Unlink Group?') }}"
+                       data-confirm-message="{{ _('<p>Are you sure you want to unlink all watches from group <strong>%(title)s</strong>?</p><p>The tag will be kept but watches will be removed from it.</p>', title=tag.title) }}"
+                       data-confirm-button="{{ _('Unlink') }}"
+                       title="{{ _('Keep the tag but unlink any watches') }}">{{ _('Unlink') }}</a>
+                    <a href="{{ url_for('rss.rss_tag_feed', tag_uuid=uuid, token=app_rss_token)}}"><img alt="{{ _('RSS Feed for this watch') }}" style="padding-left: 1em;" src="{{url_for('static_content', group='images', filename='generic_feed-icon.svg')}}" height="15"></a>
                 </td>
             </tr>
             {% endfor %}

changedetectionio/blueprint/ui/__init__.py

@@ -1,11 +1,13 @@
 import time
 from flask import Blueprint, request, redirect, url_for, flash, render_template, session
+from flask_babel import gettext
 from loguru import logger
 
 from changedetectionio.store import ChangeDetectionStore
 from changedetectionio.blueprint.ui.edit import construct_blueprint as construct_edit_blueprint
 from changedetectionio.blueprint.ui.notification import construct_blueprint as construct_notification_blueprint
 from changedetectionio.blueprint.ui.views import construct_blueprint as construct_views_blueprint
+from changedetectionio.blueprint.ui import diff, preview
 
 def _handle_operations(op, uuids, datastore, worker_handler, update_q, queuedWatchMetaData, watch_check_update, extra_data=None, emit_flash=True):
     from flask import request, flash
@@ -15,42 +17,42 @@ def _handle_operations(op, uuids, datastore, worker_handler, update_q, queuedWat
             if datastore.data['watching'].get(uuid):
                 datastore.delete(uuid)
         if emit_flash:
-            flash(f"{len(uuids)} watches deleted")
+            flash(gettext("{} watches deleted").format(len(uuids)))
 
     elif op == 'pause':
         for uuid in uuids:
             if datastore.data['watching'].get(uuid):
                 datastore.data['watching'][uuid]['paused'] = True
         if emit_flash:
-            flash(f"{len(uuids)} watches paused")
+            flash(gettext("{} watches paused").format(len(uuids)))
 
     elif op == 'unpause':
         for uuid in uuids:
             if datastore.data['watching'].get(uuid):
                 datastore.data['watching'][uuid.strip()]['paused'] = False
         if emit_flash:
-            flash(f"{len(uuids)} watches unpaused")
+            flash(gettext("{} watches unpaused").format(len(uuids)))
 
     elif (op == 'mark-viewed'):
         for uuid in uuids:
             if datastore.data['watching'].get(uuid):
                 datastore.set_last_viewed(uuid, int(time.time()))
         if emit_flash:
-            flash(f"{len(uuids)} watches updated")
+            flash(gettext("{} watches updated").format(len(uuids)))
 
     elif (op == 'mute'):
         for uuid in uuids:
             if datastore.data['watching'].get(uuid):
                 datastore.data['watching'][uuid]['notification_muted'] = True
         if emit_flash:
-            flash(f"{len(uuids)} watches muted")
+            flash(gettext("{} watches muted").format(len(uuids)))
 
     elif (op == 'unmute'):
         for uuid in uuids:
             if datastore.data['watching'].get(uuid):
                 datastore.data['watching'][uuid]['notification_muted'] = False
         if emit_flash:
-            flash(f"{len(uuids)} watches un-muted")
+            flash(gettext("{} watches un-muted").format(len(uuids)))
 
     elif (op == 'recheck'):
         for uuid in uuids:
@@ -58,34 +60,34 @@ def _handle_operations(op, uuids, datastore, worker_handler, update_q, queuedWat
                 # Recheck and require a full reprocessing
                 worker_handler.queue_item_async_safe(update_q, queuedWatchMetaData.PrioritizedItem(priority=1, item={'uuid': uuid}))
         if emit_flash:
-            flash(f"{len(uuids)} watches queued for rechecking")
+            flash(gettext("{} watches queued for rechecking").format(len(uuids)))
 
     elif (op == 'clear-errors'):
         for uuid in uuids:
             if datastore.data['watching'].get(uuid):
                 datastore.data['watching'][uuid]["last_error"] = False
         if emit_flash:
-            flash(f"{len(uuids)} watches errors cleared")
+            flash(gettext("{} watches errors cleared").format(len(uuids)))
 
     elif (op == 'clear-history'):
         for uuid in uuids:
             if datastore.data['watching'].get(uuid):
                 datastore.clear_watch_history(uuid)
         if emit_flash:
-            flash(f"{len(uuids)} watches cleared/reset.")
+            flash(gettext("{} watches cleared/reset.").format(len(uuids)))
 
     elif (op == 'notification-default'):
         from changedetectionio.notification import (
-            default_notification_format_for_watch
+            USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH
         )
         for uuid in uuids:
             if datastore.data['watching'].get(uuid):
                 datastore.data['watching'][uuid]['notification_title'] = None
                 datastore.data['watching'][uuid]['notification_body'] = None
                 datastore.data['watching'][uuid]['notification_urls'] = []
-                datastore.data['watching'][uuid]['notification_format'] = default_notification_format_for_watch
+                datastore.data['watching'][uuid]['notification_format'] = USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH
         if emit_flash:
-            flash(f"{len(uuids)} watches set to use default notification settings")
+            flash(gettext("{} watches set to use default notification settings").format(len(uuids)))
 
     elif (op == 'assign-tag'):
         op_extradata = extra_data
@@ -100,7 +102,7 @@ def _handle_operations(op, uuids, datastore, worker_handler, update_q, queuedWat
 
                         datastore.data['watching'][uuid]['tags'].append(tag_uuid)
         if emit_flash:
-            flash(f"{len(uuids)} watches were tagged")
+            flash(gettext("{} watches were tagged").format(len(uuids)))
 
     if uuids:
         for uuid in uuids:
@@ -121,6 +123,13 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, worker_handle
     views_blueprint = construct_views_blueprint(datastore, update_q, queuedWatchMetaData, watch_check_update)
     ui_blueprint.register_blueprint(views_blueprint)
 
+    # Register diff and preview blueprints
+    diff_blueprint = diff.construct_blueprint(datastore)
+    ui_blueprint.register_blueprint(diff_blueprint)
+
+    preview_blueprint = preview.construct_blueprint(datastore)
+    ui_blueprint.register_blueprint(preview_blueprint)
+
     # Import the login decorator
     from changedetectionio.auth_decorator import login_optionally_required
 
@@ -130,9 +139,9 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, worker_handle
         try:
             datastore.clear_watch_history(uuid)
         except KeyError:
-            flash('Watch not found', 'error')
+            flash(gettext('Watch not found'), 'error')
         else:
-            flash("Cleared snapshot history for watch {}".format(uuid))
+            flash(gettext("Cleared snapshot history for watch {}").format(uuid))
         return redirect(url_for('watchlist.index'))
 
     @ui_blueprint.route("/clear_history", methods=['GET', 'POST'])
@@ -144,9 +153,9 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, worker_handle
             if confirmtext == 'clear':
                 for uuid in datastore.data['watching'].keys():
                     datastore.clear_watch_history(uuid)
-                flash("Cleared snapshot history for all watches")
+                flash(gettext("Cleared snapshot history for all watches"))
             else:
-                flash('Incorrect confirmation text.', 'error')
+                flash(gettext('Incorrect confirmation text.'), 'error')
 
             return redirect(url_for('watchlist.index'))
 
@@ -180,14 +189,14 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, worker_handle
         uuid = request.args.get('uuid')
 
         if uuid != 'all' and not uuid in datastore.data['watching'].keys():
-            flash('The watch by UUID {} does not exist.'.format(uuid), 'error')
+            flash(gettext('The watch by UUID {} does not exist.').format(uuid), 'error')
             return redirect(url_for('watchlist.index'))
 
         # More for testing, possible to return the first/only
         if uuid == 'first':
             uuid = list(datastore.data['watching'].keys()).pop()
         datastore.delete(uuid)
-        flash('Deleted.')
+        flash(gettext('Deleted.'))
 
         return redirect(url_for('watchlist.index'))
 
@@ -204,7 +213,7 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, worker_handle
         if not datastore.data['watching'].get(uuid).get('paused'):
             worker_handler.queue_item_async_safe(update_q, queuedWatchMetaData.PrioritizedItem(priority=5, item={'uuid': new_uuid}))
 
-        flash('Cloned, you are editing the new watch.')
+        flash(gettext('Cloned, you are editing the new watch.'))
 
         return redirect(url_for("ui.ui_edit.edit_page", uuid=new_uuid))
 
@@ -243,13 +252,13 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, worker_handle
                         i += 1
 
         if i == 1:
-            flash("Queued 1 watch for rechecking.")
+            flash(gettext("Queued 1 watch for rechecking."))
         if i > 1:
-            flash(f"Queued {i} watches for rechecking.")
+            flash(gettext("Queued {} watches for rechecking.").format(i))
         if i == 0:
-            flash("No watches available to recheck.")
+            flash(gettext("No watches available to recheck."))
 
-        return redirect(url_for('watchlist.index'))
+        return redirect(url_for('watchlist.index', **({'tag': tag} if tag else {})))
 
     @ui_blueprint.route("/form/checkbox-operations", methods=['POST'])
     @login_optionally_required
@@ -318,7 +327,7 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, worker_handle
 
         except Exception as e:
             logger.error(f"Error sharing -{str(e)}")
-            flash(f"Could not share, something went wrong while communicating with the share server - {str(e)}", 'error')
+            flash(gettext("Could not share, something went wrong while communicating with the share server - {}").format(str(e)), 'error')
 
         return redirect(url_for('watchlist.index'))
 

changedetectionio/blueprint/ui/diff.py

@@ -0,0 +1,317 @@
+from flask import Blueprint, request, redirect, url_for, flash, render_template, make_response, send_from_directory
+from flask_babel import gettext
+
+import re
+import importlib
+from loguru import logger
+from markupsafe import Markup
+
+from changedetectionio.diff import (
+    REMOVED_STYLE, ADDED_STYLE, REMOVED_INNER_STYLE, ADDED_INNER_STYLE,
+    REMOVED_PLACEMARKER_OPEN, REMOVED_PLACEMARKER_CLOSED,
+    ADDED_PLACEMARKER_OPEN, ADDED_PLACEMARKER_CLOSED,
+    CHANGED_PLACEMARKER_OPEN, CHANGED_PLACEMARKER_CLOSED,
+    CHANGED_INTO_PLACEMARKER_OPEN, CHANGED_INTO_PLACEMARKER_CLOSED
+)
+from changedetectionio.store import ChangeDetectionStore
+from changedetectionio.auth_decorator import login_optionally_required
+
+
+def construct_blueprint(datastore: ChangeDetectionStore):
+    diff_blueprint = Blueprint('ui_diff', __name__, template_folder="../ui/templates")
+
+    @diff_blueprint.app_template_filter('diff_unescape_difference_spans')
+    def diff_unescape_difference_spans(content):
+        """Emulate Jinja2's auto-escape, then selectively unescape our diff spans."""
+        from markupsafe import escape
+
+        if not content:
+            return Markup('')
+
+        # Step 1: Escape everything like Jinja2 would (this makes it XSS-safe)
+        escaped_content = escape(str(content))
+
+        # Step 2: Unescape only our exact diff spans generated by apply_html_color_to_body()
+        # Pattern matches the exact structure:
+        # <span style="{STYLE}" role="{ROLE}" aria-label="{LABEL}" title="{TITLE}">
+
+        # Unescape outer span opening tags with full attributes (role, aria-label, title)
+        # Matches removed/added/changed/changed_into spans
+        result = re.sub(
+            rf'&lt;span style=&#34;({re.escape(REMOVED_STYLE)}|{re.escape(ADDED_STYLE)})&#34; '
+            rf'role=&#34;(deletion|insertion|note)&#34; '
+            rf'aria-label=&#34;([^&]+?)&#34; '
+            rf'title=&#34;([^&]+?)&#34;&gt;',
+            r'<span style="\1" role="\2" aria-label="\3" title="\4">',
+            str(escaped_content),
+            flags=re.IGNORECASE
+        )
+
+        # Unescape inner span opening tags (without additional attributes)
+        # This matches the darker background styles for changed parts within lines
+        result = re.sub(
+            rf'&lt;span style=&#34;({re.escape(REMOVED_INNER_STYLE)}|{re.escape(ADDED_INNER_STYLE)})&#34;&gt;',
+            r'<span style="\1">',
+            result,
+            flags=re.IGNORECASE
+        )
+
+        # Unescape closing tags (but only as many as we opened)
+        open_count = result.count('<span style=')
+        close_count = str(escaped_content).count('&lt;/span&gt;')
+
+        # Replace up to the number of spans we opened
+        for _ in range(min(open_count, close_count)):
+            result = result.replace('&lt;/span&gt;', '</span>', 1)
+
+        return Markup(result)
+
+    @diff_blueprint.route("/diff/<string:uuid>", methods=['GET'])
+    @login_optionally_required
+    def diff_history_page(uuid):
+        """
+        Render the history/diff page for a watch.
+
+        This route is processor-aware: it delegates rendering to the processor's
+        difference.py module, allowing different processor types to provide
+        custom visualizations:
+        - text_json_diff: Text/HTML diff with syntax highlighting
+        - restock_diff: Could show price charts and stock history
+        - image_diff: Could show image comparison slider/overlay
+
+        Each processor implements processors/{type}/difference.py::render()
+        If a processor doesn't have a difference module, falls back to text_json_diff.
+        """
+
+        # More for testing, possible to return the first/only
+        if uuid == 'first':
+            uuid = list(datastore.data['watching'].keys()).pop()
+
+        try:
+            watch = datastore.data['watching'][uuid]
+        except KeyError:
+            flash(gettext("No history found for the specified link, bad link?"), "error")
+            return redirect(url_for('watchlist.index'))
+
+        dates = list(watch.history.keys())
+        if not dates or len(dates) < 2:
+            flash(gettext("Not enough history (2 snapshots required) to show difference page for this watch."), "error")
+            return redirect(url_for('watchlist.index'))
+
+        # Get the processor type for this watch
+        processor_name = watch.get('processor', 'text_json_diff')
+
+        try:
+            # Try to import the processor's difference module
+            processor_module = importlib.import_module(f'changedetectionio.processors.{processor_name}.difference')
+
+            # Call the processor's render() function
+            if hasattr(processor_module, 'render'):
+                return processor_module.render(
+                    watch=watch,
+                    datastore=datastore,
+                    request=request,
+                    url_for=url_for,
+                    render_template=render_template,
+                    flash=flash,
+                    redirect=redirect
+                )
+        except (ImportError, ModuleNotFoundError) as e:
+            logger.warning(f"Processor {processor_name} does not have a difference module, falling back to text_json_diff: {e}")
+
+        # Fallback: if processor doesn't have difference module, use text_json_diff as default
+        from changedetectionio.processors.text_json_diff.difference import render as default_render
+        return default_render(
+            watch=watch,
+            datastore=datastore,
+            request=request,
+            url_for=url_for,
+            render_template=render_template,
+            flash=flash,
+            redirect=redirect
+        )
+
+    @diff_blueprint.route("/diff/<string:uuid>/extract", methods=['GET'])
+    @login_optionally_required
+    def diff_history_page_extract_GET(uuid):
+        """
+        Render the data extraction form for a watch.
+
+        This route is processor-aware: it delegates to the processor's
+        extract.py module, allowing different processor types to provide
+        custom extraction interfaces.
+
+        Each processor implements processors/{type}/extract.py::render_form()
+        If a processor doesn't have an extract module, falls back to text_json_diff.
+        """
+        # More for testing, possible to return the first/only
+        if uuid == 'first':
+            uuid = list(datastore.data['watching'].keys()).pop()
+
+        try:
+            watch = datastore.data['watching'][uuid]
+        except KeyError:
+            flash(gettext("No history found for the specified link, bad link?"), "error")
+            return redirect(url_for('watchlist.index'))
+
+        # Get the processor type for this watch
+        processor_name = watch.get('processor', 'text_json_diff')
+
+        try:
+            # Try to import the processor's extract module
+            processor_module = importlib.import_module(f'changedetectionio.processors.{processor_name}.extract')
+
+            # Call the processor's render_form() function
+            if hasattr(processor_module, 'render_form'):
+                return processor_module.render_form(
+                    watch=watch,
+                    datastore=datastore,
+                    request=request,
+                    url_for=url_for,
+                    render_template=render_template,
+                    flash=flash,
+                    redirect=redirect
+                )
+        except (ImportError, ModuleNotFoundError) as e:
+            logger.warning(f"Processor {processor_name} does not have an extract module, falling back to base extractor: {e}")
+
+        # Fallback: if processor doesn't have extract module, use base processors.extract as default
+        from changedetectionio.processors.extract import render_form as default_render_form
+        return default_render_form(
+            watch=watch,
+            datastore=datastore,
+            request=request,
+            url_for=url_for,
+            render_template=render_template,
+            flash=flash,
+            redirect=redirect
+        )
+
+    @diff_blueprint.route("/diff/<string:uuid>/extract", methods=['POST'])
+    @login_optionally_required
+    def diff_history_page_extract_POST(uuid):
+        """
+        Process the data extraction request.
+
+        This route is processor-aware: it delegates to the processor's
+        extract.py module, allowing different processor types to provide
+        custom extraction logic.
+
+        Each processor implements processors/{type}/extract.py::process_extraction()
+        If a processor doesn't have an extract module, falls back to text_json_diff.
+        """
+        # More for testing, possible to return the first/only
+        if uuid == 'first':
+            uuid = list(datastore.data['watching'].keys()).pop()
+
+        try:
+            watch = datastore.data['watching'][uuid]
+        except KeyError:
+            flash(gettext("No history found for the specified link, bad link?"), "error")
+            return redirect(url_for('watchlist.index'))
+
+        # Get the processor type for this watch
+        processor_name = watch.get('processor', 'text_json_diff')
+
+        try:
+            # Try to import the processor's extract module
+            processor_module = importlib.import_module(f'changedetectionio.processors.{processor_name}.extract')
+
+            # Call the processor's process_extraction() function
+            if hasattr(processor_module, 'process_extraction'):
+                return processor_module.process_extraction(
+                    watch=watch,
+                    datastore=datastore,
+                    request=request,
+                    url_for=url_for,
+                    make_response=make_response,
+                    send_from_directory=send_from_directory,
+                    flash=flash,
+                    redirect=redirect
+                )
+        except (ImportError, ModuleNotFoundError) as e:
+            logger.warning(f"Processor {processor_name} does not have an extract module, falling back to base extractor: {e}")
+
+        # Fallback: if processor doesn't have extract module, use base processors.extract as default
+        from changedetectionio.processors.extract import process_extraction as default_process_extraction
+        return default_process_extraction(
+            watch=watch,
+            datastore=datastore,
+            request=request,
+            url_for=url_for,
+            make_response=make_response,
+            send_from_directory=send_from_directory,
+            flash=flash,
+            redirect=redirect
+        )
+
+    @diff_blueprint.route("/diff/<string:uuid>/processor-asset/<string:asset_name>", methods=['GET'])
+    @login_optionally_required
+    def processor_asset(uuid, asset_name):
+        """
+        Serve processor-specific binary assets (images, files, etc.).
+
+        This route is processor-aware: it delegates to the processor's
+        difference.py module, allowing different processor types to serve
+        custom assets without embedding them as base64 in templates.
+
+        This solves memory issues with large binary data (e.g., screenshots)
+        by streaming them as separate HTTP responses instead of embedding
+        in the HTML template.
+
+        Each processor implements processors/{type}/difference.py::get_asset()
+        which returns (binary_data, content_type, cache_control_header).
+
+        Example URLs:
+        - /diff/{uuid}/processor-asset/before
+        - /diff/{uuid}/processor-asset/after
+        - /diff/{uuid}/processor-asset/rendered_diff
+        """
+        # More for testing, possible to return the first/only
+        if uuid == 'first':
+            uuid = list(datastore.data['watching'].keys()).pop()
+
+        try:
+            watch = datastore.data['watching'][uuid]
+        except KeyError:
+            flash(gettext("No history found for the specified link, bad link?"), "error")
+            return redirect(url_for('watchlist.index'))
+
+        # Get the processor type for this watch
+        processor_name = watch.get('processor', 'text_json_diff')
+
+        try:
+            # Try to import the processor's difference module
+            processor_module = importlib.import_module(f'changedetectionio.processors.{processor_name}.difference')
+
+            # Call the processor's get_asset() function
+            if hasattr(processor_module, 'get_asset'):
+                result = processor_module.get_asset(
+                    asset_name=asset_name,
+                    watch=watch,
+                    datastore=datastore,
+                    request=request
+                )
+
+                if result is None:
+                    from flask import abort
+                    abort(404, description=f"Asset '{asset_name}' not found")
+
+                binary_data, content_type, cache_control = result
+
+                response = make_response(binary_data)
+                response.headers['Content-Type'] = content_type
+                if cache_control:
+                    response.headers['Cache-Control'] = cache_control
+                return response
+            else:
+                logger.warning(f"Processor {processor_name} does not implement get_asset()")
+                from flask import abort
+                abort(404, description=f"Processor '{processor_name}' does not support assets")
+
+        except (ImportError, ModuleNotFoundError) as e:
+            logger.warning(f"Processor {processor_name} does not have a difference module: {e}")
+            from flask import abort
+            abort(404, description=f"Processor '{processor_name}' not found")
+
+    return diff_blueprint

changedetectionio/blueprint/ui/edit.py

@@ -1,8 +1,8 @@
-import time
 from copy import deepcopy
 import os
 import importlib.resources
-from flask import Blueprint, request, redirect, url_for, flash, render_template, make_response, send_from_directory, abort
+from flask import Blueprint, request, redirect, url_for, flash, render_template, abort
+from flask_babel import gettext
 from loguru import logger
 from jinja2 import Environment, FileSystemLoader
 
@@ -32,14 +32,14 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMe
 
         # More for testing, possible to return the first/only
         if not datastore.data['watching'].keys():
-            flash("No watches to edit", "error")
+            flash(gettext("No watches to edit"), "error")
             return redirect(url_for('watchlist.index'))
 
         if uuid == 'first':
             uuid = list(datastore.data['watching'].keys()).pop()
 
         if not uuid in datastore.data['watching']:
-            flash("No watch with the UUID %s found." % (uuid), "error")
+            flash(gettext("No watch with the UUID {} found.").format(uuid), "error")
             return redirect(url_for('watchlist.index'))
 
         switch_processor = request.args.get('switch_processor')
@@ -47,7 +47,7 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMe
             for p in processors.available_processors():
                 if p[0] == switch_processor:
                     datastore.data['watching'][uuid]['processor'] = switch_processor
-                    flash(f"Switched to mode - {p[1]}.")
+                    flash(gettext("Switched to mode - {}.").format(p[1]))
                     datastore.clear_watch_history(uuid)
                     redirect(url_for('ui_edit.edit_page', uuid=uuid))
 
@@ -66,7 +66,7 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMe
         processor_name = datastore.data['watching'][uuid].get('processor', '')
         processor_classes = next((tpl for tpl in processors.find_processors() if tpl[1] == processor_name), None)
         if not processor_classes:
-            flash(f"Cannot load the edit form for processor/plugin '{processor_classes[1]}', plugin missing?", 'error')
+            flash(gettext("Cannot load the edit form for processor/plugin '{}', plugin missing?").format(processor_classes[1]), 'error')
             return redirect(url_for('watchlist.index'))
 
         parent_module = processors.get_parent_module(processor_classes[0])
@@ -96,6 +96,26 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMe
         form.datastore = datastore
         form.watch = default
 
+        # Load processor-specific config from JSON file for GET requests
+        if request.method == 'GET' and processor_name:
+            try:
+                from changedetectionio.processors.base import difference_detection_processor
+                # Create a processor instance to access config methods
+                processor_instance = difference_detection_processor(datastore, uuid)
+                # Use processor name as filename so each processor keeps its own config
+                config_filename = f'{processor_name}.json'
+                processor_config = processor_instance.get_extra_watch_config(config_filename)
+
+                if processor_config:
+                    # Populate processor-config-* fields from JSON
+                    for config_key, config_value in processor_config.items():
+                        field_name = f'processor_config_{config_key}'
+                        if hasattr(form, field_name):
+                            getattr(form, field_name).data = config_value
+                            logger.debug(f"Loaded processor config from {config_filename}: {field_name} = {config_value}")
+            except Exception as e:
+                logger.warning(f"Failed to load processor config: {e}")
+
         for p in datastore.extra_browsers:
             form.fetch_backend.choices.append(p)
 
@@ -114,11 +134,6 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMe
 
         if request.method == 'POST' and form.validate():
 
-            # If they changed processor, it makes sense to reset it.
-            if datastore.data['watching'][uuid].get('processor') != form.data.get('processor'):
-                datastore.data['watching'][uuid].clear_watch()
-                flash("Reset watch history due to change of processor")
-
             extra_update_obj = {
                 'consecutive_filter_failures': 0,
                 'last_error' : False
@@ -129,7 +144,60 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMe
 
             extra_update_obj['time_between_check'] = form.time_between_check.data
 
-             # Ignore text
+             # Handle processor-config-* fields separately (save to JSON, not datastore)
+            processor_config_data = {}
+            fields_to_remove = []
+            for field_name, field_value in form.data.items():
+                if field_name.startswith('processor_config_'):
+                    config_key = field_name.replace('processor_config_', '')
+                    if field_value:  # Only save non-empty values
+                        processor_config_data[config_key] = field_value
+                    fields_to_remove.append(field_name)
+
+            # Save processor config to JSON file if any config data exists
+            if processor_config_data:
+                try:
+                    processor_name = form.data.get('processor')
+                    # Create a processor instance to access config methods
+                    processor_instance = processors.difference_detection_processor(datastore, uuid)
+                    # Use processor name as filename so each processor keeps its own config
+                    config_filename = f'{processor_name}.json'
+                    processor_instance.update_extra_watch_config(config_filename, processor_config_data)
+                    logger.debug(f"Saved processor config to {config_filename}: {processor_config_data}")
+
+                    # Call optional edit_hook if processor has one
+                    try:
+                        # Try to import the edit_hook module from the processor package
+                        import importlib
+                        edit_hook_module_name = f'changedetectionio.processors.{processor_name}.edit_hook'
+
+                        try:
+                            edit_hook = importlib.import_module(edit_hook_module_name)
+                            logger.debug(f"Found edit_hook module for {processor_name}")
+
+                            if hasattr(edit_hook, 'on_config_save'):
+                                logger.info(f"Calling edit_hook.on_config_save for {processor_name}")
+                                watch_obj = datastore.data['watching'][uuid]
+                                # Call hook and get updated config
+                                updated_config = edit_hook.on_config_save(watch_obj, processor_config_data, datastore)
+                                # Save updated config back to file
+                                processor_instance.update_extra_watch_config(config_filename, updated_config)
+                                logger.info(f"Edit hook updated config: {updated_config}")
+                            else:
+                                logger.debug(f"Edit hook module found but no on_config_save function")
+                        except ModuleNotFoundError:
+                            logger.debug(f"No edit_hook module for processor {processor_name} (this is normal)")
+                    except Exception as hook_error:
+                        logger.error(f"Edit hook error (non-fatal): {hook_error}", exc_info=True)
+
+                except Exception as e:
+                    logger.error(f"Failed to save processor config: {e}")
+
+            # Remove processor-config-* fields from form.data before updating datastore
+            for field_name in fields_to_remove:
+                form.data.pop(field_name, None)
+
+            # Ignore text
             form_ignore_text = form.ignore_text.data
             datastore.data['watching'][uuid]['ignore_text'] = form_ignore_text
 
@@ -168,7 +236,7 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMe
             # Recast it if need be to right data Watch handler
             watch_class = processors.get_custom_watch_obj_for_processor(form.data.get('processor'))
             datastore.data['watching'][uuid] = watch_class(datastore_path=datastore.datastore_path, default=datastore.data['watching'][uuid])
-            flash("Updated watch - unpaused!" if request.args.get('unpause_on_save') else "Updated watch.")
+            flash(gettext("Updated watch - unpaused!") if request.args.get('unpause_on_save') else gettext("Updated watch."))
 
             # Re #286 - We wait for syncing new data to disk in another thread every 60 seconds
             # But in the case something is added we should save straight away
@@ -187,7 +255,7 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMe
 
             tz_name = time_schedule_limit.get('timezone')
             if not tz_name:
-                tz_name = datastore.data['settings']['application'].get('timezone', 'UTC')
+                tz_name = datastore.data['settings']['application'].get('scheduler_timezone_default', os.getenv('TZ', 'UTC').strip())
 
             if time_schedule_limit and time_schedule_limit.get('enabled'):
                 try:
@@ -206,13 +274,13 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMe
 
             # Diff page [edit] link should go back to diff page
             if request.args.get("next") and request.args.get("next") == 'diff':
-                return redirect(url_for('ui.ui_views.diff_history_page', uuid=uuid))
+                return redirect(url_for('ui.ui_diff.diff_history_page', uuid=uuid))
 
             return redirect(url_for('watchlist.index', tag=request.args.get("tag",'')))
 
         else:
             if request.method == 'POST' and not form.validate():
-                flash("An error occurred, please see below.", "error")
+                flash(gettext("An error occurred, please see below."), "error")
 
             # JQ is difficult to install on windows and must be manually added (outside requirements.txt)
             jq_support = True
@@ -223,26 +291,25 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMe
 
             watch = datastore.data['watching'].get(uuid)
 
-            # if system or watch is configured to need a chrome type browser
-            system_uses_webdriver = datastore.data['settings']['application']['fetch_backend'] == 'html_webdriver'
-            watch_needs_selenium_or_playwright = False
-            if (watch.get('fetch_backend') == 'system' and system_uses_webdriver) or watch.get('fetch_backend') == 'html_webdriver' or watch.get('fetch_backend', '').startswith('extra_browser_'):
-                watch_needs_selenium_or_playwright = True
-
-
             from zoneinfo import available_timezones
 
-            # Only works reliably with Playwright
-
             # Import the global plugin system
-            from changedetectionio.pluggy_interface import collect_ui_edit_stats_extras
-            
+            from changedetectionio.pluggy_interface import collect_ui_edit_stats_extras, get_fetcher_capabilities
+
+            # Get fetcher capabilities instead of hardcoded logic
+            capabilities = get_fetcher_capabilities(watch, datastore)
+            app_rss_token = datastore.data['settings']['application'].get('rss_access_token'),
+
+            c = [f"processor-{watch.get('processor')}"]
+            if worker_handler.is_watch_running(uuid):
+                c.append('checking-now')
+
             template_args = {
                 'available_processors': processors.available_processors(),
                 'available_timezones': sorted(available_timezones()),
                 'browser_steps_config': browser_step_ui_config,
                 'emailprefix': os.getenv('NOTIFICATION_MAIL_BUTTON_PREFIX', False),
-                'extra_classes': 'checking-now' if worker_handler.is_watch_running(uuid) else '',
+                'extra_classes': ' '.join(c),
                 'extra_notification_token_placeholder_info': datastore.get_unique_notification_token_placeholders_available(),
                 'extra_processor_config': form.extra_tab_content(),
                 'extra_title': f" - Edit - {watch.label}",
@@ -252,16 +319,21 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMe
                 'has_special_tag_options': _watch_has_tag_options_set(watch=watch),
                 'jq_support': jq_support,
                 'playwright_enabled': os.getenv('PLAYWRIGHT_DRIVER_URL', False),
+                'app_rss_token': app_rss_token,
+                'rss_uuid_feed' : {
+                    'label': watch.label,
+                    'url': url_for('rss.rss_single_watch', uuid=watch['uuid'], token=app_rss_token)
+                },
                 'settings_application': datastore.data['settings']['application'],
                 'system_has_playwright_configured': os.getenv('PLAYWRIGHT_DRIVER_URL'),
                 'system_has_webdriver_configured': os.getenv('WEBDRIVER_URL'),
                 'ui_edit_stats_extras': collect_ui_edit_stats_extras(watch),
                 'visual_selector_data_ready': datastore.visualselector_data_is_ready(watch_uuid=uuid),
-                'timezone_default_config': datastore.data['settings']['application'].get('timezone'),
+                'timezone_default_config': datastore.data['settings']['application'].get('scheduler_timezone_default'),
                 'using_global_webdriver_wait': not default['webdriver_delay'],
                 'uuid': uuid,
                 'watch': watch,
-                'watch_needs_selenium_or_playwright': watch_needs_selenium_or_playwright,
+                'capabilities': capabilities
             }
 
             included_content = None
@@ -335,6 +407,6 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMe
                     s = re.sub(r'[0-9]+', r'\\d+', s)
                     datastore.data["watching"][uuid]['ignore_text'].append('/' + s + '/')
 
-        return f"<a href={url_for('ui.ui_views.preview_page', uuid=uuid)}>Click to preview</a>"
+        return f"<a href={url_for('ui.ui_preview.preview_page', uuid=uuid)}>Click to preview</a>"
     
     return edit_blueprint

changedetectionio/blueprint/ui/notification.py

@@ -14,11 +14,12 @@ def construct_blueprint(datastore: ChangeDetectionStore):
     @notification_blueprint.route("/notification/send-test/", methods=['POST'])
     @login_optionally_required
     def ajax_callback_send_notification_test(watch_uuid=None):
-
+        from changedetectionio.notification_service import NotificationContextData, set_basic_notification_vars
         # Watch_uuid could be unset in the case it`s used in tag editor, global settings
         import apprise
         from changedetectionio.notification.handler import process_notification
         from changedetectionio.notification.apprise_plugin.assets import apprise_asset
+        from changedetectionio.jinja2_custom import render as jinja_render
 
         from changedetectionio.notification.apprise_plugin.custom_handlers import apprise_http_custom_handler
 
@@ -37,11 +38,7 @@ def construct_blueprint(datastore: ChangeDetectionStore):
             return make_response("Error: You must have atleast one watch configured for 'test notification' to work", 400)
 
         watch = datastore.data['watching'].get(watch_uuid)
-
-        notification_urls = None
-
-        if request.form.get('notification_urls'):
-            notification_urls = request.form['notification_urls'].strip().splitlines()
+        notification_urls = request.form.get('notification_urls','').strip().splitlines()
 
         if not notification_urls:
             logger.debug("Test notification - Trying by group/tag in the edit form if available")
@@ -61,20 +58,26 @@ def construct_blueprint(datastore: ChangeDetectionStore):
             return 'Error: No Notification URLs set/found'
 
         for n_url in notification_urls:
+            # We are ONLY validating the apprise:// part here, convert all tags to something so as not to break apprise URLs
+            generic_notification_context_data = NotificationContextData()
+            generic_notification_context_data.set_random_for_validation()
+            n_url = jinja_render(template_str=n_url, **generic_notification_context_data).strip()
             if len(n_url.strip()):
                 if not apobj.add(n_url):
                     return f'Error:  {n_url} is not a valid AppRise URL.'
 
         try:
             # use the same as when it is triggered, but then override it with the form test values
-            n_object = {
+            n_object = NotificationContextData({
                 'watch_url': request.form.get('window_url', "https://changedetection.io"),
                 'notification_urls': notification_urls
-            }
+            })
 
             # Only use if present, if not set in n_object it should use the default system value
             if 'notification_format' in request.form and request.form['notification_format'].strip():
                 n_object['notification_format'] = request.form.get('notification_format', '').strip()
+            else:
+                n_object['notification_format'] = datastore.data['settings']['application'].get('notification_format')
 
             if 'notification_title' in request.form and request.form['notification_title'].strip():
                 n_object['notification_title'] = request.form.get('notification_title', '').strip()
@@ -91,7 +94,27 @@ def construct_blueprint(datastore: ChangeDetectionStore):
                 n_object['notification_body'] = "Test body"
 
             n_object['as_async'] = False
-            n_object.update(watch.extra_notification_token_values())
+
+            #  Same like in notification service, should be refactored
+            dates = list(watch.history.keys())
+            trigger_text = ''
+            snapshot_contents = ''
+
+            # Could be called as a 'test notification' with only 1 snapshot available
+            prev_snapshot = "Example text: example test\nExample text: change detection is cool\nExample text: some more examples\n"
+            current_snapshot = "Example text: example test\nExample text: change detection is fantastic\nExample text: even more examples\nExample text: a lot more examples"
+
+            if len(dates) > 1:
+                prev_snapshot = watch.get_history_snapshot(timestamp=dates[-2])
+                current_snapshot = watch.get_history_snapshot(timestamp=dates[-1])
+
+            n_object.update(set_basic_notification_vars(current_snapshot=current_snapshot,
+                                                        prev_snapshot=prev_snapshot,
+                                                        watch=watch,
+                                                        triggered_text=trigger_text,
+                                                        timestamp_changed=dates[-1] if dates else None))
+
+
             sent_obj = process_notification(n_object, datastore)
 
         except Exception as e:

changedetectionio/blueprint/ui/preview.py

@@ -0,0 +1,201 @@
+from flask import Blueprint, request, url_for, flash, render_template, redirect
+from flask_babel import gettext
+import time
+from loguru import logger
+
+from changedetectionio.store import ChangeDetectionStore
+from changedetectionio.auth_decorator import login_optionally_required
+from changedetectionio import html_tools
+
+def construct_blueprint(datastore: ChangeDetectionStore):
+    preview_blueprint = Blueprint('ui_preview', __name__, template_folder="../ui/templates")
+
+    @preview_blueprint.route("/preview/<string:uuid>", methods=['GET'])
+    @login_optionally_required
+    def preview_page(uuid):
+        """
+        Render the preview page for a watch.
+
+        This route is processor-aware: it delegates rendering to the processor's
+        preview.py module, allowing different processor types to provide
+        custom visualizations:
+        - text_json_diff: Text preview with syntax highlighting
+        - image_ssim_diff: Image preview with proper rendering
+        - restock_diff: Could show latest price/stock data
+
+        Each processor implements processors/{type}/preview.py::render()
+        If a processor doesn't have a preview module, falls back to default text preview.
+        """
+        # More for testing, possible to return the first/only
+        if uuid == 'first':
+            uuid = list(datastore.data['watching'].keys()).pop()
+
+        try:
+            watch = datastore.data['watching'][uuid]
+        except KeyError:
+            flash(gettext("No history found for the specified link, bad link?"), "error")
+            return redirect(url_for('watchlist.index'))
+
+        # Get the processor type for this watch
+        processor_name = watch.get('processor', 'text_json_diff')
+
+        try:
+            # Try to import the processor's preview module
+            import importlib
+            processor_module = importlib.import_module(f'changedetectionio.processors.{processor_name}.preview')
+
+            # Call the processor's render() function
+            if hasattr(processor_module, 'render'):
+                return processor_module.render(
+                    watch=watch,
+                    datastore=datastore,
+                    request=request,
+                    url_for=url_for,
+                    render_template=render_template,
+                    flash=flash,
+                    redirect=redirect
+                )
+        except (ImportError, ModuleNotFoundError) as e:
+            logger.debug(f"Processor {processor_name} does not have a preview module, using default preview: {e}")
+
+        # Fallback: if processor doesn't have preview module, use default text preview
+        content = []
+        versions = []
+        timestamp = None
+
+        system_uses_webdriver = datastore.data['settings']['application']['fetch_backend'] == 'html_webdriver'
+        extra_stylesheets = [url_for('static_content', group='styles', filename='diff.css')]
+
+        is_html_webdriver = False
+        if (watch.get('fetch_backend') == 'system' and system_uses_webdriver) or watch.get('fetch_backend') == 'html_webdriver' or watch.get('fetch_backend', '').startswith('extra_browser_'):
+            is_html_webdriver = True
+
+        triggered_line_numbers = []
+        ignored_line_numbers = []
+        blocked_line_numbers = []
+
+        if datastore.data['watching'][uuid].history_n == 0 and (watch.get_error_text() or watch.get_error_snapshot()):
+            flash(gettext("Preview unavailable - No fetch/check completed or triggers not reached"), "error")
+        else:
+            # So prepare the latest preview or not
+            preferred_version = request.args.get('version')
+            versions = list(watch.history.keys())
+            timestamp = versions[-1]
+            if preferred_version and preferred_version in versions:
+                timestamp = preferred_version
+
+            try:
+                versions = list(watch.history.keys())
+                content = watch.get_history_snapshot(timestamp=timestamp)
+
+                triggered_line_numbers = html_tools.strip_ignore_text(content=content,
+                                                                      wordlist=watch.get('trigger_text'),
+                                                                      mode='line numbers'
+                                                                      )
+                ignored_line_numbers = html_tools.strip_ignore_text(content=content,
+                                                                      wordlist=watch.get('ignore_text'),
+                                                                      mode='line numbers'
+                                                                      )
+                blocked_line_numbers = html_tools.strip_ignore_text(content=content,
+                                                                      wordlist=watch.get("text_should_not_be_present"),
+                                                                      mode='line numbers'
+                                                                      )
+            except Exception as e:
+                content.append({'line': f"File doesnt exist or unable to read timestamp {timestamp}", 'classes': ''})
+
+        from changedetectionio.pluggy_interface import get_fetcher_capabilities
+        capabilities = get_fetcher_capabilities(watch, datastore)
+
+        output = render_template("preview.html",
+                                 capabilities=capabilities,
+                                 content=content,
+                                 current_diff_url=watch['url'],
+                                 current_version=timestamp,
+                                 extra_stylesheets=extra_stylesheets,
+                                 extra_title=f" - Diff - {watch.label} @ {timestamp}",
+                                 highlight_ignored_line_numbers=ignored_line_numbers,
+                                 highlight_triggered_line_numbers=triggered_line_numbers,
+                                 highlight_blocked_line_numbers=blocked_line_numbers,
+                                 history_n=watch.history_n,
+                                 is_html_webdriver=is_html_webdriver,
+                                 last_error=watch['last_error'],
+                                 last_error_screenshot=watch.get_error_snapshot(),
+                                 last_error_text=watch.get_error_text(),
+                                 screenshot=watch.get_screenshot(),
+                                 uuid=uuid,
+                                 versions=versions,
+                                 watch=watch,
+                                 )
+
+        return output
+
+    @preview_blueprint.route("/preview/<string:uuid>/processor-asset/<string:asset_name>", methods=['GET'])
+    @login_optionally_required
+    def processor_asset(uuid, asset_name):
+        """
+        Serve processor-specific binary assets for preview (images, files, etc.).
+
+        This route is processor-aware: it delegates to the processor's
+        preview.py module, allowing different processor types to serve
+        custom assets without embedding them as base64 in templates.
+
+        This solves memory issues with large binary data by streaming them
+        as separate HTTP responses instead of embedding in the HTML template.
+
+        Each processor implements processors/{type}/preview.py::get_asset()
+        which returns (binary_data, content_type, cache_control_header).
+
+        Example URLs:
+        - /preview/{uuid}/processor-asset/screenshot?version=123456789
+        """
+        from flask import make_response
+
+        # More for testing, possible to return the first/only
+        if uuid == 'first':
+            uuid = list(datastore.data['watching'].keys()).pop()
+
+        try:
+            watch = datastore.data['watching'][uuid]
+        except KeyError:
+            flash(gettext("No history found for the specified link, bad link?"), "error")
+            return redirect(url_for('watchlist.index'))
+
+        # Get the processor type for this watch
+        processor_name = watch.get('processor', 'text_json_diff')
+
+        try:
+            # Try to import the processor's preview module
+            import importlib
+            processor_module = importlib.import_module(f'changedetectionio.processors.{processor_name}.preview')
+
+            # Call the processor's get_asset() function
+            if hasattr(processor_module, 'get_asset'):
+                result = processor_module.get_asset(
+                    asset_name=asset_name,
+                    watch=watch,
+                    datastore=datastore,
+                    request=request
+                )
+
+                if result is None:
+                    from flask import abort
+                    abort(404, description=f"Asset '{asset_name}' not found")
+
+                binary_data, content_type, cache_control = result
+
+                response = make_response(binary_data)
+                response.headers['Content-Type'] = content_type
+                if cache_control:
+                    response.headers['Cache-Control'] = cache_control
+                return response
+            else:
+                logger.warning(f"Processor {processor_name} does not implement get_asset()")
+                from flask import abort
+                abort(404, description=f"Processor '{processor_name}' does not support assets")
+
+        except (ImportError, ModuleNotFoundError) as e:
+            logger.warning(f"Processor {processor_name} does not have a preview module: {e}")
+            from flask import abort
+            abort(404, description=f"Processor '{processor_name}' not found")
+
+    return preview_blueprint

changedetectionio/blueprint/ui/templates/clear_all_history.html

@@ -9,13 +9,12 @@
       <input type="hidden" name="csrf_token" value="{{ csrf_token() }}" >
       <fieldset>
         <div class="pure-control-group">
-          This will remove version history (snapshots) for ALL watches, but keep
-          your list of URLs! <br />
-          You may like to use the <strong>BACKUP</strong> link first.<br />
+          {{ _('This will remove version history (snapshots) for ALL watches, but keep your list of URLs!') }} <br />
+          {{ _('You may like to use the') }} <strong>{{ _('BACKUP') }}</strong> {{ _('link first.') }}<br />
         </div>
         <br />
         <div class="pure-control-group">
-          <label for="confirmtext">Confirmation text</label>
+          <label for="confirmtext">{{ _('Confirmation text') }}</label>
           <input
             type="text"
             id="confirmtext"
@@ -25,20 +24,19 @@
             size="10"
           />
           <span class="pure-form-message-inline"
-            >Type in the word <strong>clear</strong> to confirm that you
-            understand.</span
+            >{{ _('Type in the word') }} <strong>{{ _('clear') }}</strong> {{ _('to confirm that you understand.') }}</span
           >
         </div>
         <br />
         <div class="pure-control-group">
           <button type="submit" class="pure-button pure-button-primary">
-            Clear History!
+            {{ _('Clear History!') }}
           </button>
         </div>
         <br />
         <div class="pure-control-group">
           <a href="{{url_for('watchlist.index')}}" class="pure-button button-cancel"
-            >Cancel</a
+            >{{ _('Cancel') }}</a
           >
         </div>
       </fieldset>

changedetectionio/blueprint/ui/templates/diff-offscreen-options.html

@@ -0,0 +1,12 @@
+<ul id="highlightSnippetActions">
+    <li>
+        <button class="pure-button pure-button-primary" onclick="diffToJpeg()" title="{{ _('Share diff as image') }}">{{ _('Share as Image') }}</button>
+    </li>
+    <li>
+        <a class="pure-button pure-button-primary" data-mode="exact" href="javascript:void(0);">{{ _('Ignore any lines matching') }}</a>
+    </li>
+    <li>
+        <a class="pure-button pure-button-primary" data-mode="digit-regex" href="javascript:void(0);" >{{ _('Ignore any lines matching excluding digits') }}</a>
+    </li>
+</ul>
+

changedetectionio/blueprint/ui/templates/diff.html

@@ -0,0 +1,166 @@
+{% extends 'base.html' %}
+{% from '_helpers.html' import render_field, render_checkbox_field, render_button %}
+{% block content %}
+<script>
+    const screenshot_url="{{url_for('static_content', group='screenshot', filename=uuid)}}";
+    {% if last_error_screenshot %}
+    const error_screenshot_url="{{url_for('static_content', group='screenshot', filename=uuid, error_screenshot=1) }}";
+    {% endif %}
+
+    const highlight_submit_ignore_url="{{url_for('ui.ui_edit.highlight_submit_ignore_url', uuid=uuid)}}";
+    const watch_url= {{watch_a.link|tojson}};
+
+    // Initial scroll position: if set, scroll to this line number in #difference on page load
+    const initialScrollToLineNumber = {{ initial_scroll_line_number|default('null') }};
+</script>
+<script src="https://cdn.jsdelivr.net/npm/html2canvas@1.4.1/dist/html2canvas.min.js"></script>
+<script src="{{url_for('static_content', group='js', filename='plugins.js')}}"></script>
+<script src="https://cdn.jsdelivr.net/npm/piexifjs@1.0.6/piexif.min.js"></script>
+<script src="{{url_for('static_content', group='js', filename='snippet-to-image.js')}}"></script>
+<script src="{{url_for('static_content', group='js', filename='diff-overview.js')}}" defer></script>
+
+
+<div id="settings">
+    <form class="pure-form " action="{{ url_for("ui.ui_diff.diff_history_page", uuid=uuid) }}" method="GET" id="diff-form">
+        <fieldset class="diff-fieldset">
+            {% if versions|length >= 1 %}
+                <span style="white-space: nowrap;">
+                <label id="change-from" for="diff-from-version" class="from-to-label">{{ _('From') }}</label>
+                <select id="diff-from-version" name="from_version" class="needs-localtime">
+                    {%- for version in versions|reverse -%}
+                        <option value="{{ version }}" {% if version== from_version %} selected="" {% endif %}>
+                            {{ version }}{#{% if loop.index == 2 %} (Previous){% endif %}#}
+                        </option>
+                    {%- endfor -%}
+                </select>
+                </span>
+                <span style="white-space: nowrap;">
+                <label id="change-to" for="diff-to-version" class="from-to-label">{{ _('To') }}</label>
+                <select id="diff-to-version" name="to_version" class="needs-localtime">
+                    {%- for version in versions|reverse -%}
+                        <option value="{{ version }}" {% if version== to_version %} selected="" {% endif %}>
+                            {{ version }}{#{% if loop.first %} (Current){% endif %}#}
+                        </option>
+                    {%- endfor -%}
+                </select>
+                </span>
+                {#<button type="submit" class="pure-button pure-button-primary reset-margin">Go</button>#}
+            {% endif %}
+        </fieldset>
+        <fieldset id="diff-style">
+            <span>
+                <label for="diffWords" class="pure-checkbox">
+                <input type="radio" name="type" id="diffWords" value="diffWords" {% if diff_prefs.type == 'diffWords' %}checked=""{% endif %}> {{ _('Words') }}</label>
+            </span>
+            <span>
+                <label for="diffLines" class="pure-checkbox">
+                <input type="radio" name="type" id="diffLines" value="diffLines" {% if diff_prefs.type == 'diffLines' %}checked=""{% endif %}> {{ _('Lines') }}</label>
+            </span>
+            <span>
+                <label for="ignoreWhitespace" class="pure-checkbox" id="label-diff-ignorewhitespace">
+                <input type="checkbox" id="ignoreWhitespace" name="ignoreWhitespace" {% if diff_prefs.ignoreWhitespace %}checked=""{% endif %}> {{ _('Ignore Whitespace') }}</label>
+            </span>
+            <span>
+                <label for="changesOnly" class="pure-checkbox" id="label-diff-changes">
+                <input type="checkbox" id="changesOnly" name="changesOnly" {% if diff_prefs.changesOnly %}checked=""{% endif %}> {{ _('Same/non-changed') }}</label>
+            </span>
+            <span>
+                <label for="removed" class="pure-checkbox" id="label-diff-removed">
+                <input type="checkbox" id="removed" name="removed" {% if diff_prefs.removed %}checked=""{% endif %}> {{ _('Removed') }}</label>
+            </span>
+            <span>
+                <label for="added" class="pure-checkbox" id="label-diff-added">
+                <input type="checkbox" id="added" name="added" {% if diff_prefs.added %}checked=""{% endif %}> {{ _('Added') }}</label>
+            </span>
+            <span>
+                <label for="replaced" class="pure-checkbox" id="label-diff-replaced">
+                <input type="checkbox" id="replaced"  name="replaced" {% if diff_prefs.replaced %}checked=""{% endif %}> {{ _('Replaced') }}</label>
+            </span>
+        </fieldset>
+        {%- if versions|length >= 2 -%}
+            <div id="keyboard-nav">
+                <strong>{{ _('Keyboard:') }} </strong>
+                <a href="" class="pure-button pure-button-primary" id="btn-previous"> &larr; {{ _('Previous') }}</a>
+                &nbsp; <a class="pure-button pure-button-primary" id="btn-next" href=""> &rarr; {{ _('Next') }}</a>
+            </div>
+        {%- endif -%}
+    </form>
+</div>
+
+<div id="diff-jump">
+    <a id="jump-next-diff" title="{{ _('Jump to next difference') }}">{{ _('Jump') }}</a>
+</div>
+
+<script src="{{url_for('static_content', group='js', filename='tabs.js')}}" defer></script>
+<div class="tabs">
+    <ul>
+        {% if last_error_text %}<li class="tab" id="error-text-tab"><a href="#error-text">{{ _('Error Text') }}</a></li> {% endif %}
+        {% if last_error_screenshot %}<li class="tab" id="error-screenshot-tab"><a href="#error-screenshot">{{ _('Error Screenshot') }}</a></li> {% endif %}
+        <li class="tab" id="text-tab"><a href="#text">{{ _('Text') }}</a></li>
+        <li class="tab" id="screenshot-tab"><a href="#screenshot">{{ _('Current screenshot') }}</a></li>
+        <li class="tab" id="extract-tab"><a href="{{ url_for('ui.ui_diff.diff_history_page_extract_GET', uuid=uuid)}}">{{ _('Extract Data') }}</a></li>
+    </ul>
+</div>
+
+<div id="diff-ui">
+    <div class="tab-pane-inner" id="error-text">
+        <div class="snapshot-age error">{{watch_a.error_text_ctime|format_seconds_ago}} {{ _('seconds ago.') }}</div>
+        <pre>
+            {{ last_error_text }}
+        </pre>
+    </div>
+
+    <div class="tab-pane-inner" id="error-screenshot">
+        <div class="snapshot-age error">{{watch_a.snapshot_error_screenshot_ctime|format_seconds_ago}} {{ _('seconds ago') }}</div>
+        <img id="error-screenshot-img"  style="max-width: 80%" alt="{{ _('Current error-ing screenshot from most recent request') }}" >
+    </div>
+
+    <div class="tab-pane-inner" id="text">
+    {%- if (content | default('')).split('\n') | length > 100 -%}
+        <div id="cell-diff-jump-visualiser"  style="user-select: none;">
+            {%- for cell in diff_cell_grid -%}
+            <div{% if cell.class %} class="{{ cell.class }}"{% endif %}></div>
+            {%- endfor -%}
+        </div>
+    {%- endif -%}
+        {%- if password_enabled_and_share_is_off -%}
+            <div class="tip">{{ _('Pro-tip: You can enable') }} <strong>{{ _('"share access when password is enabled"') }}</strong> {{ _('from settings.') }}
+            </div>
+        {%- endif -%}
+        <div id="text-diff-heading-area"  style="user-select: none;">
+            <div class="snapshot-age"><span>{{ from_version|format_timestamp_timeago }}</span>
+                {%- if note -%}<span class="note"><strong>{{ note }}</strong></span>{%- endif -%}
+                <a href="{{ url_for("ui.ui_preview.preview_page", uuid=uuid) }}">{{ _('Goto single snapshot') }}</a>
+            </div>
+        </div>
+        <pre id="difference" style="border-left: 2px solid #ddd;">{{ content| diff_unescape_difference_spans }}</pre>
+    <div id="diff-visualiser-area-after" style="user-select: none;">
+        <strong>{{ _('Tip:') }}</strong> {{ _('Highlight text to share or add to ignore lists.') }}
+    </div>
+    </div>
+
+    <div class="tab-pane-inner" id="screenshot">
+         <div class="tip">
+             {{ _('For now, Differences are performed on text, not graphically, only the latest screenshot is available.') }}
+         </div>
+         {% if is_html_webdriver %}
+           {% if screenshot %}
+            <div class="snapshot-age">{{watch_a.snapshot_screenshot_ctime|format_timestamp_timeago}}</div>
+            <img style="max-width: 80%" id="screenshot-img" alt="{{ _('Current screenshot from most recent request') }}" >
+           {% else %}
+              {{ _('No screenshot available just yet! Try rechecking the page.') }}
+           {% endif %}
+         {% else %}
+           <strong>{{ _('Screenshot requires Playwright/WebDriver enabled') }}</strong>
+         {% endif %}
+     </div>
+
+</div>
+
+<script>
+    const newest_version_timestamp = {{newest_version_timestamp}};
+</script>
+<script src="{{url_for('static_content', group='js', filename='diff-render.js')}}"></script>
+
+
+{% endblock %}

changedetectionio/blueprint/ui/templates/edit.html

@@ -1,12 +1,13 @@
 {% extends 'base.html' %}
 {% block content %}
-{% from '_helpers.html' import render_field, render_checkbox_field, render_button, render_time_schedule_form, playwright_warning, only_playwright_type_watches_warning, render_conditions_fieldlist_of_formfields_as_table, render_ternary_field %}
+{% from '_helpers.html' import render_field, render_checkbox_field, render_button, render_time_schedule_form, playwright_warning, only_playwright_type_watches_warning, highlight_trigger_ignored_explainer, render_conditions_fieldlist_of_formfields_as_table, render_ternary_field %}
 {% from '_common_fields.html' import render_common_settings_form %}
 <script src="{{url_for('static_content', group='js', filename='tabs.js')}}" defer></script>
 <script src="{{url_for('static_content', group='js', filename='vis.js')}}" defer></script>
 <script src="{{url_for('static_content', group='js', filename='global-settings.js')}}" defer></script>
 <script src="{{url_for('static_content', group='js', filename='scheduler.js')}}" defer></script>
 <script src="{{url_for('static_content', group='js', filename='conditions.js')}}" defer></script>
+<script src="{{url_for('static_content', group='js', filename='modal.js')}}"></script>
 
 
 <script>
@@ -43,20 +44,20 @@
 
     <div class="tabs collapsable">
         <ul>
-            <li class="tab"><a href="#general">General</a></li>
-            <li class="tab"><a href="#request">Request</a></li>
+            <li class="tab"><a href="#general">{{ _('General') }}</a></li>
+            <li class="tab"><a href="#request">{{ _('Request') }}</a></li>
             {% if extra_tab_content %}
             <li class="tab"><a href="#extras_tab">{{ extra_tab_content }}</a></li>
             {% endif %}
-            <li class="tab"><a id="browsersteps-tab" href="#browser-steps">Browser Steps</a></li>
+            <li class="tab"><a id="browsersteps-tab" href="#browser-steps">{{ _('Browser Steps') }}</a></li>
         <!-- should goto extra forms? -->
-            {% if watch['processor'] == 'text_json_diff' %}
-            <li class="tab"><a id="visualselector-tab" href="#visualselector">Visual Filter Selector</a></li>
-            <li class="tab" id="filters-and-triggers-tab"><a href="#filters-and-triggers">Filters &amp; Triggers</a></li>
-            <li class="tab" id="conditions-tab"><a href="#conditions">Conditions</a></li>
+            {% if watch['processor'] == 'text_json_diff' or watch['processor'] == 'image_ssim_diff' %}
+            <li class="tab"><a id="visualselector-tab" href="#visualselector">{{ _('Visual Filter Selector') }}</a></li>
+            <li class="tab" id="filters-and-triggers-tab"><a href="#filters-and-triggers">{{ _('Filters & Triggers') }}</a></li>
+            <li class="tab" id="conditions-tab"><a href="#conditions">{{ _('Conditions') }}</a></li>
             {% endif %}
-            <li class="tab"><a href="#notifications">Notifications</a></li>
-            <li class="tab"><a href="#stats">Stats</a></li>
+            <li class="tab"><a href="#notifications">{{ _('Notifications') }}</a></li>
+            <li class="tab"><a href="#stats">{{ _('Stats') }}</a></li>
         </ul>
     </div>
 
@@ -69,19 +70,19 @@
                 <fieldset>
                     <div class="pure-control-group">
                         {{ render_field(form.url, placeholder="https://...", required=true, class="m-d") }}
-                        <div class="pure-form-message">Some sites use JavaScript to create the content, for this you should <a href="https://github.com/dgtlmoon/changedetection.io/wiki/Fetching-pages-with-WebDriver">use the Chrome/WebDriver Fetcher</a></div>
-                        <div class="pure-form-message">Variables are supported in the URL (<a href="https://github.com/dgtlmoon/changedetection.io/wiki/Handling-variables-in-the-watched-URL">help and examples here</a>).</div>
+                        <div class="pure-form-message">{{ _('Some sites use JavaScript to create the content, for this you should') }} <a href="https://github.com/dgtlmoon/changedetection.io/wiki/Fetching-pages-with-WebDriver">{{ _('use the Chrome/WebDriver Fetcher') }}</a></div>
+                        <div class="pure-form-message">{{ _('Variables are supported in the URL') }} (<a href="https://github.com/dgtlmoon/changedetection.io/wiki/Handling-variables-in-the-watched-URL">{{ _('help and examples here') }}</a>).</div>
                     </div>
                     <div class="pure-control-group">
                         {{ render_field(form.tags) }}
-                        <span class="pure-form-message-inline">Organisational tag/group name used in the main listing page</span>
+                        <span class="pure-form-message-inline">{{ _('Organisational tag/group name used in the main listing page') }}</span>
                     </div>
                     <div class="pure-control-group inline-radio">
                         {{ render_field(form.processor) }}
                     </div>
                     <div class="pure-control-group">
                         {{ render_field(form.title, class="m-d", placeholder=watch.label) }}
-                        <span class="pure-form-message-inline">Automatically uses the page title if found, you can also use your own title/description here</span>
+                        <span class="pure-form-message-inline">{{ _('Automatically uses the page title if found, you can also use your own title/description here') }}</span>
                     </div>
                     <div class="pure-control-group time-between-check border-fieldset">
 
@@ -91,7 +92,7 @@
                             {{ render_field(form.time_between_check, class="time-check-widget") }}
 
                             <span class="pure-form-message-inline">
-                             The interval/amount of time between each check.
+                             {{ _('The interval/amount of time between each check.') }}
                             </span>
                         </div>
                         <div id="time-between-check-schedule">
@@ -106,7 +107,7 @@
                     <div class="pure-control-group">
                         {{ render_checkbox_field(form.filter_failure_notification_send) }}
                         <span class="pure-form-message-inline">
-                         Sends a notification when the filter can no longer be seen on the page, good for knowing when the page changed and your filter will not work anymore.
+                         {{ _('Sends a notification when the filter can no longer be seen on the page, good for knowing when the page changed and your filter will not work anymore.') }}
                         </span>
                     </div>
                     <div class="pure-control-group">
@@ -119,17 +120,17 @@
                     <div class="pure-control-group inline-radio">
                         {{ render_field(form.fetch_backend, class="fetch-backend") }}
                         <span class="pure-form-message-inline">
-                            <p>Use the <strong>Basic</strong> method (default) where your watched site doesn't need Javascript to render.</p>
-                            <p>The <strong>Chrome/Javascript</strong> method requires a network connection to a running WebDriver+Chrome server, set by the ENV var 'WEBDRIVER_URL'. </p>
-                            Tip: <a href="https://github.com/dgtlmoon/changedetection.io/wiki/Proxy-configuration#brightdata-proxy-support">Connect using Bright Data and Oxylabs Proxies, find out more here.</a>
+                            <p>{{ _('Use the') }} <strong>{{ _('Basic') }}</strong> {{ _('method (default) where your watched site doesn\'t need Javascript to render.') }}</p>
+                            <p>{{ _('The') }} <strong>{{ _('Chrome/Javascript') }}</strong> {{ _('method requires a network connection to a running WebDriver+Chrome server, set by the ENV var \'WEBDRIVER_URL\'.') }} </p>
+                            {{ _('Tip:') }} <a href="https://github.com/dgtlmoon/changedetection.io/wiki/Proxy-configuration#brightdata-proxy-support">{{ _('Connect using Bright Data and Oxylabs Proxies, find out more here.') }}</a>
                         </span>
                     </div>
                 {% if form.proxy %}
                     <div class="pure-control-group inline-radio">
-                          <div>{{ form.proxy.label }} <a href="" id="check-all-proxies" class="pure-button button-secondary button-xsmall" >Check/Scan all</a></div>
+                          <div>{{ form.proxy.label }} <a href="" id="check-all-proxies" class="pure-button button-secondary button-xsmall" >{{ _('Check/Scan all') }}</a></div>
                           <div>{{ form.proxy(class="fetch-backend-proxy") }}</div>
                         <span class="pure-form-message-inline">
-                        Choose a proxy for this watch
+                        {{ _('Choose a proxy for this watch') }}
                         </span>
                     </div>
                 {% endif %}
@@ -139,31 +140,29 @@
                     <div class="pure-control-group">
                         {{ render_field(form.webdriver_delay) }}
                         <div class="pure-form-message-inline">
-                            <strong>If you're having trouble waiting for the page to be fully rendered (text missing etc), try increasing the 'wait' time here.</strong>
+                            <strong>{{ _('If you\'re having trouble waiting for the page to be fully rendered (text missing etc), try increasing the \'wait\' time here.') }}</strong>
                             <br>
-                            This will wait <i>n</i> seconds before extracting the text.
+                            {{ _('This will wait') }} <i>n</i> {{ _('seconds before extracting the text.') }}
                             {% if using_global_webdriver_wait %}
-                            <br><strong>Using the current global default settings</strong>
+                            <br><strong>{{ _('Using the current global default settings') }}</strong>
                             {% endif %}
                         </div>
                     </div>
                     <div class="pure-control-group">
-                        <a class="pure-button button-secondary button-xsmall show-advanced">Show advanced options</a>
+                        <a class="pure-button button-secondary button-xsmall show-advanced">{{ _('Show advanced options') }}</a>
                     </div>
                     <div class="advanced-options"  style="display: none;">
                         {{ render_field(form.webdriver_js_execute_code) }}
                         <div class="pure-form-message-inline">
-                            Run this code before performing change detection, handy for filling in fields and other
-                            actions <a
-                                href="https://github.com/dgtlmoon/changedetection.io/wiki/Run-JavaScript-before-change-detection">More
-                            help and examples here</a>
+                            {{ _('Run this code before performing change detection, handy for filling in fields and other actions') }} <a
+                                href="https://github.com/dgtlmoon/changedetection.io/wiki/Run-JavaScript-before-change-detection">{{ _('More help and examples here') }}</a>
                         </div>
                     </div>
                 </fieldset>
                 <!-- html requests always -->
                 <fieldset data-visible-for="fetch_backend=html_requests">
                     <div class="pure-control-group">
-                        <a class="pure-button button-secondary button-xsmall show-advanced">Show advanced options</a>
+                        <a class="pure-button button-secondary button-xsmall show-advanced">{{ _('Show advanced options') }}</a>
                     </div>
                     <div class="advanced-options"  style="display: none;">
                         <div class="pure-control-group" id="request-method">
@@ -178,7 +177,7 @@
    \"year\":{% now 'Europe/Berlin', '%Y' %}
 }") }}
                         </div>
-                        <div class="pure-form-message">Variables are supported in the request body (<a href="https://github.com/dgtlmoon/changedetection.io/wiki/Handling-variables-in-the-watched-URL">help and examples here</a>).</div>
+                        <div class="pure-form-message">{{ _('Variables are supported in the request body') }} (<a href="https://github.com/dgtlmoon/changedetection.io/wiki/Handling-variables-in-the-watched-URL">{{ _('help and examples here') }}</a>).</div>
                     </div>
                 </fieldset>
             <!-- hmm -->
@@ -187,15 +186,15 @@
 Cookie: foobar
 User-Agent: wonderbra 1.0
 Math: {{ 1 + 1 }}") }}
-                        <div class="pure-form-message">Variables are supported in the request header values (<a href="https://github.com/dgtlmoon/changedetection.io/wiki/Handling-variables-in-the-watched-URL">help and examples here</a>).</div>
+                        <div class="pure-form-message">{{ _('Variables are supported in the request header values') }} (<a href="https://github.com/dgtlmoon/changedetection.io/wiki/Handling-variables-in-the-watched-URL">{{ _('help and examples here') }}</a>).</div>
                         <div class="pure-form-message-inline">
                             {% if has_extra_headers_file %}
-                                <strong>Alert! Extra headers file found and will be added to this watch!</strong>
+                                <strong>{{ _('Alert! Extra headers file found and will be added to this watch!') }}</strong>
                             {% else %}
-                                Headers can be also read from a file in your data-directory <a href="https://github.com/dgtlmoon/changedetection.io/wiki/Adding-headers-from-an-external-file">Read more here</a>
+                                {{ _('Headers can be also read from a file in your data-directory') }} <a href="https://github.com/dgtlmoon/changedetection.io/wiki/Adding-headers-from-an-external-file">{{ _('Read more here') }}</a>
                             {% endif %}
                             <br>
-                            (Not supported by Selenium browser)
+                            ({{ _('Not supported by Selenium browser') }})
                         </div>
                     </div>
             <fieldset data-visible-for="fetch_backend=html_requests fetch_backend=html_webdriver" >
@@ -206,9 +205,8 @@ Math: {{ 1 + 1 }}") }}
             </div>
 
             <div class="tab-pane-inner" id="browser-steps">
-            {% if watch_needs_selenium_or_playwright %}
-                {# Only works with playwright #}
-                {% if system_has_playwright_configured %}
+            {% if capabilities.supports_browser_steps %}
+               {% if visual_selector_data_ready %}
                 <img class="beta-logo" src="{{url_for('static_content', group='images', filename='beta-logo.png')}}" alt="New beta functionality">
                 <fieldset>
                     <div class="pure-control-group">
@@ -220,19 +218,19 @@ Math: {{ 1 + 1 }}") }}
 
                         <!---  Do this later -->
                         <div class="checkbox" style="display: none;">
-                            <input type=checkbox id="include_text_elements" > <label for="include_text_elements">Turn on text finder</label>
+                            <input type=checkbox id="include_text_elements" > <label for="include_text_elements">{{ _('Turn on text finder') }}</label>
                         </div>
 
-                        <div id="loading-status-text" style="display: none;">Please wait, first browser step can take a little time to load..<div class="spinner"></div></div>
+                        <div id="loading-status-text" style="display: none;">{{ _('Please wait, first browser step can take a little time to load..') }}<div class="spinner"></div></div>
                         <div class="flex-wrapper" >
 
                             <div id="browser-steps-ui" class="noselect">
                                 <div class="noselect"  id="browsersteps-selector-wrapper" style="width: 100%">
                                     <span class="loader" >
                                         <span id="browsersteps-click-start">
-                                            <h2 >Click here to Start</h2>
+                                            <h2 >{{ _('Click here to Start') }}</h2>
                                             <svg style="height: 3.5rem;" version="1.1" viewBox="0 0 32 32"  xml:space="preserve" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g id="start"/><g id="play_x5F_alt"><path d="M16,0C7.164,0,0,7.164,0,16s7.164,16,16,16s16-7.164,16-16S24.836,0,16,0z M10,24V8l16.008,8L10,24z" style="fill: var(--color-grey-400);"/></g></svg><br>
-                                            Please allow 10-15 seconds for the browser to connect.<br>
+                                            {{ _('Please allow 10-15 seconds for the browser to connect.') }}<br>
                                         </span>
                                         <div class="spinner"  style="display: none;"></div>
                                     </span>
@@ -241,22 +239,20 @@ Math: {{ 1 + 1 }}") }}
                                 </div>
                             </div>
                             <div id="browser-steps-fieldlist" >
-                                <span id="browser-seconds-remaining">Press "Play" to start.</span> <span style="font-size: 80%;"> (<a target="newwindow" href="https://github.com/dgtlmoon/changedetection.io/pull/478/files#diff-1a79d924d1840c485238e66772391268a89c95b781d69091384cf1ea1ac146c9R4">?</a>) </span>
+                                <span id="browser-seconds-remaining">{{ _('Press "Play" to start.') }}</span> <span style="font-size: 80%;"> (<a target="newwindow" href="https://github.com/dgtlmoon/changedetection.io/pull/478/files#diff-1a79d924d1840c485238e66772391268a89c95b781d69091384cf1ea1ac146c9R4">?</a>) </span>
                                 {{ render_field(form.browser_steps) }}
                             </div>
                         </div>
                     </div>
                 </fieldset>
                 {% else %}
-                    {# it's configured to use selenium or chrome but system says its not configured #}
-                    {{ playwright_warning() }}
-                    {% if system_has_webdriver_configured %}
-                        <strong>Selenium/Webdriver cant be used here because it wont fetch screenshots reliably.</strong>
-                    {% endif %}
+                    <strong>{{ _('Visual Selector data is not ready, watch needs to be checked atleast once.') }}</strong>
                 {% endif %}
             {% else %}
-                {# "This functionality needs chrome.." #}
-                {{ only_playwright_type_watches_warning() }}
+                <p>
+                    <strong>{{ _('Sorry, this functionality only works with fetchers that support interactive Javascript (so far only Playwright based fetchers)') }}<br>
+                    {{ _('You need to') }} <a href="#request">{{ _('Set the fetch method') }}</a> {{ _('to one that supports interactive Javascript.') }}</strong>
+                </p>
             {% endif %}
             </div>
 
@@ -266,28 +262,28 @@ Math: {{ 1 + 1 }}") }}
                     <div  class="pure-control-group inline-radio">
                       {{ render_ternary_field(form.notification_muted, BooleanField=true) }}
                     </div>
-                    {% if watch_needs_selenium_or_playwright %}
+                    {% if capabilities.supports_screenshots %}
                     <div class="pure-control-group inline-radio">
                       {{ render_checkbox_field(form.notification_screenshot) }}
                         <span class="pure-form-message-inline">
-                            <strong>Use with caution!</strong> This will easily fill up your email storage quota or flood other storages.
+                            <strong>{{ _('Use with caution!') }}</strong> {{ _('This will easily fill up your email storage quota or flood other storages.') }}
                         </span>
                     </div>
                     {% endif %}
                     <div class="field-group" id="notification-field-group">
                         {% if has_default_notification_urls %}
                         <div class="inline-warning">
-                            <img class="inline-warning-icon" src="{{url_for('static_content', group='images', filename='notice.svg')}}" alt="Look out!" title="Lookout!" >
-                            There are <a href="{{ url_for('settings.settings_page')}}#notifications">system-wide notification URLs enabled</a>, this form will override notification settings for this watch only &dash; an empty Notification URL list here will still send notifications.
+                            <img class="inline-warning-icon" src="{{url_for('static_content', group='images', filename='notice.svg')}}" alt="{{ _('Look out!') }}" title="{{ _('Lookout!') }}" >
+                            {{ _('There are') }} <a href="{{ url_for('settings.settings_page')}}#notifications">{{ _('system-wide notification URLs enabled') }}</a>, {{ _('this form will override notification settings for this watch only') }} &dash; {{ _('an empty Notification URL list here will still send notifications.') }}
                         </div>
                         {% endif %}
-                        <a href="#notifications" id="notification-setting-reset-to-default" class="pure-button button-xsmall" style="right: 20px; top: 20px; position: absolute; background-color: #5f42dd; border-radius: 4px; font-size: 70%; color: #fff">Use system defaults</a>
+                        <a href="#notifications" id="notification-setting-reset-to-default" class="pure-button button-xsmall" style="right: 20px; top: 20px; position: absolute; background-color: #5f42dd; border-radius: 4px; font-size: 70%; color: #fff">{{ _('Use system defaults') }}</a>
                         {{ render_common_settings_form(form, emailprefix, settings_application, extra_notification_token_placeholder_info) }}
                     </div>
                 </fieldset>
             </div>
 
-            {% if watch['processor'] == 'text_json_diff' %}
+            {% if watch['processor'] == 'text_json_diff' or watch['processor'] == 'image_ssim_diff' %}
 
             <div class="tab-pane-inner" id="conditions">
                     <script>
@@ -298,23 +294,23 @@ Math: {{ 1 + 1 }}") }}
                     {{ render_conditions_fieldlist_of_formfields_as_table(form.conditions) }}
                     <div class="pure-form-message-inline">
 
-                        <p id="verify-state-text">Use the verify (✓) button to test if a condition passes against the current snapshot.</p>
-                       Read a quick tutorial about <a href="https://changedetection.io/tutorial/conditional-actions-web-page-changes">using conditional web page changes here</a>.<br>
+                        <p id="verify-state-text">{{ _('Use the verify (✓) button to test if a condition passes against the current snapshot.') }}</p>
+                       {{ _('Read a quick tutorial about') }} <a href="https://changedetection.io/tutorial/conditional-actions-web-page-changes">{{ _('using conditional web page changes here') }}</a>.<br>
                     </div>
                 </div>
             </div>
             <div class="tab-pane-inner" id="filters-and-triggers">
-                <span id="activate-text-preview" class="pure-button pure-button-primary button-xsmall">Activate preview</span>
+                <span id="activate-text-preview" class="pure-button pure-button-primary button-xsmall">{{ _('Activate preview') }}</span>
               <div>
               <div id="edit-text-filter">
                     <div class="pure-control-group" id="pro-tips">
-                            <strong>Pro-tips:</strong><br>
+                            <strong>{{ _('Pro-tips:') }}</strong><br>
                             <ul>
                                 <li>
-                                    Use the preview page to see your filters and triggers highlighted.
+                                    {{ _('Use the preview page to see your filters and triggers highlighted.') }}
                                 </li>
                                 <li>
-                                    Some sites use JavaScript to create the content, for this you should <a href="https://github.com/dgtlmoon/changedetection.io/wiki/Fetching-pages-with-WebDriver">use the Chrome/WebDriver Fetcher</a>
+                                    {{ _('Some sites use JavaScript to create the content, for this you should') }} <a href="https://github.com/dgtlmoon/changedetection.io/wiki/Fetching-pages-with-WebDriver">{{ _('use the Chrome/WebDriver Fetcher') }}</a>
                                 </li>
                             </ul>
                     </div>
@@ -322,50 +318,51 @@ Math: {{ 1 + 1 }}") }}
 {% include "edit/include_subtract.html" %}
                 <div class="text-filtering border-fieldset">
                 <fieldset class="pure-group" id="text-filtering-type-options">
-                    <h3>Text filtering</h3>
-                        Limit trigger/ignore/block/extract to;<br>
+                    <h3>{{ _('Text filtering') }}</h3>
+                        {{ _('Limit trigger/ignore/block/extract to;') }}<br>
                         {{ render_checkbox_field(form.filter_text_added) }}
                         {{ render_checkbox_field(form.filter_text_replaced) }}
                         {{ render_checkbox_field(form.filter_text_removed) }}
-                    <span class="pure-form-message-inline">Note: Depending on the length and similarity of the text on each line, the algorithm may consider an <strong>addition</strong> instead of <strong>replacement</strong> for example.</span><br>
-                    <span class="pure-form-message-inline">&nbsp;So it's always better to select <strong>Added</strong>+<strong>Replaced</strong> when you're interested in new content.</span><br>
-                    <span class="pure-form-message-inline">&nbsp;When content is merely moved in a list, it will also trigger an <strong>addition</strong>, consider enabling <code><strong>Only trigger when unique lines appear</strong></code></span>
+                    <span class="pure-form-message-inline">{{ _('Note: Depending on the length and similarity of the text on each line, the algorithm may consider an') }} <strong>{{ _('addition') }}</strong> {{ _('instead of') }} <strong>{{ _('replacement') }}</strong> {{ _('for example.') }}</span><br>
+                    <span class="pure-form-message-inline">&nbsp;{{ _('So it\'s always better to select') }} <strong>{{ _('Added') }}</strong>+<strong>{{ _('Replaced') }}</strong> {{ _('when you\'re interested in new content.') }}</span><br>
+                    <span class="pure-form-message-inline">&nbsp;{{ _('When content is merely moved in a list, it will also trigger an') }} <strong>{{ _('addition') }}</strong>, {{ _('consider enabling') }} <code><strong>{{ _('Only trigger when unique lines appear') }}</strong></code></span>
                 </fieldset>
                 <fieldset class="pure-control-group">
                     {{ render_checkbox_field(form.check_unique_lines) }}
-                    <span class="pure-form-message-inline">Good for websites that just move the content around, and you want to know when NEW content is added, compares new lines against all history for this watch.</span>
+                    <span class="pure-form-message-inline">{{ _('Good for websites that just move the content around, and you want to know when NEW content is added, compares new lines against all history for this watch.') }}</span>
                 </fieldset>
                 <fieldset class="pure-control-group">
                     {{ render_checkbox_field(form.remove_duplicate_lines) }}
-                    <span class="pure-form-message-inline">Remove duplicate lines of text</span>
+                    <span class="pure-form-message-inline">{{ _('Remove duplicate lines of text') }}</span>
                 </fieldset>
                 <fieldset class="pure-control-group">
                     {{ render_checkbox_field(form.sort_text_alphabetically) }}
-                    <span class="pure-form-message-inline">Helps reduce changes detected caused by sites shuffling lines around, combine with <i>check unique lines</i> below.</span>
+                    <span class="pure-form-message-inline">{{ _('Helps reduce changes detected caused by sites shuffling lines around, combine with') }} <i>{{ _('check unique lines') }}</i> {{ _('below.') }}</span>
                 </fieldset>
                 <fieldset class="pure-control-group">
                     {{ render_checkbox_field(form.trim_text_whitespace) }}
-                    <span class="pure-form-message-inline">Remove any whitespace before and after each line of text</span>
+                    <span class="pure-form-message-inline">{{ _('Remove any whitespace before and after each line of text') }}</span>
                 </fieldset>
                 {% include "edit/text-options.html" %}
                 </div>
               </div>
               <div id="text-preview" style="display: none;" >
-                    <script>
-                        const preview_text_edit_filters_url="{{url_for('ui.ui_edit.watch_get_preview_rendered', uuid=uuid)}}";
-                    </script>
-                    <br>
-                    {#<div id="text-preview-controls"><span id="text-preview-refresh" class="pure-button button-xsmall">Refresh</span></div>#}
-                    <div class="minitabs-wrapper">
-                      <div class="minitabs-content">
-                          <div id="text-preview-inner" class="monospace-preview">
-                              <p>Loading...</p>
-                          </div>
-                          <div id="text-preview-before-inner" style="display: none;" class="monospace-preview">
-                              <p>Loading...</p>
-                          </div>
+                <script>
+                    const preview_text_edit_filters_url="{{url_for('ui.ui_edit.watch_get_preview_rendered', uuid=uuid)}}";
+                </script>
+                <br>
+                {#<div id="text-preview-controls"><span id="text-preview-refresh" class="pure-button button-xsmall">Refresh</span></div>#}
+                <div class="minitabs-wrapper">
+                  <div class="minitabs-content">
+                      <div id="text-preview-inner" class="monospace-preview">
+                          <p>{{ _('Loading...') }}</p>
                       </div>
-                    </div>
+                      <div id="text-preview-before-inner" style="display: none;" class="monospace-preview">
+                          <p>{{ _('Loading...') }}</p>
+                      </div>
+                  </div>
+                </div>
+                {{ highlight_trigger_ignored_explainer() }}
             </div>
           </div>
         </div>
@@ -377,41 +374,55 @@ Math: {{ 1 + 1 }}") }}
             {{ extra_form_content|safe }}
             </div>
         {% endif %}
-            {% if watch['processor'] == 'text_json_diff' %}
+            {% if watch['processor'] == 'text_json_diff' or watch['processor'] == 'image_ssim_diff' %}
             <div class="tab-pane-inner visual-selector-ui" id="visualselector">
                 <img class="beta-logo" src="{{url_for('static_content', group='images', filename='beta-logo.png')}}" alt="New beta functionality">
 
                 <fieldset>
                     <div class="pure-control-group">
-                        {% if watch_needs_selenium_or_playwright %}
-                            {% if system_has_playwright_configured %}
-                            <span class="pure-form-message-inline" id="visual-selector-heading">
-                                The Visual Selector tool lets you select the <i>text</i> elements that will be used for the change detection. It automatically fills-in the filters in the "CSS/JSONPath/JQ/XPath Filters" box of the <a href="#filters-and-triggers">Filters & Triggers</a> tab. Use <strong>Shift+Click</strong> to select multiple items.
-                            </span>
+                        {% if capabilities.supports_screenshots and capabilities.supports_xpath_element_data %}
+                            {% if visual_selector_data_ready %}
+                                <span class="pure-form-message-inline" id="visual-selector-heading">
+                                    {{ _('The Visual Selector tool lets you select the') }} <i>{{ _('text') }}</i> {{ _('elements that will be used for the change detection. It automatically fills-in the filters in the "CSS/JSONPath/JQ/XPath Filters" box of the') }} <a href="#filters-and-triggers">{{ _('Filters & Triggers') }}</a> {{ _('tab. Use') }} <strong>{{ _('Shift+Click') }}</strong> {{ _('to select multiple items.') }}
+                                </span>
 
-                            <div id="selector-header">
-                                <a id="clear-selector" class="pure-button button-secondary button-xsmall" style="font-size: 70%">Clear selection</a>
-                                <!-- visual selector IMG will try to load, it will either replace this or on error replace it with some handy text -->
-                                <i class="fetching-update-notice" style="font-size: 80%;">One moment, fetching screenshot and element information..</i>
-                            </div>
-                            <div id="selector-wrapper" style="display: none">
-                                <!-- request the screenshot and get the element offset info ready -->
-                                <!-- use img src ready load to know everything is ready to map out -->
-                                <!-- @todo: maybe something interesting like a field to select 'elements that contain text... and their parents n' -->
-                                <img id="selector-background" >
-                                <canvas id="selector-canvas"></canvas>
-                            </div>
-                            <div id="selector-current-xpath" style="overflow-x: hidden"><strong>Currently:</strong>&nbsp;<span class="text">Loading...</span></div>
-                        {% else %}
-                            {# The watch needed chrome but system says that playwright is not ready #}
-                            {{ playwright_warning() }}
-                        {% endif %}
-                            {% if system_has_webdriver_configured %}
-                                <strong>Selenium/Webdriver cant be used here because it wont fetch screenshots reliably.</strong>
-                            {% endif %}
+                                {% if watch['processor'] == 'image_ssim_diff' %}
+                                <div id="selection-mode-controls" style="margin: 10px 0; padding: 10px; background: var(--color-background-tab); border-radius: 5px;">
+                                    <label style="font-weight: 600; margin-right: 15px;">{{ _('Selection Mode:') }}</label>
+                                    <label style="margin-right: 15px;">
+                                        <input type="radio" name="selector-mode" value="element" style="margin-right: 5px;">
+                                        {{ _('Select by element') }}
+                                    </label>
+                                    <label>
+                                        <input type="radio" name="selector-mode" value="draw" checked style="margin-right: 5px;">
+                                        {{ _('Draw area') }}
+                                    </label>
+                                    {{ render_field(form.processor_config_bounding_box) }}
+                                    {{ render_field(form.processor_config_selection_mode) }}
+                                </div>
+                                {% endif %}
+
+                                <div id="selector-header">
+                                    <a id="clear-selector" class="pure-button button-secondary button-xsmall" style="font-size: 70%">{{ _('Clear selection') }}</a>
+                                    <!-- visual selector IMG will try to load, it will either replace this or on error replace it with some handy text -->
+                                    <i class="fetching-update-notice" style="font-size: 80%;">{{ _('One moment, fetching screenshot and element information..') }}</i>
+                                </div>
+                                <div id="selector-wrapper" style="display: none">
+                                    <!-- request the screenshot and get the element offset info ready -->
+                                    <!-- use img src ready load to know everything is ready to map out -->
+                                    <!-- @todo: maybe something interesting like a field to select 'elements that contain text... and their parents n' -->
+                                    <img id="selector-background" >
+                                    <canvas id="selector-canvas"></canvas>
+                                </div>
+                                <div id="selector-current-xpath" style="overflow-x: hidden"><strong>{{ _('Currently:') }}</strong>&nbsp;<span class="text">{{ _('Loading...') }}</span></div>
+                            {%  else %}
+                                <strong>{{ _('Visual Selector data is not ready, watch needs to be checked atleast once.') }}</strong>
+                            {%  endif %}
                     {% else %}
-                        {# "This functionality needs chrome.." #}
-                        {{ only_playwright_type_watches_warning() }}
+                        <p>
+                            <strong>{{ _('Sorry, this functionality only works with fetchers that support Javascript and screenshots (such as playwright etc).') }}<br>
+                            {{ _('You need to') }} <a href="#request">{{ _('Set the fetch method') }}</a> {{ _('to one that supports Javascript and screenshots.') }}</strong>
+                        </p>
                     {% endif %}
                     </div>
                 </fieldset>
@@ -427,27 +438,27 @@ Math: {{ 1 + 1 }}") }}
                     <table class="pure-table" id="stats-table">
                         <tbody>
                         <tr>
-                            <td>Check count</td>
+                            <td>{{ _('Check count') }}</td>
                             <td>{{ "{:,}".format( watch.check_count) }}</td>
                         </tr>
                         <tr>
-                            <td>Consecutive filter failures</td>
+                            <td>{{ _('Consecutive filter failures') }}</td>
                             <td>{{ "{:,}".format( watch.consecutive_filter_failures) }}</td>
                         </tr>
                         <tr>
-                            <td>History length</td>
+                            <td>{{ _('History length') }}</td>
                             <td>{{ "{:,}".format(watch.history|length) }}</td>
                         </tr>
                         <tr>
-                            <td>Last fetch duration</td>
+                            <td>{{ _('Last fetch duration') }}</td>
                             <td>{{ watch.fetch_time }}s</td>
                         </tr>
                         <tr>
-                            <td>Notification alert count</td>
+                            <td>{{ _('Notification alert count') }}</td>
                             <td>{{ watch.notification_alert_count }}</td>
                         </tr>
                         <tr>
-                            <td>Server type reply</td>
+                            <td>{{ _('Server type reply') }}</td>
                             <td>{{ watch.get('remote_server_reply') }}</td>
                         </tr>
                         </tbody>
@@ -461,7 +472,7 @@ Math: {{ 1 + 1 }}") }}
 
                     {% if watch.history_n %}
                         <p>
-                             <a href="{{url_for('ui.ui_edit.watch_get_latest_html', uuid=uuid)}}" class="pure-button button-small">Download latest HTML snapshot</a>
+                             <a href="{{url_for('ui.ui_edit.watch_get_latest_html', uuid=uuid)}}" class="pure-button button-small">{{ _('Download latest HTML snapshot') }}</a>
                         </p>
                     {% endif %}
 
@@ -471,11 +482,22 @@ Math: {{ 1 + 1 }}") }}
                 <div class="pure-control-group">
                     {{ render_button(form.save_button) }}
                     <a href="{{url_for('ui.form_delete', uuid=uuid)}}"
-                       class="pure-button button-error ">Delete</a>
+                       class="pure-button button-error"
+                       data-requires-confirm
+                       data-confirm-type="danger"
+                       data-confirm-title="{{ _('Delete Watch?') }}"
+                       data-confirm-message="<p>{{ _('Are you sure you want to delete the watch for:') }}</p><p><strong>{{ watch.get('url', 'this watch') }}</strong></p><p>{{ _('This action cannot be undone.') }}</p>"
+                       data-confirm-button="{{ _('Delete') }}">{{ _('Delete') }}</a>
                     {% if watch.history_n %}<a href="{{url_for('ui.clear_watch_history', uuid=uuid)}}"
-                       class="pure-button button-error">Clear History</a>{% endif %}
+                       class="pure-button button-error"
+                       data-requires-confirm
+                       data-confirm-type="warning"
+                       data-confirm-title="{{ _('Clear History?') }}"
+                       data-confirm-message="<p>{{ _('Are you sure you want to clear all history for:') }}</p><p><strong>{{ watch.get('url', 'this watch') }}</strong></p><p>{{ _('This will remove all snapshots and previous versions. This action cannot be undone.') }}</p>"
+                       data-confirm-button="{{ _('Clear History') }}">{{ _('Clear History') }}</a>{% endif %}
                     <a href="{{url_for('ui.form_clone', uuid=uuid)}}"
-                       class="pure-button">Clone &amp; Edit</a>
+                       class="pure-button">{{ _('Clone & Edit') }}</a>
+                 <a href="{{ url_for('rss.rss_single_watch', uuid=uuid, token=app_rss_token)}}"><img alt="{{ _('RSS Feed for this watch') }}" style="padding: .5em 1em;" src="{{url_for('static_content', group='images', filename='generic_feed-icon.svg')}}" height="15"></a>
                 </div>
             </div>
         </form>

changedetectionio/blueprint/ui/templates/preview.html

@@ -1,9 +1,11 @@
 {% extends 'base.html' %}
-
+{% from '_helpers.html' import highlight_trigger_ignored_explainer %}
 {% block content %}
     <script>
         const screenshot_url = "{{url_for('static_content', group='screenshot', filename=uuid)}}";
-        const triggered_line_numbers = {{ triggered_line_numbers|tojson }};
+        const triggered_line_numbers = {{ highlight_triggered_line_numbers|tojson }};
+        const ignored_line_numbers = {{ highlight_ignored_line_numbers|tojson }};
+        const blocked_line_numbers = {{ highlight_blocked_line_numbers|tojson }};
         {% if last_error_screenshot %}
             const error_screenshot_url = "{{url_for('static_content', group='screenshot', filename=uuid, error_screenshot=1) }}";
         {% endif %}
@@ -14,10 +16,10 @@
     <script src="{{ url_for('static_content', group='js', filename='preview.js') }}" defer></script>
     <script src="{{ url_for('static_content', group='js', filename='tabs.js') }}" defer></script>
     {% if versions|length >= 2 %}
-        <div id="settings" style="text-align: center;">
+        <div id="diff-form" style="text-align: center;">
             <form class="pure-form " action="" method="POST">
                 <fieldset>
-                    <label for="preview-version">Select timestamp</label> <select id="preview-version"
+                    <label for="preview-version">{{ _('Select timestamp') }}</label> <select id="preview-version"
                                                                                  name="from_version"
                                                                                  class="needs-localtime">
                     {% for version in versions|reverse %}
@@ -26,27 +28,27 @@
                         </option>
                     {% endfor %}
                 </select>
-                    <button type="submit" class="pure-button pure-button-primary">Go</button>
+                    <button type="submit" class="pure-button pure-button-primary">{{ _('Go') }}</button>
 
                 </fieldset>
             </form>
                 <br>
-                <strong>Keyboard: </strong><a href="" class="pure-button pure-button-primary" id="btn-previous">
-                &larr; Previous</a> &nbsp; <a class="pure-button pure-button-primary" id="btn-next" href="">
-                &rarr; Next</a>
+                <strong>{{ _('Keyboard:') }} </strong><a href="" class="pure-button pure-button-primary" id="btn-previous">
+                &larr; {{ _('Previous') }}</a> &nbsp; <a class="pure-button pure-button-primary" id="btn-next" href="">
+                &rarr; {{ _('Next') }}</a>
         </div>
     {% endif %}
 
     <div class="tabs">
         <ul>
             {% if last_error_text %}
-                <li class="tab" id="error-text-tab"><a href="#error-text">Error Text</a></li> {% endif %}
+                <li class="tab" id="error-text-tab"><a href="#error-text">{{ _('Error Text') }}</a></li> {% endif %}
             {% if last_error_screenshot %}
-                <li class="tab" id="error-screenshot-tab"><a href="#error-screenshot">Error Screenshot</a>
+                <li class="tab" id="error-screenshot-tab"><a href="#error-screenshot">{{ _('Error Screenshot') }}</a>
                 </li> {% endif %}
             {% if history_n > 0 %}
-                <li class="tab" id="text-tab"><a href="#text">Text</a></li>
-                <li class="tab" id="screenshot-tab"><a href="#screenshot">Screenshot</a></li>
+                <li class="tab" id="text-tab"><a href="#text">{{ _('Text') }}</a></li>
+                <li class="tab" id="screenshot-tab"><a href="#screenshot">{{ _('Current screenshot') }}</a></li>
             {% endif %}
         </ul>
     </div>
@@ -54,50 +56,39 @@
 
     <div id="diff-ui">
         <div class="tab-pane-inner" id="error-text">
-            <div class="snapshot-age error">{{ watch.error_text_ctime|format_seconds_ago }} seconds ago</div>
+            <div class="snapshot-age error">{{ watch.error_text_ctime|format_seconds_ago }} {{ _('seconds ago') }}</div>
             <pre>
             {{ last_error_text }}
         </pre>
         </div>
 
         <div class="tab-pane-inner" id="error-screenshot">
-            <div class="snapshot-age error">{{ watch.snapshot_error_screenshot_ctime|format_seconds_ago }} seconds ago
+            <div class="snapshot-age error">{{ watch.snapshot_error_screenshot_ctime|format_seconds_ago }} {{ _('seconds ago') }}
             </div>
             <img id="error-screenshot-img" style="max-width: 80%"
-                 alt="Current erroring screenshot from most recent request">
+                 alt="{{ _('Current erroring screenshot from most recent request') }}">
         </div>
 
         <div class="tab-pane-inner" id="text">
+            {{ highlight_trigger_ignored_explainer() }}
             <div class="snapshot-age">{{ current_version|format_timestamp_timeago }}</div>
-            <span class="tip"><strong>Pro-tip</strong>: Highlight text to add to ignore filters</span>
-
-            <table>
-                <tbody>
-                <tr>
-                    <td id="diff-col" class="highlightable-filter">
-                        <pre style="border-left: 2px solid #ddd;">
-{{ content }}
-                        </pre>
-                    </td>
-                </tr>
-                </tbody>
-            </table>
+            <pre id="difference" style="border-left: 2px solid #ddd;">{{ content| diff_unescape_difference_spans }}</pre>
         </div>
 
         <div class="tab-pane-inner" id="screenshot">
             <div class="tip">
-                For now, Differences are performed on text, not graphically, only the latest screenshot is available.
+                {{ _('For now, Differences are performed on text, not graphically, only the latest screenshot is available.') }}
             </div>
             <br>
-            {% if is_html_webdriver %}
+            {% if capabilities.supports_screenshots %}
                 {% if screenshot %}
                     <div class="snapshot-age">{{ watch.snapshot_screenshot_ctime|format_timestamp_timeago }}</div>
-                    <img style="max-width: 80%" id="screenshot-img" alt="Current screenshot from most recent request">
+                    <img style="max-width: 80%" id="screenshot-img" alt="{{ _('Current screenshot from most recent request') }}">
                 {% else %}
-                    No screenshot available just yet! Try rechecking the page.
+                    {{ _('No screenshot available just yet! Try rechecking the page.') }}
                 {% endif %}
             {% else %}
-                <strong>Screenshot requires Playwright/WebDriver enabled</strong>
+                <strong>{{ _('Screenshot requires a Content Fetcher ( Sockpuppetbrowser, selenium, etc ) that supports screenshots.') }}</strong>
             {% endif %}
         </div>
     </div>

changedetectionio/blueprint/ui/views.py

@@ -1,207 +1,12 @@
-from flask import Blueprint, request, redirect, url_for, flash, render_template, make_response, send_from_directory, abort
-import os
-import time
-from loguru import logger
-
+from flask import Blueprint, request, redirect, url_for, flash
+from flask_babel import gettext
 from changedetectionio.store import ChangeDetectionStore
 from changedetectionio.auth_decorator import login_optionally_required
-from changedetectionio import html_tools
 from changedetectionio import worker_handler
 
+
 def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMetaData, watch_check_update):
     views_blueprint = Blueprint('ui_views', __name__, template_folder="../ui/templates")
-    
-    @views_blueprint.route("/preview/<string:uuid>", methods=['GET'])
-    @login_optionally_required
-    def preview_page(uuid):
-        content = []
-        versions = []
-        timestamp = None
-
-        # More for testing, possible to return the first/only
-        if uuid == 'first':
-            uuid = list(datastore.data['watching'].keys()).pop()
-
-        try:
-            watch = datastore.data['watching'][uuid]
-        except KeyError:
-            flash("No history found for the specified link, bad link?", "error")
-            return redirect(url_for('watchlist.index'))
-
-        system_uses_webdriver = datastore.data['settings']['application']['fetch_backend'] == 'html_webdriver'
-        extra_stylesheets = [url_for('static_content', group='styles', filename='diff.css')]
-
-        is_html_webdriver = False
-        if (watch.get('fetch_backend') == 'system' and system_uses_webdriver) or watch.get('fetch_backend') == 'html_webdriver' or watch.get('fetch_backend', '').startswith('extra_browser_'):
-            is_html_webdriver = True
-        triggered_line_numbers = []
-        if datastore.data['watching'][uuid].history_n == 0 and (watch.get_error_text() or watch.get_error_snapshot()):
-            flash("Preview unavailable - No fetch/check completed or triggers not reached", "error")
-        else:
-            # So prepare the latest preview or not
-            preferred_version = request.args.get('version')
-            versions = list(watch.history.keys())
-            timestamp = versions[-1]
-            if preferred_version and preferred_version in versions:
-                timestamp = preferred_version
-
-            try:
-                versions = list(watch.history.keys())
-                content = watch.get_history_snapshot(timestamp)
-
-                triggered_line_numbers = html_tools.strip_ignore_text(content=content,
-                                                                      wordlist=watch['trigger_text'],
-                                                                      mode='line numbers'
-                                                                      )
-
-            except Exception as e:
-                content.append({'line': f"File doesnt exist or unable to read timestamp {timestamp}", 'classes': ''})
-
-        output = render_template("preview.html",
-                                 content=content,
-                                 current_version=timestamp,
-                                 history_n=watch.history_n,
-                                 extra_stylesheets=extra_stylesheets,
-                                 extra_title=f" - Diff - {watch.label} @ {timestamp}",
-                                 triggered_line_numbers=triggered_line_numbers,
-                                 current_diff_url=watch['url'],
-                                 screenshot=watch.get_screenshot(),
-                                 watch=watch,
-                                 uuid=uuid,
-                                 is_html_webdriver=is_html_webdriver,
-                                 last_error=watch['last_error'],
-                                 last_error_text=watch.get_error_text(),
-                                 last_error_screenshot=watch.get_error_snapshot(),
-                                 versions=versions
-                                )
-
-        return output
-
-    @views_blueprint.route("/diff/<string:uuid>", methods=['POST'])
-    @login_optionally_required
-    def diff_history_page_build_report(uuid):
-        from changedetectionio import forms
-
-        # More for testing, possible to return the first/only
-        if uuid == 'first':
-            uuid = list(datastore.data['watching'].keys()).pop()
-
-        try:
-            watch = datastore.data['watching'][uuid]
-        except KeyError:
-            flash("No history found for the specified link, bad link?", "error")
-            return redirect(url_for('watchlist.index'))
-
-        # For submission of requesting an extract
-        extract_form = forms.extractDataForm(formdata=request.form,
-                                             data={'extract_regex': request.form.get('extract_regex', '')}
-                                             )
-        if not extract_form.validate():
-            flash("An error occurred, please see below.", "error")
-            return _render_diff_template(uuid, extract_form)
-
-        else:
-            extract_regex = request.form.get('extract_regex', '').strip()
-            output = watch.extract_regex_from_all_history(extract_regex)
-            if output:
-                watch_dir = os.path.join(datastore.datastore_path, uuid)
-                response = make_response(send_from_directory(directory=watch_dir, path=output, as_attachment=True))
-                response.headers['Content-type'] = 'text/csv'
-                response.headers['Cache-Control'] = 'no-cache, no-store, must-revalidate'
-                response.headers['Pragma'] = 'no-cache'
-                response.headers['Expires'] = "0"
-                return response
-
-            flash('No matches found while scanning all of the watch history for that RegEx.', 'error')
-        return redirect(url_for('ui.ui_views.diff_history_page', uuid=uuid) + '#extract')
-
-    def _render_diff_template(uuid, extract_form=None):
-        """Helper function to render the diff template with all required data"""
-        from changedetectionio import forms
-
-        # More for testing, possible to return the first/only
-        if uuid == 'first':
-            uuid = list(datastore.data['watching'].keys()).pop()
-
-        extra_stylesheets = [url_for('static_content', group='styles', filename='diff.css')]
-        try:
-            watch = datastore.data['watching'][uuid]
-        except KeyError:
-            flash("No history found for the specified link, bad link?", "error")
-            return redirect(url_for('watchlist.index'))
-
-        # Use provided form or create a new one
-        if extract_form is None:
-            extract_form = forms.extractDataForm(formdata=request.form,
-                                                 data={'extract_regex': request.form.get('extract_regex', '')}
-                                                 )
-
-        history = watch.history
-        dates = list(history.keys())
-
-        # If a "from_version" was requested, then find it (or the closest one)
-        # Also set "from version" to be the closest version to the one that was last viewed.
-
-        best_last_viewed_timestamp = watch.get_from_version_based_on_last_viewed
-        from_version_timestamp = best_last_viewed_timestamp if best_last_viewed_timestamp else dates[-2]
-        from_version = request.args.get('from_version', from_version_timestamp )
-
-        # Use the current one if nothing was specified
-        to_version = request.args.get('to_version', str(dates[-1]))
-
-        try:
-            to_version_file_contents = watch.get_history_snapshot(timestamp=to_version)
-        except Exception as e:
-            logger.error(f"Unable to read watch history to-version for version {to_version}: {str(e)}")
-            to_version_file_contents = f"Unable to read to-version at {to_version}.\n"
-
-        try:
-            from_version_file_contents = watch.get_history_snapshot(timestamp=from_version)
-        except Exception as e:
-            logger.error(f"Unable to read watch history from-version for version {from_version}: {str(e)}")
-            from_version_file_contents = f"Unable to read to-version {from_version}.\n"
-
-        screenshot_url = watch.get_screenshot()
-
-        system_uses_webdriver = datastore.data['settings']['application']['fetch_backend'] == 'html_webdriver'
-
-        is_html_webdriver = False
-        if (watch.get('fetch_backend') == 'system' and system_uses_webdriver) or watch.get('fetch_backend') == 'html_webdriver' or watch.get('fetch_backend', '').startswith('extra_browser_'):
-            is_html_webdriver = True
-
-        password_enabled_and_share_is_off = False
-        if datastore.data['settings']['application'].get('password') or os.getenv("SALTED_PASS", False):
-            password_enabled_and_share_is_off = not datastore.data['settings']['application'].get('shared_diff_access')
-
-        datastore.set_last_viewed(uuid, time.time())
-
-        return render_template("diff.html",
-                                 current_diff_url=watch['url'],
-                                 from_version=str(from_version),
-                                 to_version=str(to_version),
-                                 extra_stylesheets=extra_stylesheets,
-                                 extra_title=f" - Diff - {watch.label}",
-                                 extract_form=extract_form,
-                                 is_html_webdriver=is_html_webdriver,
-                                 last_error=watch['last_error'],
-                                 last_error_screenshot=watch.get_error_snapshot(),
-                                 last_error_text=watch.get_error_text(),
-                                 left_sticky=True,
-                                 newest=to_version_file_contents,
-                                 newest_version_timestamp=dates[-1],
-                                 password_enabled_and_share_is_off=password_enabled_and_share_is_off,
-                                 from_version_file_contents=from_version_file_contents,
-                                 to_version_file_contents=to_version_file_contents,
-                                 screenshot=screenshot_url,
-                                 uuid=uuid,
-                                 versions=dates, # All except current/last
-                                 watch_a=watch
-                                 )
-
-    @views_blueprint.route("/diff/<string:uuid>", methods=['GET'])
-    @login_optionally_required
-    def diff_history_page(uuid):
-        return _render_diff_template(uuid)
 
     @views_blueprint.route("/form/add/quickwatch", methods=['POST'])
     @login_optionally_required
@@ -216,7 +21,7 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMe
 
         url = request.form.get('url').strip()
         if datastore.url_exists(url):
-            flash(f'Warning, URL {url} already exists', "notice")
+            flash(gettext('Warning, URL {} already exists').format(url), "notice")
 
         add_paused = request.form.get('edit_and_watch_submit_button') != None
         processor = request.form.get('processor', 'text_json_diff')
@@ -224,12 +29,12 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMe
 
         if new_uuid:
             if add_paused:
-                flash('Watch added in Paused state, saving will unpause.')
+                flash(gettext('Watch added in Paused state, saving will unpause.'))
                 return redirect(url_for('ui.ui_edit.edit_page', uuid=new_uuid, unpause_on_save=1, tag=request.args.get('tag')))
             else:
                 # Straight into the queue.
                 worker_handler.queue_item_async_safe(update_q, queuedWatchMetaData.PrioritizedItem(priority=1, item={'uuid': new_uuid}))
-                flash("Watch added.")
+                flash(gettext("Watch added."))
 
         return redirect(url_for('watchlist.index', tag=request.args.get('tag','')))
 

changedetectionio/blueprint/watchlist/__init__.py

@@ -6,6 +6,7 @@ from flask_login import current_user
 from flask_paginate import Pagination, get_page_parameter
 
 from changedetectionio import forms
+from changedetectionio import processors
 from changedetectionio.store import ChangeDetectionStore
 from changedetectionio.auth_decorator import login_optionally_required
 
@@ -90,6 +91,9 @@ def construct_blueprint(datastore: ChangeDetectionStore, update_q, queuedWatchMe
             hosted_sticky=os.getenv("SALTED_PASS", False) == False,
             now_time_server=round(time.time()),
             pagination=pagination,
+            processor_badge_texts=processors.get_processor_badge_texts(),
+            processor_descriptions=processors.get_processor_descriptions(),
+            processor_badge_css=processors.get_processor_badge_css(),
             queued_uuids=[q_uuid.item['uuid'] for q_uuid in update_q.queue],
             search_q=request.args.get('q', '').strip(),
             sort_attribute=request.args.get('sort') if request.args.get('sort') else request.cookies.get('sort'),

changedetectionio/blueprint/watchlist/templates/watch-overview.html

@@ -3,6 +3,7 @@
 {%- from '_helpers.html' import render_simple_field, render_field, render_nolabel_field, sort_by_title -%}
 <script src="{{url_for('static_content', group='js', filename='jquery-3.6.0.min.js')}}"></script>
 <script src="{{url_for('static_content', group='js', filename='watch-overview.js')}}" defer></script>
+<script src="{{url_for('static_content', group='js', filename='modal.js')}}"></script>
 <script>let nowtimeserver={{ now_time_server }};</script>
 <script>let favicon_baseURL="{{ url_for('static_content', group='favicon', filename="PLACEHOLDER")}}";</script>
 <script>
@@ -18,17 +19,20 @@ document.addEventListener('DOMContentLoaded', function() {
     background-repeat: no-repeat;
     transition: background-size 0.9s ease
 }
+
+/* Auto-generated processor badge colors */
+{{ processor_badge_css|safe }}
 </style>
 <div class="box" id="form-quick-watch-add">
 
     <form class="pure-form" action="{{ url_for('ui.ui_views.form_quick_watch_add', tag=active_tag_uuid) }}" method="POST" id="new-watch-form">
         <input type="hidden" name="csrf_token" value="{{ csrf_token() }}" >
         <fieldset>
-            <legend>Add a new web page change detection watch</legend>
+            <legend>{{ _('Add a new web page change detection watch') }}</legend>
             <div id="watch-add-wrapper-zone">
                     {{ render_nolabel_field(form.url, placeholder="https://...", required=true) }}
-                    {{ render_nolabel_field(form.watch_submit_button, title="Watch this URL!" ) }}
-                    {{ render_nolabel_field(form.edit_and_watch_submit_button, title="Edit first then Watch") }}
+                    {{ render_nolabel_field(form.watch_submit_button, title=_("Watch this URL!") ) }}
+                    {{ render_nolabel_field(form.edit_and_watch_submit_button, title=_("Edit first then Watch") ) }}
             </div>
             <div id="watch-group-tag">
                {{ render_field(form.tags, value=active_tag.title if active_tag_uuid else '', placeholder="Watch group / tag", class="transparent-field") }}
@@ -38,7 +42,7 @@ document.addEventListener('DOMContentLoaded', function() {
             </div>
 
         </fieldset>
-        <span style="color:#eee; font-size: 80%;"><img alt="Create a shareable link" style="height: 1em;display:inline-block;" src="{{url_for('static_content', group='images', filename='spread-white.svg')}}" > Tip: You can also add 'shared' watches. <a href="https://github.com/dgtlmoon/changedetection.io/wiki/Sharing-a-Watch">More info</a></span>
+        <span style="color:#eee; font-size: 80%;"><img alt="{{ _('Create a shareable link') }}" style="height: 1em;display:inline-block;" src="{{url_for('static_content', group='images', filename='spread-white.svg')}}" > {{ _("Tip: You can also add 'shared' watches.") }} <a href="https://github.com/dgtlmoon/changedetection.io/wiki/Sharing-a-Watch">{{ _('More info') }}</a></span>
     </form>
 </div>
 <div class="box">
@@ -46,24 +50,34 @@ document.addEventListener('DOMContentLoaded', function() {
     <input type="hidden" name="csrf_token" value="{{ csrf_token() }}" >
     <input type="hidden" id="op_extradata" name="op_extradata" value="" >
     <div id="checkbox-operations">
-        <button class="pure-button button-secondary button-xsmall"  name="op" value="pause"><i data-feather="pause" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>Pause</button>
-        <button class="pure-button button-secondary button-xsmall"  name="op" value="unpause"><i data-feather="play" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>UnPause</button>
-        <button class="pure-button button-secondary button-xsmall"  name="op" value="mute"><i data-feather="volume-x" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>Mute</button>
-        <button class="pure-button button-secondary button-xsmall"  name="op" value="unmute"><i data-feather="volume-2" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>UnMute</button>
-        <button class="pure-button button-secondary button-xsmall" name="op" value="recheck"><i data-feather="refresh-cw" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>Recheck</button>
-        <button class="pure-button button-secondary button-xsmall" name="op" value="assign-tag" id="checkbox-assign-tag"><i data-feather="tag" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>Tag</button>
-        <button class="pure-button button-secondary button-xsmall" name="op" value="mark-viewed"><i data-feather="eye" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>Mark viewed</button>
-        <button class="pure-button button-secondary button-xsmall" name="op" value="notification-default"><i data-feather="bell" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>Use default notification</button>
-        <button class="pure-button button-secondary button-xsmall" name="op" value="clear-errors"><i data-feather="x-circle" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>Clear errors</button>
-        <button class="pure-button button-secondary button-xsmall" style="background: #dd4242;" name="op" value="clear-history"><i data-feather="trash-2" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>Clear/reset history</button>
-        <button class="pure-button button-secondary button-xsmall" style="background: #dd4242;" name="op" value="delete"><i data-feather="trash" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>Delete</button>
+        <button class="pure-button button-secondary button-xsmall"  name="op" value="pause"><i data-feather="pause" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>{{ _('Pause') }}</button>
+        <button class="pure-button button-secondary button-xsmall"  name="op" value="unpause"><i data-feather="play" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>{{ _('UnPause') }}</button>
+        <button class="pure-button button-secondary button-xsmall"  name="op" value="mute"><i data-feather="volume-x" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>{{ _('Mute') }}</button>
+        <button class="pure-button button-secondary button-xsmall"  name="op" value="unmute"><i data-feather="volume-2" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>{{ _('UnMute') }}</button>
+        <button class="pure-button button-secondary button-xsmall" name="op" value="recheck"><i data-feather="refresh-cw" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>{{ _('Recheck') }}</button>
+        <button class="pure-button button-secondary button-xsmall" name="op" value="assign-tag" id="checkbox-assign-tag"><i data-feather="tag" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>{{ _('Tag') }}</button>
+        <button class="pure-button button-secondary button-xsmall" name="op" value="mark-viewed"><i data-feather="eye" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>{{ _('Mark viewed') }}</button>
+        <button class="pure-button button-secondary button-xsmall" name="op" value="notification-default"><i data-feather="bell" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>{{ _('Use default notification') }}</button>
+        <button class="pure-button button-secondary button-xsmall" name="op" value="clear-errors"><i data-feather="x-circle" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>{{ _('Clear errors') }}</button>
+        <button class="pure-button button-secondary button-xsmall" style="background: #dd4242;" name="op" value="clear-history"
+                       data-requires-confirm
+                       data-confirm-type="danger"
+                       data-confirm-title="{{ _('Clear Histories') }}"
+                       data-confirm-message="{{ _('<p>Are you sure you want to clear history for the selected items?</p><p>This action cannot be undone.</p>') }}"
+                       data-confirm-button="{{ _('OK') }}"><i data-feather="trash-2" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>{{ _('Clear/reset history') }}</button>
+        <button class="pure-button button-secondary button-xsmall" style="background: #dd4242;" name="op" value="delete"
+                       data-requires-confirm
+                       data-confirm-type="danger"
+                       data-confirm-title="{{ _('Delete Watches?') }}"
+                       data-confirm-message="{{ _('<p>Are you sure you want to delete the selected watches?</strong></p><p>This action cannot be undone.</p>') }}"
+                       data-confirm-button="{{ _('Delete') }}"><i data-feather="trash" style="width: 14px; height: 14px; stroke: white; margin-right: 4px;"></i>{{ _('Delete') }}</button>
     </div>
     {%- if watches|length >= pagination.per_page -%}
         {{ pagination.info }}
     {%- endif -%}
-    {%- if search_q -%}<div id="search-result-info">Searching "<strong><i>{{search_q}}</i></strong>"</div>{%- endif -%}
+    {%- if search_q -%}<div id="search-result-info">{{ _('Searching') }} "<strong><i>{{search_q}}</i></strong>"</div>{%- endif -%}
     <div>
-        <a href="{{url_for('watchlist.index')}}" class="pure-button button-tag {{'active' if not active_tag_uuid }}">All</a>
+        <a href="{{url_for('watchlist.index')}}" class="pure-button button-tag {{'active' if not active_tag_uuid }}">{{ _('All') }}</a>
 
     <!-- tag list -->
     {%- for uuid, tag in tags -%}
@@ -101,19 +115,19 @@ document.addEventListener('DOMContentLoaded', function() {
                     &nbsp;
                     <a class="{{ 'active '+link_order if sort_attribute == 'notification_muted' else 'inactive' }}" href="{{url_for('watchlist.index', sort='notification_muted', order=link_order, tag=active_tag_uuid)}}"><i data-feather="volume-2" style="vertical-align: bottom; width: 14px; height: 14px;  margin-right: 4px;"></i><span class='arrow {{link_order}}'></span></a>
                 </th>
-                <th><a class="{{ 'active '+link_order if sort_attribute == 'label' else 'inactive' }}" href="{{url_for('watchlist.index', sort='label', order=link_order, tag=active_tag_uuid)}}">Website <span class='arrow {{link_order}}'></span></a></th>
+                <th><a class="{{ 'active '+link_order if sort_attribute == 'label' else 'inactive' }}" href="{{url_for('watchlist.index', sort='label', order=link_order, tag=active_tag_uuid)}}">{{ _('Website') }} <span class='arrow {{link_order}}'></span></a></th>
              {%- if any_has_restock_price_processor -%}
-                <th>Restock &amp; Price</th>
+                <th>{{ _('Restock & Price') }}</th>
              {%- endif -%}
-                <th><a class="{{ 'active '+link_order if sort_attribute == 'last_checked' else 'inactive' }}" href="{{url_for('watchlist.index', sort='last_checked', order=link_order, tag=active_tag_uuid)}}"><span class="hide-on-mobile">Last</span> Checked <span class='arrow {{link_order}}'></span></a></th>
-                <th><a class="{{ 'active '+link_order if sort_attribute == 'last_changed' else 'inactive' }}" href="{{url_for('watchlist.index', sort='last_changed', order=link_order, tag=active_tag_uuid)}}"><span class="hide-on-mobile">Last</span> Changed <span class='arrow {{link_order}}'></span></a></th>
+                <th><a class="{{ 'active '+link_order if sort_attribute == 'last_checked' else 'inactive' }}" href="{{url_for('watchlist.index', sort='last_checked', order=link_order, tag=active_tag_uuid)}}"><span class="hide-on-mobile">{{ _('Last') }}</span> {{ _('Checked') }} <span class='arrow {{link_order}}'></span></a></th>
+                <th><a class="{{ 'active '+link_order if sort_attribute == 'last_changed' else 'inactive' }}" href="{{url_for('watchlist.index', sort='last_changed', order=link_order, tag=active_tag_uuid)}}"><span class="hide-on-mobile">{{ _('Last') }}</span> {{ _('Changed') }} <span class='arrow {{link_order}}'></span></a></th>
                 <th class="empty-cell"></th>
             </tr>
             </thead>
             <tbody>
             {%- if not watches|length -%}
             <tr>
-                <td colspan="{{ cols_required }}" style="text-wrap: wrap;">No website watches configured, please add a URL in the box above, or <a href="{{ url_for('imports.import_page')}}" >import a list</a>.</td>
+                <td colspan="{{ cols_required }}" style="text-wrap: wrap;">{{ _('No website watches configured, please add a URL in the box above, or') }} <a href="{{ url_for('imports.import_page')}}" >{{ _('import a list') }}</a>.</td>
             </tr>
             {%- endif -%}
 
@@ -167,14 +181,14 @@ document.addEventListener('DOMContentLoaded', function() {
                             {% endif %}
                            <a class="external" target="_blank" rel="noopener" href="{{ watch.link.replace('source:','') }}">&nbsp;</a>
                         </span>
-                            <div class="error-text" style="display:none;">{{ watch.compile_error_texts(has_proxies=datastore.proxy_list) }}</div>
+                            <div class="error-text" style="display:none;">{{ watch.compile_error_texts(has_proxies=datastore.proxy_list)|safe }}</div>
                             {%- if watch['processor'] == 'text_json_diff'  -%}
                                 {%- if watch['has_ldjson_price_data'] and not watch['track_ldjson_price_data']  -%}
                                 <div class="ldjson-price-track-offer">Switch to Restock & Price watch mode? <a href="{{url_for('price_data_follower.accept', uuid=watch.uuid)}}" class="pure-button button-xsmall">Yes</a> <a href="{{url_for('price_data_follower.reject', uuid=watch.uuid)}}" class="">No</a></div>
                                 {%- endif -%}
                             {%- endif -%}
-                            {%- if watch['processor'] == 'restock_diff' -%}
-                                <span class="tracking-ldjson-price-data" title="Automatically following embedded price information"><img src="{{url_for('static_content', group='images', filename='price-tag-icon.svg')}}"  class="status-icon price-follow-tag-icon" > Price</span>
+                            {%- if watch['processor'] and watch['processor'] in processor_badge_texts -%}
+                                <span class="processor-badge processor-badge-{{ watch['processor'] }}" title="{{ processor_descriptions.get(watch['processor'], watch['processor']) }}">{{ processor_badge_texts[watch['processor']] }}</span>
                             {%- endif -%}
                             {%- for watch_tag_uuid, watch_tag in datastore.get_all_tags_for_watch(watch['uuid']).items() -%}
                               <span class="watch-tag-list">{{ watch_tag.title }}</span>
@@ -182,11 +196,9 @@ document.addEventListener('DOMContentLoaded', function() {
                         </div>
                     <div class="status-icons">
                             <a class="link-spread" href="{{url_for('ui.form_share_put_watch', uuid=watch.uuid)}}"><img src="{{url_for('static_content', group='images', filename='spread.svg')}}" class="status-icon icon icon-spread" title="Create a link to share watch config with others" ></a>
-                            {%- if watch.get_fetch_backend == "html_webdriver"
-                                 or ( watch.get_fetch_backend == "system" and system_default_fetcher == 'html_webdriver'  )
-                                 or "extra_browser_" in watch.get_fetch_backend
-                            -%}
-                            <img class="status-icon" src="{{url_for('static_content', group='images', filename='google-chrome-icon.png')}}" alt="Using a Chrome browser" title="Using a Chrome browser" >
+                            {%- set effective_fetcher = watch.get_fetch_backend if watch.get_fetch_backend != "system" else system_default_fetcher -%}
+                            {%- if effective_fetcher and ("html_webdriver" in effective_fetcher or "html_" in effective_fetcher or "extra_browser_" in effective_fetcher) -%}
+                                {{ effective_fetcher|fetcher_status_icons }}
                             {%- endif -%}
                             {%- if watch.is_pdf  -%}<img class="status-icon" src="{{url_for('static_content', group='images', filename='pdf-icon.svg')}}" alt="Converting PDF to text" >{%- endif -%}
                             {%- if watch.has_browser_steps -%}<img class="status-icon status-browsersteps" src="{{url_for('static_content', group='images', filename='steps.svg')}}" alt="Browser Steps is enabled" >{%- endif -%}
@@ -198,20 +210,20 @@ document.addEventListener('DOMContentLoaded', function() {
                 <td class="restock-and-price">
                     {%- if watch['processor'] == 'restock_diff'  -%}
                         {%- if watch.has_restock_info -%}
-                            <span class="restock-label {{'in-stock' if watch['restock']['in_stock'] else 'not-in-stock' }}" title="Detecting restock and price">
+                            <span class="restock-label {{'in-stock' if watch['restock']['in_stock'] else 'not-in-stock' }}" title="{{ _('Detecting restock and price') }}">
                                 <!-- maybe some object watch['processor'][restock_diff] or.. -->
-                                 {%- if watch['restock']['in_stock']-%}  In stock {%- else-%}  Not in stock {%- endif -%}
+                                 {%- if watch['restock']['in_stock']-%}  {{ _('In stock') }} {%- else-%}  {{ _('Not in stock') }} {%- endif -%}
                             </span>
                         {%- endif -%}
 
                         {%- if watch.get('restock') and watch['restock']['price'] != None -%}
                             {%- if watch['restock']['price'] != None -%}
-                                <span class="restock-label price" title="Price">
-                                {{ watch['restock']['price']|format_number_locale }} {{ watch['restock']['currency'] }}
+                                <span class="restock-label price" title="{{ _('Price') }}">
+                                {{ watch['restock']['price']|format_number_locale if watch['restock'].get('price') else '' }} {{ watch['restock'].get('currency','') }}
                                 </span>
                             {%- endif -%}
                         {%- elif not watch.has_restock_info -%}
-                            <span class="restock-label error">No information</span>
+                            <span class="restock-label error">{{ _('No information') }}</span>
                         {%- endif -%}
                     {%- endif -%}
                 </td>
@@ -219,24 +231,24 @@ document.addEventListener('DOMContentLoaded', function() {
             {#last_checked becomes fetch-start-time#}
                 <td class="last-checked" data-timestamp="{{ watch.last_checked }}" data-fetchduration={{ watch.fetch_time }} data-eta_complete="{{ watch.last_checked+watch.fetch_time }}" >
                     <div class="spinner-wrapper" style="display:none;" >
-                        <span class="spinner"></span><span>&nbsp;Checking now</span>
+                        <span class="spinner"></span><span class="status-text">&nbsp;{{ _('Checking now') }}</span>
                     </div>
                     <span class="innertext">{{watch|format_last_checked_time|safe}}</span>
                 </td>
                 <td class="last-changed" data-timestamp="{{ watch.last_changed }}">{%- if watch.history_n >=2 and watch.last_changed >0 -%}
                     {{watch.last_changed|format_timestamp_timeago}}
                     {%- else -%}
-                    Not yet
+                    {{ _('Not yet') }}
                     {%- endif -%}
                 </td>
                 <td class="buttons">
                     <div>
                     {%- set target_attr = ' target="' ~ watch.uuid ~ '"' if datastore.data['settings']['application']['ui'].get('open_diff_in_new_tab') else '' -%}
-                    <a href="" class="already-in-queue-button recheck pure-button pure-button-primary" style="display: none;" disabled="disabled">Queued</a>
-                    <a href="{{ url_for('ui.form_watch_checknow', uuid=watch.uuid, tag=request.args.get('tag')) }}" data-op='recheck' class="ajax-op recheck pure-button pure-button-primary">Recheck</a>
-                    <a href="{{ url_for('ui.ui_edit.edit_page', uuid=watch.uuid, tag=active_tag_uuid)}}#general" class="pure-button pure-button-primary">Edit</a>
-                    <a href="{{ url_for('ui.ui_views.diff_history_page', uuid=watch.uuid)}}" {{target_attr}} class="pure-button pure-button-primary history-link" style="display: none;">History</a>
-                    <a href="{{ url_for('ui.ui_views.preview_page', uuid=watch.uuid)}}" {{target_attr}} class="pure-button pure-button-primary preview-link" style="display: none;">Preview</a>
+                    <a href="" class="already-in-queue-button recheck pure-button pure-button-primary" style="display: none;" disabled="disabled">{{ _('Queued') }}</a>
+                    <a href="{{ url_for('ui.form_watch_checknow', uuid=watch.uuid, tag=request.args.get('tag')) }}" data-op='recheck' class="ajax-op recheck pure-button pure-button-primary">{{ _('Recheck') }}</a>
+                    <a href="{{ url_for('ui.ui_edit.edit_page', uuid=watch.uuid, tag=active_tag_uuid)}}#general" class="pure-button pure-button-primary">{{ _('Edit') }}</a>
+                    <a href="{{ url_for('ui.ui_diff.diff_history_page', uuid=watch.uuid)}}" {{target_attr}} class="pure-button pure-button-primary history-link" style="display: none;">{{ _('History') }}</a>
+                    <a href="{{ url_for('ui.ui_preview.preview_page', uuid=watch.uuid)}}" {{target_attr}} class="pure-button pure-button-primary preview-link" style="display: none;">{{ _('Preview') }}</a>
                     </div>
                 </td>
             </tr>
@@ -245,22 +257,21 @@ document.addEventListener('DOMContentLoaded', function() {
         </table>
         <ul id="post-list-buttons">
             <li id="post-list-with-errors" style="display: none;" >
-                <a href="{{url_for('watchlist.index', with_errors=1, tag=request.args.get('tag')) }}" class="pure-button button-tag button-error">With errors ({{ errored_count }})</a>
+                <a href="{{url_for('watchlist.index', with_errors=1, tag=request.args.get('tag')) }}" class="pure-button button-tag button-error">{{ _('With errors') }} ({{ errored_count }})</a>
             </li>
             <li id="post-list-mark-views" style="display: none;" >
-                <a href="{{url_for('ui.mark_all_viewed',with_errors=request.args.get('with_errors',0)) }}" class="pure-button button-tag " id="mark-all-viewed">Mark all viewed</a>
+                <a href="{{url_for('ui.mark_all_viewed',with_errors=request.args.get('with_errors',0)) }}" class="pure-button button-tag " id="mark-all-viewed">{{ _('Mark all viewed') }}</a>
             </li>
         {%-  if active_tag_uuid -%}
             <li id="post-list-mark-views-tag">
-                <a href="{{url_for('ui.mark_all_viewed', tag=active_tag_uuid) }}" class="pure-button button-tag " id="mark-all-viewed">Mark all viewed in '{{active_tag.title}}'</a>
+                <a href="{{url_for('ui.mark_all_viewed', tag=active_tag_uuid) }}" class="pure-button button-tag " id="mark-all-viewed">{{ _("Mark all viewed in '%(title)s'", title=active_tag.title) }}</a>
             </li>
         {%-  endif -%}
             <li id="post-list-unread" style="display: none;" >
-                <a href="{{url_for('watchlist.index', unread=1, tag=request.args.get('tag')) }}" class="pure-button button-tag">Unread (<span id="unread-tab-counter">{{ unread_changes_count }}</span>)</a>
+                <a href="{{url_for('watchlist.index', unread=1, tag=request.args.get('tag')) }}" class="pure-button button-tag">{{ _('Unread') }} (<span id="unread-tab-counter">{{ unread_changes_count }}</span>)</a>
             </li>
             <li>
-               <a href="{{ url_for('ui.form_watch_checknow', tag=active_tag_uuid, with_errors=request.args.get('with_errors',0)) }}" class="pure-button button-tag" id="recheck-all">Recheck
-                all {% if active_tag_uuid %}  in '{{active_tag.title}}'{%endif%}</a>
+               <a href="{{ url_for('ui.form_watch_checknow', tag=active_tag_uuid, with_errors=request.args.get('with_errors',0)) }}" class="pure-button button-tag" id="recheck-all">{{ _('Recheck all') }} {% if active_tag_uuid %}  {{ _("in '%(title)s'", title=active_tag.title) }}{%endif%}</a>
             </li>
             <li>
                 <a href="{{ url_for('rss.feed', tag=active_tag_uuid, token=app_rss_token)}}"><img alt="RSS Feed" id="feed-icon" src="{{url_for('static_content', group='images', filename='generic_feed-icon.svg')}}" height="15"></a>

changedetectionio/conditions/plugins/levenshtein_plugin.py

@@ -1,3 +1,7 @@
+"""
+Levenshtein distance and similarity plugin for text change detection.
+Provides metrics for measuring text similarity between snapshots.
+"""
 import pluggy
 from loguru import logger
 

changedetectionio/conditions/plugins/wordcount_plugin.py

@@ -1,3 +1,7 @@
+"""
+Word count plugin for content analysis.
+Provides word count metrics for snapshot content.
+"""
 import pluggy
 from loguru import logger
 
@@ -14,7 +18,7 @@ def count_words_in_history(watch, incoming_text=None):
         elif watch.history.keys():
             # When called from UI extras to count latest snapshot
             latest_key = list(watch.history.keys())[-1]
-            latest_content = watch.get_history_snapshot(latest_key)
+            latest_content = watch.get_history_snapshot(timestamp=latest_key)
             return len(latest_content.split())
         return 0
     except Exception as e:

changedetectionio/content_fetchers/__init__.py

@@ -7,6 +7,9 @@ import os
 # Visual Selector scraper - 'Button' is there because some sites have <button>OUT OF STOCK</button>.
 visualselector_xpath_selectors = 'div,span,form,table,tbody,tr,td,a,p,ul,li,h1,h2,h3,h4,header,footer,section,article,aside,details,main,nav,section,summary,button'
 
+# Import hookimpl from centralized pluggy interface
+from changedetectionio.pluggy_interface import hookimpl
+
 SCREENSHOT_MAX_HEIGHT_DEFAULT = 20000
 SCREENSHOT_DEFAULT_QUALITY = 40
 
@@ -18,7 +21,9 @@ SCREENSHOT_MAX_TOTAL_HEIGHT = int(os.getenv("SCREENSHOT_MAX_HEIGHT", SCREENSHOT_
 # The size at which we will switch to stitching method, when below this (and
 # MAX_TOTAL_HEIGHT which can be set by a user) we will use the default
 # screenshot method.
-SCREENSHOT_SIZE_STITCH_THRESHOLD = 8000
+# Increased from 8000 to 10000 for better performance (fewer chunks = faster)
+# Most modern GPUs support 16384x16384 textures, so 1280x10000 is safe
+SCREENSHOT_SIZE_STITCH_THRESHOLD = int(os.getenv("SCREENSHOT_CHUNK_HEIGHT", 10000))
 
 # available_fetchers() will scan this implementation looking for anything starting with html_
 # this information is used in the form selections
@@ -35,17 +40,54 @@ def available_fetchers():
     # See the if statement at the bottom of this file for how we switch between playwright and webdriver
     import inspect
     p = []
+
+    # Get built-in fetchers (but skip plugin fetchers that were added via setattr)
     for name, obj in inspect.getmembers(sys.modules[__name__], inspect.isclass):
         if inspect.isclass(obj):
             # @todo html_ is maybe better as fetcher_ or something
             # In this case, make sure to edit the default one in store.py and fetch_site_status.py
             if name.startswith('html_'):
-                t = tuple([name, obj.fetcher_description])
-                p.append(t)
+                # Skip plugin fetchers that were already registered
+                if name not in _plugin_fetchers:
+                    t = tuple([name, obj.fetcher_description])
+                    p.append(t)
+
+    # Get plugin fetchers from cache (already loaded at module init)
+    for name, fetcher_class in _plugin_fetchers.items():
+        if hasattr(fetcher_class, 'fetcher_description'):
+            t = tuple([name, fetcher_class.fetcher_description])
+            p.append(t)
+        else:
+            logger.warning(f"Plugin fetcher '{name}' does not have fetcher_description attribute")
 
     return p
 
 
+def get_plugin_fetchers():
+    """Load and return all plugin fetchers from the centralized plugin manager."""
+    from changedetectionio.pluggy_interface import plugin_manager
+
+    fetchers = {}
+    try:
+        # Call the register_content_fetcher hook from all registered plugins
+        results = plugin_manager.hook.register_content_fetcher()
+        for result in results:
+            if result:
+                name, fetcher_class = result
+                fetchers[name] = fetcher_class
+                # Register in current module so hasattr() checks work
+                setattr(sys.modules[__name__], name, fetcher_class)
+                logger.info(f"Registered plugin fetcher: {name} - {getattr(fetcher_class, 'fetcher_description', 'No description')}")
+    except Exception as e:
+        logger.error(f"Error loading plugin fetchers: {e}")
+
+    return fetchers
+
+
+# Initialize plugins at module load time
+_plugin_fetchers = get_plugin_fetchers()
+
+
 # Decide which is the 'real' HTML webdriver, this is more a system wide config
 # rather than site-specific.
 use_playwright_as_chrome_fetcher = os.getenv('PLAYWRIGHT_DRIVER_URL', False)
@@ -62,3 +104,8 @@ else:
     logger.debug("Falling back to selenium as fetcher")
     from .webdriver_selenium import fetcher as html_webdriver
 
+
+# Register built-in fetchers as plugins after all imports are complete
+from changedetectionio.pluggy_interface import register_builtin_fetchers
+register_builtin_fetchers()
+

changedetectionio/content_fetchers/base.py

@@ -51,6 +51,7 @@ class Fetcher():
     favicon_blob = None
     instock_data = None
     instock_data_js = ""
+    screenshot_format = None
     status_code = None
     webdriver_js_execute_code = None
     xpath_data = None
@@ -64,6 +65,47 @@ class Fetcher():
     # Time ONTOP of the system defined env minimum time
     render_extract_delay = 0
 
+    # Fetcher capability flags - subclasses should override these
+    # These indicate what features the fetcher supports
+    supports_browser_steps = False      # Can execute browser automation steps
+    supports_screenshots = False        # Can capture page screenshots
+    supports_xpath_element_data = False # Can extract xpath element positions/data for visual selector
+
+    def __init__(self, **kwargs):
+        if kwargs and 'screenshot_format' in kwargs:
+            self.screenshot_format = kwargs.get('screenshot_format')
+
+
+    @classmethod
+    def get_status_icon_data(cls):
+        """Return data for status icon to display in the watch overview.
+
+        This method can be overridden by subclasses to provide custom status icons.
+
+        Returns:
+            dict or None: Dictionary with icon data:
+                {
+                    'filename': 'icon-name.svg',  # Icon filename
+                    'alt': 'Alt text',            # Alt attribute
+                    'title': 'Tooltip text',      # Title attribute
+                    'style': 'height: 1em;'       # Optional inline CSS
+                }
+                Or None if no icon
+        """
+        return None
+
+    def clear_content(self):
+        """
+        Explicitly clear all content from memory to free up heap space.
+        Call this after content has been saved to disk.
+        """
+        self.content = None
+        if hasattr(self, 'raw_content'):
+            self.raw_content = None
+        self.screenshot = None
+        self.xpath_data = None
+        # Keep headers and status_code as they're small
+
     @abstractmethod
     def get_error(self):
         return self.error
@@ -80,12 +122,13 @@ class Fetcher():
                   request_method=None,
                   timeout=None,
                   url=None,
+                  watch_uuid=None,
                   ):
         # Should set self.error, self.status_code and self.content
         pass
 
     @abstractmethod
-    def quit(self, watch=None):
+    async def quit(self, watch=None):
         return
 
     @abstractmethod
@@ -128,7 +171,7 @@ class Fetcher():
     async def iterate_browser_steps(self, start_url=None):
         from changedetectionio.blueprint.browser_steps.browser_steps import steppable_browser_interface
         from playwright._impl._errors import TimeoutError, Error
-        from changedetectionio.safe_jinja import render as jinja_render
+        from changedetectionio.jinja2_custom import render as jinja_render
         step_n = 0
 
         if self.browser_steps is not None and len(self.browser_steps):

changedetectionio/content_fetchers/playwright.py

@@ -9,10 +9,10 @@ from changedetectionio.content_fetchers import SCREENSHOT_MAX_HEIGHT_DEFAULT, vi
 from changedetectionio.content_fetchers.base import Fetcher, manage_user_agent
 from changedetectionio.content_fetchers.exceptions import PageUnloadable, Non200ErrorCodeReceived, EmptyReply, ScreenshotUnavailable
 
-async def capture_full_page_async(page):
+async def capture_full_page_async(page, screenshot_format='JPEG'):
     import os
     import time
-    from multiprocessing import Process, Pipe
+    import multiprocessing
 
     start = time.time()
 
@@ -26,8 +26,20 @@ async def capture_full_page_async(page):
     step_size = SCREENSHOT_SIZE_STITCH_THRESHOLD # Size that won't cause GPU to overflow
     screenshot_chunks = []
     y = 0
+    elements_locked = False
 
     if page_height > page.viewport_size['height']:
+
+        # Lock all element dimensions BEFORE screenshot to prevent CSS media queries from resizing
+        # capture_full_page_async() changes viewport height which triggers @media (min-height) rules
+        lock_elements_js_path = os.path.join(os.path.dirname(__file__), 'res', 'lock-elements-sizing.js')
+        with open(lock_elements_js_path, 'r') as f:
+            lock_elements_js = f.read()
+        await page.evaluate(lock_elements_js)
+        elements_locked = True
+
+        logger.debug("Element dimensions locked before screenshot capture")
+
         if page_height < step_size:
             step_size = page_height # Incase page is bigger than default viewport but smaller than proposed step size
         logger.debug(f"Setting bigger viewport to step through large page width W{page.viewport_size['width']}xH{step_size} because page_height > viewport_size")
@@ -35,36 +47,68 @@ async def capture_full_page_async(page):
         await page.set_viewport_size({'width': page.viewport_size['width'], 'height': step_size})
 
     # Capture screenshots in chunks up to the max total height
+    # Use PNG for better quality (no compression artifacts), JPEG for smaller size
+    screenshot_type = screenshot_format.lower() if screenshot_format else 'jpeg'
+    # PNG should use quality 100, JPEG uses configurable quality
+    screenshot_quality = 100 if screenshot_type == 'png' else int(os.getenv("SCREENSHOT_QUALITY", 72))
+
     while y < min(page_height, SCREENSHOT_MAX_TOTAL_HEIGHT):
+        # Only scroll if not at the top (y > 0)
+        if y > 0:
+            await page.evaluate(f"window.scrollTo(0, {y})")
+
+        # Request GC only before screenshot (not 3x per chunk)
         await page.request_gc()
-        await page.evaluate(f"window.scrollTo(0, {y})")
-        await page.request_gc()
-        screenshot_chunks.append(await page.screenshot(
-            type="jpeg",
-            full_page=False,
-            quality=int(os.getenv("SCREENSHOT_QUALITY", 72))
-        ))
+
+        screenshot_kwargs = {
+            'type': screenshot_type,
+            'full_page': False
+        }
+        # Only pass quality parameter for jpeg (PNG doesn't support it in Playwright)
+        if screenshot_type == 'jpeg':
+            screenshot_kwargs['quality'] = screenshot_quality
+
+        screenshot_chunks.append(await page.screenshot(**screenshot_kwargs))
         y += step_size
-        await page.request_gc()
 
     # Restore original viewport size
     await page.set_viewport_size({'width': original_viewport['width'], 'height': original_viewport['height']})
 
+    # Unlock element dimensions if they were locked
+    if elements_locked:
+        unlock_elements_js_path = os.path.join(os.path.dirname(__file__), 'res', 'unlock-elements-sizing.js')
+        with open(unlock_elements_js_path, 'r') as f:
+            unlock_elements_js = f.read()
+        await page.evaluate(unlock_elements_js)
+        logger.debug("Element dimensions unlocked after screenshot capture")
+
     # If we have multiple chunks, stitch them together
     if len(screenshot_chunks) > 1:
-        from changedetectionio.content_fetchers.screenshot_handler import stitch_images_worker
         logger.debug(f"Screenshot stitching {len(screenshot_chunks)} chunks together")
-        parent_conn, child_conn = Pipe()
-        p = Process(target=stitch_images_worker, args=(child_conn, screenshot_chunks, page_height, SCREENSHOT_MAX_TOTAL_HEIGHT))
-        p.start()
-        screenshot = parent_conn.recv_bytes()
-        p.join()
+
+        # For small number of chunks (2-3), stitch inline to avoid multiprocessing overhead
+        # Only use separate process for many chunks (4+) to avoid blocking the event loop
+        if len(screenshot_chunks) <= 3:
+            from changedetectionio.content_fetchers.screenshot_handler import stitch_images_inline
+            screenshot = stitch_images_inline(screenshot_chunks, page_height, SCREENSHOT_MAX_TOTAL_HEIGHT)
+        else:
+            # Use separate process for many chunks to avoid blocking
+            # Always use spawn for thread safety - consistent behavior in tests and production
+            from changedetectionio.content_fetchers.screenshot_handler import stitch_images_worker
+            ctx = multiprocessing.get_context('spawn')
+            parent_conn, child_conn = ctx.Pipe()
+            p = ctx.Process(target=stitch_images_worker, args=(child_conn, screenshot_chunks, page_height, SCREENSHOT_MAX_TOTAL_HEIGHT))
+            p.start()
+            screenshot = parent_conn.recv_bytes()
+            p.join()
+            # Explicit cleanup
+            del p
+            del parent_conn, child_conn
+
         logger.debug(
             f"Screenshot (chunked/stitched) - Page height: {page_height} Capture height: {SCREENSHOT_MAX_TOTAL_HEIGHT} - Stitched together in {time.time() - start:.2f}s")
         # Explicit cleanup
         del screenshot_chunks
-        del p
-        del parent_conn, child_conn
         screenshot_chunks = None
         return screenshot
 
@@ -89,8 +133,22 @@ class fetcher(Fetcher):
 
     proxy = None
 
-    def __init__(self, proxy_override=None, custom_browser_connection_url=None):
-        super().__init__()
+    # Capability flags
+    supports_browser_steps = True
+    supports_screenshots = True
+    supports_xpath_element_data = True
+
+    @classmethod
+    def get_status_icon_data(cls):
+        """Return Chrome browser icon data for Playwright fetcher."""
+        return {
+            'filename': 'google-chrome-icon.png',
+            'alt': 'Using a Chrome browser',
+            'title': 'Using a Chrome browser'
+        }
+
+    def __init__(self, proxy_override=None, custom_browser_connection_url=None, **kwargs):
+        super().__init__(**kwargs)
 
         self.browser_type = os.getenv("PLAYWRIGHT_BROWSER_TYPE", 'chromium').strip('"')
 
@@ -125,7 +183,7 @@ class fetcher(Fetcher):
 
     async def screenshot_step(self, step_n=''):
         super().screenshot_step(step_n=step_n)
-        screenshot = await capture_full_page_async(page=self.page)
+        screenshot = await capture_full_page_async(page=self.page, screenshot_format=self.screenshot_format)
 
 
         if self.browser_steps_screenshot_path is not None:
@@ -139,7 +197,7 @@ class fetcher(Fetcher):
         content = await self.page.content()
         destination = os.path.join(self.browser_steps_screenshot_path, 'step_{}.html'.format(step_n))
         logger.debug(f"Saving step HTML to {destination}")
-        with open(destination, 'w') as f:
+        with open(destination, 'w', encoding='utf-8') as f:
             f.write(content)
 
     async def run(self,
@@ -151,8 +209,10 @@ class fetcher(Fetcher):
                   request_body=None,
                   request_headers=None,
                   request_method=None,
+                  screenshot_format=None,
                   timeout=None,
                   url=None,
+                  watch_uuid=None,
                   ):
 
         from playwright.async_api import async_playwright
@@ -244,7 +304,7 @@ class fetcher(Fetcher):
                     logger.error(f"Error fetching FavIcon info {str(e)}, continuing.")
 
             if self.status_code != 200 and not ignore_status_codes:
-                screenshot = await capture_full_page_async(self.page)
+                screenshot = await capture_full_page_async(self.page, screenshot_format=self.screenshot_format)
                 raise Non200ErrorCodeReceived(url=url, status_code=self.status_code, screenshot=screenshot)
 
             if not empty_pages_are_a_change and len((await self.page.content()).strip()) == 0:
@@ -293,7 +353,7 @@ class fetcher(Fetcher):
             # acceptable screenshot quality here
             try:
                 # The actual screenshot - this always base64 and needs decoding! horrible! huge CPU usage
-                self.screenshot = await capture_full_page_async(page=self.page)
+                self.screenshot = await capture_full_page_async(page=self.page, screenshot_format=self.screenshot_format)
 
             except Exception as e:
                 # It's likely the screenshot was too long/big and something crashed
@@ -330,4 +390,17 @@ class fetcher(Fetcher):
                 browser = None
 
 
+# Plugin registration for built-in fetcher
+class PlaywrightFetcherPlugin:
+    """Plugin class that registers the Playwright fetcher as a built-in plugin."""
+
+    def register_content_fetcher(self):
+        """Register the Playwright fetcher"""
+        return ('html_webdriver', fetcher)
+
+
+# Create module-level instance for plugin registration
+playwright_plugin = PlaywrightFetcherPlugin()
+
+
 

changedetectionio/content_fetchers/puppeteer.py

@@ -20,10 +20,10 @@ from changedetectionio.content_fetchers.exceptions import PageUnloadable, Non200
 # Screenshots also travel via the ws:// (websocket) meaning that the binary data is base64 encoded
 # which will significantly increase the IO size between the server and client, it's recommended to use the lowest
 # acceptable screenshot quality here
-async def capture_full_page(page):
+async def capture_full_page(page, screenshot_format='JPEG'):
     import os
     import time
-    from multiprocessing import Process, Pipe
+    import multiprocessing
 
     start = time.time()
 
@@ -41,11 +41,25 @@ async def capture_full_page(page):
     # which will significantly increase the IO size between the server and client, it's recommended to use the lowest
     # acceptable screenshot quality here
 
+    # Use PNG for better quality (no compression artifacts), JPEG for smaller size
+    screenshot_type = screenshot_format.lower() if screenshot_format else 'jpeg'
+    # PNG should use quality 100, JPEG uses configurable quality
+    screenshot_quality = 100 if screenshot_type == 'png' else int(os.getenv("SCREENSHOT_QUALITY", 72))
 
     step_size = SCREENSHOT_SIZE_STITCH_THRESHOLD # Something that will not cause the GPU to overflow when taking the screenshot
     screenshot_chunks = []
     y = 0
+    elements_locked = False
     if page_height > page.viewport['height']:
+        # Lock all element dimensions BEFORE screenshot to prevent CSS media queries from resizing
+        # capture_full_page() changes viewport height which triggers @media (min-height) rules
+        lock_elements_js_path = os.path.join(os.path.dirname(__file__), 'res', 'lock-elements-sizing.js')
+        with open(lock_elements_js_path, 'r') as f:
+            lock_elements_js = f.read()
+        await page.evaluate(lock_elements_js)
+        elements_locked = True
+        logger.debug("Element dimensions locked before screenshot capture")
+
         if page_height < step_size:
             step_size = page_height # Incase page is bigger than default viewport but smaller than proposed step size
         await page.setViewport({'width': page.viewport['width'], 'height': step_size})
@@ -60,18 +74,34 @@ async def capture_full_page(page):
             y
         )
 
-        screenshot_chunks.append(await page.screenshot(type_='jpeg',
-                                                       fullPage=False,
-                                                       quality=int(os.getenv("SCREENSHOT_QUALITY", 72))))
+        screenshot_kwargs = {
+            'type_': screenshot_type,
+            'fullPage': False
+        }
+        # PNG doesn't support quality parameter in Puppeteer
+        if screenshot_type == 'jpeg':
+            screenshot_kwargs['quality'] = screenshot_quality
+
+        screenshot_chunks.append(await page.screenshot(**screenshot_kwargs))
         y += step_size
 
     await page.setViewport({'width': original_viewport['width'], 'height': original_viewport['height']})
 
+    # Unlock element dimensions if they were locked
+    if elements_locked:
+        unlock_elements_js_path = os.path.join(os.path.dirname(__file__), 'res', 'unlock-elements-sizing.js')
+        with open(unlock_elements_js_path, 'r') as f:
+            unlock_elements_js = f.read()
+        await page.evaluate(unlock_elements_js)
+        logger.debug("Element dimensions unlocked after screenshot capture")
+
     if len(screenshot_chunks) > 1:
+        # Always use spawn for thread safety - consistent behavior in tests and production
         from changedetectionio.content_fetchers.screenshot_handler import stitch_images_worker
         logger.debug(f"Screenshot stitching {len(screenshot_chunks)} chunks together")
-        parent_conn, child_conn = Pipe()
-        p = Process(target=stitch_images_worker, args=(child_conn, screenshot_chunks, page_height, SCREENSHOT_MAX_TOTAL_HEIGHT))
+        ctx = multiprocessing.get_context('spawn')
+        parent_conn, child_conn = ctx.Pipe()
+        p = ctx.Process(target=stitch_images_worker, args=(child_conn, screenshot_chunks, page_height, SCREENSHOT_MAX_TOTAL_HEIGHT))
         p.start()
         screenshot = parent_conn.recv_bytes()
         p.join()
@@ -93,13 +123,27 @@ class fetcher(Fetcher):
     if os.getenv("PLAYWRIGHT_DRIVER_URL"):
         fetcher_description += " via '{}'".format(os.getenv("PLAYWRIGHT_DRIVER_URL"))
 
+    browser = None
     browser_type = ''
     command_executor = ''
-
     proxy = None
 
-    def __init__(self, proxy_override=None, custom_browser_connection_url=None):
-        super().__init__()
+    # Capability flags
+    supports_browser_steps = True
+    supports_screenshots = True
+    supports_xpath_element_data = True
+
+    @classmethod
+    def get_status_icon_data(cls):
+        """Return Chrome browser icon data for Puppeteer fetcher."""
+        return {
+            'filename': 'google-chrome-icon.png',
+            'alt': 'Using a Chrome browser',
+            'title': 'Using a Chrome browser'
+        }
+
+    def __init__(self, proxy_override=None, custom_browser_connection_url=None, **kwargs):
+        super().__init__(**kwargs)
 
         if custom_browser_connection_url:
             self.browser_connection_is_custom = True
@@ -128,21 +172,20 @@ class fetcher(Fetcher):
                 proxy_url += f"{parsed.hostname}{port}{parsed.path}{q}"
                 self.browser_connection_url += f"{r}--proxy-server={proxy_url}"
 
-    # def screenshot_step(self, step_n=''):
-    #     screenshot = self.page.screenshot(type='jpeg', full_page=True, quality=85)
-    #
-    #     if self.browser_steps_screenshot_path is not None:
-    #         destination = os.path.join(self.browser_steps_screenshot_path, 'step_{}.jpeg'.format(step_n))
-    #         logger.debug(f"Saving step screenshot to {destination}")
-    #         with open(destination, 'wb') as f:
-    #             f.write(screenshot)
-    #
-    # def save_step_html(self, step_n):
-    #     content = self.page.content()
-    #     destination = os.path.join(self.browser_steps_screenshot_path, 'step_{}.html'.format(step_n))
-    #     logger.debug(f"Saving step HTML to {destination}")
-    #     with open(destination, 'w') as f:
-    #         f.write(content)
+    async def quit(self, watch=None):
+        try:
+            await self.page.close()
+            del self.page
+        except Exception as e:
+            pass
+
+        try:
+            await self.browser.close()
+            del self.browser
+        except Exception as e:
+            pass
+
+        logger.info("Cleanup puppeteer complete.")
 
     async def fetch_page(self,
                          current_include_filters,
@@ -153,8 +196,10 @@ class fetcher(Fetcher):
                          request_body,
                          request_headers,
                          request_method,
+                         screenshot_format,
                          timeout,
                          url,
+                         watch_uuid
                          ):
         import re
         self.delete_browser_steps_screenshots()
@@ -170,9 +215,9 @@ class fetcher(Fetcher):
         # Connect directly using the specified browser_ws_endpoint
         # @todo timeout
         try:
-            browser = await pyppeteer_instance.connect(browserWSEndpoint=self.browser_connection_url,
-                                                       ignoreHTTPSErrors=True
-                                                       )
+            self.browser = await pyppeteer_instance.connect(browserWSEndpoint=self.browser_connection_url,
+                                                            ignoreHTTPSErrors=True
+                                                            )
         except websockets.exceptions.InvalidStatusCode as e:
             raise BrowserConnectError(msg=f"Error while trying to connect the browser, Code {e.status_code} (check your access, whitelist IP, password etc)")
         except websockets.exceptions.InvalidURI:
@@ -181,7 +226,7 @@ class fetcher(Fetcher):
             raise BrowserConnectError(msg=f"Error connecting to the browser - Exception '{str(e)}'")
 
         # more reliable is to just request a new page
-        self.page = await browser.newPage()
+        self.page = await self.browser.newPage()
         
         # Add console handler to capture console.log from favicon fetcher
         #self.page.on('console', lambda msg: logger.debug(f"Browser console [{msg.type}]: {msg.text}"))
@@ -196,7 +241,6 @@ class fetcher(Fetcher):
                     "height": int(match.group(2))
                 })
                 logger.debug(f"Puppeteer viewport size {self.page.viewport}")
-
         try:
             from pyppeteerstealth import inject_evasions_into_page
         except ImportError:
@@ -241,33 +285,47 @@ class fetcher(Fetcher):
         #            browsersteps_interface = steppable_browser_interface()
         #            browsersteps_interface.page = self.page
 
-        async def handle_frame_navigation(event):
-            logger.debug(f"Frame navigated: {event}")
-            w = extra_wait - 2 if extra_wait > 4 else 2
-            logger.debug(f"Waiting {w} seconds before calling Page.stopLoading...")
-            await asyncio.sleep(w)
-            logger.debug("Issuing stopLoading command...")
-            await self.page._client.send('Page.stopLoading')
-            logger.debug("stopLoading command sent!")
+        # Enable Network domain to detect when first bytes arrive
+        await self.page._client.send('Network.enable')
 
-        self.page._client.on('Page.frameStartedNavigating', lambda event: asyncio.create_task(handle_frame_navigation(event)))
-        self.page._client.on('Page.frameStartedLoading', lambda event: asyncio.create_task(handle_frame_navigation(event)))
-        self.page._client.on('Page.frameStoppedLoading', lambda event: logger.debug(f"Frame stopped loading: {event}"))
+        async def setup_frame_handlers_on_first_response(event):
+            # Only trigger for the main document response
+            if event.get('type') == 'Document':
+                logger.debug("First response received, setting up frame handlers for forced page stop load.")
+
+                # De-register this listener - we only need it once
+                self.page._client.remove_listener('Network.responseReceived', setup_frame_handlers_on_first_response)
+
+                # Now set up the frame navigation handlers
+                async def handle_frame_navigation(event):
+                    # Wait n seconds after the frameStartedLoading, not from any frameStartedLoading/frameStartedNavigating
+                    logger.debug(f"Frame navigated: {event}")
+                    w = extra_wait - 2 if extra_wait > 4 else 2
+                    logger.debug(f"Waiting {w} seconds before calling Page.stopLoading...")
+                    await asyncio.sleep(w)
+                    logger.debug("Issuing stopLoading command...")
+                    await self.page._client.send('Page.stopLoading')
+                    logger.debug("stopLoading command sent!")
+
+                self.page._client.on('Page.frameStartedNavigating', lambda e: asyncio.create_task(handle_frame_navigation(e)))
+                self.page._client.on('Page.frameStartedLoading', lambda e: asyncio.create_task(handle_frame_navigation(e)))
+                self.page._client.on('Page.frameStoppedLoading', lambda e: logger.debug(f"Frame stopped loading: {e}"))
+
+        # Listen for first response to trigger frame handler setup
+        self.page._client.on('Network.responseReceived', setup_frame_handlers_on_first_response)
 
         response = None
         attempt=0
         while not response:
             logger.debug(f"Attempting page fetch {url} attempt {attempt}")
-            response = await self.page.goto(url)
+            response = await self.page.goto(url, timeout=0)
             await asyncio.sleep(1 + extra_wait)
             if response:
                 break
             if not response:
                 logger.warning("Page did not fetch! trying again!")
             if response is None and attempt>=2:
-                await self.page.close()
-                await browser.close()
-                logger.warning(f"Content Fetcher > Response object was none (as in, the response from the browser was empty, not just the content) exiting attmpt {attempt}")
+                logger.warning(f"Content Fetcher > Response object was none (as in, the response from the browser was empty, not just the content) exiting attempt {attempt}")
                 raise EmptyReply(url=url, status_code=None)
             attempt+=1
 
@@ -279,8 +337,6 @@ class fetcher(Fetcher):
         except Exception as e:
             logger.warning("Got exception when running evaluate on custom JS code")
             logger.error(str(e))
-            await self.page.close()
-            await browser.close()
             # This can be ok, we will try to grab what we could retrieve
             raise PageUnloadable(url=url, status_code=None, message=str(e))
 
@@ -290,8 +346,6 @@ class fetcher(Fetcher):
             # https://github.com/dgtlmoon/changedetection.io/discussions/2122#discussioncomment-8241962
             logger.critical(f"Response from the browser/Playwright did not have a status_code! Response follows.")
             logger.critical(response)
-            await self.page.close()
-            await browser.close()
             raise PageUnloadable(url=url, status_code=None, message=str(e))
 
         if fetch_favicon:
@@ -301,7 +355,7 @@ class fetcher(Fetcher):
                 logger.error(f"Error fetching FavIcon info {str(e)}, continuing.")
 
         if self.status_code != 200 and not ignore_status_codes:
-            screenshot = await capture_full_page(page=self.page)
+            screenshot = await capture_full_page(page=self.page, screenshot_format=self.screenshot_format)
 
             raise Non200ErrorCodeReceived(url=url, status_code=self.status_code, screenshot=screenshot)
 
@@ -309,8 +363,6 @@ class fetcher(Fetcher):
 
         if not empty_pages_are_a_change and len(content.strip()) == 0:
             logger.error("Content Fetcher > Content was empty (empty_pages_are_a_change is False), closing browsers")
-            await self.page.close()
-            await browser.close()
             raise EmptyReply(url=url, status_code=response.status)
 
         # Run Browser Steps here
@@ -328,6 +380,12 @@ class fetcher(Fetcher):
             await self.page.evaluate(f"var include_filters=''")
 
         MAX_TOTAL_HEIGHT = int(os.getenv("SCREENSHOT_MAX_HEIGHT", SCREENSHOT_MAX_HEIGHT_DEFAULT))
+
+        self.content = await self.page.content
+
+        # Now take screenshot (scrolling may trigger layout changes, but measurements are already captured)
+        logger.debug(f"Screenshot format {self.screenshot_format}")
+        self.screenshot = await capture_full_page(page=self.page, screenshot_format=self.screenshot_format)
         self.xpath_data = await self.page.evaluate(XPATH_ELEMENT_JS, {
             "visualselector_xpath_selectors": visualselector_xpath_selectors,
             "max_height": MAX_TOTAL_HEIGHT
@@ -335,17 +393,10 @@ class fetcher(Fetcher):
         if not self.xpath_data:
             raise Exception(f"Content Fetcher > xPath scraper failed. Please report this URL so we can fix it :)")
 
+
         self.instock_data = await self.page.evaluate(INSTOCK_DATA_JS)
 
-        self.content = await self.page.content
-
-        self.screenshot = await capture_full_page(page=self.page)
-
         # It's good to log here in the case that the browser crashes on shutting down but we still get the data we need
-        logger.success(f"Fetching '{url}' complete, closing page")
-        await self.page.close()
-        logger.success(f"Fetching '{url}' complete, closing browser")
-        await browser.close()
         logger.success(f"Fetching '{url}' complete, exiting puppeteer fetch.")
 
     async def main(self, **kwargs):
@@ -360,8 +411,10 @@ class fetcher(Fetcher):
                   request_body=None,
                   request_headers=None,
                   request_method=None,
+                  screenshot_format=None,
                   timeout=None,
                   url=None,
+                  watch_uuid=None,
                   ):
 
         #@todo make update_worker async which could run any of these content_fetchers within memory and time constraints
@@ -378,9 +431,24 @@ class fetcher(Fetcher):
                 request_body=request_body,
                 request_headers=request_headers,
                 request_method=request_method,
+                screenshot_format=None,
                 timeout=timeout,
                 url=url,
+                watch_uuid=watch_uuid,
             ), timeout=max_time
             )
         except asyncio.TimeoutError:
             raise (BrowserFetchTimedOut(msg=f"Browser connected but was unable to process the page in {max_time} seconds."))
+
+
+# Plugin registration for built-in fetcher
+class PuppeteerFetcherPlugin:
+    """Plugin class that registers the Puppeteer fetcher as a built-in plugin."""
+
+    def register_content_fetcher(self):
+        """Register the Puppeteer fetcher"""
+        return ('html_webdriver', fetcher)
+
+
+# Create module-level instance for plugin registration
+puppeteer_plugin = PuppeteerFetcherPlugin()

changedetectionio/content_fetchers/requests.py

@@ -1,7 +1,9 @@
 from loguru import logger
 import hashlib
 import os
+import re
 import asyncio
+from functools import partial
 from changedetectionio import strtobool
 from changedetectionio.content_fetchers.exceptions import BrowserStepsInUnsupportedFetcher, EmptyReply, Non200ErrorCodeReceived
 from changedetectionio.content_fetchers.base import Fetcher
@@ -11,8 +13,8 @@ from changedetectionio.content_fetchers.base import Fetcher
 class fetcher(Fetcher):
     fetcher_description = "Basic fast Plaintext/HTTP Client"
 
-    def __init__(self, proxy_override=None, custom_browser_connection_url=None):
-        super().__init__()
+    def __init__(self, proxy_override=None, custom_browser_connection_url=None, **kwargs):
+        super().__init__(**kwargs)
         self.proxy_override = proxy_override
         # browser_connection_url is none because its always 'launched locally'
 
@@ -25,7 +27,9 @@ class fetcher(Fetcher):
             ignore_status_codes=False,
             current_include_filters=None,
             is_binary=False,
-            empty_pages_are_a_change=False):
+            empty_pages_are_a_change=False,
+            watch_uuid=None,
+            ):
         """Synchronous version of run - the original requests implementation"""
 
         import chardet
@@ -51,6 +55,7 @@ class fetcher(Fetcher):
 
         session = requests.Session()
 
+
         if strtobool(os.getenv('ALLOW_FILE_URI', 'false')) and url.startswith('file://'):
             from requests_file import FileAdapter
             session.mount('file://', FileAdapter())
@@ -75,9 +80,22 @@ class fetcher(Fetcher):
         if not is_binary:
             # Don't run this for PDF (and requests identified as binary) takes a _long_ time
             if not r.headers.get('content-type') or not 'charset=' in r.headers.get('content-type'):
-                encoding = chardet.detect(r.content)['encoding']
-                if encoding:
-                    r.encoding = encoding
+                # For XML/RSS feeds, check the XML declaration for encoding attribute
+                # This is more reliable than chardet which can misdetect UTF-8 as MacRoman
+                content_type = r.headers.get('content-type', '').lower()
+                if 'xml' in content_type or 'rss' in content_type:
+                    # Look for <?xml version="1.0" encoding="UTF-8"?>
+                    xml_encoding_match = re.search(rb'<\?xml[^>]+encoding=["\']([^"\']+)["\']', r.content[:200])
+                    if xml_encoding_match:
+                        r.encoding = xml_encoding_match.group(1).decode('ascii')
+                    else:
+                        # Default to UTF-8 for XML if no encoding found
+                        r.encoding = 'utf-8'
+                else:
+                    # For other content types, use chardet
+                    encoding = chardet.detect(r.content)['encoding']
+                    if encoding:
+                        r.encoding = encoding
 
         self.headers = r.headers
 
@@ -103,6 +121,12 @@ class fetcher(Fetcher):
 
         self.raw_content = r.content
 
+        # If the content is an image, set it as screenshot for SSIM/visual comparison
+        content_type = r.headers.get('content-type', '').lower()
+        if 'image/' in content_type:
+            self.screenshot = r.content
+            logger.debug(f"Image content detected ({content_type}), set as screenshot for comparison")
+
     async def run(self,
                   fetch_favicon=True,
                   current_include_filters=None,
@@ -112,8 +136,10 @@ class fetcher(Fetcher):
                   request_body=None,
                   request_headers=None,
                   request_method=None,
+                  screenshot_format=None,
                   timeout=None,
                   url=None,
+                  watch_uuid=None,
                   ):
         """Async wrapper that runs the synchronous requests code in a thread pool"""
         
@@ -131,11 +157,12 @@ class fetcher(Fetcher):
                 ignore_status_codes=ignore_status_codes,
                 current_include_filters=current_include_filters,
                 is_binary=is_binary,
-                empty_pages_are_a_change=empty_pages_are_a_change
+                empty_pages_are_a_change=empty_pages_are_a_change,
+                watch_uuid=watch_uuid,
             )
         )
 
-    def quit(self, watch=None):
+    async def quit(self, watch=None):
 
         # In case they switched to `requests` fetcher from something else
         # Then the screenshot could be old, in any case, it's not used here.
@@ -148,3 +175,15 @@ class fetcher(Fetcher):
                 except Exception as e:
                     logger.warning(f"Failed to unlink screenshot: {screenshot} - {e}")
 
+
+# Plugin registration for built-in fetcher
+class RequestsFetcherPlugin:
+    """Plugin class that registers the requests fetcher as a built-in plugin."""
+
+    def register_content_fetcher(self):
+        """Register the requests fetcher"""
+        return ('html_requests', fetcher)
+
+
+# Create module-level instance for plugin registration
+requests_plugin = RequestsFetcherPlugin()

changedetectionio/content_fetchers/res/lock-elements-sizing.js

@@ -0,0 +1,93 @@
+/**
+ * Lock Element Dimensions for Screenshot Capture
+ *
+ * THE PROBLEM:
+ * When taking full-page screenshots of tall pages, Chrome/Puppeteer/Playwright need to:
+ * 1. Temporarily change the viewport height to a large value (e.g., 800px → 3809px)
+ * 2. Take screenshots in chunks while scrolling
+ * 3. Stitch the chunks together
+ *
+ * However, changing the viewport height triggers CSS media queries like:
+ *   @media (min-height: 860px) { .ad { height: 250px; } }
+ *
+ * This causes elements (especially ads) to resize during screenshot capture, creating a mismatch:
+ * - Screenshot shows element at NEW size (after media query triggered)
+ * - xpath element coordinates measured at OLD size (before viewport change)
+ * - Visual selector overlays don't align with screenshot
+ *
+ * EXAMPLE BUG:
+ * - Initial viewport: 1280x800, ad height: 138px, article position: 279px ✓
+ * - Viewport changes to 1280x3809 for screenshot
+ * - Media query triggers: ad expands to 250px
+ * - All content below shifts down by 112px (250-138)
+ * - Article now at position: 391px (279+112)
+ * - But xpath data says 279px → 112px mismatch! ✗
+ *
+ * THE SOLUTION:
+ * Before changing viewport, lock ALL element dimensions with !important inline styles.
+ * Inline styles with !important override media query CSS, preventing layout changes.
+ *
+ * WHAT THIS SCRIPT DOES:
+ * 1. Iterates through every element on the page
+ * 2. Captures current computed dimensions (width, height)
+ * 3. Sets inline styles with !important to freeze those dimensions
+ * 4. Disables ResizeObserver API (for JS-based resizing)
+ * 5. When viewport changes for screenshot, media queries can't resize anything
+ * 6. Layout remains consistent → xpath coordinates match screenshot ✓
+ *
+ * USAGE:
+ * Execute this script BEFORE calling capture_full_page() / screenshot functions.
+ * The page must be fully loaded and settled at its initial viewport size.
+ * No need to restore state afterward - page is closed after screenshot.
+ *
+ * PERFORMANCE:
+ * - Iterates all DOM elements (can be 1000s on complex pages)
+ * - Typically completes in 50-200ms
+ * - One-time cost before screenshot, well worth it for coordinate accuracy
+ *
+ * @see https://github.com/dgtlmoon/changedetection.io/issues/XXXX
+ */
+
+(() => {
+    // Store original styles in a global WeakMap for later restoration
+    window.__elementSizingRestore = new WeakMap();
+
+    // Lock ALL element dimensions to prevent media query layout changes
+    document.querySelectorAll('*').forEach(el => {
+        const computed = window.getComputedStyle(el);
+        const rect = el.getBoundingClientRect();
+
+        // Save original inline style values BEFORE locking
+        const properties = ['height', 'min-height', 'max-height', 'width', 'min-width', 'max-width'];
+        const originalStyles = {};
+        properties.forEach(prop => {
+            originalStyles[prop] = {
+                value: el.style.getPropertyValue(prop),
+                priority: el.style.getPropertyPriority(prop)
+            };
+        });
+        window.__elementSizingRestore.set(el, originalStyles);
+
+        // Lock dimensions with !important to override media queries
+        if (rect.height > 0) {
+            el.style.setProperty('height', computed.height, 'important');
+            el.style.setProperty('min-height', computed.height, 'important');
+            el.style.setProperty('max-height', computed.height, 'important');
+        }
+        if (rect.width > 0) {
+            el.style.setProperty('width', computed.width, 'important');
+            el.style.setProperty('min-width', computed.width, 'important');
+            el.style.setProperty('max-width', computed.width, 'important');
+        }
+    });
+
+    // Also disable ResizeObserver for JS-based resizing
+    window.ResizeObserver = class {
+        constructor() {}
+        observe() {}
+        unobserve() {}
+        disconnect() {}
+    };
+
+    console.log('✓ Element dimensions locked to prevent media query changes during screenshot');
+})();

changedetectionio/content_fetchers/res/unlock-elements-sizing.js

@@ -0,0 +1,52 @@
+/**
+ * Unlock Element Dimensions After Screenshot Capture
+ *
+ * This script removes the inline !important styles that were applied by lock-elements-sizing.js
+ * and restores elements to their original state using the WeakMap created during locking.
+ *
+ * USAGE:
+ * Execute this script AFTER completing screenshot capture and restoring the viewport.
+ * This allows the page to return to its normal responsive behavior.
+ *
+ * WHAT THIS SCRIPT DOES:
+ * 1. Iterates through every element that was locked
+ * 2. Reads original style values from the global WeakMap
+ * 3. Restores original inline styles (or removes them if they weren't set originally)
+ * 4. Cleans up the WeakMap
+ *
+ * @see lock-elements-sizing.js for the locking mechanism
+ */
+
+(() => {
+    // Check if the restore map exists
+    if (!window.__elementSizingRestore) {
+        console.log('⚠ Element sizing restore map not found - elements may not have been locked');
+        return;
+    }
+
+    // Restore all locked dimension styles to their original state
+    document.querySelectorAll('*').forEach(el => {
+        const originalStyles = window.__elementSizingRestore.get(el);
+
+        if (originalStyles) {
+            const properties = ['height', 'min-height', 'max-height', 'width', 'min-width', 'max-width'];
+
+            properties.forEach(prop => {
+                const original = originalStyles[prop];
+
+                if (original.value) {
+                    // Restore original value with original priority
+                    el.style.setProperty(prop, original.value, original.priority || '');
+                } else {
+                    // Was not set originally, so remove it
+                    el.style.removeProperty(prop);
+                }
+            });
+        }
+    });
+
+    // Clean up the global WeakMap
+    delete window.__elementSizingRestore;
+
+    console.log('✓ Element dimensions unlocked - page restored to original state');
+})();

changedetectionio/content_fetchers/screenshot_handler.py

@@ -8,14 +8,90 @@ from loguru import logger
 
 from changedetectionio.content_fetchers import SCREENSHOT_MAX_HEIGHT_DEFAULT, SCREENSHOT_DEFAULT_QUALITY
 
+# Cache font to avoid loading on every stitch
+_cached_font = None
+
+def _get_caption_font():
+    """Get or create cached font for caption text."""
+    global _cached_font
+    if _cached_font is None:
+        from PIL import ImageFont
+        try:
+            _cached_font = ImageFont.truetype("arial.ttf", 35)
+        except IOError:
+            _cached_font = ImageFont.load_default()
+    return _cached_font
+
+
+def stitch_images_inline(chunks_bytes, original_page_height, capture_height):
+    """
+    Stitch image chunks together inline (no multiprocessing).
+    Optimized for small number of chunks (2-3) to avoid process creation overhead.
+
+    Args:
+        chunks_bytes: List of JPEG image bytes
+        original_page_height: Original page height in pixels
+        capture_height: Maximum capture height
+
+    Returns:
+        bytes: Stitched JPEG image
+    """
+    import os
+    import io
+    from PIL import Image, ImageDraw
+
+    # Load images from byte chunks
+    images = [Image.open(io.BytesIO(b)) for b in chunks_bytes]
+    total_height = sum(im.height for im in images)
+    max_width = max(im.width for im in images)
+
+    # Create stitched image
+    stitched = Image.new('RGB', (max_width, total_height))
+    y_offset = 0
+    for im in images:
+        stitched.paste(im, (0, y_offset))
+        y_offset += im.height
+        im.close()  # Close immediately after pasting
+
+    # Draw caption only if page was trimmed
+    if original_page_height > capture_height:
+        draw = ImageDraw.Draw(stitched)
+        caption_text = f"WARNING: Screenshot was {original_page_height}px but trimmed to {capture_height}px because it was too long"
+        padding = 10
+        font = _get_caption_font()
+
+        bbox = draw.textbbox((0, 0), caption_text, font=font)
+        text_width = bbox[2] - bbox[0]
+        text_height = bbox[3] - bbox[1]
+
+        # Draw white background rectangle
+        draw.rectangle([(0, 0), (max_width, text_height + 2 * padding)], fill=(255, 255, 255))
+
+        # Draw text centered
+        text_x = (max_width - text_width) // 2
+        draw.text((text_x, padding), caption_text, font=font, fill=(255, 0, 0))
+
+    # Encode to JPEG
+    output = io.BytesIO()
+    stitched.save(output, format="JPEG", quality=int(os.getenv("SCREENSHOT_QUALITY", SCREENSHOT_DEFAULT_QUALITY)), optimize=True)
+    result = output.getvalue()
+
+    # Cleanup
+    stitched.close()
+
+    return result
+
 
 def stitch_images_worker(pipe_conn, chunks_bytes, original_page_height, capture_height):
+    """
+    Stitch image chunks together in a separate process.
+    Used for large number of chunks (4+) to avoid blocking the main event loop.
+    """
     import os
     import io
     from PIL import Image, ImageDraw, ImageFont
 
     try:
-
         # Load images from byte chunks
         images = [Image.open(io.BytesIO(b)) for b in chunks_bytes]
         total_height = sum(im.height for im in images)
@@ -27,21 +103,17 @@ def stitch_images_worker(pipe_conn, chunks_bytes, original_page_height, capture_
         for im in images:
             stitched.paste(im, (0, y_offset))
             y_offset += im.height
+            im.close()  # Close immediately after pasting
 
-        # Draw caption on top (overlaid, not extending canvas)
-        draw = ImageDraw.Draw(stitched)
-
+        # Draw caption only if page was trimmed
         if original_page_height > capture_height:
+            draw = ImageDraw.Draw(stitched)
             caption_text = f"WARNING: Screenshot was {original_page_height}px but trimmed to {capture_height}px because it was too long"
             padding = 10
-            font_size = 35
-            font_color = (255, 0, 0)
-            background_color = (255, 255, 255)
 
-
-            # Try to load a proper font
+            # Try to load font
             try:
-                font = ImageFont.truetype("arial.ttf", font_size)
+                font = ImageFont.truetype("arial.ttf", 35)
             except IOError:
                 font = ImageFont.load_default()
 
@@ -49,19 +121,16 @@ def stitch_images_worker(pipe_conn, chunks_bytes, original_page_height, capture_
             text_width = bbox[2] - bbox[0]
             text_height = bbox[3] - bbox[1]
 
-            # Draw white rectangle background behind text
-            rect_top = 0
-            rect_bottom = text_height + 2 * padding
-            draw.rectangle([(0, rect_top), (max_width, rect_bottom)], fill=background_color)
+            # Draw white background rectangle
+            draw.rectangle([(0, 0), (max_width, text_height + 2 * padding)], fill=(255, 255, 255))
 
-            # Draw text centered horizontally, 10px padding from top of the rectangle
+            # Draw text centered
             text_x = (max_width - text_width) // 2
-            text_y = padding
-            draw.text((text_x, text_y), caption_text, font=font, fill=font_color)
+            draw.text((text_x, padding), caption_text, font=font, fill=(255, 0, 0))
 
-        # Encode and send image
+        # Encode and send image with optimization
         output = io.BytesIO()
-        stitched.save(output, format="JPEG", quality=int(os.getenv("SCREENSHOT_QUALITY", SCREENSHOT_DEFAULT_QUALITY)))
+        stitched.save(output, format="JPEG", quality=int(os.getenv("SCREENSHOT_QUALITY", SCREENSHOT_DEFAULT_QUALITY)), optimize=True)
         pipe_conn.send_bytes(output.getvalue())
 
         stitched.close()

changedetectionio/content_fetchers/webdriver_selenium.py

@@ -14,8 +14,22 @@ class fetcher(Fetcher):
     proxy = None
     proxy_url = None
 
-    def __init__(self, proxy_override=None, custom_browser_connection_url=None):
-        super().__init__()
+    # Capability flags
+    supports_browser_steps = True
+    supports_screenshots = True
+    supports_xpath_element_data = True
+
+    @classmethod
+    def get_status_icon_data(cls):
+        """Return Chrome browser icon data for WebDriver fetcher."""
+        return {
+            'filename': 'google-chrome-icon.png',
+            'alt': 'Using a Chrome browser',
+            'title': 'Using a Chrome browser'
+        }
+
+    def __init__(self, proxy_override=None, custom_browser_connection_url=None, **kwargs):
+        super().__init__(**kwargs)
         from urllib.parse import urlparse
         from selenium.webdriver.common.proxy import Proxy
 
@@ -55,8 +69,10 @@ class fetcher(Fetcher):
                   request_body=None,
                   request_headers=None,
                   request_method=None,
+                  screenshot_format=None,
                   timeout=None,
                   url=None,
+                  watch_uuid=None,
                   ):
 
         import asyncio
@@ -131,7 +147,21 @@ class fetcher(Fetcher):
                 time.sleep(int(os.getenv("WEBDRIVER_DELAY_BEFORE_CONTENT_READY", 5)) + self.render_extract_delay)
                 self.content = driver.page_source
                 self.headers = {}
-                self.screenshot = driver.get_screenshot_as_png()
+
+                # Selenium always captures as PNG, convert to JPEG if needed
+                screenshot_png = driver.get_screenshot_as_png()
+
+                # Convert to JPEG if requested (for smaller file size)
+                if self.screenshot_format and self.screenshot_format.upper() == 'JPEG':
+                    from PIL import Image
+                    import io
+                    img = Image.open(io.BytesIO(screenshot_png))
+                    jpeg_buffer = io.BytesIO()
+                    img.save(jpeg_buffer, format='JPEG', quality=int(os.getenv("SCREENSHOT_QUALITY", 72)))
+                    self.screenshot = jpeg_buffer.getvalue()
+                    img.close()
+                else:
+                    self.screenshot = screenshot_png
             except Exception as e:
                 driver.quit()
                 raise e
@@ -141,3 +171,16 @@ class fetcher(Fetcher):
         # Run the selenium operations in a thread pool to avoid blocking the event loop
         loop = asyncio.get_event_loop()
         await loop.run_in_executor(None, _run_sync)
+
+
+# Plugin registration for built-in fetcher
+class WebDriverSeleniumFetcherPlugin:
+    """Plugin class that registers the WebDriver Selenium fetcher as a built-in plugin."""
+
+    def register_content_fetcher(self):
+        """Register the WebDriver Selenium fetcher"""
+        return ('html_webdriver', fetcher)
+
+
+# Create module-level instance for plugin registration
+webdriver_selenium_plugin = WebDriverSeleniumFetcherPlugin()

changedetectionio/diff.py

@@ -1,113 +0,0 @@
-import difflib
-from typing import List, Iterator, Union
-
-REMOVED_STYLE = "background-color: #fadad7; color: #b30000;"
-ADDED_STYLE = "background-color: #eaf2c2; color: #406619;"
-
-def same_slicer(lst: List[str], start: int, end: int) -> List[str]:
-    """Return a slice of the list, or a single element if start == end."""
-    return lst[start:end] if start != end else [lst[start]]
-
-def customSequenceMatcher(
-    before: List[str],
-    after: List[str],
-    include_equal: bool = False,
-    include_removed: bool = True,
-    include_added: bool = True,
-    include_replaced: bool = True,
-    include_change_type_prefix: bool = True,
-    html_colour: bool = False
-) -> Iterator[List[str]]:
-    """
-    Compare two sequences and yield differences based on specified parameters.
-
-    Args:
-        before (List[str]): Original sequence
-        after (List[str]): Modified sequence
-        include_equal (bool): Include unchanged parts
-        include_removed (bool): Include removed parts
-        include_added (bool): Include added parts
-        include_replaced (bool): Include replaced parts
-        include_change_type_prefix (bool): Add prefixes to indicate change types
-        html_colour (bool): Use HTML background colors for differences
-
-    Yields:
-        List[str]: Differences between sequences
-    """
-    cruncher = difflib.SequenceMatcher(isjunk=lambda x: x in " \t", a=before, b=after)
-
-
-
-    for tag, alo, ahi, blo, bhi in cruncher.get_opcodes():
-        if include_equal and tag == 'equal':
-            yield before[alo:ahi]
-        elif include_removed and tag == 'delete':
-            if html_colour:
-                yield [f'<span style="{REMOVED_STYLE}">{line}</span>' for line in same_slicer(before, alo, ahi)]
-            else:
-                yield [f"(removed) {line}" for line in same_slicer(before, alo, ahi)] if include_change_type_prefix else same_slicer(before, alo, ahi)
-        elif include_replaced and tag == 'replace':
-            if html_colour:
-                yield [f'<span style="{REMOVED_STYLE}">{line}</span>' for line in same_slicer(before, alo, ahi)] + \
-                      [f'<span style="{ADDED_STYLE}">{line}</span>' for line in same_slicer(after, blo, bhi)]
-            else:
-                yield [f"(changed) {line}" for line in same_slicer(before, alo, ahi)] + \
-                      [f"(into) {line}" for line in same_slicer(after, blo, bhi)] if include_change_type_prefix else same_slicer(before, alo, ahi) + same_slicer(after, blo, bhi)
-        elif include_added and tag == 'insert':
-            if html_colour:
-                yield [f'<span style="{ADDED_STYLE}">{line}</span>' for line in same_slicer(after, blo, bhi)]
-            else:
-                yield [f"(added) {line}" for line in same_slicer(after, blo, bhi)] if include_change_type_prefix else same_slicer(after, blo, bhi)
-
-def render_diff(
-    previous_version_file_contents: str,
-    newest_version_file_contents: str,
-    include_equal: bool = False,
-    include_removed: bool = True,
-    include_added: bool = True,
-    include_replaced: bool = True,
-    line_feed_sep: str = "\n",
-    include_change_type_prefix: bool = True,
-    patch_format: bool = False,
-    html_colour: bool = False
-) -> str:
-    """
-    Render the difference between two file contents.
-
-    Args:
-        previous_version_file_contents (str): Original file contents
-        newest_version_file_contents (str): Modified file contents
-        include_equal (bool): Include unchanged parts
-        include_removed (bool): Include removed parts
-        include_added (bool): Include added parts
-        include_replaced (bool): Include replaced parts
-        line_feed_sep (str): Separator for lines in output
-        include_change_type_prefix (bool): Add prefixes to indicate change types
-        patch_format (bool): Use patch format for output
-        html_colour (bool): Use HTML background colors for differences
-
-    Returns:
-        str: Rendered difference
-    """
-    newest_lines = [line.rstrip() for line in newest_version_file_contents.splitlines()]
-    previous_lines = [line.rstrip() for line in previous_version_file_contents.splitlines()] if previous_version_file_contents else []
-
-    if patch_format:
-        patch = difflib.unified_diff(previous_lines, newest_lines)
-        return line_feed_sep.join(patch)
-
-    rendered_diff = customSequenceMatcher(
-        before=previous_lines,
-        after=newest_lines,
-        include_equal=include_equal,
-        include_removed=include_removed,
-        include_added=include_added,
-        include_replaced=include_replaced,
-        include_change_type_prefix=include_change_type_prefix,
-        html_colour=html_colour
-    )
-
-    def flatten(lst: List[Union[str, List[str]]]) -> str:
-        return line_feed_sep.join(flatten(x) if isinstance(x, list) else x for x in lst)
-
-    return flatten(rendered_diff)

changedetectionio/diff/__init__.py

@@ -0,0 +1,479 @@
+"""
+Diff rendering module for change detection.
+
+This module provides functions for rendering differences between text content,
+with support for various output formats and tokenization strategies.
+"""
+
+import difflib
+from typing import List, Iterator, Union
+from loguru import logger
+import diff_match_patch as dmp_module
+import re
+import time
+
+from .tokenizers import TOKENIZERS, tokenize_words_and_html
+
+# Remember! gmail, outlook etc dont support <style> must be inline.
+# Gmail: strips <ins> and <del> tags entirely.
+# This is for the WHOLE line background style
+REMOVED_STYLE = "background-color: #fadad7; color: #b30000;"
+ADDED_STYLE = "background-color: #eaf2c2; color: #406619;"
+HTML_REMOVED_STYLE = REMOVED_STYLE  # Export alias for handler.py
+HTML_ADDED_STYLE = ADDED_STYLE      # Export alias for handler.py
+
+# Darker backgrounds for nested highlighting (changed parts within lines)
+REMOVED_INNER_STYLE = "background-color: #ff867a; color: #111;"
+ADDED_INNER_STYLE = "background-color: #b2e841; color: #444;"
+HTML_CHANGED_STYLE = REMOVED_STYLE
+HTML_CHANGED_INTO_STYLE = ADDED_STYLE
+
+# Placemarker constants - these get replaced by apply_service_tweaks() in handler.py
+# Something that cant get escaped to HTML by accident
+REMOVED_PLACEMARKER_OPEN = '@removed_PLACEMARKER_OPEN'
+REMOVED_PLACEMARKER_CLOSED = '@removed_PLACEMARKER_CLOSED'
+
+ADDED_PLACEMARKER_OPEN = '@added_PLACEMARKER_OPEN'
+ADDED_PLACEMARKER_CLOSED = '@added_PLACEMARKER_CLOSED'
+
+CHANGED_PLACEMARKER_OPEN = '@changed_PLACEMARKER_OPEN'
+CHANGED_PLACEMARKER_CLOSED = '@changed_PLACEMARKER_CLOSED'
+
+CHANGED_INTO_PLACEMARKER_OPEN = '@changed_into_PLACEMARKER_OPEN'
+CHANGED_INTO_PLACEMARKER_CLOSED = '@changed_into_PLACEMARKER_CLOSED'
+
+# Compiled regex patterns for performance
+WHITESPACE_NORMALIZE_RE = re.compile(r'\s+')
+
+
+def render_inline_word_diff(before_line: str, after_line: str, ignore_junk: bool = False, markdown_style: str = None, tokenizer: str = 'words_and_html') -> tuple[str, bool]:
+    """
+    Render word-level differences between two lines inline using diff-match-patch library.
+
+    Args:
+        before_line: Original line text
+        after_line: Modified line text
+        ignore_junk: Ignore whitespace-only changes
+        markdown_style: Unused (kept for backwards compatibility)
+        tokenizer: Name of tokenizer to use from TOKENIZERS registry (default: 'words_and_html')
+
+    Returns:
+        tuple[str, bool]: (diff output with inline word-level highlighting, has_changes flag)
+    """
+    # Normalize whitespace if ignore_junk is enabled
+    if ignore_junk:
+        # Normalize whitespace: replace multiple spaces/tabs with single space
+        before_normalized = WHITESPACE_NORMALIZE_RE.sub(' ', before_line)
+        after_normalized = WHITESPACE_NORMALIZE_RE.sub(' ', after_line)
+    else:
+        before_normalized = before_line
+        after_normalized = after_line
+
+    # Use diff-match-patch with word-level tokenization
+    # Strategy: Use linesToChars to treat words as atomic units
+    dmp = dmp_module.diff_match_patch()
+
+    # Get the tokenizer function from the registry
+    tokenizer_func = TOKENIZERS.get(tokenizer, tokenize_words_and_html)
+
+    # Tokenize both lines using the selected tokenizer
+    before_tokens = tokenizer_func(before_normalized)
+    after_tokens = tokenizer_func(after_normalized or ' ')
+
+    # Create mappings for linesToChars (using it for word-mode)
+    # Join tokens with newline so each "line" is a token
+    before_text = '\n'.join(before_tokens)
+    after_text = '\n'.join(after_tokens)
+
+    # Use linesToChars for word-mode diffing
+    lines_result = dmp.diff_linesToChars(before_text, after_text)
+    line_before, line_after, line_array = lines_result
+
+    # Perform diff on the encoded strings
+    diffs = dmp.diff_main(line_before, line_after, False)
+
+    # Convert back to original text
+    dmp.diff_charsToLines(diffs, line_array)
+
+    # Remove the newlines we added for tokenization
+    diffs = [(op, text.replace('\n', '')) for op, text in diffs]
+
+    # DON'T apply semantic cleanup here - it would break token boundaries
+    # (e.g., "63" -> "66" would become "6" + "3" vs "6" + "6")
+    # We want to preserve the tokenizer's word boundaries
+
+    # Check if there are any changes
+    has_changes = any(op != 0 for op, _ in diffs)
+
+    if ignore_junk and not has_changes:
+        return after_line, False
+
+    # Check if the whole line is replaced (no unchanged content)
+    whole_line_replaced = not any(op == 0 and text.strip() for op, text in diffs)
+
+    # Build the output using placemarkers
+    # When whole line is replaced, wrap entire removed content once and entire added content once
+    if whole_line_replaced:
+        removed_tokens = []
+        added_tokens = []
+
+        for op, text in diffs:
+            if op == 0:  # Equal (e.g., whitespace tokens in common positions)
+                # Include in both removed and added to preserve spacing
+                removed_tokens.append(text)
+                added_tokens.append(text)
+            elif op == -1:  # Deletion
+                removed_tokens.append(text)
+            elif op == 1:  # Insertion
+                added_tokens.append(text)
+
+        # Join all tokens and wrap the entire string once for removed, once for added
+        result_parts = []
+
+        if removed_tokens:
+            removed_full = ''.join(removed_tokens).rstrip()
+            trailing_removed = ''.join(removed_tokens)[len(removed_full):] if len(''.join(removed_tokens)) > len(removed_full) else ''
+            result_parts.append(f'{CHANGED_PLACEMARKER_OPEN}{removed_full}{CHANGED_PLACEMARKER_CLOSED}{trailing_removed}')
+
+        if added_tokens:
+            if result_parts:  # Add newline between removed and added
+                result_parts.append('\n')
+            added_full = ''.join(added_tokens).rstrip()
+            trailing_added = ''.join(added_tokens)[len(added_full):] if len(''.join(added_tokens)) > len(added_full) else ''
+            result_parts.append(f'{CHANGED_INTO_PLACEMARKER_OPEN}{added_full}{CHANGED_INTO_PLACEMARKER_CLOSED}{trailing_added}')
+
+        return ''.join(result_parts), has_changes
+    else:
+        # Inline changes within the line
+        result_parts = []
+        for op, text in diffs:
+            if op == 0:  # Equal
+                result_parts.append(text)
+            elif op == 1:  # Insertion
+                # Don't wrap empty content (e.g., whitespace-only tokens after rstrip)
+                content = text.rstrip()
+                trailing = text[len(content):] if len(text) > len(content) else ''
+                if content:
+                    result_parts.append(f'{ADDED_PLACEMARKER_OPEN}{content}{ADDED_PLACEMARKER_CLOSED}{trailing}')
+                else:
+                    result_parts.append(trailing)
+            elif op == -1:  # Deletion
+                # Don't wrap empty content (e.g., whitespace-only tokens after rstrip)
+                content = text.rstrip()
+                trailing = text[len(content):] if len(text) > len(content) else ''
+                if content:
+                    result_parts.append(f'{REMOVED_PLACEMARKER_OPEN}{content}{REMOVED_PLACEMARKER_CLOSED}{trailing}')
+                else:
+                    result_parts.append(trailing)
+
+        return ''.join(result_parts), has_changes
+
+
+def render_nested_line_diff(before_line: str, after_line: str, ignore_junk: bool = False, tokenizer: str = 'words_and_html') -> tuple[str, str, bool]:
+    """
+    Render line-level differences with nested highlighting for changed parts.
+
+    Returns two separate lines:
+    - Before line: light red background with dark red on removed parts
+    - After line: light green background with dark green on added parts
+
+    Args:
+        before_line: Original line text
+        after_line: Modified line text
+        ignore_junk: Ignore whitespace-only changes
+        tokenizer: Name of tokenizer to use from TOKENIZERS registry
+
+    Returns:
+        tuple[str, str, bool]: (before_with_highlights, after_with_highlights, has_changes)
+    """
+    # Normalize whitespace if ignore_junk is enabled
+    if ignore_junk:
+        before_normalized = WHITESPACE_NORMALIZE_RE.sub(' ', before_line)
+        after_normalized = WHITESPACE_NORMALIZE_RE.sub(' ', after_line)
+    else:
+        before_normalized = before_line
+        after_normalized = after_line
+
+    # Use diff-match-patch with word-level tokenization
+    dmp = dmp_module.diff_match_patch()
+
+    # Get the tokenizer function from the registry
+    tokenizer_func = TOKENIZERS.get(tokenizer, tokenize_words_and_html)
+
+    # Tokenize both lines
+    before_tokens = tokenizer_func(before_normalized)
+    after_tokens = tokenizer_func(after_normalized or ' ')
+
+    # Create mappings for linesToChars
+    before_text = '\n'.join(before_tokens)
+    after_text = '\n'.join(after_tokens)
+
+    # Use linesToChars for word-mode diffing
+    lines_result = dmp.diff_linesToChars(before_text, after_text)
+    line_before, line_after, line_array = lines_result
+
+    # Perform diff on the encoded strings
+    diffs = dmp.diff_main(line_before, line_after, False)
+
+    # Convert back to original text
+    dmp.diff_charsToLines(diffs, line_array)
+
+    # Remove the newlines we added for tokenization
+    diffs = [(op, text.replace('\n', '')) for op, text in diffs]
+
+    # DON'T apply semantic cleanup here - it would break token boundaries
+    # (e.g., "63" -> "66" would become "6" + "3" vs "6" + "6")
+    # We want to preserve the tokenizer's word boundaries
+
+    # Check if there are any changes
+    has_changes = any(op != 0 for op, _ in diffs)
+
+    if ignore_junk and not has_changes:
+        return before_line, after_line, False
+
+    # Build the before line (with nested highlighting for removed parts)
+    before_parts = []
+    for op, text in diffs:
+        if op == 0:  # Equal
+            before_parts.append(text)
+        elif op == -1:  # Deletion (in before)
+            before_parts.append(f'<span style="{REMOVED_INNER_STYLE}">{text}</span>')
+        # Skip insertions (op == 1) for the before line
+
+    before_content = ''.join(before_parts)
+
+    # Build the after line (with nested highlighting for added parts)
+    after_parts = []
+    for op, text in diffs:
+        if op == 0:  # Equal
+            after_parts.append(text)
+        elif op == 1:  # Insertion (in after)
+            after_parts.append(f'<span style="{ADDED_INNER_STYLE}">{text}</span>')
+        # Skip deletions (op == -1) for the after line
+
+    after_content = ''.join(after_parts)
+
+    # Wrap content with placemarkers (inner HTML highlighting is preserved)
+    before_html = f'{CHANGED_PLACEMARKER_OPEN}{before_content}{CHANGED_PLACEMARKER_CLOSED}'
+    after_html = f'{CHANGED_INTO_PLACEMARKER_OPEN}{after_content}{CHANGED_INTO_PLACEMARKER_CLOSED}'
+
+    return before_html, after_html, has_changes
+
+
+def same_slicer(lst: List[str], start: int, end: int) -> List[str]:
+    """Return a slice of the list, or a single element if start == end."""
+    return lst[start:end] if start != end else [lst[start]]
+
+def customSequenceMatcher(
+    before: List[str],
+    after: List[str],
+    include_equal: bool = False,
+    include_removed: bool = True,
+    include_added: bool = True,
+    include_replaced: bool = True,
+    include_change_type_prefix: bool = True,
+    word_diff: bool = False,
+    context_lines: int = 0,
+    case_insensitive: bool = False,
+    ignore_junk: bool = False,
+    tokenizer: str = 'words_and_html'
+) -> Iterator[List[str]]:
+    """
+    Compare two sequences and yield differences based on specified parameters.
+
+    Args:
+        before (List[str]): Original sequence
+        after (List[str]): Modified sequence
+        include_equal (bool): Include unchanged parts
+        include_removed (bool): Include removed parts
+        include_added (bool): Include added parts
+        include_replaced (bool): Include replaced parts
+        include_change_type_prefix (bool): Add prefixes to indicate change types
+        word_diff (bool): Use word-level diffing for replaced lines (controls inline rendering)
+        context_lines (int): Number of unchanged lines to show around changes (like grep -C)
+        case_insensitive (bool): Perform case-insensitive comparison
+        ignore_junk (bool): Ignore whitespace-only changes
+        tokenizer (str): Name of tokenizer to use from TOKENIZERS registry (default: 'words_and_html')
+
+    Yields:
+        List[str]: Differences between sequences
+    """
+    # Prepare sequences for comparison (lowercase if case-insensitive, normalize whitespace if ignore_junk)
+    def prepare_line(line):
+        if case_insensitive:
+            line = line.lower()
+        if ignore_junk:
+            # Normalize whitespace: replace multiple spaces/tabs with single space
+            line = WHITESPACE_NORMALIZE_RE.sub(' ', line)
+        return line
+
+    compare_before = [prepare_line(line) for line in before]
+    compare_after = [prepare_line(line) for line in after]
+
+    cruncher = difflib.SequenceMatcher(isjunk=lambda x: x in " \t", a=compare_before, b=compare_after)
+
+    # When context_lines is set and include_equal is False, we need to track which equal lines to include
+    if context_lines > 0 and not include_equal:
+        opcodes = list(cruncher.get_opcodes())
+        # Mark equal ranges that should be included based on context
+        included_equal_ranges = set()
+
+        for i, (tag, alo, ahi, blo, bhi) in enumerate(opcodes):
+            if tag != 'equal':
+                # Include context lines before this change
+                for j in range(max(0, i - 1), i):
+                    if opcodes[j][0] == 'equal':
+                        prev_alo, prev_ahi = opcodes[j][1], opcodes[j][2]
+                        # Include last N lines of the previous equal block
+                        context_start = max(prev_alo, prev_ahi - context_lines)
+                        for line_num in range(context_start, prev_ahi):
+                            included_equal_ranges.add(line_num)
+
+                # Include context lines after this change
+                for j in range(i + 1, min(len(opcodes), i + 2)):
+                    if opcodes[j][0] == 'equal':
+                        next_alo, next_ahi = opcodes[j][1], opcodes[j][2]
+                        # Include first N lines of the next equal block
+                        context_end = min(next_ahi, next_alo + context_lines)
+                        for line_num in range(next_alo, context_end):
+                            included_equal_ranges.add(line_num)
+
+    # Remember! gmail, outlook etc dont support <style> must be inline.
+    # Gmail: strips <ins> and <del> tags entirely.
+    for tag, alo, ahi, blo, bhi in cruncher.get_opcodes():
+        if tag == 'equal':
+            if include_equal:
+                yield before[alo:ahi]
+            elif context_lines > 0:
+                # Only include equal lines that are in the context range
+                context_lines_to_include = [before[i] for i in range(alo, ahi) if i in included_equal_ranges]
+                if context_lines_to_include:
+                    yield context_lines_to_include
+        elif include_removed and tag == 'delete':
+            if include_change_type_prefix:
+                yield [f'{REMOVED_PLACEMARKER_OPEN}{line}{REMOVED_PLACEMARKER_CLOSED}' for line in same_slicer(before, alo, ahi)]
+            else:
+                yield same_slicer(before, alo, ahi)
+        elif include_replaced and tag == 'replace':
+            before_lines = same_slicer(before, alo, ahi)
+            after_lines = same_slicer(after, blo, bhi)
+
+            # Use inline word-level diff for single line replacements when word_diff is enabled
+            if word_diff and len(before_lines) == 1 and len(after_lines) == 1:
+                inline_diff, has_changes = render_inline_word_diff(before_lines[0], after_lines[0], ignore_junk=ignore_junk, tokenizer=tokenizer)
+                # Check if there are any actual changes (not just whitespace when ignore_junk is enabled)
+                if ignore_junk and not has_changes:
+                    # No real changes, skip this line
+                    continue
+                yield [inline_diff]
+            else:
+                # Fall back to line-level diff for multi-line changes
+                if include_change_type_prefix:
+                    yield [f'{CHANGED_PLACEMARKER_OPEN}{line}{CHANGED_PLACEMARKER_CLOSED}' for line in before_lines] + \
+                          [f'{CHANGED_INTO_PLACEMARKER_OPEN}{line}{CHANGED_INTO_PLACEMARKER_CLOSED}' for line in after_lines]
+                else:
+                    yield before_lines + after_lines
+        elif include_added and tag == 'insert':
+            if include_change_type_prefix:
+                yield [f'{ADDED_PLACEMARKER_OPEN}{line}{ADDED_PLACEMARKER_CLOSED}' for line in same_slicer(after, blo, bhi)]
+            else:
+                yield same_slicer(after, blo, bhi)
+
+def render_diff(
+    previous_version_file_contents: str,
+    newest_version_file_contents: str,
+    include_equal: bool = False,
+    include_removed: bool = True,
+    include_added: bool = True,
+    include_replaced: bool = True,
+    include_change_type_prefix: bool = True,
+    patch_format: bool = False,
+    word_diff: bool = True,
+    context_lines: int = 0,
+    case_insensitive: bool = False,
+    ignore_junk: bool = False,
+    tokenizer: str = 'words_and_html'
+) -> str:
+    """
+    Render the difference between two file contents.
+
+    Args:
+        previous_version_file_contents (str): Original file contents
+        newest_version_file_contents (str): Modified file contents
+        include_equal (bool): Include unchanged parts
+        include_removed (bool): Include removed parts
+        include_added (bool): Include added parts
+        include_replaced (bool): Include replaced parts
+        include_change_type_prefix (bool): Add prefixes to indicate change types
+        patch_format (bool): Use patch format for output
+        word_diff (bool): Use word-level diffing for replaced lines (controls inline rendering)
+        context_lines (int): Number of unchanged lines to show around changes (like grep -C)
+        case_insensitive (bool): Perform case-insensitive comparison, By default the test_json_diff/process.py is case sensitive, so this follows same logic
+        ignore_junk (bool): Ignore whitespace-only changes
+        tokenizer (str): Name of tokenizer to use from TOKENIZERS registry (default: 'words_and_html')
+
+    Returns:
+        str: Rendered difference
+    """
+    newest_lines = [line.rstrip() for line in newest_version_file_contents.splitlines()]
+    previous_lines = [line.rstrip() for line in previous_version_file_contents.splitlines()] if previous_version_file_contents else []
+    now = time.time()
+    logger.debug(
+        f"diff options: "
+        f"include_equal={include_equal}, "
+        f"include_removed={include_removed}, "
+        f"include_added={include_added}, "
+        f"include_replaced={include_replaced}, "
+        f"include_change_type_prefix={include_change_type_prefix}, "
+        f"patch_format={patch_format}, "
+        f"word_diff={word_diff}, "
+        f"context_lines={context_lines}, "
+        f"case_insensitive={case_insensitive}, "
+        f"ignore_junk={ignore_junk}, "
+        f"tokenizer={tokenizer}"
+    )
+    if patch_format:
+        patch = difflib.unified_diff(previous_lines, newest_lines)
+        return "\n".join(patch)
+
+    rendered_diff = customSequenceMatcher(
+        before=previous_lines,
+        after=newest_lines,
+        include_equal=include_equal,
+        include_removed=include_removed,
+        include_added=include_added,
+        include_replaced=include_replaced,
+        include_change_type_prefix=include_change_type_prefix,
+        word_diff=word_diff,
+        context_lines=context_lines,
+        case_insensitive=case_insensitive,
+        ignore_junk=ignore_junk,
+        tokenizer=tokenizer
+    )
+
+    def flatten(lst: List[Union[str, List[str]]]) -> str:
+        result = []
+        for x in lst:
+            if isinstance(x, list):
+                result.extend(x)
+            else:
+                result.append(x)
+        return "\n".join(result)
+
+    logger.debug(f"Diff generated in {time.time() - now:.2f}s")
+
+    return flatten(rendered_diff)
+
+
+# Export main public API
+__all__ = [
+    'render_diff',
+    'customSequenceMatcher',
+    'render_inline_word_diff',
+    'render_nested_line_diff',
+    'TOKENIZERS',
+    'REMOVED_STYLE',
+    'ADDED_STYLE',
+    'REMOVED_INNER_STYLE',
+    'ADDED_INNER_STYLE',
+]

changedetectionio/diff/tokenizers/__init__.py

@@ -0,0 +1,23 @@
+"""
+Tokenizers for diff operations.
+
+This module provides various tokenization strategies for use with the diff system.
+New tokenizers can be easily added by:
+1. Creating a new module in this directory
+2. Importing and registering it in the TOKENIZERS dictionary below
+"""
+
+from .natural_text import tokenize_words
+from .words_and_html import tokenize_words_and_html
+
+# Tokenizer registry - maps tokenizer names to functions
+TOKENIZERS = {
+    'words': tokenize_words,
+    'words_and_html': tokenize_words_and_html,
+}
+
+__all__ = [
+    'tokenize_words',
+    'tokenize_words_and_html',
+    'TOKENIZERS',
+]

changedetectionio/diff/tokenizers/natural_text.py

@@ -0,0 +1,44 @@
+"""
+Simple word tokenizer using whitespace boundaries.
+
+This is a simpler tokenizer that treats all whitespace as token boundaries
+without special handling for HTML tags or other markup.
+"""
+
+from typing import List
+
+
+def tokenize_words(text: str) -> List[str]:
+    """
+    Split text into words using simple whitespace boundaries.
+
+    This is a simpler tokenizer that treats all whitespace as token boundaries
+    without special handling for HTML tags.
+
+    Args:
+        text: Input text to tokenize
+
+    Returns:
+        List of tokens (words and whitespace)
+
+    Examples:
+        >>> tokenize_words("Hello world")
+        ['Hello', ' ', 'world']
+        >>> tokenize_words("one  two")
+        ['one', ' ', ' ', 'two']
+    """
+    tokens = []
+    current = ''
+
+    for char in text:
+        if char.isspace():
+            if current:
+                tokens.append(current)
+                current = ''
+            tokens.append(char)
+        else:
+            current += char
+
+    if current:
+        tokens.append(current)
+    return tokens

changedetectionio/diff/tokenizers/words_and_html.py

@@ -0,0 +1,61 @@
+"""
+Tokenizer that preserves HTML tags as atomic units while splitting on whitespace.
+
+This tokenizer is specifically designed for HTML content where:
+- HTML tags should remain intact (e.g., '<p>', '<a href="...">')
+- Whitespace tokens are preserved for accurate diff reconstruction
+- Words are split on whitespace boundaries
+"""
+
+from typing import List
+
+
+def tokenize_words_and_html(text: str) -> List[str]:
+    """
+    Split text into words and boundaries (spaces, HTML tags).
+
+    This tokenizer preserves HTML tags as atomic units while splitting on whitespace.
+    Useful for content that contains HTML markup.
+
+    Args:
+        text: Input text to tokenize
+
+    Returns:
+        List of tokens (words, spaces, HTML tags)
+
+    Examples:
+        >>> tokenize_words_and_html("<p>Hello world</p>")
+        ['<p>', 'Hello', ' ', 'world', '</p>']
+        >>> tokenize_words_and_html("<a href='test.com'>link</a>")
+        ['<a href=\\'test.com\\'>', 'link', '</a>']
+    """
+    tokens = []
+    current = ''
+    in_tag = False
+
+    for char in text:
+        if char == '<':
+            # Start of HTML tag
+            if current:
+                tokens.append(current)
+                current = ''
+            current = '<'
+            in_tag = True
+        elif char == '>' and in_tag:
+            # End of HTML tag
+            current += '>'
+            tokens.append(current)
+            current = ''
+            in_tag = False
+        elif char.isspace() and not in_tag:
+            # Space outside of tag
+            if current:
+                tokens.append(current)
+                current = ''
+            tokens.append(char)
+        else:
+            current += char
+
+    if current:
+        tokens.append(current)
+    return tokens

changedetectionio/flask_app.py

@@ -23,8 +23,10 @@ from flask import (
     render_template,
     request,
     send_from_directory,
+    session,
     url_for,
 )
+from urllib.parse import urlparse
 from flask_compress import Compress as FlaskCompress
 from flask_login import current_user
 from flask_restful import abort, Api
@@ -34,13 +36,15 @@ from flask_cors import CORS
 # Make this a global singleton to avoid multiple signal objects
 watch_check_update = signal('watch_check_update', doc='Signal sent when a watch check is completed')
 from flask_wtf import CSRFProtect
+from flask_babel import Babel, gettext, get_locale
 from loguru import logger
 
 from changedetectionio import __version__
 from changedetectionio import queuedWatchMetaData
-from changedetectionio.api import Watch, WatchHistory, WatchSingleHistory, CreateWatch, Import, SystemInfo, Tag, Tags, Notifications, WatchFavicon
+from changedetectionio.api import Watch, WatchHistory, WatchSingleHistory, WatchHistoryDiff, CreateWatch, Import, SystemInfo, Tag, Tags, Notifications, WatchFavicon
 from changedetectionio.api.Search import Search
 from .time_handler import is_within_schedule
+from changedetectionio.languages import get_available_languages, get_language_codes, get_flag_for_locale, get_timeago_locale
 
 datastore = None
 
@@ -66,6 +70,10 @@ CORS(app)
 
 # Super handy for compressing large BrowserSteps responses and others
 FlaskCompress(app)
+app.config['COMPRESS_MIN_SIZE'] = 4096
+app.config['COMPRESS_MIMETYPES'] = ['text/html', 'text/css', 'text/javascript', 'application/json', 'application/javascript', 'image/svg+xml']
+app.config['TEMPLATES_AUTO_RELOAD'] = False
+
 
 # Stop browser caching of assets
 app.config['SEND_FILE_MAX_AGE_DEFAULT'] = 0
@@ -78,9 +86,29 @@ if os.getenv('FLASK_SERVER_NAME'):
 
 #app.config["EXPLAIN_TEMPLATE_LOADING"] = True
 
-# Disables caching of the templates
-app.config['TEMPLATES_AUTO_RELOAD'] = True
+
 app.jinja_env.add_extension('jinja2.ext.loopcontrols')
+
+# Configure Jinja2 to search for templates in plugin directories
+def _configure_plugin_templates():
+    """Configure Jinja2 loader to include plugin template directories."""
+    from jinja2 import ChoiceLoader, FileSystemLoader
+    from changedetectionio.pluggy_interface import get_plugin_template_paths
+
+    # Get plugin template paths
+    plugin_template_paths = get_plugin_template_paths()
+
+    if plugin_template_paths:
+        # Create a ChoiceLoader that searches app templates first, then plugin templates
+        loaders = [app.jinja_loader]  # Keep the default app loader first
+        for path in plugin_template_paths:
+            loaders.append(FileSystemLoader(path))
+
+        app.jinja_loader = ChoiceLoader(loaders)
+        logger.info(f"Configured Jinja2 to search {len(plugin_template_paths)} plugin template directories")
+
+# Configure plugin templates (called after plugins are loaded)
+_configure_plugin_templates()
 csrf = CSRFProtect()
 csrf.init_app(app)
 notification_debug_log=[]
@@ -101,12 +129,12 @@ def init_app_secret(datastore_path):
     path = os.path.join(datastore_path, "secret.txt")
 
     try:
-        with open(path, "r") as f:
+        with open(path, "r", encoding='utf-8') as f:
             secret = f.read()
 
     except FileNotFoundError:
         import secrets
-        with open(path, "w") as f:
+        with open(path, "w", encoding='utf-8') as f:
             secret = secrets.token_hex(32)
             f.write(secret)
 
@@ -133,6 +161,11 @@ def get_socketio_path():
     # Socket.IO will be available at {prefix}/socket.io/
     return prefix
 
+@app.template_global('is_safe_valid_url')
+def _is_safe_valid_url(test_url):
+    from .validate_url import is_safe_valid_url
+    return is_safe_valid_url(test_url)
+
 
 @app.template_filter('format_number_locale')
 def _jinja2_filter_format_number_locale(value: float) -> str:
@@ -178,16 +211,26 @@ def _get_worker_status_info():
 def _jinja2_filter_datetime(watch_obj, format="%Y-%m-%d %H:%M:%S"):
 
     if watch_obj['last_checked'] == 0:
-        return 'Not yet'
+        return gettext('Not yet')
 
-    return timeago.format(int(watch_obj['last_checked']), time.time())
+    locale = get_timeago_locale(str(get_locale()))
+    try:
+        return timeago.format(int(watch_obj['last_checked']), time.time(), locale)
+    except:
+        # Fallback to English if locale not supported by timeago
+        return timeago.format(int(watch_obj['last_checked']), time.time(), 'en')
 
 @app.template_filter('format_timestamp_timeago')
 def _jinja2_filter_datetimestamp(timestamp, format="%Y-%m-%d %H:%M:%S"):
     if not timestamp:
-        return 'Not yet'
+        return gettext('Not yet')
 
-    return timeago.format(int(timestamp), time.time())
+    locale = get_timeago_locale(str(get_locale()))
+    try:
+        return timeago.format(int(timestamp), time.time(), locale)
+    except:
+        # Fallback to English if locale not supported by timeago
+        return timeago.format(int(timestamp), time.time(), 'en')
 
 
 @app.template_filter('pagination_slice')
@@ -201,10 +244,59 @@ def _jinja2_filter_pagination_slice(arr, skip):
 @app.template_filter('format_seconds_ago')
 def _jinja2_filter_seconds_precise(timestamp):
     if timestamp == False:
-        return 'Not yet'
+        return gettext('Not yet')
 
     return format(int(time.time()-timestamp), ',d')
 
+@app.template_filter('fetcher_status_icons')
+def _jinja2_filter_fetcher_status_icons(fetcher_name):
+    """Get status icon HTML for a given fetcher.
+
+    This filter checks both built-in fetchers and plugin fetchers for status icons.
+
+    Args:
+        fetcher_name: The fetcher name (e.g., 'html_webdriver', 'html_js_zyte')
+
+    Returns:
+        str: HTML string containing status icon elements
+    """
+    from changedetectionio import content_fetchers
+    from changedetectionio.pluggy_interface import collect_fetcher_status_icons
+    from markupsafe import Markup
+    from flask import url_for
+
+    icon_data = None
+
+    # First check if it's a plugin fetcher (plugins have priority)
+    plugin_icon_data = collect_fetcher_status_icons(fetcher_name)
+    if plugin_icon_data:
+        icon_data = plugin_icon_data
+    # Check if it's a built-in fetcher
+    elif hasattr(content_fetchers, fetcher_name):
+        fetcher_class = getattr(content_fetchers, fetcher_name)
+        if hasattr(fetcher_class, 'get_status_icon_data'):
+            icon_data = fetcher_class.get_status_icon_data()
+
+    # Build HTML from icon data
+    if icon_data and isinstance(icon_data, dict):
+        # Use 'group' from icon_data if specified, otherwise default to 'images'
+        group = icon_data.get('group', 'images')
+
+        # Try to use url_for, but fall back to manual URL building if endpoint not registered yet
+        try:
+            icon_url = url_for('static_content', group=group, filename=icon_data['filename'])
+        except:
+            # Fallback: build URL manually respecting APPLICATION_ROOT
+            from flask import request
+            app_root = request.script_root if hasattr(request, 'script_root') else ''
+            icon_url = f"{app_root}/static/{group}/{icon_data['filename']}"
+
+        style_attr = f' style="{icon_data["style"]}"' if icon_data.get('style') else ''
+        html = f'<img class="status-icon" src="{icon_url}" alt="{icon_data["alt"]}" title="{icon_data["title"]}"{style_attr}>'
+        return Markup(html)
+
+    return ''
+
 # Import login_optionally_required from auth_decorator
 from changedetectionio.auth_decorator import login_optionally_required
 
@@ -259,6 +351,13 @@ def changedetection_app(config=None, datastore_o=None):
     global datastore, socketio_server
     datastore = datastore_o
 
+    # Import and create a wrapper for is_safe_url that has access to app
+    from changedetectionio.is_safe_url import is_safe_url as _is_safe_url
+
+    def is_safe_url(target):
+        """Wrapper for is_safe_url that passes the app instance"""
+        return _is_safe_url(target, app)
+
     # so far just for read-only via tests, but this will be moved eventually to be the main source
     # (instead of the global var)
     app.config['DATASTORE'] = datastore_o
@@ -269,7 +368,33 @@ def changedetection_app(config=None, datastore_o=None):
     login_manager = flask_login.LoginManager(app)
     login_manager.login_view = 'login'
     app.secret_key = init_app_secret(config['datastore_path'])
-    
+
+    # Initialize Flask-Babel for i18n support
+    available_languages = get_available_languages()
+    language_codes = get_language_codes()
+
+    def get_locale():
+        # 1. Try to get locale from session (user explicitly selected)
+        if 'locale' in session:
+            locale = session['locale']
+            logger.trace(f"DEBUG: get_locale() returning from session: {locale}")
+            return locale
+        # 2. Fall back to Accept-Language header
+        locale = request.accept_languages.best_match(language_codes)
+        logger.trace(f"DEBUG: get_locale() returning from Accept-Language: {locale}")
+        return locale
+
+    # Initialize Babel with locale selector
+    babel = Babel(app, locale_selector=get_locale)
+
+    # Make i18n functions available to templates
+    app.jinja_env.globals.update(
+        _=gettext,
+        get_locale=get_locale,
+        get_flag_for_locale=get_flag_for_locale,
+        available_languages=available_languages
+    )
+
     # Set up a request hook to check authentication for all routes
     @app.before_request
     def check_authentication():
@@ -280,6 +405,12 @@ def changedetection_app(config=None, datastore_o=None):
             if request.endpoint and request.endpoint == 'static_content' and request.view_args:
                 # Handled by static_content handler
                 return None
+            # Permitted - static flag icons need to load on login page
+            elif request.endpoint and request.endpoint == 'static_flags':
+                return None
+            # Permitted - language selection should work on login page
+            elif request.endpoint and request.endpoint == 'set_language':
+                return None
             # Permitted
             elif request.endpoint and 'login' in request.endpoint:
                 return None
@@ -302,6 +433,9 @@ def changedetection_app(config=None, datastore_o=None):
                 return login_manager.unauthorized()
 
 
+    watch_api.add_resource(WatchHistoryDiff,
+                           '/api/v1/watch/<string:uuid>/difference/<string:from_timestamp>/<string:to_timestamp>',
+                           resource_class_kwargs={'datastore': datastore})
     watch_api.add_resource(WatchSingleHistory,
                            '/api/v1/watch/<string:uuid>/history/<string:timestamp>',
                            resource_class_kwargs={'datastore': datastore, 'update_q': update_q})
@@ -345,25 +479,62 @@ def changedetection_app(config=None, datastore_o=None):
 
     @login_manager.unauthorized_handler
     def unauthorized_handler():
-        flash("You must be logged in, please log in.", 'error')
-        return redirect(url_for('login', next=url_for('watchlist.index')))
+        # Pass the current request path so users are redirected back after login
+        return redirect(url_for('login', redirect=request.path))
 
     @app.route('/logout')
     def logout():
         flask_login.logout_user()
+
+        # Check if there's a redirect parameter to return to after re-login
+        redirect_url = request.args.get('redirect')
+
+        # If redirect is provided and safe, pass it to login page
+        if redirect_url and is_safe_url(redirect_url):
+            return redirect(url_for('login', redirect=redirect_url))
+
+        # Otherwise just go to watchlist
+        return redirect(url_for('watchlist.index'))
+
+    @app.route('/set-language/<locale>')
+    def set_language(locale):
+        """Set the user's preferred language in the session"""
+        # Validate the locale against available languages
+        if locale in language_codes:
+            session['locale'] = locale
+        else:
+            logger.error(f"Invalid locale {locale}, available: {language_codes}")
+
+        # Check if there's a redirect parameter to return to the same page
+        redirect_url = request.args.get('redirect')
+
+        # If redirect is provided and safe, use it
+        if redirect_url and is_safe_url(redirect_url):
+            return redirect(redirect_url)
+
+        # Otherwise redirect to watchlist
         return redirect(url_for('watchlist.index'))
 
     # https://github.com/pallets/flask/blob/93dd1709d05a1cf0e886df6223377bdab3b077fb/examples/tutorial/flaskr/__init__.py#L39
     # You can divide up the stuff like this
     @app.route('/login', methods=['GET', 'POST'])
     def login():
+        # Extract and validate the redirect parameter
+        redirect_url = request.args.get('redirect') or request.form.get('redirect')
+
+        # Validate the redirect URL - default to watchlist if invalid
+        if redirect_url and is_safe_url(redirect_url):
+            validated_redirect = redirect_url
+        else:
+            validated_redirect = url_for('watchlist.index')
 
         if request.method == 'GET':
             if flask_login.current_user.is_authenticated:
-                flash("Already logged in")
-                return redirect(url_for("watchlist.index"))
-
-            output = render_template("login.html")
+                # Already logged in - redirect immediately to the target
+                flash(gettext("Already logged in"))
+                return redirect(validated_redirect)
+            flash(gettext("You must be logged in, please log in."), 'error')
+            output = render_template("login.html", redirect_url=validated_redirect)
             return output
 
         user = User()
@@ -373,23 +544,13 @@ def changedetection_app(config=None, datastore_o=None):
 
         if (user.check_password(password)):
             flask_login.login_user(user, remember=True)
-
-            # For now there's nothing else interesting here other than the index/list page
-            # It's more reliable and safe to ignore the 'next' redirect
-            # When we used...
-            # next = request.args.get('next')
-            # return redirect(next or url_for('watchlist.index'))
-            # We would sometimes get login loop errors on sites hosted in sub-paths
-
-            # note for the future:
-            #            if not is_safe_url(next):
-            #                return flask.abort(400)
-            return redirect(url_for('watchlist.index'))
+            # Redirect to the validated URL after successful login
+            return redirect(validated_redirect)
 
         else:
-            flash('Incorrect password', 'error')
+            flash(gettext('Incorrect password'), 'error')
 
-        return redirect(url_for('login'))
+        return redirect(url_for('login', redirect=redirect_url if redirect_url else None))
 
     @app.before_request
     def before_request_handle_cookie_x_settings():
@@ -399,6 +560,40 @@ def changedetection_app(config=None, datastore_o=None):
             app.config['SESSION_COOKIE_PATH'] = request.headers['X-Forwarded-Prefix']
         return None
 
+    @app.route("/static/flags/<path:flag_path>", methods=['GET'])
+    def static_flags(flag_path):
+        """Handle flag icon files with subdirectories"""
+        from flask import make_response
+        import re
+
+        # flag_path comes in as "1x1/de.svg" or "4x3/de.svg"
+        if re.match(r'^(1x1|4x3)/[a-z0-9-]+\.svg$', flag_path.lower()):
+            # Reconstruct the path safely with additional validation
+            parts = flag_path.lower().split('/')
+            if len(parts) != 2:
+                abort(404)
+
+            subdir = parts[0]
+            svg_file = parts[1]
+
+            # Extra validation: ensure subdir is exactly 1x1 or 4x3
+            if subdir not in ['1x1', '4x3']:
+                abort(404)
+
+            # Extra validation: ensure svg_file only contains safe characters
+            if not re.match(r'^[a-z0-9-]+\.svg$', svg_file):
+                abort(404)
+
+            try:
+                response = make_response(send_from_directory(f"static/flags/{subdir}", svg_file))
+                response.headers['Content-type'] = 'image/svg+xml'
+                response.headers['Cache-Control'] = 'max-age=86400, public'  # Cache for 24 hours
+                return response
+            except FileNotFoundError:
+                abort(404)
+        else:
+            abort(404)
+
     @app.route("/static/<string:group>/<string:filename>", methods=['GET'])
     def static_content(group, filename):
         from flask import make_response
@@ -483,6 +678,31 @@ def changedetection_app(config=None, datastore_o=None):
             except FileNotFoundError:
                 abort(404)
 
+        # Handle plugin group specially
+        if group == 'plugin':
+            # Serve files from plugin static directories
+            from changedetectionio.pluggy_interface import plugin_manager
+            import os as os_check
+
+            for plugin_name, plugin_obj in plugin_manager.list_name_plugin():
+                if hasattr(plugin_obj, 'plugin_static_path'):
+                    try:
+                        static_path = plugin_obj.plugin_static_path()
+                        if static_path and os_check.path.isdir(static_path):
+                            # Check if file exists in plugin's static directory
+                            plugin_file_path = os_check.path.join(static_path, filename)
+                            if os_check.path.isfile(plugin_file_path):
+                                # Found the file in a plugin
+                                response = make_response(send_from_directory(static_path, filename))
+                                response.headers['Cache-Control'] = 'max-age=3600, public'  # Cache for 1 hour
+                                return response
+                    except Exception as e:
+                        logger.debug(f"Error checking plugin {plugin_name} for static file: {e}")
+                        pass
+
+            # File not found in any plugin
+            abort(404)
+
         # These files should be in our subdirectory
         try:
             return send_from_directory(f"static/{group}", path=filename)
@@ -789,15 +1009,19 @@ def ticker_thread_check_time_launch_checks():
 
             # @todo - Maybe make this a hook?
             # Time schedule limit - Decide between watch or global settings
+            scheduler_source = None
             if watch.get('time_between_check_use_default'):
                 time_schedule_limit = datastore.data['settings']['requests'].get('time_schedule_limit', {})
-                logger.trace(f"{uuid} Time scheduler - Using system/global settings")
+                scheduler_source = 'system/global settings'
+
             else:
                 time_schedule_limit = watch.get('time_schedule_limit')
-                logger.trace(f"{uuid} Time scheduler - Using watch settings (not global settings)")
-            tz_name = datastore.data['settings']['application'].get('timezone', 'UTC')
+                scheduler_source = 'watch'
+
+            tz_name = datastore.data['settings']['application'].get('scheduler_timezone_default', os.getenv('TZ', 'UTC').strip())
 
             if time_schedule_limit and time_schedule_limit.get('enabled'):
+                logger.trace(f"{uuid} Time scheduler - Using scheduler settings from {scheduler_source}")
                 try:
                     result = is_within_schedule(time_schedule_limit=time_schedule_limit,
                                                 default_tz=tz_name
@@ -809,6 +1033,7 @@ def ticker_thread_check_time_launch_checks():
                     logger.error(
                         f"{uuid} - Recheck scheduler, error handling timezone, check skipped - TZ name '{tz_name}' - {str(e)}")
                     return False
+
             # If they supplied an individual entry minutes to threshold.
             threshold = recheck_time_system_seconds if watch.get('time_between_check_use_default') else watch.threshold_seconds()
 

changedetectionio/forms.py

@@ -2,15 +2,21 @@ import os
 import re
 from loguru import logger
 from wtforms.widgets.core import TimeInput
+from flask_babel import lazy_gettext as _l, gettext
 
-from changedetectionio.blueprint.rss import RSS_FORMAT_TYPES
+from changedetectionio.blueprint.rss import RSS_FORMAT_TYPES, RSS_TEMPLATE_TYPE_OPTIONS, RSS_TEMPLATE_HTML_DEFAULT
 from changedetectionio.conditions.form import ConditionFormRow
+from changedetectionio.notification_service import NotificationContextData
+from changedetectionio.processors.image_ssim_diff import SCREENSHOT_COMPARISON_THRESHOLD_OPTIONS, \
+    SCREENSHOT_COMPARISON_THRESHOLD_OPTIONS_DEFAULT
 from changedetectionio.strtobool import strtobool
+from changedetectionio import processors
 
 from wtforms import (
     BooleanField,
     Form,
     Field,
+    FloatField,
     IntegerField,
     RadioField,
     SelectField,
@@ -27,11 +33,8 @@ from wtforms.utils import unset_value
 
 from wtforms.validators import ValidationError
 
-from validators.url import url as url_validator
-
 from changedetectionio.widgets import TernaryNoneBooleanField
 
-
 # default
 # each select <option data-enabled="enabled-0-0"
 from changedetectionio.blueprint.browser_steps.browser_steps import browser_step_ui_config
@@ -57,8 +60,8 @@ valid_method = {
 
 default_method = 'GET'
 allow_simplehost = not strtobool(os.getenv('BLOCK_SIMPLEHOSTS', 'False'))
-REQUIRE_ATLEAST_ONE_TIME_PART_MESSAGE_DEFAULT='At least one time interval (weeks, days, hours, minutes, or seconds) must be specified.'
-REQUIRE_ATLEAST_ONE_TIME_PART_WHEN_NOT_GLOBAL_DEFAULT='At least one time interval (weeks, days, hours, minutes, or seconds) must be specified when not using global settings.'
+REQUIRE_ATLEAST_ONE_TIME_PART_MESSAGE_DEFAULT=_l('At least one time interval (weeks, days, hours, minutes, or seconds) must be specified.')
+REQUIRE_ATLEAST_ONE_TIME_PART_WHEN_NOT_GLOBAL_DEFAULT=_l('At least one time interval (weeks, days, hours, minutes, or seconds) must be specified when not using global settings.')
 
 class StringListField(StringField):
     widget = widgets.TextArea()
@@ -158,7 +161,7 @@ class TimeStringField(Field):
             time_str = valuelist[0]
             # Simple validation for HH:MM format
             if not time_str or len(time_str.split(":")) != 2:
-                raise ValidationError("Invalid time format. Use HH:MM.")
+                raise ValidationError(_l("Invalid time format. Use HH:MM."))
             self.data = time_str
 
 
@@ -174,15 +177,15 @@ class validateTimeZoneName(object):
         from zoneinfo import available_timezones
         python_timezones = available_timezones()
         if field.data and field.data not in python_timezones:
-            raise ValidationError("Not a valid timezone name")
+            raise ValidationError(_l("Not a valid timezone name"))
 
 class ScheduleLimitDaySubForm(Form):
-    enabled = BooleanField("not set", default=True)
-    start_time = TimeStringField("Start At", default="00:00", validators=[validators.Optional()])
-    duration = FormField(TimeDurationForm, label="Run duration")
+    enabled = BooleanField(_l("not set"), default=True)
+    start_time = TimeStringField(_l("Start At"), default="00:00", validators=[validators.Optional()])
+    duration = FormField(TimeDurationForm, label=_l("Run duration"))
 
 class ScheduleLimitForm(Form):
-    enabled = BooleanField("Use time scheduler", default=False)
+    enabled = BooleanField(_l("Use time scheduler"), default=False)
     # Because the label for=""" doesnt line up/work with the actual checkbox
     monday = FormField(ScheduleLimitDaySubForm, label="")
     tuesday = FormField(ScheduleLimitDaySubForm, label="")
@@ -192,7 +195,7 @@ class ScheduleLimitForm(Form):
     saturday = FormField(ScheduleLimitDaySubForm, label="")
     sunday = FormField(ScheduleLimitDaySubForm, label="")
 
-    timezone = StringField("Optional timezone to run in",
+    timezone = StringField(_l("Optional timezone to run in"),
                                   render_kw={"list": "timezones"},
                                   validators=[validateTimeZoneName()]
                                   )
@@ -206,13 +209,13 @@ class ScheduleLimitForm(Form):
         **kwargs,
     ):
         super().__init__(formdata, obj, prefix, data, meta, **kwargs)
-        self.monday.form.enabled.label.text="Monday"
-        self.tuesday.form.enabled.label.text = "Tuesday"
-        self.wednesday.form.enabled.label.text = "Wednesday"
-        self.thursday.form.enabled.label.text = "Thursday"
-        self.friday.form.enabled.label.text = "Friday"
-        self.saturday.form.enabled.label.text = "Saturday"
-        self.sunday.form.enabled.label.text = "Sunday"
+        self.monday.form.enabled.label.text=_l("Monday")
+        self.tuesday.form.enabled.label.text = _l("Tuesday")
+        self.wednesday.form.enabled.label.text = _l("Wednesday")
+        self.thursday.form.enabled.label.text = _l("Thursday")
+        self.friday.form.enabled.label.text = _l("Friday")
+        self.saturday.form.enabled.label.text = _l("Saturday")
+        self.sunday.form.enabled.label.text = _l("Sunday")
 
 
 def validate_time_between_check_has_values(form):
@@ -237,7 +240,7 @@ class RequiredTimeInterval(object):
     Use this with FormField(TimeBetweenCheckForm, validators=[RequiredTimeInterval()]).
     """
     def __init__(self, message=None):
-        self.message = message or 'At least one time interval (weeks, days, hours, minutes, or seconds) must be specified.'
+        self.message = message or _l('At least one time interval (weeks, days, hours, minutes, or seconds) must be specified.')
 
     def __call__(self, form, field):
         if not validate_time_between_check_has_values(field.form):
@@ -245,11 +248,11 @@ class RequiredTimeInterval(object):
 
 
 class TimeBetweenCheckForm(Form):
-    weeks = IntegerField('Weeks', validators=[validators.Optional(), validators.NumberRange(min=0, message="Should contain zero or more seconds")])
-    days = IntegerField('Days', validators=[validators.Optional(), validators.NumberRange(min=0, message="Should contain zero or more seconds")])
-    hours = IntegerField('Hours', validators=[validators.Optional(), validators.NumberRange(min=0, message="Should contain zero or more seconds")])
-    minutes = IntegerField('Minutes', validators=[validators.Optional(), validators.NumberRange(min=0, message="Should contain zero or more seconds")])
-    seconds = IntegerField('Seconds', validators=[validators.Optional(), validators.NumberRange(min=0, message="Should contain zero or more seconds")])
+    weeks = IntegerField(_l('Weeks'), validators=[validators.Optional(), validators.NumberRange(min=0, message=_l("Should contain zero or more seconds"))])
+    days = IntegerField(_l('Days'), validators=[validators.Optional(), validators.NumberRange(min=0, message=_l("Should contain zero or more seconds"))])
+    hours = IntegerField(_l('Hours'), validators=[validators.Optional(), validators.NumberRange(min=0, message=_l("Should contain zero or more seconds"))])
+    minutes = IntegerField(_l('Minutes'), validators=[validators.Optional(), validators.NumberRange(min=0, message=_l("Should contain zero or more seconds"))])
+    seconds = IntegerField(_l('Seconds'), validators=[validators.Optional(), validators.NumberRange(min=0, message=_l("Should contain zero or more seconds"))])
     # @todo add total seconds minimum validatior = minimum_seconds_recheck_time
 
     def __init__(self, formdata=None, obj=None, prefix="", data=None, meta=None, **kwargs):
@@ -469,11 +472,16 @@ class ValidateAppRiseServers(object):
         import apprise
         from .notification.apprise_plugin.assets import apprise_asset
         from .notification.apprise_plugin.custom_handlers import apprise_http_custom_handler  # noqa: F401
+        from changedetectionio.jinja2_custom import render as jinja_render
 
         apobj = apprise.Apprise(asset=apprise_asset)
 
         for server_url in field.data:
-            url = server_url.strip()
+            generic_notification_context_data = NotificationContextData()
+            # Make sure something is atleast in all those regular token fields
+            generic_notification_context_data.set_random_for_validation()
+
+            url = jinja_render(template_str=server_url.strip(), **generic_notification_context_data).strip()
             if url.startswith("#"):
                 continue
 
@@ -487,9 +495,8 @@ class ValidateJinja2Template(object):
     """
     def __call__(self, form, field):
         from changedetectionio import notification
-
+        from changedetectionio.jinja2_custom import create_jinja_env
         from jinja2 import BaseLoader, TemplateSyntaxError, UndefinedError
-        from jinja2.sandbox import ImmutableSandboxedEnvironment
         from jinja2.meta import find_undeclared_variables
         import jinja2.exceptions
 
@@ -497,9 +504,13 @@ class ValidateJinja2Template(object):
         joined_data = ' '.join(map(str, field.data)) if isinstance(field.data, list) else f"{field.data}"
 
         try:
-            jinja2_env = ImmutableSandboxedEnvironment(loader=BaseLoader, extensions=['jinja2_time.TimeExtension'])
-            jinja2_env.globals.update(notification.valid_tokens)
-            # Extra validation tokens provided on the form_class(... extra_tokens={}) setup
+            # Use the shared helper to create a properly configured environment
+            jinja2_env = create_jinja_env(loader=BaseLoader)
+
+            # Add notification tokens for validation
+            static_token_placeholders = NotificationContextData()
+            static_token_placeholders.set_random_for_validation()
+            jinja2_env.globals.update(static_token_placeholders)
             if hasattr(field, 'extra_notification_tokens'):
                 jinja2_env.globals.update(field.extra_notification_tokens)
 
@@ -511,6 +522,7 @@ class ValidateJinja2Template(object):
         except jinja2.exceptions.SecurityError as e:
             raise ValidationError(f"This is not a valid Jinja2 template: {e}") from e
 
+        # Check for undeclared variables
         ast = jinja2_env.parse(joined_data)
         undefined = ", ".join(find_undeclared_variables(ast))
         if undefined:
@@ -533,19 +545,10 @@ class validateURL(object):
 
 
 def validate_url(test_url):
-    # If hosts that only contain alphanumerics are allowed ("localhost" for example)
-    try:
-        url_validator(test_url, simple_host=allow_simplehost)
-    except validators.ValidationError:
-        #@todo check for xss
-        message = f"'{test_url}' is not a valid URL."
+    from changedetectionio.validate_url import is_safe_valid_url
+    if not is_safe_valid_url(test_url):
         # This should be wtforms.validators.
-        raise ValidationError(message)
-
-    from .model.Watch import is_safe_url
-    if not is_safe_url(test_url):
-        # This should be wtforms.validators.
-        raise ValidationError('Watch protocol is not permitted by SAFE_PROTOCOL_REGEX or incorrect URL format')
+        raise ValidationError('Watch protocol is not permitted or invalid URL format')
 
 
 class ValidateSinglePythonRegexString(object):
@@ -678,15 +681,57 @@ class ValidateCSSJSONXPATHInput(object):
                 except:
                     raise ValidationError("A system-error occurred when validating your jq expression")
 
-class quickWatchForm(Form):
-    from . import processors
+class ValidateSimpleURL:
+    """Validate that the value can be parsed by urllib.parse.urlparse() and has a scheme/netloc."""
+    def __init__(self, message=None):
+        self.message = message or "Invalid URL."
 
+    def __call__(self, form, field):
+        data = (field.data or "").strip()
+        if not data:
+            return  # empty is OK — pair with validators.Optional()
+        from urllib.parse import urlparse
+
+        parsed = urlparse(data)
+        if not parsed.scheme or not parsed.netloc:
+            raise ValidationError(self.message)
+
+class ValidateStartsWithRegex(object):
+    def __init__(self, regex, *, flags=0, message=None, allow_empty=True, split_lines=True):
+        # compile with given flags (we’ll pass re.IGNORECASE below)
+        self.pattern = re.compile(regex, flags) if isinstance(regex, str) else regex
+        self.message = message
+        self.allow_empty = allow_empty
+        self.split_lines = split_lines
+
+    def __call__(self, form, field):
+        data = field.data
+        if not data:
+            return
+
+        # normalize into list of lines
+        if isinstance(data, str) and self.split_lines:
+            lines = data.splitlines()
+        elif isinstance(data, (list, tuple)):
+            lines = data
+        else:
+            lines = [data]
+
+        for line in lines:
+            stripped = line.strip()
+            if not stripped:
+                if self.allow_empty:
+                    continue
+                raise ValidationError(self.message or _l("Empty value not allowed."))
+            if not self.pattern.match(stripped):
+                raise ValidationError(self.message or _l("Invalid value."))
+
+class quickWatchForm(Form):
     url = fields.URLField('URL', validators=[validateURL()])
     tags = StringTagUUID('Group tag', [validators.Optional()])
-    watch_submit_button = SubmitField('Watch', render_kw={"class": "pure-button pure-button-primary"})
-    processor = RadioField(u'Processor', choices=processors.available_processors(), default="text_json_diff")
-    edit_and_watch_submit_button = SubmitField('Edit > Watch', render_kw={"class": "pure-button pure-button-primary"})
-
+    watch_submit_button = SubmitField(_l('Watch'), render_kw={"class": "pure-button pure-button-primary"})
+    processor = RadioField(_l('Processor'), choices=lambda: processors.available_processors(), default="text_json_diff")
+    edit_and_watch_submit_button = SubmitField(_l('Edit > Watch'), render_kw={"class": "pure-button pure-button-primary"})
 
 
 # Common to a single watch and the global settings
@@ -699,33 +744,40 @@ class commonSettingsForm(Form):
         self.notification_title.extra_notification_tokens = kwargs.get('extra_notification_tokens', {})
         self.notification_urls.extra_notification_tokens = kwargs.get('extra_notification_tokens', {})
 
-    fetch_backend = RadioField(u'Fetch Method', choices=content_fetchers.available_fetchers(), validators=[ValidateContentFetcherIsReady()])
-    notification_body = TextAreaField('Notification Body', default='{{ watch_url }} had a change.', validators=[validators.Optional(), ValidateJinja2Template()])
-    notification_format = SelectField('Notification format', choices=valid_notification_formats.keys())
-    notification_title = StringField('Notification Title', default='ChangeDetection.io Notification - {{ watch_url }}', validators=[validators.Optional(), ValidateJinja2Template()])
-    notification_urls = StringListField('Notification URL List', validators=[validators.Optional(), ValidateAppRiseServers(), ValidateJinja2Template()])
-    processor = RadioField( label=u"Processor - What do you want to achieve?", choices=processors.available_processors(), default="text_json_diff")
-    timezone = StringField("Timezone for watch schedule", render_kw={"list": "timezones"}, validators=[validateTimeZoneName()])
-    webdriver_delay = IntegerField('Wait seconds before extracting text', validators=[validators.Optional(), validators.NumberRange(min=1, message="Should contain one or more seconds")])
+    fetch_backend = RadioField(_l('Fetch Method'), choices=content_fetchers.available_fetchers(), validators=[ValidateContentFetcherIsReady()])
+    notification_body = TextAreaField(_l('Notification Body'), default='{{ watch_url }} had a change.', validators=[validators.Optional(), ValidateJinja2Template()])
+    notification_format = SelectField(_l('Notification format'), choices=list(valid_notification_formats.items()))
+    notification_title = StringField(_l('Notification Title'), default='ChangeDetection.io Notification - {{ watch_url }}', validators=[validators.Optional(), ValidateJinja2Template()])
+    notification_urls = StringListField(_l('Notification URL List'), validators=[validators.Optional(), ValidateAppRiseServers(), ValidateJinja2Template()])
+    processor = RadioField( label=_l("Processor - What do you want to achieve?"), choices=lambda: processors.available_processors(), default="text_json_diff")
+    scheduler_timezone_default = StringField(_l("Default timezone for watch check scheduler"), render_kw={"list": "timezones"}, validators=[validateTimeZoneName()])
+    webdriver_delay = IntegerField(_l('Wait seconds before extracting text'), validators=[validators.Optional(), validators.NumberRange(min=1, message=_l("Should contain one or more seconds"))])
+
+# Not true anymore but keep the validate_ hook for future use, we convert color tags
+#    def validate_notification_urls(self, field):
+#        """Validate that HTML Color format is not used with Telegram"""
+#        if self.notification_format.data == 'HTML Color' and field.data:
+#            for url in field.data:
+#                if url and ('tgram://' in url or 'discord://' in url or 'discord.com/api/webhooks' in url):
+#                    raise ValidationError('HTML Color format is not supported by Telegram and Discord. Please choose another Notification Format (Plain Text, HTML, or Markdown to HTML).')
 
 
 class importForm(Form):
-    from . import processors
-    processor = RadioField(u'Processor', choices=processors.available_processors(), default="text_json_diff")
-    urls = TextAreaField('URLs')
-    xlsx_file = FileField('Upload .xlsx file', validators=[FileAllowed(['xlsx'], 'Must be .xlsx file!')])
-    file_mapping = SelectField('File mapping', [validators.DataRequired()], choices={('wachete', 'Wachete mapping'), ('custom','Custom mapping')})
+    processor = RadioField(_l('Processor'), choices=lambda: processors.available_processors(), default="text_json_diff")
+    urls = TextAreaField(_l('URLs'))
+    xlsx_file = FileField(_l('Upload .xlsx file'), validators=[FileAllowed(['xlsx'], _l('Must be .xlsx file!'))])
+    file_mapping = SelectField(_l('File mapping'), [validators.DataRequired()], choices={('wachete', 'Wachete mapping'), ('custom','Custom mapping')})
 
 class SingleBrowserStep(Form):
 
-    operation = SelectField('Operation', [validators.Optional()], choices=browser_step_ui_config.keys())
+    operation = SelectField(_l('Operation'), [validators.Optional()], choices=browser_step_ui_config.keys())
 
     # maybe better to set some <script>var..
-    selector = StringField('Selector', [validators.Optional()], render_kw={"placeholder": "CSS or xPath selector"})
-    optional_value = StringField('value', [validators.Optional()], render_kw={"placeholder": "Value"})
+    selector = StringField(_l('Selector'), [validators.Optional()], render_kw={"placeholder": "CSS or xPath selector"})
+    optional_value = StringField(_l('value'), [validators.Optional()], render_kw={"placeholder": "Value"})
 #   @todo move to JS? ajax fetch new field?
-#    remove_button = SubmitField('-', render_kw={"type": "button", "class": "pure-button pure-button-primary", 'title': 'Remove'})
-#    add_button = SubmitField('+', render_kw={"type": "button", "class": "pure-button pure-button-primary", 'title': 'Add new step after'})
+#    remove_button = SubmitField(_l('-'), render_kw={"type": "button", "class": "pure-button pure-button-primary", 'title': 'Remove'})
+#    add_button = SubmitField(_l('+'), render_kw={"type": "button", "class": "pure-button pure-button-primary", 'title': 'Add new step after'})
 
 class processor_text_json_diff_form(commonSettingsForm):
 
@@ -741,49 +793,48 @@ class processor_text_json_diff_form(commonSettingsForm):
 
     time_schedule_limit = FormField(ScheduleLimitForm)
 
-    time_between_check_use_default = BooleanField('Use global settings for time between check and scheduler.', default=False)
+    time_between_check_use_default = BooleanField(_l('Use global settings for time between check and scheduler.'), default=False)
 
-    include_filters = StringListField('CSS/JSONPath/JQ/XPath Filters', [ValidateCSSJSONXPATHInput()], default='')
+    include_filters = StringListField(_l('CSS/JSONPath/JQ/XPath Filters'), [ValidateCSSJSONXPATHInput()], default='')
 
-    subtractive_selectors = StringListField('Remove elements', [ValidateCSSJSONXPATHInput(allow_json=False)])
+    subtractive_selectors = StringListField(_l('Remove elements'), [ValidateCSSJSONXPATHInput(allow_json=False)])
 
-    extract_text = StringListField('Extract text', [ValidateListRegex()])
+    extract_text = StringListField(_l('Extract text'), [ValidateListRegex()])
 
-    title = StringField('Title', default='')
+    title = StringField(_l('Title'), default='')
 
-    ignore_text = StringListField('Ignore lines containing', [ValidateListRegex()])
+    ignore_text = StringListField(_l('Ignore lines containing'), [ValidateListRegex()])
     headers = StringDictKeyValue('Request headers')
-    body = TextAreaField('Request body', [validators.Optional()])
-    method = SelectField('Request method', choices=valid_method, default=default_method)
-    ignore_status_codes = BooleanField('Ignore status codes (process non-2xx status codes as normal)', default=False)
-    check_unique_lines = BooleanField('Only trigger when unique lines appear in all history', default=False)
-    remove_duplicate_lines = BooleanField('Remove duplicate lines of text', default=False)
-    sort_text_alphabetically =  BooleanField('Sort text alphabetically', default=False)
-    strip_ignored_lines = TernaryNoneBooleanField('Strip ignored lines', default=None)
-    trim_text_whitespace = BooleanField('Trim whitespace before and after text', default=False)
+    body = TextAreaField(_l('Request body'), [validators.Optional()])
+    method = SelectField(_l('Request method'), choices=valid_method, default=default_method)
+    ignore_status_codes = BooleanField(_l('Ignore status codes (process non-2xx status codes as normal)'), default=False)
+    check_unique_lines = BooleanField(_l('Only trigger when unique lines appear in all history'), default=False)
+    remove_duplicate_lines = BooleanField(_l('Remove duplicate lines of text'), default=False)
+    sort_text_alphabetically =  BooleanField(_l('Sort text alphabetically'), default=False)
+    strip_ignored_lines = TernaryNoneBooleanField(_l('Strip ignored lines'), default=None)
+    trim_text_whitespace = BooleanField(_l('Trim whitespace before and after text'), default=False)
 
-    filter_text_added = BooleanField('Added lines', default=True)
-    filter_text_replaced = BooleanField('Replaced/changed lines', default=True)
-    filter_text_removed = BooleanField('Removed lines', default=True)
+    filter_text_added = BooleanField(_l('Added lines'), default=True)
+    filter_text_replaced = BooleanField(_l('Replaced/changed lines'), default=True)
+    filter_text_removed = BooleanField(_l('Removed lines'), default=True)
 
-    trigger_text = StringListField('Keyword triggers - Trigger/wait for text', [validators.Optional(), ValidateListRegex()])
+    trigger_text = StringListField(_l('Keyword triggers - Trigger/wait for text'), [validators.Optional(), ValidateListRegex()])
     if os.getenv("PLAYWRIGHT_DRIVER_URL"):
         browser_steps = FieldList(FormField(SingleBrowserStep), min_entries=10)
-    text_should_not_be_present = StringListField('Block change-detection while text matches', [validators.Optional(), ValidateListRegex()])
-    webdriver_js_execute_code = TextAreaField('Execute JavaScript before change detection', render_kw={"rows": "5"}, validators=[validators.Optional()])
+    text_should_not_be_present = StringListField(_l('Block change-detection while text matches'), [validators.Optional(), ValidateListRegex()])
+    webdriver_js_execute_code = TextAreaField(_l('Execute JavaScript before change detection'), render_kw={"rows": "5"}, validators=[validators.Optional()])
 
-    save_button = SubmitField('Save', render_kw={"class": "pure-button pure-button-primary"})
+    save_button = SubmitField(_l('Save'), render_kw={"class": "pure-button pure-button-primary"})
 
-    proxy = RadioField('Proxy')
+    proxy = RadioField(_l('Proxy'))
     # filter_failure_notification_send @todo make ternary
-    filter_failure_notification_send = BooleanField(
-        'Send a notification when the filter can no longer be found on the page', default=False)
-    notification_muted = TernaryNoneBooleanField('Notifications', default=None, yes_text="Muted", no_text="On")
-    notification_screenshot = BooleanField('Attach screenshot to notification (where possible)', default=False)
+    filter_failure_notification_send = BooleanField(_l('Send a notification when the filter can no longer be found on the page'), default=False)
+    notification_muted = TernaryNoneBooleanField(_l('Notifications'), default=None, yes_text=_l("Muted"), no_text=_l("On"))
+    notification_screenshot = BooleanField(_l('Attach screenshot to notification (where possible)'), default=False)
 
-    conditions_match_logic = RadioField(u'Match', choices=[('ALL', 'Match all of the following'),('ANY', 'Match any of the following')], default='ALL')
+    conditions_match_logic = RadioField(_l('Match'), choices=[('ALL', _l('Match all of the following')),('ANY', _l('Match any of the following'))], default='ALL')
     conditions = FieldList(FormField(ConditionFormRow), min_entries=1)  # Add rule logic here
-    use_page_title_in_list = TernaryNoneBooleanField('Use page <title> in list', default=None)
+    use_page_title_in_list = TernaryNoneBooleanField(_l('Use page <title> in list'), default=None)
 
     def extra_tab_content(self):
         return None
@@ -795,12 +846,12 @@ class processor_text_json_diff_form(commonSettingsForm):
         if not super().validate():
             return False
 
-        from changedetectionio.safe_jinja import render as jinja_render
+        from changedetectionio.jinja2_custom import render as jinja_render
         result = True
 
         # Fail form validation when a body is set for a GET
         if self.method.data == 'GET' and self.body.data:
-            self.body.errors.append('Body must be empty when Request Method is set to GET')
+            self.body.errors.append(gettext('Body must be empty when Request Method is set to GET'))
             result = False
 
         # Attempt to validate jinja2 templates in the URL
@@ -809,11 +860,11 @@ class processor_text_json_diff_form(commonSettingsForm):
         except ModuleNotFoundError as e:
             # incase jinja2_time or others is missing
             logger.error(e)
-            self.url.errors.append(f'Invalid template syntax configuration: {e}')
+            self.url.errors.append(gettext('Invalid template syntax configuration: %(error)s') % {'error': e})
             result = False
         except Exception as e:
             logger.error(e)
-            self.url.errors.append(f'Invalid template syntax: {e}')
+            self.url.errors.append(gettext('Invalid template syntax: %(error)s') % {'error': e})
             result = False
 
         # Attempt to validate jinja2 templates in the body
@@ -823,11 +874,11 @@ class processor_text_json_diff_form(commonSettingsForm):
             except ModuleNotFoundError as e:
                 # incase jinja2_time or others is missing
                 logger.error(e)
-                self.body.errors.append(f'Invalid template syntax configuration: {e}')
+                self.body.errors.append(gettext('Invalid template syntax configuration: %(error)s') % {'error': e})
                 result = False
             except Exception as e:
                 logger.error(e)
-                self.body.errors.append(f'Invalid template syntax: {e}')
+                self.body.errors.append(gettext('Invalid template syntax: %(error)s') % {'error': e})
                 result = False
 
         # Attempt to validate jinja2 templates in the headers
@@ -838,11 +889,11 @@ class processor_text_json_diff_form(commonSettingsForm):
             except ModuleNotFoundError as e:
                 # incase jinja2_time or others is missing
                 logger.error(e)
-                self.headers.errors.append(f'Invalid template syntax configuration: {e}')
+                self.headers.errors.append(gettext('Invalid template syntax configuration: %(error)s') % {'error': e})
                 result = False
             except Exception as e:
                 logger.error(e)
-                self.headers.errors.append(f'Invalid template syntax in "{header}" header: {e}')
+                self.headers.errors.append(gettext('Invalid template syntax in \"%(header)s\" header: %(error)s') % {'header': header, 'error': e})
                 result = False
 
         return result
@@ -858,92 +909,130 @@ class processor_text_json_diff_form(commonSettingsForm):
     ):
         super().__init__(formdata, obj, prefix, data, meta, **kwargs)
         if kwargs and kwargs.get('default_system_settings'):
-            default_tz = kwargs.get('default_system_settings').get('application', {}).get('timezone')
+            default_tz = kwargs.get('default_system_settings').get('application', {}).get('scheduler_timezone_default')
             if default_tz:
                 self.time_schedule_limit.form.timezone.render_kw['placeholder'] = default_tz
 
 
 
 class SingleExtraProxy(Form):
-
     # maybe better to set some <script>var..
-    proxy_name = StringField('Name', [validators.Optional()], render_kw={"placeholder": "Name"})
-    proxy_url = StringField('Proxy URL', [validators.Optional()], render_kw={"placeholder": "socks5:// or regular proxy http://user:pass@...:3128", "size":50})
-    # @todo do the validation here instead
+    proxy_name = StringField(_l('Name'), [validators.Optional()], render_kw={"placeholder": "Name"})
+    proxy_url = StringField(_l('Proxy URL'), [
+        validators.Optional(),
+        ValidateStartsWithRegex(
+            regex=r'^(https?|socks5)://',  # ✅ main pattern
+            flags=re.IGNORECASE,  # ✅ makes it case-insensitive
+            message=_l('Proxy URLs must start with http://, https:// or socks5://'),
+        ),
+        ValidateSimpleURL()
+    ], render_kw={"placeholder": "socks5:// or regular proxy http://user:pass@...:3128", "size":50})
 
 class SingleExtraBrowser(Form):
-    browser_name = StringField('Name', [validators.Optional()], render_kw={"placeholder": "Name"})
-    browser_connection_url = StringField('Browser connection URL', [validators.Optional()], render_kw={"placeholder": "wss://brightdata... wss://oxylabs etc", "size":50})
-    # @todo do the validation here instead
+    browser_name = StringField(_l('Name'), [validators.Optional()], render_kw={"placeholder": "Name"})
+    browser_connection_url = StringField(_l('Browser connection URL'), [
+        validators.Optional(),
+        ValidateStartsWithRegex(
+            regex=r'^(wss?|ws)://',
+            flags=re.IGNORECASE,
+            message=_l('Browser URLs must start with wss:// or ws://')
+        ),
+        ValidateSimpleURL()
+    ], render_kw={"placeholder": "wss://brightdata... wss://oxylabs etc", "size":50})
 
 class DefaultUAInputForm(Form):
-    html_requests = StringField('Plaintext requests', validators=[validators.Optional()], render_kw={"placeholder": "<default>"})
+    html_requests = StringField(_l('Plaintext requests'), validators=[validators.Optional()], render_kw={"placeholder": "<default>"})
     if os.getenv("PLAYWRIGHT_DRIVER_URL") or os.getenv("WEBDRIVER_URL"):
-        html_webdriver = StringField('Chrome requests', validators=[validators.Optional()], render_kw={"placeholder": "<default>"})
+        html_webdriver = StringField(_l('Chrome requests'), validators=[validators.Optional()], render_kw={"placeholder": "<default>"})
 
 # datastore.data['settings']['requests']..
 class globalSettingsRequestForm(Form):
     time_between_check = RequiredFormField(TimeBetweenCheckForm)
     time_schedule_limit = FormField(ScheduleLimitForm)
-    proxy = RadioField('Proxy')
-    jitter_seconds = IntegerField('Random jitter seconds ± check',
+    proxy = RadioField(_l('Default proxy'))
+    jitter_seconds = IntegerField(_l('Random jitter seconds ± check'),
                                   render_kw={"style": "width: 5em;"},
-                                  validators=[validators.NumberRange(min=0, message="Should contain zero or more seconds")])
+                                  validators=[validators.NumberRange(min=0, message=_l("Should contain zero or more seconds"))])
     
-    workers = IntegerField('Number of fetch workers',
+    workers = IntegerField(_l('Number of fetch workers'),
                           render_kw={"style": "width: 5em;"},
                           validators=[validators.NumberRange(min=1, max=50,
-                                                             message="Should be between 1 and 50")])
-    
+                                                             message=_l("Should be between 1 and 50"))])
+
+    timeout = IntegerField(_l('Requests timeout in seconds'),
+                           render_kw={"style": "width: 5em;"},
+                           validators=[validators.NumberRange(min=1, max=999,
+                                                              message=_l("Should be between 1 and 999"))])
+
     extra_proxies = FieldList(FormField(SingleExtraProxy), min_entries=5)
     extra_browsers = FieldList(FormField(SingleExtraBrowser), min_entries=5)
 
-    default_ua = FormField(DefaultUAInputForm, label="Default User-Agent overrides")
+    default_ua = FormField(DefaultUAInputForm, label=_l("Default User-Agent overrides"))
 
     def validate_extra_proxies(self, extra_validators=None):
         for e in self.data['extra_proxies']:
             if e.get('proxy_name') or e.get('proxy_url'):
                 if not e.get('proxy_name','').strip() or not e.get('proxy_url','').strip():
-                    self.extra_proxies.errors.append('Both a name, and a Proxy URL is required.')
+                    self.extra_proxies.errors.append(gettext('Both a name, and a Proxy URL is required.'))
                     return False
 
 class globalSettingsApplicationUIForm(Form):
-    open_diff_in_new_tab = BooleanField("Open 'History' page in a new tab", default=True, validators=[validators.Optional()])
-    socket_io_enabled = BooleanField('Realtime UI Updates Enabled', default=True, validators=[validators.Optional()])
-    favicons_enabled = BooleanField('Favicons Enabled', default=True, validators=[validators.Optional()])
-    use_page_title_in_list = BooleanField('Use page <title> in watch overview list') #BooleanField=True
+    open_diff_in_new_tab = BooleanField(_l("Open 'History' page in a new tab"), default=True, validators=[validators.Optional()])
+    socket_io_enabled = BooleanField(_l('Realtime UI Updates Enabled'), default=True, validators=[validators.Optional()])
+    favicons_enabled = BooleanField(_l('Favicons Enabled'), default=True, validators=[validators.Optional()])
+    use_page_title_in_list = BooleanField(_l('Use page <title> in watch overview list')) #BooleanField=True
 
 # datastore.data['settings']['application']..
 class globalSettingsApplicationForm(commonSettingsForm):
 
-    api_access_token_enabled = BooleanField('API access token security check enabled', default=True, validators=[validators.Optional()])
-    base_url = StringField('Notification base URL override',
+    api_access_token_enabled = BooleanField(_l('API access token security check enabled'), default=True, validators=[validators.Optional()])
+    base_url = StringField(_l('Notification base URL override'),
                            validators=[validators.Optional()],
                            render_kw={"placeholder": os.getenv('BASE_URL', 'Not set')}
                            )
-    empty_pages_are_a_change =  BooleanField('Treat empty pages as a change?', default=False)
-    fetch_backend = RadioField('Fetch Method', default="html_requests", choices=content_fetchers.available_fetchers(), validators=[ValidateContentFetcherIsReady()])
-    global_ignore_text = StringListField('Ignore Text', [ValidateListRegex()])
-    global_subtractive_selectors = StringListField('Remove elements', [ValidateCSSJSONXPATHInput(allow_json=False)])
-    ignore_whitespace = BooleanField('Ignore whitespace')
+    empty_pages_are_a_change =  BooleanField(_l('Treat empty pages as a change?'), default=False)
+    fetch_backend = RadioField(_l('Fetch Method'), default="html_requests", choices=content_fetchers.available_fetchers(), validators=[ValidateContentFetcherIsReady()])
+    global_ignore_text = StringListField(_l('Ignore Text'), [ValidateListRegex()])
+    global_subtractive_selectors = StringListField(_l('Remove elements'), [ValidateCSSJSONXPATHInput(allow_json=False)])
+    ignore_whitespace = BooleanField(_l('Ignore whitespace'))
+
+    # Screenshot comparison settings
+    min_change_percentage = FloatField(
+        'Screenshot: Minimum Change Percentage',
+        validators=[
+            validators.Optional(),
+            validators.NumberRange(min=0.0, max=100.0, message=_l('Must be between 0 and 100'))
+        ],
+        default=0.1,
+        render_kw={"placeholder": "0.1", "style": "width: 8em;"}
+    )
+
     password = SaltyPasswordField()
-    pager_size = IntegerField('Pager size',
+    pager_size = IntegerField(_l('Pager size'),
                               render_kw={"style": "width: 5em;"},
                               validators=[validators.NumberRange(min=0,
-                                                                 message="Should be atleast zero (disabled)")])
+                                                                 message=_l("Should be atleast zero (disabled)"))])
 
-    rss_content_format = SelectField('RSS Content format', choices=RSS_FORMAT_TYPES)
+    rss_content_format = SelectField(_l('RSS Content format'), choices=list(RSS_FORMAT_TYPES.items()))
+    rss_template_type = SelectField(_l('RSS <description> body built from'), choices=list(RSS_TEMPLATE_TYPE_OPTIONS.items()))
+    rss_template_override = TextAreaField(_l('RSS "System default" template override'), render_kw={"rows": "5", "placeholder": RSS_TEMPLATE_HTML_DEFAULT}, validators=[validators.Optional(), ValidateJinja2Template()])
 
-    removepassword_button = SubmitField('Remove password', render_kw={"class": "pure-button pure-button-primary"})
-    render_anchor_tag_content = BooleanField('Render anchor tag content', default=False)
-    shared_diff_access = BooleanField('Allow anonymous access to watch history page when password is enabled', default=False, validators=[validators.Optional()])
-    strip_ignored_lines = BooleanField('Strip ignored lines')
-    rss_hide_muted_watches = BooleanField('Hide muted watches from RSS feed', default=True,
+    removepassword_button = SubmitField(_l('Remove password'), render_kw={"class": "pure-button pure-button-primary"})
+    render_anchor_tag_content = BooleanField(_l('Render anchor tag content'), default=False)
+    shared_diff_access = BooleanField(_l('Allow anonymous access to watch history page when password is enabled'), default=False, validators=[validators.Optional()])
+    strip_ignored_lines = BooleanField(_l('Strip ignored lines'))
+    rss_hide_muted_watches = BooleanField(_l('Hide muted watches from RSS feed'), default=True,
                                       validators=[validators.Optional()])
-    filter_failure_notification_threshold_attempts = IntegerField('Number of times the filter can be missing before sending a notification',
+
+    rss_reader_mode = BooleanField(_l('Enable RSS reader mode '), default=False, validators=[validators.Optional()])
+    rss_diff_length = IntegerField(label=_l('Number of changes to show in watch RSS feed'),
+                                   render_kw={"style": "width: 5em;"},
+                                   validators=[validators.NumberRange(min=0, message=_l("Should contain zero or more attempts"))])
+
+    filter_failure_notification_threshold_attempts = IntegerField(_l('Number of times the filter can be missing before sending a notification'),
                                                                   render_kw={"style": "width: 5em;"},
                                                                   validators=[validators.NumberRange(min=0,
-                                                                                                     message="Should contain zero or more attempts")])
+                                                                                                     message=_l("Should contain zero or more attempts"))])
     ui = FormField(globalSettingsApplicationUIForm)
 
 
@@ -959,9 +1048,9 @@ class globalSettingsForm(Form):
 
     requests = FormField(globalSettingsRequestForm)
     application = FormField(globalSettingsApplicationForm)
-    save_button = SubmitField('Save', render_kw={"class": "pure-button pure-button-primary"})
+    save_button = SubmitField(_l('Save'), render_kw={"class": "pure-button pure-button-primary"})
 
 
 class extractDataForm(Form):
-    extract_regex = StringField('RegEx to extract', validators=[validators.DataRequired(), ValidateSinglePythonRegexString()])
-    extract_submit_button = SubmitField('Extract as CSV', render_kw={"class": "pure-button pure-button-primary"})
+    extract_regex = StringField(_l('RegEx to extract'), validators=[validators.DataRequired(), ValidateSinglePythonRegexString()])
+    extract_submit_button = SubmitField(_l('Extract as CSV'), render_kw={"class": "pure-button pure-button-primary"})

changedetectionio/html_tools.py

@@ -1,5 +1,6 @@
+from functools import lru_cache
+
 from loguru import logger
-from lxml import etree
 from typing import List
 import html
 import json
@@ -14,7 +15,6 @@ TITLE_RE = re.compile(r"<title[^>]*>(.*?)</title>", re.I | re.S)
 META_CS  = re.compile(r'<meta[^>]+charset=["\']?\s*([a-z0-9_\-:+.]+)', re.I)
 META_CT  = re.compile(r'<meta[^>]+http-equiv=["\']?content-type["\']?[^>]*content=["\'][^>]*charset=([a-z0-9_\-:+.]+)', re.I)
 
-
 # 'price' , 'lowPrice', 'highPrice' are usually under here
 # All of those may or may not appear on different websites - I didnt find a way todo case-insensitive searching here
 LD_JSON_PRODUCT_OFFER_SELECTORS = ["json:$..offers", "json:$..Offers"]
@@ -23,9 +23,9 @@ class JSONNotFound(ValueError):
     def __init__(self, msg):
         ValueError.__init__(self, msg)
 
-
 # Doesn't look like python supports forward slash auto enclosure in re.findall
 # So convert it to inline flag "(?i)foobar" type configuration
+@lru_cache(maxsize=100)
 def perl_style_slash_enclosed_regex_to_options(regex):
 
     res = re.search(PERL_STYLE_REGEX, regex, re.IGNORECASE)
@@ -58,13 +58,17 @@ def include_filters(include_filters, html_content, append_pretty_line_formatting
 
     return html_block
 
-def subtractive_css_selector(css_selector, html_content):
+def subtractive_css_selector(css_selector, content):
     from bs4 import BeautifulSoup
-    soup = BeautifulSoup(html_content, "html.parser")
+    soup = BeautifulSoup(content, "html.parser")
 
     # So that the elements dont shift their index, build a list of elements here which will be pointers to their place in the DOM
     elements_to_remove = soup.select(css_selector)
 
+    if not elements_to_remove:
+        # Better to return the original that rebuild with BeautifulSoup
+        return content
+
     # Then, remove them in a separate loop
     for item in elements_to_remove:
         item.decompose()
@@ -72,6 +76,7 @@ def subtractive_css_selector(css_selector, html_content):
     return str(soup)
 
 def subtractive_xpath_selector(selectors: List[str], html_content: str) -> str:
+    from lxml import etree
     # Parse the HTML content using lxml
     html_tree = etree.HTML(html_content)
 
@@ -83,6 +88,10 @@ def subtractive_xpath_selector(selectors: List[str], html_content: str) -> str:
         # Collect elements for each selector
         elements_to_remove.extend(html_tree.xpath(selector))
 
+    # If no elements were found, return the original HTML content
+    if not elements_to_remove:
+        return html_content
+
     # Then, remove them in a separate loop
     for element in elements_to_remove:
         if element.getparent() is not None:  # Ensure the element has a parent before removing
@@ -100,7 +109,7 @@ def element_removal(selectors: List[str], html_content):
     xpath_selectors = []
 
     for selector in selectors:
-        if selector.startswith(('xpath:', 'xpath1:', '//')):
+        if selector.strip().startswith(('xpath:', 'xpath1:', '//')):
             # Handle XPath selectors separately
             xpath_selector = selector.removeprefix('xpath:').removeprefix('xpath1:')
             xpath_selectors.append(xpath_selector)
@@ -163,75 +172,131 @@ def elementpath_tostring(obj):
     return str(obj)
 
 # Return str Utf-8 of matched rules
-def xpath_filter(xpath_filter, html_content, append_pretty_line_formatting=False, is_rss=False):
+def xpath_filter(xpath_filter, html_content, append_pretty_line_formatting=False, is_xml=False):
+    """
+
+    :param xpath_filter:
+    :param html_content:
+    :param append_pretty_line_formatting:
+    :param is_xml: set to true if is XML or is RSS (RSS is XML)
+    :return:
+    """
     from lxml import etree, html
     import elementpath
     # xpath 2.0-3.1
     from elementpath.xpath3 import XPath3Parser
 
     parser = etree.HTMLParser()
-    if is_rss:
-        # So that we can keep CDATA for cdata_in_document_to_text() to process
-        parser = etree.XMLParser(strip_cdata=False)
-
-    tree = html.fromstring(bytes(html_content, encoding='utf-8'), parser=parser)
-    html_block = ""
-
-    r = elementpath.select(tree, xpath_filter.strip(), namespaces={'re': 'http://exslt.org/regular-expressions'}, parser=XPath3Parser)
-    #@note: //title/text() wont work where <title>CDATA..
-
-    if type(r) != list:
-        r = [r]
-
-    for element in r:
-        # When there's more than 1 match, then add the suffix to separate each line
-        # And where the matched result doesn't include something that will cause Inscriptis to add a newline
-        # (This way each 'match' reliably has a new-line in the diff)
-        # Divs are converted to 4 whitespaces by inscriptis
-        if append_pretty_line_formatting and len(html_block) and (not hasattr( element, 'tag' ) or not element.tag in (['br', 'hr', 'div', 'p'])):
-            html_block += TEXT_FILTER_LIST_LINE_SUFFIX
-
-        if type(element) == str:
-            html_block += element
-        elif issubclass(type(element), etree._Element) or issubclass(type(element), etree._ElementTree):
-            html_block += etree.tostring(element, pretty_print=True).decode('utf-8')
+    tree = None
+    try:
+        if is_xml:
+            # So that we can keep CDATA for cdata_in_document_to_text() to process
+            parser = etree.XMLParser(strip_cdata=False)
+            # For XML/RSS content, use etree.fromstring to properly handle XML declarations
+            tree = etree.fromstring(html_content.encode('utf-8') if isinstance(html_content, str) else html_content, parser=parser)
         else:
-            html_block += elementpath_tostring(element)
+            tree = html.fromstring(html_content, parser=parser)
+        html_block = ""
 
-    return html_block
+        # Build namespace map for XPath queries
+        namespaces = {'re': 'http://exslt.org/regular-expressions'}
+
+        # Handle default namespace in documents (common in RSS/Atom feeds, but can occur in any XML)
+        # XPath spec: unprefixed element names have no namespace, not the default namespace
+        # Solution: Register the default namespace with empty string prefix in elementpath
+        # This is primarily for RSS/Atom feeds but works for any XML with default namespace
+        if hasattr(tree, 'nsmap') and tree.nsmap and None in tree.nsmap:
+            # Register the default namespace with empty string prefix for elementpath
+            # This allows //title to match elements in the default namespace
+            namespaces[''] = tree.nsmap[None]
+
+        r = elementpath.select(tree, xpath_filter.strip(), namespaces=namespaces, parser=XPath3Parser)
+        #@note: //title/text() now works with default namespaces (fixed by registering '' prefix)
+        #@note: //title/text() wont work where <title>CDATA.. (use cdata_in_document_to_text first)
+
+        if type(r) != list:
+            r = [r]
+
+        for element in r:
+            # When there's more than 1 match, then add the suffix to separate each line
+            # And where the matched result doesn't include something that will cause Inscriptis to add a newline
+            # (This way each 'match' reliably has a new-line in the diff)
+            # Divs are converted to 4 whitespaces by inscriptis
+            if append_pretty_line_formatting and len(html_block) and (not hasattr( element, 'tag' ) or not element.tag in (['br', 'hr', 'div', 'p'])):
+                html_block += TEXT_FILTER_LIST_LINE_SUFFIX
+
+            if type(element) == str:
+                html_block += element
+            elif issubclass(type(element), etree._Element) or issubclass(type(element), etree._ElementTree):
+                # Use 'xml' method for RSS/XML content, 'html' for HTML content
+                # parser will be XMLParser if we detected XML content
+                method = 'xml' if (is_xml or isinstance(parser, etree.XMLParser)) else 'html'
+                html_block += etree.tostring(element, pretty_print=True, method=method, encoding='unicode')
+            else:
+                html_block += elementpath_tostring(element)
+
+        return html_block
+    finally:
+        # Explicitly clear the tree to free memory
+        # lxml trees can hold significant memory, especially with large documents
+        if tree is not None:
+            tree.clear()
 
 # Return str Utf-8 of matched rules
 # 'xpath1:'
-def xpath1_filter(xpath_filter, html_content, append_pretty_line_formatting=False, is_rss=False):
+def xpath1_filter(xpath_filter, html_content, append_pretty_line_formatting=False, is_xml=False):
     from lxml import etree, html
 
     parser = None
-    if is_rss:
-        # So that we can keep CDATA for cdata_in_document_to_text() to process
-        parser = etree.XMLParser(strip_cdata=False)
-
-    tree = html.fromstring(bytes(html_content, encoding='utf-8'), parser=parser)
-    html_block = ""
-
-    r = tree.xpath(xpath_filter.strip(), namespaces={'re': 'http://exslt.org/regular-expressions'})
-    #@note: //title/text() wont work where <title>CDATA..
-
-    for element in r:
-        # When there's more than 1 match, then add the suffix to separate each line
-        # And where the matched result doesn't include something that will cause Inscriptis to add a newline
-        # (This way each 'match' reliably has a new-line in the diff)
-        # Divs are converted to 4 whitespaces by inscriptis
-        if append_pretty_line_formatting and len(html_block) and (not hasattr(element, 'tag') or not element.tag in (['br', 'hr', 'div', 'p'])):
-            html_block += TEXT_FILTER_LIST_LINE_SUFFIX
-
-        # Some kind of text, UTF-8 or other
-        if isinstance(element, (str, bytes)):
-            html_block += element
+    tree = None
+    try:
+        if is_xml:
+            # So that we can keep CDATA for cdata_in_document_to_text() to process
+            parser = etree.XMLParser(strip_cdata=False)
+            # For XML/RSS content, use etree.fromstring to properly handle XML declarations
+            tree = etree.fromstring(html_content.encode('utf-8') if isinstance(html_content, str) else html_content, parser=parser)
         else:
-            # Return the HTML which will get parsed as text
-            html_block += etree.tostring(element, pretty_print=True).decode('utf-8')
+            tree = html.fromstring(html_content, parser=parser)
+        html_block = ""
 
-    return html_block
+        # Build namespace map for XPath queries
+        namespaces = {'re': 'http://exslt.org/regular-expressions'}
+
+        # NOTE: lxml's native xpath() does NOT support empty string prefix for default namespace
+        # For documents with default namespace (RSS/Atom feeds), users must use:
+        #   - local-name(): //*[local-name()='title']/text()
+        #   - Or use xpath_filter (not xpath1_filter) which supports default namespaces
+        # XPath spec: unprefixed element names have no namespace, not the default namespace
+
+        r = tree.xpath(xpath_filter.strip(), namespaces=namespaces)
+        #@note: xpath1 (lxml) does NOT automatically handle default namespaces
+        #@note: Use //*[local-name()='element'] or switch to xpath_filter for default namespace support
+        #@note: //title/text() wont work where <title>CDATA.. (use cdata_in_document_to_text first)
+
+        for element in r:
+            # When there's more than 1 match, then add the suffix to separate each line
+            # And where the matched result doesn't include something that will cause Inscriptis to add a newline
+            # (This way each 'match' reliably has a new-line in the diff)
+            # Divs are converted to 4 whitespaces by inscriptis
+            if append_pretty_line_formatting and len(html_block) and (not hasattr(element, 'tag') or not element.tag in (['br', 'hr', 'div', 'p'])):
+                html_block += TEXT_FILTER_LIST_LINE_SUFFIX
+
+            # Some kind of text, UTF-8 or other
+            if isinstance(element, (str, bytes)):
+                html_block += element
+            else:
+                # Return the HTML/XML which will get parsed as text
+                # Use 'xml' method for RSS/XML content, 'html' for HTML content
+                # parser will be XMLParser if we detected XML content
+                method = 'xml' if (is_xml or isinstance(parser, etree.XMLParser)) else 'html'
+                html_block += etree.tostring(element, pretty_print=True, method=method, encoding='unicode')
+
+        return html_block
+    finally:
+        # Explicitly clear the tree to free memory
+        # lxml trees can hold significant memory, especially with large documents
+        if tree is not None:
+            tree.clear()
 
 # Extract/find element
 def extract_element(find='title', html_content=''):
@@ -295,70 +360,92 @@ def _get_stripped_text_from_json_match(match):
 
     return stripped_text_from_html
 
+def extract_json_blob_from_html(content, ensure_is_ldjson_info_type, json_filter):
+    from bs4 import BeautifulSoup
+    stripped_text_from_html = ''
+
+    # Foreach <script json></script> blob.. just return the first that matches json_filter
+    # As a last resort, try to parse the whole <body>
+    soup = BeautifulSoup(content, 'html.parser')
+
+    if ensure_is_ldjson_info_type:
+        bs_result = soup.find_all('script', {"type": "application/ld+json"})
+    else:
+        bs_result = soup.find_all('script')
+    bs_result += soup.find_all('body')
+
+    bs_jsons = []
+
+    for result in bs_result:
+        # result.text is how bs4 magically strips JSON from the body
+        content_start = result.text.lstrip("\ufeff").strip()[:100] if result.text else ''
+        # Skip empty tags, and things that dont even look like JSON
+        if not result.text or not (content_start[0] == '{' or content_start[0] == '['):
+            continue
+        try:
+            json_data = json.loads(result.text)
+            bs_jsons.append(json_data)
+        except json.JSONDecodeError:
+            # Skip objects which cannot be parsed
+            continue
+
+    if not bs_jsons:
+        raise JSONNotFound("No parsable JSON found in this document")
+
+    for json_data in bs_jsons:
+        stripped_text_from_html = _parse_json(json_data, json_filter)
+
+        if ensure_is_ldjson_info_type:
+            # Could sometimes be list, string or something else random
+            if isinstance(json_data, dict):
+                # If it has LD JSON 'key' @type, and @type is 'product', and something was found for the search
+                # (Some sites have multiple of the same ld+json @type='product', but some have the review part, some have the 'price' part)
+                # @type could also be a list although non-standard ("@type": ["Product", "SubType"],)
+                # LD_JSON auto-extract also requires some content PLUS the ldjson to be present
+                # 1833 - could be either str or dict, should not be anything else
+
+                t = json_data.get('@type')
+                if t and stripped_text_from_html:
+
+                    if isinstance(t, str) and t.lower() == ensure_is_ldjson_info_type.lower():
+                        break
+                    # The non-standard part, some have a list
+                    elif isinstance(t, list):
+                        if ensure_is_ldjson_info_type.lower() in [x.lower().strip() for x in t]:
+                            break
+
+        elif stripped_text_from_html:
+            break
+
+    return stripped_text_from_html
+
 # content - json
 # json_filter - ie json:$..price
 # ensure_is_ldjson_info_type - str "product", optional, "@type == product" (I dont know how to do that as a json selector)
 def extract_json_as_string(content, json_filter, ensure_is_ldjson_info_type=None):
-    from bs4 import BeautifulSoup
 
     stripped_text_from_html = False
 # https://github.com/dgtlmoon/changedetection.io/pull/2041#issuecomment-1848397161w
     # Try to parse/filter out the JSON, if we get some parser error, then maybe it's embedded within HTML tags
-    try:
-        # .lstrip("\ufeff") strings ByteOrderMark from UTF8 and still lets the UTF work
-        stripped_text_from_html = _parse_json(json.loads(content.lstrip("\ufeff") ), json_filter)
-    except json.JSONDecodeError as e:
-        logger.warning(str(e))
 
-        # Foreach <script json></script> blob.. just return the first that matches json_filter
-        # As a last resort, try to parse the whole <body>
-        soup = BeautifulSoup(content, 'html.parser')
+    # Looks like clean JSON, dont bother extracting from HTML
 
-        if ensure_is_ldjson_info_type:
-            bs_result = soup.find_all('script', {"type": "application/ld+json"})
-        else:
-            bs_result = soup.find_all('script')
-        bs_result += soup.find_all('body')
+    content_start = content.lstrip("\ufeff").strip()[:100]
 
-        bs_jsons = []
-        for result in bs_result:
-            # Skip empty tags, and things that dont even look like JSON
-            if not result.text or '{' not in result.text:
-                continue
-            try:
-                json_data = json.loads(result.text)
-                bs_jsons.append(json_data)
-            except json.JSONDecodeError:
-                # Skip objects which cannot be parsed
-                continue
-
-        if not bs_jsons:
-            raise JSONNotFound("No parsable JSON found in this document")
-        
-        for json_data in bs_jsons:
-            stripped_text_from_html = _parse_json(json_data, json_filter)
-
-            if ensure_is_ldjson_info_type:
-                # Could sometimes be list, string or something else random
-                if isinstance(json_data, dict):
-                    # If it has LD JSON 'key' @type, and @type is 'product', and something was found for the search
-                    # (Some sites have multiple of the same ld+json @type='product', but some have the review part, some have the 'price' part)
-                    # @type could also be a list although non-standard ("@type": ["Product", "SubType"],)
-                    # LD_JSON auto-extract also requires some content PLUS the ldjson to be present
-                    # 1833 - could be either str or dict, should not be anything else
-
-                    t = json_data.get('@type')
-                    if t and stripped_text_from_html:
-
-                        if isinstance(t, str) and t.lower() == ensure_is_ldjson_info_type.lower():
-                            break
-                        # The non-standard part, some have a list
-                        elif isinstance(t, list):
-                            if ensure_is_ldjson_info_type.lower() in [x.lower().strip() for x in t]:
-                                break
-
-            elif stripped_text_from_html:
-                break
+    if content_start[0] == '{' or content_start[0] == '[':
+        try:
+            # .lstrip("\ufeff") strings ByteOrderMark from UTF8 and still lets the UTF work
+            stripped_text_from_html = _parse_json(json.loads(content.lstrip("\ufeff")), json_filter)
+        except json.JSONDecodeError as e:
+            logger.warning(f"Error processing JSON {content[:20]}...{str(e)})")
+    else:
+        # Probably something else, go fish inside for it
+        try:
+            stripped_text_from_html = extract_json_blob_from_html(content=content,
+                                                                  ensure_is_ldjson_info_type=ensure_is_ldjson_info_type,
+                                                                  json_filter=json_filter                                                                  )
+        except json.JSONDecodeError as e:
+            logger.warning(f"Error processing JSON while extracting JSON from HTML blob {content[:20]}...{str(e)})")
 
     if not stripped_text_from_html:
         # Re 265 - Just return an empty string when filter not found
@@ -377,7 +464,13 @@ def strip_ignore_text(content, wordlist, mode="content"):
     ignore_regex_multiline = []
     ignored_lines = []
 
+    if not content:
+        return ''
+
     for k in wordlist:
+        # Skip empty strings to avoid matching everything
+        if not k or not k.strip():
+            continue
         # Is it a regex?
         res = re.search(PERL_STYLE_REGEX, k, re.IGNORECASE)
         if res:

changedetectionio/is_safe_url.py

@@ -0,0 +1,113 @@
+"""
+URL redirect validation module for preventing open redirect vulnerabilities.
+
+This module provides functionality to safely validate redirect URLs, ensuring they:
+1. Point to internal routes only (no external redirects)
+2. Are properly normalized (preventing browser parsing differences)
+3. Match registered Flask routes (no fake/non-existent pages)
+4. Are fully logged for security monitoring
+
+References:
+- https://flask-login.readthedocs.io/ (safe redirect patterns)
+- https://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-v-user-logins
+- https://www.pythonkitchen.com/how-prevent-open-redirect-vulnerab-flask/
+"""
+
+from urllib.parse import urlparse, urljoin
+from flask import request
+from loguru import logger
+
+
+def is_safe_url(target, app):
+    """
+    Validate that a redirect URL is safe to prevent open redirect vulnerabilities.
+
+    This follows Flask/Werkzeug best practices by ensuring the redirect URL:
+    1. Is a relative path starting with exactly one '/'
+    2. Does not start with '//' (double-slash attack)
+    3. Has no external protocol handlers
+    4. Points to a valid registered route in the application
+    5. Is properly normalized to prevent browser parsing differences
+
+    Args:
+        target: The URL to validate (e.g., '/settings', '/login#top')
+        app: The Flask application instance (needed for route validation)
+
+    Returns:
+        bool: True if the URL is safe for redirection, False otherwise
+
+    Examples:
+        >>> is_safe_url('/settings', app)
+        True
+        >>> is_safe_url('//evil.com', app)
+        False
+        >>> is_safe_url('/settings#general', app)
+        True
+        >>> is_safe_url('/fake-page', app)
+        False
+    """
+    if not target:
+        return False
+
+    # Normalize the URL to prevent browser parsing differences
+    # Strip whitespace and replace backslashes (which some browsers interpret as forward slashes)
+    target = target.strip()
+    target = target.replace('\\', '/')
+
+    # First, check if it starts with // or more (double-slash attack)
+    if target.startswith('//'):
+        logger.warning(f"Blocked redirect attempt with double-slash: {target}")
+        return False
+
+    # Parse the URL to check for scheme and netloc
+    parsed = urlparse(target)
+
+    # Block any URL with a scheme (http://, https://, javascript:, etc.)
+    if parsed.scheme:
+        logger.warning(f"Blocked redirect attempt with scheme: {target}")
+        return False
+
+    # Block any URL with a network location (netloc)
+    # This catches patterns like //evil.com, user@host, etc.
+    if parsed.netloc:
+        logger.warning(f"Blocked redirect attempt with netloc: {target}")
+        return False
+
+    # At this point, we have a relative URL with no scheme or netloc
+    # Use urljoin to resolve it and verify it points to the same host
+    ref_url = urlparse(request.host_url)
+    test_url = urlparse(urljoin(request.host_url, target))
+
+    # Check: ensure the resolved URL has the same netloc as current host
+    if not (test_url.scheme in ('http', 'https') and ref_url.netloc == test_url.netloc):
+        logger.warning(f"Blocked redirect attempt with mismatched netloc: {target}")
+        return False
+
+    # Additional validation: Check if the URL matches a registered route
+    # This prevents redirects to non-existent pages or unintended endpoints
+    try:
+        # Get the path without query string and fragment
+        # Fragments (like #general) are automatically stripped by urlparse
+        path = parsed.path
+
+        # Create a URL adapter bound to the server name
+        adapter = app.url_map.bind(ref_url.netloc)
+
+        # Try to match the path to a registered route
+        # This will raise NotFound if the route doesn't exist
+        endpoint, values = adapter.match(path, return_rule=False)
+
+        # Block redirects to static file endpoints - these are catch-all routes
+        # that would match arbitrary paths, potentially allowing unintended redirects
+        if endpoint in ('static_content', 'static', 'static_flags'):
+            logger.warning(f"Blocked redirect to static endpoint: {target}")
+            return False
+
+        # Successfully matched a valid route
+        logger.debug(f"Validated safe redirect to endpoint '{endpoint}': {target}")
+        return True
+
+    except Exception as e:
+        # Route doesn't exist or can't be matched
+        logger.warning(f"Blocked redirect to non-existent route: {target} (error: {e})")
+        return False

changedetectionio/jinja2_custom/__init__.py

@@ -0,0 +1,22 @@
+"""
+Jinja2 custom extensions and safe rendering utilities.
+"""
+from .extensions.TimeExtension import TimeExtension
+from .safe_jinja import (
+    render,
+    render_fully_escaped,
+    create_jinja_env,
+    JINJA2_MAX_RETURN_PAYLOAD_SIZE,
+    DEFAULT_JINJA2_EXTENSIONS,
+)
+from .plugins.regex import regex_replace
+
+__all__ = [
+    'TimeExtension',
+    'render',
+    'render_fully_escaped',
+    'create_jinja_env',
+    'JINJA2_MAX_RETURN_PAYLOAD_SIZE',
+    'DEFAULT_JINJA2_EXTENSIONS',
+    'regex_replace',
+]

changedetectionio/jinja2_custom/extensions/TimeExtension.py

@@ -0,0 +1,221 @@
+"""
+Jinja2 TimeExtension - Custom date/time handling for templates.
+
+This extension provides the {% now %} tag for Jinja2 templates, offering timezone-aware
+date/time formatting with support for time offsets.
+
+Why This Extension Exists:
+    The Arrow library has a now() function (arrow.now()), but Jinja2 templates cannot
+    directly call Python functions - they need extensions or filters to expose functionality.
+
+    This TimeExtension serves as a Jinja2-to-Arrow bridge that:
+
+    1. Makes Arrow accessible in templates - Jinja2 requires registering functions/tags
+       through extensions. You cannot use arrow.now() directly in a template.
+
+    2. Provides template-friendly syntax - Instead of complex Python code, you get clean tags:
+       {% now 'UTC' %}
+       {% now 'UTC' + 'hours=2' %}
+       {% now 'Europe/London', '%Y-%m-%d' %}
+
+    3. Adds convenience features on top of Arrow:
+       - Default timezone from environment variable (TZ) or config
+       - Default datetime format configuration
+       - Offset syntax parsing: 'hours=2,minutes=30' → shift(hours=2, minutes=30)
+       - Empty string timezone support to use configured defaults
+
+    4. Maintains security - Works within Jinja2's sandboxed environment so users
+       cannot access arbitrary Python code or objects.
+
+    Essentially, this is a Jinja2 wrapper around arrow.now() and arrow.shift() that
+    provides user-friendly template syntax while maintaining security.
+
+Basic Usage:
+    {% now 'UTC' %}
+    # Output: Wed, 09 Dec 2015 23:33:01
+
+Custom Format:
+    {% now 'UTC', '%Y-%m-%d %H:%M:%S' %}
+    # Output: 2015-12-09 23:33:01
+
+Timezone Support:
+    {% now 'America/New_York' %}
+    {% now 'Europe/London' %}
+    {% now '' %}  # Uses default timezone from environment.default_timezone
+
+Time Offsets (Addition):
+    {% now 'UTC' + 'hours=2' %}
+    {% now 'UTC' + 'hours=2,minutes=30' %}
+    {% now 'UTC' + 'days=1,hours=2,minutes=15,seconds=10' %}
+
+Time Offsets (Subtraction):
+    {% now 'UTC' - 'minutes=11' %}
+    {% now 'UTC' - 'days=2,minutes=33,seconds=1' %}
+
+Time Offsets with Custom Format:
+    {% now 'UTC' + 'hours=2', '%Y-%m-%d %H:%M:%S' %}
+    # Output: 2015-12-10 01:33:01
+
+Weekday Support (for finding next/previous weekday):
+    {% now 'UTC' + 'weekday=0' %}  # Next Monday (0=Monday, 6=Sunday)
+    {% now 'UTC' + 'weekday=4' %}  # Next Friday
+
+Configuration:
+    - Default timezone: Set via TZ environment variable or override environment.default_timezone
+    - Default format: '%a, %d %b %Y %H:%M:%S' (can be overridden via environment.datetime_format)
+
+Environment Customization:
+    from changedetectionio.jinja2_custom import create_jinja_env
+
+    jinja2_env = create_jinja_env()
+    jinja2_env.default_timezone = 'America/New_York'  # Override default timezone
+    jinja2_env.datetime_format = '%Y-%m-%d %H:%M'      # Override default format
+
+Supported Offset Parameters:
+    - years, months, weeks, days
+    - hours, minutes, seconds, microseconds
+    - weekday (0=Monday through 6=Sunday, must be integer)
+
+Note:
+    This extension uses the Arrow library for timezone-aware datetime handling.
+    All timezone names should be valid IANA timezone identifiers (e.g., 'America/New_York').
+"""
+import arrow
+
+from jinja2 import nodes
+from jinja2.ext import Extension
+import os
+
+class TimeExtension(Extension):
+    """
+    Jinja2 Extension providing the {% now %} tag for timezone-aware date/time rendering.
+
+    This extension adds two attributes to the Jinja2 environment:
+    - datetime_format: Default strftime format string (default: '%a, %d %b %Y %H:%M:%S')
+    - default_timezone: Default timezone for rendering (default: TZ env var or 'UTC')
+
+    Both can be overridden after environment creation by setting the attributes directly.
+    """
+
+    tags = {'now'}
+
+    def __init__(self, environment):
+        """Jinja2 Extension constructor."""
+        super().__init__(environment)
+
+        environment.extend(
+            datetime_format='%a, %d %b %Y %H:%M:%S',
+            default_timezone=os.getenv('TZ', 'UTC').strip()
+        )
+
+    def _datetime(self, timezone, operator, offset, datetime_format):
+        """
+        Get current datetime with time offset applied.
+
+        Args:
+            timezone: IANA timezone identifier (e.g., 'UTC', 'America/New_York') or empty string for default
+            operator: '+' for addition or '-' for subtraction
+            offset: Comma-separated offset parameters (e.g., 'hours=2,minutes=30')
+            datetime_format: strftime format string or None to use environment default
+
+        Returns:
+            Formatted datetime string with offset applied
+
+        Example:
+            _datetime('UTC', '+', 'hours=2,minutes=30', '%Y-%m-%d %H:%M:%S')
+            # Returns current time + 2.5 hours
+        """
+        # Use default timezone if none specified
+        if not timezone or timezone == '':
+            timezone = self.environment.default_timezone
+
+        d = arrow.now(timezone)
+
+        # parse shift params from offset and include operator
+        shift_params = {}
+        for param in offset.split(','):
+            interval, value = param.split('=')
+            shift_params[interval.strip()] = float(operator + value.strip())
+
+        # Fix weekday parameter can not be float
+        if 'weekday' in shift_params:
+            shift_params['weekday'] = int(shift_params['weekday'])
+
+        d = d.shift(**shift_params)
+
+        if datetime_format is None:
+            datetime_format = self.environment.datetime_format
+        return d.strftime(datetime_format)
+
+    def _now(self, timezone, datetime_format):
+        """
+        Get current datetime without any offset.
+
+        Args:
+            timezone: IANA timezone identifier (e.g., 'UTC', 'America/New_York') or empty string for default
+            datetime_format: strftime format string or None to use environment default
+
+        Returns:
+            Formatted datetime string for current time
+
+        Example:
+            _now('America/New_York', '%Y-%m-%d %H:%M:%S')
+            # Returns current time in New York timezone
+        """
+        # Use default timezone if none specified
+        if not timezone or timezone == '':
+            timezone = self.environment.default_timezone
+
+        if datetime_format is None:
+            datetime_format = self.environment.datetime_format
+        return arrow.now(timezone).strftime(datetime_format)
+
+    def parse(self, parser):
+        """
+        Parse the {% now %} tag and generate appropriate AST nodes.
+
+        This method is called by Jinja2 when it encounters a {% now %} tag.
+        It parses the tag syntax and determines whether to call _now() or _datetime()
+        based on whether offset operations (+ or -) are present.
+
+        Supported syntax:
+            {% now 'timezone' %}                              -> calls _now()
+            {% now 'timezone', 'format' %}                    -> calls _now()
+            {% now 'timezone' + 'offset' %}                   -> calls _datetime()
+            {% now 'timezone' + 'offset', 'format' %}         -> calls _datetime()
+            {% now 'timezone' - 'offset', 'format' %}         -> calls _datetime()
+
+        Args:
+            parser: Jinja2 parser instance
+
+        Returns:
+            nodes.Output: AST output node containing the formatted datetime string
+        """
+        lineno = next(parser.stream).lineno
+
+        node = parser.parse_expression()
+
+        if parser.stream.skip_if('comma'):
+            datetime_format = parser.parse_expression()
+        else:
+            datetime_format = nodes.Const(None)
+
+        if isinstance(node, nodes.Add):
+            call_method = self.call_method(
+                '_datetime',
+                [node.left, nodes.Const('+'), node.right, datetime_format],
+                lineno=lineno,
+            )
+        elif isinstance(node, nodes.Sub):
+            call_method = self.call_method(
+                '_datetime',
+                [node.left, nodes.Const('-'), node.right, datetime_format],
+                lineno=lineno,
+            )
+        else:
+            call_method = self.call_method(
+                '_now',
+                [node, datetime_format],
+                lineno=lineno,
+            )
+        return nodes.Output([call_method], lineno=lineno)

changedetectionio/jinja2_custom/plugins/__init__.py

@@ -0,0 +1,6 @@
+"""
+Jinja2 custom filter plugins for changedetection.io
+"""
+from .regex import regex_replace
+
+__all__ = ['regex_replace']

changedetectionio/jinja2_custom/plugins/regex.py

@@ -0,0 +1,98 @@
+"""
+Regex filter plugin for Jinja2 templates.
+
+Provides regex_replace filter for pattern-based string replacements in templates.
+"""
+import re
+import signal
+from loguru import logger
+
+
+def regex_replace(value: str, pattern: str, replacement: str = '', count: int = 0) -> str:
+    """
+    Replace occurrences of a regex pattern in a string.
+
+    Security: Protected against ReDoS (Regular Expression Denial of Service) attacks:
+    - Limits input value size to prevent excessive processing
+    - Uses timeout mechanism to prevent runaway regex operations
+    - Validates pattern complexity to prevent catastrophic backtracking
+
+    Args:
+        value: The input string to perform replacements on
+        pattern: The regex pattern to search for
+        replacement: The replacement string (default: '')
+        count: Maximum number of replacements (0 = replace all, default: 0)
+
+    Returns:
+        String with replacements applied, or original value on error
+
+    Example:
+        {{ "hello world" | regex_replace("world", "universe") }}
+        {{ diff | regex_replace("<td>([^<]+)</td><td>([^<]+)</td>", "Label1: \\1\\nLabel2: \\2") }}
+
+    Security limits:
+        - Maximum input size: 10MB
+        - Maximum pattern length: 500 characters
+        - Operation timeout: 10 seconds
+        - Dangerous nested quantifier patterns are rejected
+    """
+    # Security limits
+    MAX_INPUT_SIZE = 1024 * 1024 * 10 # 10MB max input size
+    MAX_PATTERN_LENGTH = 500  # Maximum regex pattern length
+    REGEX_TIMEOUT_SECONDS = 10  # Maximum time for regex operation
+
+    # Validate input sizes
+    value_str = str(value)
+    if len(value_str) > MAX_INPUT_SIZE:
+        logger.warning(f"regex_replace: Input too large ({len(value_str)} bytes), truncating")
+        value_str = value_str[:MAX_INPUT_SIZE]
+
+    if len(pattern) > MAX_PATTERN_LENGTH:
+        logger.warning(f"regex_replace: Pattern too long ({len(pattern)} chars), rejecting")
+        return value_str
+
+    # Check for potentially dangerous patterns (basic checks)
+    # Nested quantifiers like (a+)+ can cause catastrophic backtracking
+    dangerous_patterns = [
+        r'\([^)]*\+[^)]*\)\+',  # (x+)+
+        r'\([^)]*\*[^)]*\)\+',  # (x*)+
+        r'\([^)]*\+[^)]*\)\*',  # (x+)*
+        r'\([^)]*\*[^)]*\)\*',  # (x*)*
+    ]
+
+    for dangerous in dangerous_patterns:
+        if re.search(dangerous, pattern):
+            logger.warning(f"regex_replace: Potentially dangerous pattern detected: {pattern}")
+            return value_str
+
+    def timeout_handler(signum, frame):
+        raise TimeoutError("Regex operation timed out")
+
+    try:
+        # Set up timeout for regex operation (Unix-like systems only)
+        # This prevents ReDoS attacks
+        old_handler = None
+        if hasattr(signal, 'SIGALRM'):
+            old_handler = signal.signal(signal.SIGALRM, timeout_handler)
+            signal.alarm(REGEX_TIMEOUT_SECONDS)
+
+        try:
+            result = re.sub(pattern, replacement, value_str, count=count)
+        finally:
+            # Cancel the alarm
+            if hasattr(signal, 'SIGALRM'):
+                signal.alarm(0)
+                if old_handler is not None:
+                    signal.signal(signal.SIGALRM, old_handler)
+
+        return result
+
+    except TimeoutError:
+        logger.error(f"regex_replace: Regex operation timed out - possible ReDoS attack. Pattern: {pattern}")
+        return value_str
+    except re.error as e:
+        logger.warning(f"regex_replace: Invalid regex pattern: {e}")
+        return value_str
+    except Exception as e:
+        logger.error(f"regex_replace: Unexpected error: {e}")
+        return value_str

changedetectionio/jinja2_custom/safe_jinja.py

@@ -0,0 +1,58 @@
+"""
+Safe Jinja2 render with max payload sizes
+
+See https://jinja.palletsprojects.com/en/3.1.x/sandbox/#security-considerations
+"""
+
+import jinja2.sandbox
+import typing as t
+import os
+from .extensions.TimeExtension import TimeExtension
+from .plugins import regex_replace
+
+JINJA2_MAX_RETURN_PAYLOAD_SIZE = 1024 * int(os.getenv("JINJA2_MAX_RETURN_PAYLOAD_SIZE_KB", 1024 * 10))
+
+# Default extensions - can be overridden in create_jinja_env()
+DEFAULT_JINJA2_EXTENSIONS = [TimeExtension]
+
+def create_jinja_env(extensions=None, **kwargs) -> jinja2.sandbox.ImmutableSandboxedEnvironment:
+    """
+    Create a sandboxed Jinja2 environment with our custom extensions and default timezone.
+
+    Args:
+        extensions: List of extension classes to use (defaults to DEFAULT_JINJA2_EXTENSIONS)
+        **kwargs: Additional arguments to pass to ImmutableSandboxedEnvironment
+
+    Returns:
+        Configured Jinja2 environment
+    """
+    if extensions is None:
+        extensions = DEFAULT_JINJA2_EXTENSIONS
+
+    jinja2_env = jinja2.sandbox.ImmutableSandboxedEnvironment(
+        extensions=extensions,
+        **kwargs
+    )
+
+    # Get default timezone from environment variable
+    default_timezone = os.getenv('TZ', 'UTC').strip()
+    jinja2_env.default_timezone = default_timezone
+
+    # Register custom filters
+    jinja2_env.filters['regex_replace'] = regex_replace
+
+    return jinja2_env
+
+
+# This is used for notifications etc, so actually it's OK to send custom HTML such as <a href> etc, but it should limit what data is available.
+# (Which also limits available functions that could be called)
+def render(template_str, **args: t.Any) -> str:
+    jinja2_env = create_jinja_env()
+    output = jinja2_env.from_string(template_str).render(args)
+    return output[:JINJA2_MAX_RETURN_PAYLOAD_SIZE]
+
+def render_fully_escaped(content):
+    env = jinja2.sandbox.ImmutableSandboxedEnvironment(autoescape=True)
+    template = env.from_string("{{ some_html|e }}")
+    return template.render(some_html=content)
+

changedetectionio/languages.py

@@ -0,0 +1,103 @@
+"""
+Language configuration for i18n support
+Automatically discovers available languages from translations directory
+"""
+import os
+from pathlib import Path
+
+
+def get_timeago_locale(flask_locale):
+    """
+    Convert Flask-Babel locale codes to timeago library locale codes.
+
+    The Python timeago library (https://github.com/hustcc/timeago) supports 48 locales
+    but uses different naming conventions than Flask-Babel. This function maps between them.
+
+    Notable differences:
+    - Chinese: Flask uses 'zh', timeago uses 'zh_CN'
+    - Portuguese: Flask uses 'pt', timeago uses 'pt_PT' or 'pt_BR'
+    - Swedish: Flask uses 'sv', timeago uses 'sv_SE'
+    - Norwegian: Flask uses 'no', timeago uses 'nb_NO' or 'nn_NO'
+    - Hindi: Flask uses 'hi', timeago uses 'in_HI'
+    - Czech: Flask uses 'cs', but timeago doesn't support Czech - fallback to English
+
+    Args:
+        flask_locale (str): Flask-Babel locale code (e.g., 'cs', 'zh', 'pt')
+
+    Returns:
+        str: timeago library locale code (e.g., 'en', 'zh_CN', 'pt_PT')
+    """
+    locale_map = {
+        'zh': 'zh_CN',      # Chinese Simplified
+        'pt': 'pt_PT',      # Portuguese (Portugal)
+        'sv': 'sv_SE',      # Swedish
+        'no': 'nb_NO',      # Norwegian Bokmål
+        'hi': 'in_HI',      # Hindi
+        'cs': 'en',         # Czech not supported by timeago, fallback to English
+    }
+    return locale_map.get(flask_locale, flask_locale)
+
+# Language metadata: flag icon CSS class and native name
+# Using flag-icons library: https://flagicons.lipis.dev/
+LANGUAGE_DATA = {
+    'en': {'flag': 'fi fi-gb fis', 'name': 'English'},
+    'de': {'flag': 'fi fi-de fis', 'name': 'Deutsch'},
+    'fr': {'flag': 'fi fi-fr fis', 'name': 'Français'},
+    'ko': {'flag': 'fi fi-kr fis', 'name': '한국어'},
+    'cs': {'flag': 'fi fi-cz fis', 'name': 'Čeština'},
+    'es': {'flag': 'fi fi-es fis', 'name': 'Español'},
+    'pt': {'flag': 'fi fi-pt fis', 'name': 'Português'},
+    'it': {'flag': 'fi fi-it fis', 'name': 'Italiano'},
+    'ja': {'flag': 'fi fi-jp fis', 'name': '日本語'},
+    'zh': {'flag': 'fi fi-cn fis', 'name': '中文 (简体)'},
+    'zh_TW': {'flag': 'fi fi-tw fis', 'name': '繁體中文'},
+    'ru': {'flag': 'fi fi-ru fis', 'name': 'Русский'},
+    'pl': {'flag': 'fi fi-pl fis', 'name': 'Polski'},
+    'nl': {'flag': 'fi fi-nl fis', 'name': 'Nederlands'},
+    'sv': {'flag': 'fi fi-se fis', 'name': 'Svenska'},
+    'da': {'flag': 'fi fi-dk fis', 'name': 'Dansk'},
+    'no': {'flag': 'fi fi-no fis', 'name': 'Norsk'},
+    'fi': {'flag': 'fi fi-fi fis', 'name': 'Suomi'},
+    'tr': {'flag': 'fi fi-tr fis', 'name': 'Türkçe'},
+    'ar': {'flag': 'fi fi-sa fis', 'name': 'العربية'},
+    'hi': {'flag': 'fi fi-in fis', 'name': 'हिन्दी'},
+}
+
+
+def get_available_languages():
+    """
+    Discover available languages by scanning the translations directory
+    Returns a dict of available languages with their metadata
+    """
+    translations_dir = Path(__file__).parent / 'translations'
+
+    # Always include English as base language
+    available = {
+        'en': LANGUAGE_DATA['en']
+    }
+
+    # Scan for translation directories
+    if translations_dir.exists():
+        for lang_dir in translations_dir.iterdir():
+            if lang_dir.is_dir() and lang_dir.name in LANGUAGE_DATA:
+                # Check if messages.po exists
+                po_file = lang_dir / 'LC_MESSAGES' / 'messages.po'
+                if po_file.exists():
+                    available[lang_dir.name] = LANGUAGE_DATA[lang_dir.name]
+
+    return available
+
+
+def get_language_codes():
+    """Get list of available language codes"""
+    return list(get_available_languages().keys())
+
+
+def get_flag_for_locale(locale):
+    """Get flag emoji for a locale, or globe if unknown"""
+    return LANGUAGE_DATA.get(locale, {}).get('flag', '🌐')
+
+
+def get_name_for_locale(locale):
+    """Get native name for a locale"""
+    return LANGUAGE_DATA.get(locale, {}).get('name', locale.upper())

changedetectionio/model/App.py

@@ -1,6 +1,7 @@
 from os import getenv
+from copy import deepcopy
 
-from changedetectionio.blueprint.rss import RSS_FORMAT_TYPES
+from changedetectionio.blueprint.rss import RSS_FORMAT_TYPES, RSS_CONTENT_FORMAT_DEFAULT
 
 from changedetectionio.notification import (
     default_notification_body,
@@ -45,6 +46,7 @@ class model(dict):
                     'global_subtractive_selectors': [],
                     'ignore_whitespace': True,
                     'ignore_status_codes': False, #@todo implement, as ternary.
+                    'ssim_threshold': '0.96',  # Default SSIM threshold for screenshot comparison
                     'notification_body': default_notification_body,
                     'notification_format': default_notification_format,
                     'notification_title': default_notification_title,
@@ -53,13 +55,17 @@ class model(dict):
                     'password': False,
                     'render_anchor_tag_content': False,
                     'rss_access_token': None,
-                    'rss_content_format': RSS_FORMAT_TYPES[0][0],
+                    'rss_content_format': RSS_CONTENT_FORMAT_DEFAULT,
+                    'rss_template_type': 'system_default',
+                    'rss_template_override': None,
+                    'rss_diff_length': 5,
                     'rss_hide_muted_watches': True,
+                    'rss_reader_mode': False,
+                    'scheduler_timezone_default': None,  # Default IANA timezone name
                     'schema_version' : 0,
                     'shared_diff_access': False,
                     'strip_ignored_lines': False,
                     'tags': {}, #@todo use Tag.model initialisers
-                    'timezone': None, # Default IANA timezone name
                     'webdriver_delay': None , # Extra delay in seconds before extracting text
                     'ui': {
                         'use_page_title_in_list': True,
@@ -73,12 +79,13 @@ class model(dict):
 
     def __init__(self, *arg, **kw):
         super(model, self).__init__(*arg, **kw)
-        self.update(self.base_config)
+        # CRITICAL: deepcopy to avoid sharing mutable objects between instances
+        self.update(deepcopy(self.base_config))
 
 
 def parse_headers_from_text_file(filepath):
     headers = {}
-    with open(filepath, 'r') as f:
+    with open(filepath, 'r', encoding='utf-8') as f:
         for l in f.readlines():
             l = l.strip()
             if not l.startswith('#') and ':' in l:

changedetectionio/model/Watch.py

@@ -1,42 +1,155 @@
 from blinker import signal
+from changedetectionio.validate_url import is_safe_valid_url
 
 from changedetectionio.strtobool import strtobool
-from changedetectionio.safe_jinja import render as jinja_render
+from changedetectionio.jinja2_custom import render as jinja_render
 from . import watch_base
 import os
 import re
 from pathlib import Path
 from loguru import logger
 
-from .. import safe_jinja
+from .. import jinja2_custom as safe_jinja
+from ..diff import ADDED_PLACEMARKER_OPEN
 from ..html_tools import TRANSLATE_WHITESPACE_TABLE
 
-# Allowable protocols, protects against javascript: etc
-# file:// is further checked by ALLOW_FILE_URI
-SAFE_PROTOCOL_REGEX='^(http|https|ftp|file):'
+
+def _brotli_compress_worker(conn, filepath, mode=None):
+    """
+    Worker function to compress data with brotli in a separate process.
+    This isolates memory - when process exits, OS reclaims all memory.
+
+    Args:
+        conn: multiprocessing.Pipe connection to receive data
+        filepath: destination file path
+        mode: brotli compression mode (e.g., brotli.MODE_TEXT)
+    """
+    import brotli
+
+    try:
+        # Receive data from parent process via pipe (avoids pickle overhead)
+        contents = conn.recv()
+
+        if mode is not None:
+            compressed_data = brotli.compress(contents, mode=mode)
+        else:
+            compressed_data = brotli.compress(contents)
+
+        with open(filepath, 'wb') as f:
+            f.write(compressed_data)
+
+        # Send success status back
+        conn.send(True)
+        # No need for explicit cleanup - process exit frees all memory
+    except Exception as e:
+        logger.error(f"Brotli compression worker failed: {e}")
+        conn.send(False)
+    finally:
+        conn.close()
+
+
+def _brotli_subprocess_save(contents, filepath, mode=None, timeout=30, fallback_uncompressed=False):
+    """
+    Save compressed data using subprocess to isolate memory.
+    Uses Pipe to avoid pickle overhead for large data.
+
+    Args:
+        contents: data to compress (str or bytes)
+        filepath: destination file path
+        mode: brotli compression mode (e.g., brotli.MODE_TEXT)
+        timeout: subprocess timeout in seconds
+        fallback_uncompressed: if True, save uncompressed on failure; if False, raise exception
+
+    Returns:
+        str: actual filepath saved (may differ from input if fallback used)
+
+    Raises:
+        Exception: if compression fails and fallback_uncompressed is False
+    """
+    import brotli
+    import multiprocessing
+    import sys
+
+    # Ensure contents are bytes
+    if isinstance(contents, str):
+        contents = contents.encode('utf-8')
+
+    # Use explicit spawn context for thread safety (avoids fork() with multi-threaded parent)
+    # Always use spawn - consistent behavior in tests and production
+    ctx = multiprocessing.get_context('spawn')
+    parent_conn, child_conn = ctx.Pipe()
+
+    # Run compression in subprocess using spawn (not fork)
+    proc = ctx.Process(target=_brotli_compress_worker, args=(child_conn, filepath, mode))
+
+    # Windows-safe: Set daemon=False explicitly to avoid issues with process cleanup
+    proc.daemon = False
+    proc.start()
+
+    try:
+        # Send data to subprocess via pipe (avoids pickle)
+        parent_conn.send(contents)
+
+        # Wait for result with timeout
+        if parent_conn.poll(timeout):
+            success = parent_conn.recv()
+        else:
+            success = False
+            logger.warning(f"Brotli compression subprocess timed out after {timeout}s")
+            # Graceful termination with platform-aware cleanup
+            try:
+                proc.terminate()
+            except Exception as term_error:
+                logger.debug(f"Process termination issue (may be normal on Windows): {term_error}")
+
+        parent_conn.close()
+        proc.join(timeout=5)
+
+        # Force kill if still alive after graceful termination
+        if proc.is_alive():
+            try:
+                if sys.platform == 'win32':
+                    # Windows: use kill() which is more forceful
+                    proc.kill()
+                else:
+                    # Unix: terminate() already sent SIGTERM, now try SIGKILL
+                    proc.kill()
+                proc.join(timeout=2)
+            except Exception as kill_error:
+                logger.warning(f"Failed to kill brotli compression process: {kill_error}")
+
+        # Check if file was created successfully
+        if success and os.path.exists(filepath):
+            return filepath
+
+    except Exception as e:
+        logger.error(f"Brotli compression error: {e}")
+        try:
+            parent_conn.close()
+        except:
+            pass
+        try:
+            proc.terminate()
+            proc.join(timeout=2)
+        except:
+            pass
+
+    # Compression failed
+    if fallback_uncompressed:
+        logger.warning(f"Brotli compression failed for {filepath}, saving uncompressed")
+        fallback_path = filepath.replace('.br', '')
+        with open(fallback_path, 'wb') as f:
+            f.write(contents)
+        return fallback_path
+    else:
+        raise Exception(f"Brotli compression subprocess failed for {filepath}")
+
 FAVICON_RESAVE_THRESHOLD_SECONDS=86400
 
 
 minimum_seconds_recheck_time = int(os.getenv('MINIMUM_SECONDS_RECHECK_TIME', 3))
 mtable = {'seconds': 1, 'minutes': 60, 'hours': 3600, 'days': 86400, 'weeks': 86400 * 7}
 
-
-def is_safe_url(test_url):
-    # See https://github.com/dgtlmoon/changedetection.io/issues/1358
-
-    # Remove 'source:' prefix so we dont get 'source:javascript:' etc
-    # 'source:' is a valid way to tell us to return the source
-
-    r = re.compile(re.escape('source:'), re.IGNORECASE)
-    test_url = r.sub('', test_url)
-
-    pattern = re.compile(os.getenv('SAFE_PROTOCOL_REGEX', SAFE_PROTOCOL_REGEX), re.IGNORECASE)
-    if not pattern.match(test_url.strip()):
-        return False
-
-    return True
-
-
 class model(watch_base):
     __newest_history_key = None
     __history_n = 0
@@ -79,7 +192,7 @@ class model(watch_base):
     def link(self):
 
         url = self.get('url', '')
-        if not is_safe_url(url):
+        if not is_safe_valid_url(url):
             return 'DISABLED'
 
         ready_url = url
@@ -89,9 +202,8 @@ class model(watch_base):
                 ready_url = jinja_render(template_str=url)
             except Exception as e:
                 logger.critical(f"Invalid URL template for: '{url}' - {str(e)}")
-                from flask import (
-                    flash, Markup, url_for
-                )
+                from flask import flash, url_for
+                from markupsafe import Markup
                 message = Markup('<a href="{}#general">The URL {} is invalid and cannot be used, click to edit</a>'.format(
                     url_for('ui.ui_edit.edit_page', uuid=self.get('uuid')), self.get('url', '')))
                 flash(message, 'error')
@@ -101,7 +213,7 @@ class model(watch_base):
             ready_url=ready_url.replace('source:', '')
 
         # Also double check it after any Jinja2 formatting just incase
-        if not is_safe_url(ready_url):
+        if not is_safe_valid_url(ready_url):
             return 'DISABLED'
         return ready_url
 
@@ -112,11 +224,29 @@ class model(watch_base):
         domain = parsed.hostname
         return domain
 
+    @property
+    def history_index_filename(self):
+        # So that you dont try to view different histories in different 'diff' setups, can confuse cdio.
+        processor = self.get('processor')
+        if not processor or self.get('processor') == 'text_json_diff':
+            return 'history.txt'
+        else:
+            return f'history-{processor}.txt'
+
     def clear_watch(self):
         import pathlib
 
+        # Get list of processor config files to preserve
+        from changedetectionio.processors import find_processors
+        processor_names = [name for cls, name in find_processors()]
+        processor_config_files = {f"{name}.json" for name in processor_names}
+
         # JSON Data, Screenshots, Textfiles (history index and snapshots), HTML in the future etc
+        # But preserve processor config files (they're configuration, not history data)
         for item in pathlib.Path(str(self.watch_data_dir)).rglob("*.*"):
+            # Skip processor config files
+            if item.name in processor_config_files:
+                continue
             os.unlink(item)
 
         # Force the attr to recalculate
@@ -204,22 +334,25 @@ class model(watch_base):
             return []
 
         # Read the history file as a dict
-        fname = os.path.join(self.watch_data_dir, "history.txt")
+        fname = os.path.join(self.watch_data_dir, self.history_index_filename)
         if os.path.isfile(fname):
             logger.debug(f"Reading watch history index for {self.get('uuid')}")
-            with open(fname, "r") as f:
+            with open(fname, "r", encoding='utf-8') as f:
                 for i in f.readlines():
                     if ',' in i:
                         k, v = i.strip().split(',', 2)
 
                         # The index history could contain a relative path, so we need to make the fullpath
                         # so that python can read it
-                        if not '/' in v and not '\'' in v:
+                        # Cross-platform: check for any path separator (works on Windows and Unix)
+                        if os.sep not in v and '/' not in v and '\\' not in v:
+                            # Relative filename only, no path separators
                             v = os.path.join(self.watch_data_dir, v)
                         else:
                             # It's possible that they moved the datadir on older versions
                             # So the snapshot exists but is in a different path
-                            snapshot_fname = v.split('/')[-1]
+                            # Cross-platform: use os.path.basename instead of split('/')
+                            snapshot_fname = os.path.basename(v)
                             proposed_new_path = os.path.join(self.watch_data_dir, snapshot_fname)
                             if not os.path.exists(v) and os.path.exists(proposed_new_path):
                                 v = proposed_new_path
@@ -237,7 +370,7 @@ class model(watch_base):
 
     @property
     def has_history(self):
-        fname = os.path.join(self.watch_data_dir, "history.txt")
+        fname = os.path.join(self.watch_data_dir, self.history_index_filename)
         return os.path.isfile(fname)
 
     @property
@@ -295,65 +428,121 @@ class model(watch_base):
         # When the 'last viewed' timestamp is less than the oldest snapshot, return oldest
         return sorted_keys[-1]
 
-    def get_history_snapshot(self, timestamp):
+    def get_history_snapshot(self, timestamp=None, filepath=None):
+        """
+        Accepts either timestamp or filepath
+        :param timestamp:
+        :param filepath:
+        :return:
+        """
         import brotli
-        filepath = self.history[timestamp]
 
-        # See if a brotli versions exists and switch to that
-        if not filepath.endswith('.br') and os.path.isfile(f"{filepath}.br"):
-            filepath = f"{filepath}.br"
+        if not filepath:
+            filepath = self.history[timestamp]
 
-        # OR in the backup case that the .br does not exist, but the plain one does
-        if filepath.endswith('.br') and not os.path.isfile(filepath):
-            if os.path.isfile(filepath.replace('.br', '')):
-                filepath = filepath.replace('.br', '')
+        # Check if binary file (image, PDF, etc.)
+        # Binary files are NEVER saved with .br compression, only text files are
+        binary_extensions = ('.png', '.jpg', '.jpeg', '.gif', '.webp', '.pdf', '.bin', '.jfif')
+        is_binary = any(filepath.endswith(ext) for ext in binary_extensions)
 
+        # Only look for .br versions for text files
+        if not is_binary:
+            # See if a brotli version exists and switch to that (text files only)
+            if not filepath.endswith('.br') and os.path.isfile(f"{filepath}.br"):
+                filepath = f"{filepath}.br"
+
+            # OR in the backup case that the .br does not exist, but the plain one does
+            if filepath.endswith('.br') and not os.path.isfile(filepath):
+                if os.path.isfile(filepath.replace('.br', '')):
+                    filepath = filepath.replace('.br', '')
+
+        # Handle .br compressed text files
         if filepath.endswith('.br'):
             # Brotli doesnt have a fileheader to detect it, so we rely on filename
             # https://www.rfc-editor.org/rfc/rfc7932
+            # Note: .br should ONLY exist for text files, never binary
             with open(filepath, 'rb') as f:
-                return(brotli.decompress(f.read()).decode('utf-8'))
+                return brotli.decompress(f.read()).decode('utf-8')
 
+        # Binary file - return raw bytes
+        if is_binary:
+            with open(filepath, 'rb') as f:
+                return f.read()
+
+        # Text file - decode to string
         with open(filepath, 'r', encoding='utf-8', errors='ignore') as f:
             return f.read()
 
-   # Save some text file to the appropriate path and bump the history
+    def _write_atomic(self, dest, data):
+        """Write data atomically to dest using a temp file"""
+        if not os.path.exists(dest):
+            import tempfile
+            with tempfile.NamedTemporaryFile('wb', delete=False, dir=self.watch_data_dir) as tmp:
+                tmp.write(data)
+                tmp.flush()
+                os.fsync(tmp.fileno())
+                tmp_path = tmp.name
+            os.replace(tmp_path, dest)
+
+    # Save some text file to the appropriate path and bump the history
     # result_obj from fetch_site_status.run()
-    def save_history_text(self, contents, timestamp, snapshot_id):
-        import brotli
-        import tempfile
-        logger.trace(f"{self.get('uuid')} - Updating history.txt with timestamp {timestamp}")
+    def save_history_blob(self, contents, timestamp, snapshot_id):
+
+        logger.trace(f"{self.get('uuid')} - Updating {self.history_index_filename} with timestamp {timestamp}")
 
         self.ensure_data_dir_exists()
 
         threshold = int(os.getenv('SNAPSHOT_BROTLI_COMPRESSION_THRESHOLD', 1024))
         skip_brotli = strtobool(os.getenv('DISABLE_BROTLI_TEXT_SNAPSHOT', 'False'))
 
-        # Decide on snapshot filename and destination path
-        if not skip_brotli and len(contents) > threshold:
-            snapshot_fname = f"{snapshot_id}.txt.br"
-            encoded_data = brotli.compress(contents.encode('utf-8'), mode=brotli.MODE_TEXT)
+        # Binary data - detect file type and save without compression
+        if isinstance(contents, bytes):
+            try:
+                import puremagic
+                detections = puremagic.magic_string(contents[:2048])
+                ext = detections[0].extension if detections else 'bin'
+                # Strip leading dot if present (puremagic returns extensions like '.jfif')
+                ext = ext.lstrip('.')
+                if detections:
+                    logger.trace(f"Detected file type: {detections[0].mime_type} -> extension: {ext}")
+            except Exception as e:
+                logger.warning(f"puremagic detection failed: {e}, using 'bin' extension")
+                ext = 'bin'
+
+            snapshot_fname = f"{snapshot_id}.{ext}"
+            dest = os.path.join(self.watch_data_dir, snapshot_fname)
+            self._write_atomic(dest, contents)
+            logger.trace(f"Saved binary snapshot as {snapshot_fname} ({len(contents)} bytes)")
+
+        # Text data - use brotli compression if enabled and above threshold
         else:
-            snapshot_fname = f"{snapshot_id}.txt"
-            encoded_data = contents.encode('utf-8')
+            if not skip_brotli and len(contents) > threshold:
+                # Compressed text
+                import brotli
+                snapshot_fname = f"{snapshot_id}.txt.br"
+                dest = os.path.join(self.watch_data_dir, snapshot_fname)
 
-        dest = os.path.join(self.watch_data_dir, snapshot_fname)
-
-        # Write snapshot file atomically if it doesn't exist
-        if not os.path.exists(dest):
-            with tempfile.NamedTemporaryFile('wb', delete=False, dir=self.watch_data_dir) as tmp:
-                tmp.write(encoded_data)
-                tmp.flush()
-                os.fsync(tmp.fileno())
-                tmp_path = tmp.name
-            os.rename(tmp_path, dest)
+                if not os.path.exists(dest):
+                    try:
+                        actual_dest = _brotli_subprocess_save(contents, dest, mode=brotli.MODE_TEXT, fallback_uncompressed=True)
+                        if actual_dest != dest:
+                            snapshot_fname = os.path.basename(actual_dest)
+                    except Exception as e:
+                        logger.error(f"{self.get('uuid')} - Brotli compression failed: {e}")
+                        # Fallback to uncompressed
+                        snapshot_fname = f"{snapshot_id}.txt"
+                        dest = os.path.join(self.watch_data_dir, snapshot_fname)
+                        self._write_atomic(dest, contents.encode('utf-8'))
+            else:
+                # Plain text
+                snapshot_fname = f"{snapshot_id}.txt"
+                dest = os.path.join(self.watch_data_dir, snapshot_fname)
+                self._write_atomic(dest, contents.encode('utf-8'))
 
         # Append to history.txt atomically
-        index_fname = os.path.join(self.watch_data_dir, "history.txt")
+        index_fname = os.path.join(self.watch_data_dir, self.history_index_filename)
         index_line = f"{timestamp},{snapshot_fname}\n"
 
-        # Lets try force flush here since it's usually a very small file
-        # If this still fails in the future then try reading all to memory first, re-writing etc
         with open(index_fname, 'a', encoding='utf-8') as f:
             f.write(index_line)
             f.flush()
@@ -401,7 +590,7 @@ class model(watch_base):
         # Compare each lines (set) against each history text file (set) looking for something new..
         existing_history = set({})
         for k, v in self.history.items():
-            content = self.get_history_snapshot(k)
+            content = self.get_history_snapshot(filepath=v)
 
             if ignore_whitespace:
                 alist = set([line.translate(TRANSLATE_WHITESPACE_TABLE).lower() for line in content.splitlines()])
@@ -605,7 +794,7 @@ class model(watch_base):
         """Return the text saved from a previous request that resulted in a non-200 error"""
         fname = os.path.join(self.watch_data_dir, "last-error.txt")
         if os.path.isfile(fname):
-            with open(fname, 'r') as f:
+            with open(fname, 'r', encoding='utf-8') as f:
                 return f.read()
         return False
 
@@ -658,7 +847,7 @@ class model(watch_base):
         for k, fname in self.history.items():
             if os.path.isfile(fname):
                 if True:
-                    contents = self.get_history_snapshot(k)
+                    contents = self.get_history_snapshot(timestamp=k)
                     res = re.findall(regex, contents, re.MULTILINE)
                     if res:
                         if not csv_writer:
@@ -751,7 +940,7 @@ class model(watch_base):
             # If a previous attempt doesnt yet exist, just snarf the previous snapshot instead
             dates = list(self.history.keys())
             if len(dates):
-                return self.get_history_snapshot(dates[-1])
+                return self.get_history_snapshot(timestamp=dates[-1])
             else:
                 return ''
 
@@ -761,25 +950,13 @@ class model(watch_base):
     def save_last_text_fetched_before_filters(self, contents):
         import brotli
         filepath = os.path.join(self.watch_data_dir, 'last-fetched.br')
-        with open(filepath, 'wb') as f:
-            f.write(brotli.compress(contents, mode=brotli.MODE_TEXT))
+        _brotli_subprocess_save(contents, filepath, mode=brotli.MODE_TEXT, fallback_uncompressed=False)
 
     def save_last_fetched_html(self, timestamp, contents):
-        import brotli
-
         self.ensure_data_dir_exists()
         snapshot_fname = f"{timestamp}.html.br"
         filepath = os.path.join(self.watch_data_dir, snapshot_fname)
-
-        with open(filepath, 'wb') as f:
-            contents = contents.encode('utf-8') if isinstance(contents, str) else contents
-            try:
-                f.write(brotli.compress(contents))
-            except Exception as e:
-                logger.warning(f"{self.get('uuid')} - Unable to compress snapshot, saving as raw data to {filepath}")
-                logger.warning(e)
-                f.write(contents)
-
+        _brotli_subprocess_save(contents, filepath, mode=None, fallback_uncompressed=True)
         self._prune_last_fetched_html_snapshots()
 
     def get_fetched_html(self, timestamp):
@@ -837,6 +1014,7 @@ class model(watch_base):
         # has app+request context, we can use url_for()
         if has_app_context:
             if last_error:
+                last_error = safe_jinja.render_fully_escaped(last_error)
                 if '403' in last_error:
                     if has_proxies:
                         output.append(str(Markup(f"{last_error} - <a href=\"{url_for('settings.settings_page', uuid=self.get('uuid'))}\">Try other proxies/location</a>&nbsp;'")))
@@ -846,7 +1024,9 @@ class model(watch_base):
                     output.append(str(Markup(last_error)))
 
             if self.get('last_notification_error'):
-                output.append(str(Markup(f"<div class=\"notification-error\"><a href=\"{url_for('settings.notification_logs')}\">{ self.get('last_notification_error') }</a></div>")))
+                txt = safe_jinja.render_fully_escaped(self.get('last_notification_error'))
+                result = f'<div class="notification-error"><a href="{url_for("settings.notification_logs")}">{txt}</a></div>'
+                output.append(result)
 
         else:
             # Lo_Fi version - no app context, cant rely on Jinja2 Markup

changedetectionio/model/__init__.py

@@ -2,7 +2,7 @@ import os
 import uuid
 
 from changedetectionio import strtobool
-default_notification_format_for_watch = 'System default'
+USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH = 'System default'
 CONDITIONS_MATCH_LOGIC_DEFAULT = 'ALL'
 
 class watch_base(dict):
@@ -44,7 +44,7 @@ class watch_base(dict):
             'method': 'GET',
             'notification_alert_count': 0,
             'notification_body': None,
-            'notification_format': default_notification_format_for_watch,
+            'notification_format': USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH,
             'notification_muted': False,
             'notification_screenshot': False,  # Include the latest screenshot if available and supported by the apprise URL
             'notification_title': None,

changedetectionio/notification/__init__.py

@@ -1,35 +1,16 @@
-from changedetectionio.model import default_notification_format_for_watch
+from changedetectionio.model import USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH
 
-ult_notification_format_for_watch = 'System default'
-default_notification_format = 'HTML Color'
+default_notification_format = 'htmlcolor'
 default_notification_body = '{{watch_url}} had a change.\n---\n{{diff}}\n---\n'
 default_notification_title = 'ChangeDetection.io Notification - {{watch_url}}'
 
 # The values (markdown etc) are from apprise NotifyFormat,
 # But to avoid importing the whole heavy module just use the same strings here.
 valid_notification_formats = {
-    'Text': 'text',
-    'Markdown': 'markdown',
-    'HTML': 'html',
-    'HTML Color': 'htmlcolor',
+    'text': 'Plain Text',
+    'html': 'HTML',
+    'htmlcolor': 'HTML Color',
+    'markdown': 'Markdown to HTML',
     # Used only for editing a watch (not for global)
-    default_notification_format_for_watch: default_notification_format_for_watch
-}
-
-
-valid_tokens = {
-    'base_url': '',
-    'current_snapshot': '',
-    'diff': '',
-    'diff_added': '',
-    'diff_full': '',
-    'diff_patch': '',
-    'diff_removed': '',
-    'diff_url': '',
-    'preview_url': '',
-    'triggered_text': '',
-    'watch_tag': '',
-    'watch_title': '',
-    'watch_url': '',
-    'watch_uuid': '',
+    USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH: USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH
 }

changedetectionio/notification/apprise_plugin/custom_handlers.py

@@ -1,10 +1,61 @@
+"""
+Custom Apprise HTTP Handlers with format= Parameter Support
+
+IMPORTANT: This module works around a limitation in Apprise's @notify decorator.
+
+THE PROBLEM:
+-------------
+When using Apprise's @notify decorator to create custom notification handlers, the
+decorator creates a CustomNotifyPlugin that uses parse_url(..., simple=True) to parse
+URLs. This simple parsing mode does NOT extract the format= query parameter from the URL
+and set it as a top-level parameter that NotifyBase.__init__ can use to set notify_format.
+
+As a result:
+1. URL: post://example.com/webhook?format=html
+2. Apprise parses this and sees format=html in qsd (query string dictionary)
+3. But it does NOT extract it and pass it to NotifyBase.__init__
+4. NotifyBase defaults to notify_format=TEXT
+5. When you call apobj.notify(body="<html>...", body_format="html"):
+   - Apprise sees: input format = html, output format (notify_format) = text
+   - Apprise calls convert_between("html", "text", body)
+   - This strips all HTML tags, leaving only plain text
+6. Your custom handler receives stripped plain text instead of HTML
+
+THE SOLUTION:
+-------------
+Instead of using the @notify decorator directly, we:
+1. Manually register custom plugins using plugins.N_MGR.add()
+2. Create a CustomHTTPHandler class that extends CustomNotifyPlugin
+3. Override __init__ to extract format= from qsd and set it as kwargs['format']
+4. Call NotifyBase.__init__ which properly sets notify_format from kwargs['format']
+5. Set up _default_args like CustomNotifyPlugin does for compatibility
+
+This ensures that when format=html is in the URL:
+- notify_format is set to HTML
+- Apprise sees: input format = html, output format = html
+- No conversion happens (convert_between returns content unchanged)
+- Your custom handler receives the original HTML intact
+
+TESTING:
+--------
+To verify this works:
+>>> apobj = apprise.Apprise()
+>>> apobj.add('post://localhost:5005/test?format=html')
+>>> for server in apobj:
+...     print(server.notify_format)  # Should print: html (not text)
+>>> apobj.notify(body='<span>Test</span>', body_format='html')
+# Your handler should receive '<span>Test</span>' not 'Test'
+"""
+
 import json
 import re
 from urllib.parse import unquote_plus
 
 import requests
-from apprise.decorators import notify
-from apprise.utils.parse import parse_url as apprise_parse_url
+from apprise import plugins
+from apprise.decorators.base import CustomNotifyPlugin
+from apprise.utils.parse import parse_url as apprise_parse_url, url_assembly
+from apprise.utils.logic import dict_full_update
 from loguru import logger
 from requests.structures import CaseInsensitiveDict
 
@@ -12,13 +63,66 @@ SUPPORTED_HTTP_METHODS = {"get", "post", "put", "delete", "patch", "head"}
 
 
 def notify_supported_methods(func):
+    """Register custom HTTP method handlers that properly support format= parameter."""
     for method in SUPPORTED_HTTP_METHODS:
-        func = notify(on=method)(func)
-        # Add support for https, for each supported http method
-        func = notify(on=f"{method}s")(func)
+        _register_http_handler(method, func)
+        _register_http_handler(f"{method}s", func)
     return func
 
 
+def _register_http_handler(schema, send_func):
+    """Register a custom HTTP handler that extracts format= from URL query parameters."""
+
+    # Parse base URL
+    base_url = f"{schema}://"
+    base_args = apprise_parse_url(base_url, default_schema=schema, verify_host=False, simple=True)
+
+    class CustomHTTPHandler(CustomNotifyPlugin):
+        secure_protocol = schema
+        service_name = f"Custom HTTP - {schema.upper()}"
+        _base_args = base_args
+
+        def __init__(self, **kwargs):
+            # Extract format from qsd and set it as a top-level kwarg
+            # This allows NotifyBase.__init__ to properly set notify_format
+            if 'qsd' in kwargs and 'format' in kwargs['qsd']:
+                kwargs['format'] = kwargs['qsd']['format']
+
+            # Call NotifyBase.__init__ (skip CustomNotifyPlugin.__init__)
+            super(CustomNotifyPlugin, self).__init__(**kwargs)
+
+            # Set up _default_args like CustomNotifyPlugin does
+            self._default_args = {}
+            kwargs.pop("secure", None)
+            dict_full_update(self._default_args, self._base_args)
+            dict_full_update(self._default_args, kwargs)
+            self._default_args["url"] = url_assembly(**self._default_args)
+
+        __send = staticmethod(send_func)
+
+        def send(self, body, title="", notify_type="info", *args, **kwargs):
+            """Call the custom send function."""
+            try:
+                result = self.__send(
+                    body, title, notify_type,
+                    *args,
+                    meta=self._default_args,
+                    **kwargs
+                )
+                return True if result is None else bool(result)
+            except Exception as e:
+                self.logger.warning(f"Exception in custom HTTP handler: {e}")
+                return False
+
+    # Register the plugin
+    plugins.N_MGR.add(
+        plugin=CustomHTTPHandler,
+        schemas=schema,
+        send_func=send_func,
+        url=base_url,
+    )
+
+
 def _get_auth(parsed_url: dict) -> str | tuple[str, str]:
     user: str | None = parsed_url.get("user")
     password: str | None = parsed_url.get("password")
@@ -70,9 +174,12 @@ def apprise_http_custom_handler(
     title: str,
     notify_type: str,
     meta: dict,
+    body_format: str = None,
     *args,
     **kwargs,
 ) -> bool:
+
+
     url: str = meta.get("url")
     schema: str = meta.get("schema")
     method: str = re.sub(r"s$", "", schema).upper()
@@ -88,25 +195,16 @@ def apprise_http_custom_handler(
 
     url = re.sub(rf"^{schema}", "https" if schema.endswith("s") else "http", parsed_url.get("url"))
 
-    try:
-        response = requests.request(
-            method=method,
-            url=url,
-            auth=auth,
-            headers=headers,
-            params=params,
-            data=body.encode("utf-8") if isinstance(body, str) else body,
-        )
+    response = requests.request(
+        method=method,
+        url=url,
+        auth=auth,
+        headers=headers,
+        params=params,
+        data=body.encode("utf-8") if isinstance(body, str) else body,
+    )
 
-        response.raise_for_status()
+    response.raise_for_status()
 
-        logger.info(f"Successfully sent custom notification to {url}")
-        return True
-
-    except requests.RequestException as e:
-        logger.error(f"Remote host error while sending custom notification to {url}: {e}")
-        return False
-
-    except Exception as e:
-        logger.error(f"Unexpected error occurred while sending custom notification to {url}: {e}")
-        return False
+    logger.info(f"Successfully sent custom notification to {url}")
+    return True

changedetectionio/notification/apprise_plugin/discord.py

@@ -0,0 +1,286 @@
+"""
+Custom Discord plugin for changedetection.io
+Extends Apprise's Discord plugin to support custom colored embeds for removed/added content
+"""
+from apprise.plugins.discord import NotifyDiscord
+from apprise.decorators import notify
+from apprise.common import NotifyFormat
+from loguru import logger
+
+# Import placeholders from changedetection's diff module
+from ...diff import (
+    REMOVED_PLACEMARKER_OPEN,
+    REMOVED_PLACEMARKER_CLOSED,
+    ADDED_PLACEMARKER_OPEN,
+    ADDED_PLACEMARKER_CLOSED,
+    CHANGED_PLACEMARKER_OPEN,
+    CHANGED_PLACEMARKER_CLOSED,
+    CHANGED_INTO_PLACEMARKER_OPEN,
+    CHANGED_INTO_PLACEMARKER_CLOSED,
+)
+
+# Discord embed sidebar colors for different change types
+DISCORD_COLOR_UNCHANGED = 8421504   # Gray (#808080)
+DISCORD_COLOR_REMOVED = 16711680    # Red (#FF0000)
+DISCORD_COLOR_ADDED = 65280         # Green (#00FF00)
+DISCORD_COLOR_CHANGED = 16753920    # Orange (#FFA500)
+DISCORD_COLOR_CHANGED_INTO = 3447003  # Blue (#5865F2 - Discord blue)
+DISCORD_COLOR_WARNING = 16776960    # Yellow (#FFFF00)
+
+
+class NotifyDiscordCustom(NotifyDiscord):
+    """
+    Custom Discord notification handler that supports multiple colored embeds
+    for showing removed (red) and added (green) content separately.
+    """
+
+    def send(self, body, title="", notify_type=None, attach=None, **kwargs):
+        """
+        Override send method to create custom embeds with red/green colors
+        for removed/added content when placeholders are present.
+        """
+
+        # Check if body contains our diff placeholders
+        has_removed = REMOVED_PLACEMARKER_OPEN in body
+        has_added = ADDED_PLACEMARKER_OPEN in body
+        has_changed = CHANGED_PLACEMARKER_OPEN in body
+        has_changed_into = CHANGED_INTO_PLACEMARKER_OPEN in body
+
+        # If we have diff placeholders and we're in markdown/html format, create custom embeds
+        if (has_removed or has_added or has_changed or has_changed_into) and self.notify_format in (NotifyFormat.MARKDOWN, NotifyFormat.HTML):
+            return self._send_with_colored_embeds(body, title, notify_type, attach, **kwargs)
+
+        # Otherwise, use the parent class's default behavior
+        return super().send(body, title, notify_type, attach, **kwargs)
+
+    def _send_with_colored_embeds(self, body, title, notify_type, attach, **kwargs):
+        """
+        Send Discord message with embeds in the original diff order.
+        Preserves the sequence: unchanged -> removed -> added -> unchanged, etc.
+        """
+        from datetime import datetime, timezone
+
+        payload = {
+            "tts": self.tts,
+            "wait": self.tts is False,
+        }
+
+        if self.flags:
+            payload["flags"] = self.flags
+
+        # Acquire image_url
+        image_url = self.image_url(notify_type)
+
+        if self.avatar and (image_url or self.avatar_url):
+            payload["avatar_url"] = self.avatar_url if self.avatar_url else image_url
+
+        if self.user:
+            payload["username"] = self.user
+
+        # Associate our thread_id with our message
+        params = {"thread_id": self.thread_id} if self.thread_id else None
+
+        # Build embeds array preserving order
+        embeds = []
+
+        # Add title as plain bold text in message content (not an embed)
+        if title:
+            payload["content"] = f"**{title}**"
+
+        # Parse the body into ordered chunks
+        chunks = self._parse_body_into_chunks(body)
+
+        # Discord limits:
+        # - Max 10 embeds per message
+        # - Max 6000 characters total across all embeds
+        # - Max 4096 characters per embed description
+        max_embeds = 10
+        max_total_chars = 6000
+        max_embed_description = 4096
+
+        # All 10 embed slots are available for content
+        max_content_embeds = max_embeds
+
+        # Start character count
+        total_chars = 0
+
+        # Create embeds from chunks in order (no titles, just color coding)
+        for chunk_type, content in chunks:
+            if not content.strip():
+                continue
+
+            # Truncate individual embed description if needed
+            if len(content) > max_embed_description:
+                content = content[:max_embed_description - 3] + "..."
+
+            # Check if we're approaching the embed count limit
+            # We need room for the warning embed, so stop at max_content_embeds - 1
+            current_content_embeds = len(embeds)
+            if current_content_embeds >= max_content_embeds - 1:
+                # Add a truncation notice (this will be the 10th embed)
+                embeds.append({
+                    "description": "⚠️ Content truncated (Discord 10 embed limit reached) - Tip: Select 'Plain Text' or 'HTML' format for longer diffs",
+                    "color": DISCORD_COLOR_WARNING,
+                })
+                break
+
+            # Check if adding this embed would exceed total character limit
+            if total_chars + len(content) > max_total_chars:
+                # Add a truncation notice
+                remaining_chars = max_total_chars - total_chars
+                if remaining_chars > 100:
+                    # Add partial content if we have room
+                    truncated_content = content[:remaining_chars - 100] + "..."
+                    embeds.append({
+                        "description": truncated_content,
+                        "color": (DISCORD_COLOR_UNCHANGED if chunk_type == "unchanged"
+                                 else DISCORD_COLOR_REMOVED if chunk_type == "removed"
+                                 else DISCORD_COLOR_ADDED),
+                    })
+                embeds.append({
+                    "description": "⚠️ Content truncated (Discord 6000 char limit reached)\nTip: Select 'Plain Text' or 'HTML' format for longer diffs",
+                    "color": DISCORD_COLOR_WARNING,
+                })
+                break
+
+            if chunk_type == "unchanged":
+                embeds.append({
+                    "description": content,
+                    "color": DISCORD_COLOR_UNCHANGED,
+                })
+            elif chunk_type == "removed":
+                embeds.append({
+                    "description": content,
+                    "color": DISCORD_COLOR_REMOVED,
+                })
+            elif chunk_type == "added":
+                embeds.append({
+                    "description": content,
+                    "color": DISCORD_COLOR_ADDED,
+                })
+            elif chunk_type == "changed":
+                # Changed (old value) - use orange to distinguish from pure removal
+                embeds.append({
+                    "description": content,
+                    "color": DISCORD_COLOR_CHANGED,
+                })
+            elif chunk_type == "changed_into":
+                # Changed into (new value) - use blue to distinguish from pure addition
+                embeds.append({
+                    "description": content,
+                    "color": DISCORD_COLOR_CHANGED_INTO,
+                })
+
+            total_chars += len(content)
+
+        if embeds:
+            payload["embeds"] = embeds
+
+        # Send the payload using parent's _send method
+        if not self._send(payload, params=params):
+            return False
+
+        # Handle attachments if present
+        if attach and self.attachment_support:
+            payload.update({
+                "tts": False,
+                "wait": True,
+            })
+            payload.pop("embeds", None)
+            payload.pop("content", None)
+            payload.pop("allow_mentions", None)
+
+            for attachment in attach:
+                self.logger.info(f"Posting Discord Attachment {attachment.name}")
+                if not self._send(payload, params=params, attach=attachment):
+                    return False
+
+        return True
+
+    def _parse_body_into_chunks(self, body):
+        """
+        Parse the body into ordered chunks of (type, content) tuples.
+        Types: "unchanged", "removed", "added", "changed", "changed_into"
+        Preserves the original order of the diff.
+        """
+        chunks = []
+        position = 0
+
+        while position < len(body):
+            # Find the next marker
+            next_removed = body.find(REMOVED_PLACEMARKER_OPEN, position)
+            next_added = body.find(ADDED_PLACEMARKER_OPEN, position)
+            next_changed = body.find(CHANGED_PLACEMARKER_OPEN, position)
+            next_changed_into = body.find(CHANGED_INTO_PLACEMARKER_OPEN, position)
+
+            # Determine which marker comes first
+            if next_removed == -1 and next_added == -1 and next_changed == -1 and next_changed_into == -1:
+                # No more markers, rest is unchanged
+                if position < len(body):
+                    chunks.append(("unchanged", body[position:]))
+                break
+
+            # Find the earliest marker
+            next_marker_pos = None
+            next_marker_type = None
+
+            # Compare all marker positions to find the earliest
+            markers = []
+            if next_removed != -1:
+                markers.append((next_removed, "removed"))
+            if next_added != -1:
+                markers.append((next_added, "added"))
+            if next_changed != -1:
+                markers.append((next_changed, "changed"))
+            if next_changed_into != -1:
+                markers.append((next_changed_into, "changed_into"))
+
+            if markers:
+                next_marker_pos, next_marker_type = min(markers, key=lambda x: x[0])
+
+            # Add unchanged content before the marker
+            if next_marker_pos > position:
+                chunks.append(("unchanged", body[position:next_marker_pos]))
+
+            # Find the closing marker
+            if next_marker_type == "removed":
+                open_marker = REMOVED_PLACEMARKER_OPEN
+                close_marker = REMOVED_PLACEMARKER_CLOSED
+            elif next_marker_type == "added":
+                open_marker = ADDED_PLACEMARKER_OPEN
+                close_marker = ADDED_PLACEMARKER_CLOSED
+            elif next_marker_type == "changed":
+                open_marker = CHANGED_PLACEMARKER_OPEN
+                close_marker = CHANGED_PLACEMARKER_CLOSED
+            else:  # changed_into
+                open_marker = CHANGED_INTO_PLACEMARKER_OPEN
+                close_marker = CHANGED_INTO_PLACEMARKER_CLOSED
+
+            close_pos = body.find(close_marker, next_marker_pos)
+
+            if close_pos == -1:
+                # No closing marker, take rest as this type
+                content = body[next_marker_pos + len(open_marker):]
+                chunks.append((next_marker_type, content))
+                break
+            else:
+                # Extract content between markers
+                content = body[next_marker_pos + len(open_marker):close_pos]
+                chunks.append((next_marker_type, content))
+                position = close_pos + len(close_marker)
+
+        return chunks
+
+
+# Register the custom Discord handler with Apprise
+# This will override the built-in discord:// handler
+@notify(on="discord")
+def discord_custom_wrapper(body, title, notify_type, meta, body_format=None, *args, **kwargs):
+    """
+    Wrapper function to make the custom Discord handler work with Apprise's decorator system.
+    Note: This decorator approach may not work for overriding built-in plugins.
+    The class-based approach above is the proper way to extend NotifyDiscord.
+    """
+    logger.info("Custom Discord handler called")
+    # This is here for potential future use with decorator-based registration
+    return True

changedetectionio/notification/email_helpers.py

@@ -0,0 +1,42 @@
+def as_monospaced_html_email(content: str, title: str) -> str:
+    """
+    Wraps `content` in a minimal, email-safe HTML template
+    that forces monospace rendering across Gmail, Hotmail, Apple Mail, etc.
+
+    Args:
+        content: The body text (plain text or HTML-like).
+        title: The title plaintext
+    Returns:
+        A complete HTML document string suitable for sending as an email body.
+    """
+
+    # All line feed types should be removed and then this function should only be fed <br>'s
+    # Then it works with our <pre> styling without double linefeeds
+    content = content.translate(str.maketrans('', '', '\r\n'))
+
+    if title:
+        import html
+        title = html.escape(title)
+    else:
+        title = ''
+    # 2. Full email-safe HTML
+    html_email = f"""<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <meta name="x-apple-disable-message-reformatting">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+  <!--[if mso]>
+    <style>
+      body, div, pre, td {{ font-family: "Courier New", Courier, monospace !important; }}
+    </style>
+  <![endif]-->
+  <title>{title}</title>
+</head>
+<body style="-webkit-text-size-adjust:100%;-ms-text-size-adjust:100%;">
+  <pre role="article" aria-roledescription="email" lang="en"
+       style="font-family: monospace, 'Courier New', Courier; font-size: 0.9rem;
+              white-space: pre-wrap; word-break: break-word;">{content}</pre>
+</body>
+</html>"""
+    return html_email

changedetectionio/notification/handler.py

@@ -1,30 +1,333 @@
 
 import time
+import re
 import apprise
+from apprise import NotifyFormat
 from loguru import logger
+from urllib.parse import urlparse
 from .apprise_plugin.assets import apprise_asset, APPRISE_AVATAR_URL
+from .email_helpers import as_monospaced_html_email
+from ..diff import HTML_REMOVED_STYLE, REMOVED_PLACEMARKER_OPEN, REMOVED_PLACEMARKER_CLOSED, ADDED_PLACEMARKER_OPEN, HTML_ADDED_STYLE, \
+    ADDED_PLACEMARKER_CLOSED, CHANGED_INTO_PLACEMARKER_OPEN, CHANGED_INTO_PLACEMARKER_CLOSED, CHANGED_PLACEMARKER_OPEN, \
+    CHANGED_PLACEMARKER_CLOSED, HTML_CHANGED_STYLE, HTML_CHANGED_INTO_STYLE
+import re
 
-def process_notification(n_object, datastore):
-    from changedetectionio.safe_jinja import render as jinja_render
-    from . import default_notification_format_for_watch, default_notification_format, valid_notification_formats
+from ..notification_service import NotificationContextData, add_rendered_diff_to_notification_vars
+
+newline_re = re.compile(r'\r\n|\r|\n')
+
+def markup_text_links_to_html(body):
+    """
+    Convert plaintext to HTML with clickable links.
+    Uses Jinja2's escape and Markup for XSS safety.
+    """
+    from linkify_it import LinkifyIt
+    from markupsafe import Markup, escape
+
+    linkify = LinkifyIt()
+
+    # Match URLs in the ORIGINAL text (before escaping)
+    matches = linkify.match(body)
+
+    if not matches:
+        # No URLs, just escape everything
+        return Markup(escape(body))
+
+    result = []
+    last_index = 0
+
+    # Process each URL match
+    for match in matches:
+        # Add escaped text before the URL
+        if match.index > last_index:
+            text_part = body[last_index:match.index]
+            result.append(escape(text_part))
+
+        # Add the link with escaped URL (both in href and display)
+        url = match.url
+        result.append(Markup(f'<a href="{escape(url)}">{escape(url)}</a>'))
+
+        last_index = match.last_index
+
+    # Add remaining escaped text
+    if last_index < len(body):
+        result.append(escape(body[last_index:]))
+
+    # Join all parts
+    return str(Markup(''.join(str(part) for part in result)))
+
+def notification_format_align_with_apprise(n_format : str):
+    """
+    Correctly align changedetection's formats with apprise's formats
+    Probably these are the same - but good to be sure.
+    These set the expected OUTPUT format type
+    :param n_format:
+    :return:
+    """
+
+    if n_format.startswith('html'):
+        # Apprise only knows 'html' not 'htmlcolor' etc, which shouldnt matter here
+        n_format = NotifyFormat.HTML.value
+    elif n_format.startswith('markdown'):
+        # probably the same but just to be safe
+        n_format = NotifyFormat.MARKDOWN.value
+    elif n_format.startswith('text'):
+        # probably the same but just to be safe
+        n_format = NotifyFormat.TEXT.value
+    else:
+        n_format = NotifyFormat.TEXT.value
+
+    return n_format
+
+
+def apply_html_color_to_body(n_body: str):
+    # https://github.com/dgtlmoon/changedetection.io/issues/821#issuecomment-1241837050
+    n_body = n_body.replace(REMOVED_PLACEMARKER_OPEN,
+                            f'<span style="{HTML_REMOVED_STYLE}" role="deletion" aria-label="Removed text" title="Removed text">')
+    n_body = n_body.replace(REMOVED_PLACEMARKER_CLOSED, f'</span>')
+    n_body = n_body.replace(ADDED_PLACEMARKER_OPEN,
+                            f'<span style="{HTML_ADDED_STYLE}" role="insertion" aria-label="Added text" title="Added text">')
+    n_body = n_body.replace(ADDED_PLACEMARKER_CLOSED, f'</span>')
+    # Handle changed/replaced lines (old → new)
+    n_body = n_body.replace(CHANGED_PLACEMARKER_OPEN,
+                            f'<span style="{HTML_CHANGED_STYLE}" role="note" aria-label="Changed text" title="Changed text">')
+    n_body = n_body.replace(CHANGED_PLACEMARKER_CLOSED, f'</span>')
+    n_body = n_body.replace(CHANGED_INTO_PLACEMARKER_OPEN,
+                            f'<span style="{HTML_CHANGED_INTO_STYLE}" role="note" aria-label="Changed into" title="Changed into">')
+    n_body = n_body.replace(CHANGED_INTO_PLACEMARKER_CLOSED, f'</span>')
+    return n_body
+
+def apply_discord_markdown_to_body(n_body):
+    """
+    Discord does not support <del> but it supports non-standard ~~strikethrough~~
+    :param n_body:
+    :return:
+    """
+    import re
+    # Define the mapping between your placeholders and markdown markers
+    replacements = [
+        (REMOVED_PLACEMARKER_OPEN, '~~', REMOVED_PLACEMARKER_CLOSED, '~~'),
+        (ADDED_PLACEMARKER_OPEN, '**', ADDED_PLACEMARKER_CLOSED, '**'),
+        (CHANGED_PLACEMARKER_OPEN, '~~', CHANGED_PLACEMARKER_CLOSED, '~~'),
+        (CHANGED_INTO_PLACEMARKER_OPEN, '**', CHANGED_INTO_PLACEMARKER_CLOSED, '**'),
+    ]
+    # So that the markdown gets added without any whitespace following it which would break it
+    for open_tag, open_md, close_tag, close_md in replacements:
+        # Regex: match opening tag, optional whitespace, capture the content, optional whitespace, then closing tag
+        pattern = re.compile(
+            re.escape(open_tag) + r'(\s*)(.*?)?(\s*)' + re.escape(close_tag),
+            flags=re.DOTALL
+        )
+        n_body = pattern.sub(lambda m: f"{m.group(1)}{open_md}{m.group(2)}{close_md}{m.group(3)}", n_body)
+    return n_body
+
+def apply_standard_markdown_to_body(n_body):
+    """
+    Apprise does not support ~~strikethrough~~ but it will convert <del> to HTML strikethrough.
+    :param n_body:
+    :return:
+    """
+    import re
+    # Define the mapping between your placeholders and markdown markers
+    replacements = [
+        (REMOVED_PLACEMARKER_OPEN, '<del>', REMOVED_PLACEMARKER_CLOSED, '</del>'),
+        (ADDED_PLACEMARKER_OPEN, '**', ADDED_PLACEMARKER_CLOSED, '**'),
+        (CHANGED_PLACEMARKER_OPEN, '<del>', CHANGED_PLACEMARKER_CLOSED, '</del>'),
+        (CHANGED_INTO_PLACEMARKER_OPEN, '**', CHANGED_INTO_PLACEMARKER_CLOSED, '**'),
+    ]
+
+    # So that the markdown gets added without any whitespace following it which would break it
+    for open_tag, open_md, close_tag, close_md in replacements:
+        # Regex: match opening tag, optional whitespace, capture the content, optional whitespace, then closing tag
+        pattern = re.compile(
+            re.escape(open_tag) + r'(\s*)(.*?)?(\s*)' + re.escape(close_tag),
+            flags=re.DOTALL
+        )
+        n_body = pattern.sub(lambda m: f"{m.group(1)}{open_md}{m.group(2)}{close_md}{m.group(3)}", n_body)
+    return n_body
+
+
+def replace_placemarkers_in_text(text, url, requested_output_format):
+    """
+    Replace diff placemarkers in text based on the URL service type and requested output format.
+    Used for both notification title and body to ensure consistent placeholder replacement.
+
+    :param text: The text to process
+    :param url: The notification URL (to detect service type)
+    :param requested_output_format: The output format (html, htmlcolor, markdown, text, etc.)
+    :return: Processed text with placemarkers replaced
+    """
+    if not text:
+        return text
+
+    if url.startswith('tgram://'):
+        # Telegram only supports a limited subset of HTML
+        # Use strikethrough for removed content, bold for added content
+        text = text.replace(REMOVED_PLACEMARKER_OPEN, '<s>')
+        text = text.replace(REMOVED_PLACEMARKER_CLOSED, '</s>')
+        text = text.replace(ADDED_PLACEMARKER_OPEN, '<b>')
+        text = text.replace(ADDED_PLACEMARKER_CLOSED, '</b>')
+        # Handle changed/replaced lines (old → new)
+        text = text.replace(CHANGED_PLACEMARKER_OPEN, '<s>')
+        text = text.replace(CHANGED_PLACEMARKER_CLOSED, '</s>')
+        text = text.replace(CHANGED_INTO_PLACEMARKER_OPEN, '<b>')
+        text = text.replace(CHANGED_INTO_PLACEMARKER_CLOSED, '</b>')
+    elif (url.startswith('discord://') or url.startswith('https://discordapp.com/api/webhooks')
+          or url.startswith('https://discord.com/api')) and requested_output_format == 'html':
+        # Discord doesn't support HTML, use Discord markdown
+        text = apply_discord_markdown_to_body(n_body=text)
+    elif requested_output_format == 'htmlcolor':
+        # https://github.com/dgtlmoon/changedetection.io/issues/821#issuecomment-1241837050
+        text = text.replace(REMOVED_PLACEMARKER_OPEN, f'<span style="{HTML_REMOVED_STYLE}" role="deletion" aria-label="Removed text" title="Removed text">')
+        text = text.replace(REMOVED_PLACEMARKER_CLOSED, f'</span>')
+        text = text.replace(ADDED_PLACEMARKER_OPEN, f'<span style="{HTML_ADDED_STYLE}" role="insertion" aria-label="Added text" title="Added text">')
+        text = text.replace(ADDED_PLACEMARKER_CLOSED, f'</span>')
+        # Handle changed/replaced lines (old → new)
+        text = text.replace(CHANGED_PLACEMARKER_OPEN, f'<span style="{HTML_CHANGED_STYLE}" role="note" aria-label="Changed text" title="Changed text">')
+        text = text.replace(CHANGED_PLACEMARKER_CLOSED, f'</span>')
+        text = text.replace(CHANGED_INTO_PLACEMARKER_OPEN, f'<span style="{HTML_CHANGED_INTO_STYLE}" role="note" aria-label="Changed into" title="Changed into">')
+        text = text.replace(CHANGED_INTO_PLACEMARKER_CLOSED, f'</span>')
+    elif requested_output_format == 'markdown':
+        # Markdown to HTML - Apprise will convert this to HTML
+        text = apply_standard_markdown_to_body(n_body=text)
+    else:
+        # plaintext, html, and default - use simple text markers
+        text = text.replace(REMOVED_PLACEMARKER_OPEN, '(removed) ')
+        text = text.replace(REMOVED_PLACEMARKER_CLOSED, '')
+        text = text.replace(ADDED_PLACEMARKER_OPEN, '(added) ')
+        text = text.replace(ADDED_PLACEMARKER_CLOSED, '')
+        text = text.replace(CHANGED_PLACEMARKER_OPEN, f'(changed) ')
+        text = text.replace(CHANGED_PLACEMARKER_CLOSED, f'')
+        text = text.replace(CHANGED_INTO_PLACEMARKER_OPEN, f'(into) ')
+        text = text.replace(CHANGED_INTO_PLACEMARKER_CLOSED, f'')
+
+    return text
+
+def apply_service_tweaks(url, n_body, n_title, requested_output_format):
+
+    logger.debug(f"Applying markup in '{requested_output_format}' mode")
+
+    # Re 323 - Limit discord length to their 2000 char limit total or it wont send.
+    # Because different notifications may require different pre-processing, run each sequentially :(
+    # 2000 bytes minus -
+    #     200 bytes for the overhead of the _entire_ json payload, 200 bytes for {tts, wait, content} etc headers
+    #     Length of URL - Incase they specify a longer custom avatar_url
+
+    if not n_body or not n_body.strip():
+        return url, n_body, n_title
+
+    # Normalize URL scheme to lowercase to prevent case-sensitivity issues
+    # e.g., "Discord://webhook" -> "discord://webhook", "TGRAM://bot123" -> "tgram://bot123"
+    scheme_separator_pos = url.find('://')
+    if scheme_separator_pos > 0:
+        url = url[:scheme_separator_pos].lower() + url[scheme_separator_pos:]
+
+    # So if no avatar_url is specified, add one so it can be correctly calculated into the total payload
+    parsed = urlparse(url)
+    k = '?' if not parsed.query else '&'
+    if url and not 'avatar_url' in url \
+            and not url.startswith('mail') \
+            and not url.startswith('post') \
+            and not url.startswith('get') \
+            and not url.startswith('delete') \
+            and not url.startswith('put'):
+        url += k + f"avatar_url={APPRISE_AVATAR_URL}"
+
+    # Replace placemarkers in title first (this was the missing piece causing the bug)
+    # Titles are ALWAYS plain text across all notification services (Discord embeds, Slack attachments,
+    # email Subject headers, etc.), so we always use 'text' format for title placemarker replacement
+    # Looking over apprise library it seems that all plugins only expect plain-text.
+    n_title = replace_placemarkers_in_text(n_title, url, 'text')
+
+    if url.startswith('tgram://'):
+        # Telegram only supports a limit subset of HTML, remove the '<br>' we place in.
+        # re https://github.com/dgtlmoon/changedetection.io/issues/555
+        # @todo re-use an existing library we have already imported to strip all non-allowed tags
+        n_body = n_body.replace('<br>', '\n')
+        n_body = n_body.replace('</br>', '\n')
+        n_body = newline_re.sub('\n', n_body)
+
+        # Replace placemarkers for body
+        n_body = replace_placemarkers_in_text(n_body, url, requested_output_format)
+
+        # real limit is 4096, but minus some for extra metadata
+        payload_max_size = 3600
+        body_limit = max(0, payload_max_size - len(n_title))
+        n_title = n_title[0:payload_max_size]
+        n_body = n_body[0:body_limit]
+
+    elif (url.startswith('discord://') or url.startswith('https://discordapp.com/api/webhooks')
+          or url.startswith('https://discord.com/api'))\
+            and 'html' in requested_output_format:
+        # Discord doesn't support HTML, replace <br> with newlines
+        n_body = n_body.strip().replace('<br>', '\n')
+        n_body = n_body.replace('</br>', '\n')
+        n_body = newline_re.sub('\n', n_body)
+
+        # Don't replace placeholders or truncate here - let the custom Discord plugin handle it
+        # The plugin will use embeds (6000 char limit across all embeds) if placeholders are present,
+        # or plain content (2000 char limit) otherwise
+
+        # Only do placeholder replacement if NOT using htmlcolor (which triggers embeds in custom plugin)
+        if requested_output_format == 'html':
+            # No diff placeholders, use Discord markdown for any other formatting
+            # Use Discord markdown: strikethrough for removed, bold for added
+            n_body = replace_placemarkers_in_text(n_body, url, requested_output_format)
+
+            # Apply 2000 char limit for plain content
+            payload_max_size = 1700
+            body_limit = max(0, payload_max_size - len(n_title))
+            n_title = n_title[0:payload_max_size]
+            n_body = n_body[0:body_limit]
+        # else: our custom Discord plugin will convert any placeholders left over into embeds with color bars
+
+    # Is not discord/tgram and they want htmlcolor
+    elif requested_output_format == 'htmlcolor':
+        n_body = replace_placemarkers_in_text(n_body, url, requested_output_format)
+        n_body = newline_re.sub('<br>\n', n_body)
+    elif requested_output_format == 'html':
+        n_body = replace_placemarkers_in_text(n_body, url, requested_output_format)
+        n_body = newline_re.sub('<br>\n', n_body)
+    elif requested_output_format == 'markdown':
+        # Markdown to HTML - Apprise will convert this to HTML
+        n_body = replace_placemarkers_in_text(n_body, url, requested_output_format)
+
+    else: #plaintext etc default
+        n_body = replace_placemarkers_in_text(n_body, url, requested_output_format)
+
+    return url, n_body, n_title
+
+
+def process_notification(n_object: NotificationContextData, datastore):
+    from changedetectionio.jinja2_custom import render as jinja_render
+    from . import USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH, default_notification_format, valid_notification_formats
     # be sure its registered
     from .apprise_plugin.custom_handlers import apprise_http_custom_handler
+    # Register custom Discord plugin
+    from .apprise_plugin.discord import NotifyDiscordCustom
+
+    if not isinstance(n_object, NotificationContextData):
+        raise TypeError(f"Expected NotificationContextData, got {type(n_object)}")
 
     now = time.time()
     if n_object.get('notification_timestamp'):
         logger.trace(f"Time since queued {now-n_object['notification_timestamp']:.3f}s")
+
     # Insert variables into the notification content
     notification_parameters = create_notification_parameters(n_object, datastore)
 
-    n_format = valid_notification_formats.get(
-        n_object.get('notification_format', default_notification_format),
-        valid_notification_formats[default_notification_format],
-    )
+    requested_output_format = n_object.get('notification_format', default_notification_format)
+    logger.debug(f"Requested notification output format: '{requested_output_format}'")
 
     # If we arrived with 'System default' then look it up
-    if n_format == default_notification_format_for_watch and datastore.data['settings']['application'].get('notification_format') != default_notification_format_for_watch:
+    if requested_output_format == USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH:
         # Initially text or whatever
-        n_format = datastore.data['settings']['application'].get('notification_format', valid_notification_formats[default_notification_format])
+        requested_output_format = datastore.data['settings']['application'].get('notification_format', default_notification_format)
+
+    requested_output_format_original = requested_output_format
+
+    # Now clean it up so it fits perfectly with apprise
+    requested_output_format = notification_format_align_with_apprise(n_format=requested_output_format)
 
     logger.trace(f"Complete notification body including Jinja and placeholders calculated in  {time.time() - now:.2f}s")
 
@@ -39,99 +342,122 @@ def process_notification(n_object, datastore):
 
     apobj = apprise.Apprise(debug=True, asset=apprise_asset)
 
+    # Override Apprise's built-in Discord plugin with our custom one
+    # This allows us to use colored embeds for diff content
+    # First remove the built-in discord plugin, then add our custom one
+    apprise.plugins.N_MGR.remove('discord')
+    apprise.plugins.N_MGR.add(NotifyDiscordCustom, schemas='discord')
+
     if not n_object.get('notification_urls'):
         return None
 
-    with apprise.LogCapture(level=apprise.logging.DEBUG) as logs:
+    n_object.update(add_rendered_diff_to_notification_vars(
+        notification_scan_text=n_object.get('notification_body', '')+n_object.get('notification_title', ''),
+        current_snapshot=n_object.get('current_snapshot'),
+        prev_snapshot=n_object.get('prev_snapshot'),
+        # Should always be false for 'text' mode or its too hard to read
+        # But otherwise, this could be some setting
+        word_diff=False if requested_output_format_original == 'text' else True,
+        )
+    )
+
+    with (apprise.LogCapture(level=apprise.logging.DEBUG) as logs):
         for url in n_object['notification_urls']:
 
-            # Get the notification body from datastore
             n_body = jinja_render(template_str=n_object.get('notification_body', ''), **notification_parameters)
-            if n_object.get('notification_format', '').startswith('HTML'):
-                n_body = n_body.replace("\n", '<br>')
-
             n_title = jinja_render(template_str=n_object.get('notification_title', ''), **notification_parameters)
 
+            if n_object.get('markup_text_links_to_html_links'):
+                n_body = markup_text_links_to_html(body=n_body)
+
             url = url.strip()
-            if url.startswith('#'):
-                logger.trace(f"Skipping commented out notification URL - {url}")
+            if not url or url.startswith('#'):
+                logger.debug(f"Skipping commented out or empty notification URL - '{url}'")
                 continue
 
-            if not url:
-                logger.warning(f"Process Notification: skipping empty notification URL.")
-                continue
-
-            logger.info(f">> Process Notification: AppRise notifying {url}")
+            logger.info(f">> Process Notification: AppRise start notifying '{url}'")
             url = jinja_render(template_str=url, **notification_parameters)
 
-            # Re 323 - Limit discord length to their 2000 char limit total or it wont send.
-            # Because different notifications may require different pre-processing, run each sequentially :(
-            # 2000 bytes minus -
-            #     200 bytes for the overhead of the _entire_ json payload, 200 bytes for {tts, wait, content} etc headers
-            #     Length of URL - Incase they specify a longer custom avatar_url
+            # If it's a plaintext document, and they want HTML type email/alerts, so it needs to be escaped
+            watch_mime_type = n_object.get('watch_mime_type')
+            if watch_mime_type and 'text/' in watch_mime_type.lower() and not 'html' in watch_mime_type.lower():
+                if 'html' in requested_output_format:
+                    from markupsafe import escape
+                    n_body = str(escape(n_body))
 
-            # So if no avatar_url is specified, add one so it can be correctly calculated into the total payload
-            k = '?' if not '?' in url else '&'
-            if not 'avatar_url' in url \
-                    and not url.startswith('mail') \
-                    and not url.startswith('post') \
-                    and not url.startswith('get') \
-                    and not url.startswith('delete') \
-                    and not url.startswith('put'):
-                url += k + f"avatar_url={APPRISE_AVATAR_URL}"
+            if 'html' in requested_output_format:
+                # Since the n_body is always some kind of text from the 'diff' engine, attempt to preserve whitespaces that get sent to the HTML output
+                # But only where its more than 1 consecutive whitespace, otherwise "and this" becomes "and&nbsp;this" etc which is too much.
+                n_body = n_body.replace('  ', '&nbsp;&nbsp;')
 
-            if url.startswith('tgram://'):
-                # Telegram only supports a limit subset of HTML, remove the '<br>' we place in.
-                # re https://github.com/dgtlmoon/changedetection.io/issues/555
-                # @todo re-use an existing library we have already imported to strip all non-allowed tags
-                n_body = n_body.replace('<br>', '\n')
-                n_body = n_body.replace('</br>', '\n')
-                # real limit is 4096, but minus some for extra metadata
-                payload_max_size = 3600
-                body_limit = max(0, payload_max_size - len(n_title))
-                n_title = n_title[0:payload_max_size]
-                n_body = n_body[0:body_limit]
+            (url, n_body, n_title) = apply_service_tweaks(url=url, n_body=n_body, n_title=n_title, requested_output_format=requested_output_format_original)
 
-            elif url.startswith('discord://') or url.startswith('https://discordapp.com/api/webhooks') or url.startswith(
-                    'https://discord.com/api'):
-                # real limit is 2000, but minus some for extra metadata
-                payload_max_size = 1700
-                body_limit = max(0, payload_max_size - len(n_title))
-                n_title = n_title[0:payload_max_size]
-                n_body = n_body[0:body_limit]
+            apprise_input_format = "NO-THANKS-WE-WILL-MANAGE-ALL-OF-THIS"
 
-            elif url.startswith('mailto'):
-                # Apprise will default to HTML, so we need to override it
-                # So that whats' generated in n_body is in line with what is going to be sent.
-                # https://github.com/caronc/apprise/issues/633#issuecomment-1191449321
-                if not 'format=' in url and (n_format == 'Text' or n_format == 'Markdown'):
-                    prefix = '?' if not '?' in url else '&'
-                    # Apprise format is lowercase text https://github.com/caronc/apprise/issues/633
-                    n_format = n_format.lower()
-                    url = f"{url}{prefix}format={n_format}"
-                # If n_format == HTML, then apprise email should default to text/html and we should be sending HTML only
+            if not 'format=' in url:
+                parsed_url = urlparse(url)
+                prefix_add_to_url = '?' if not parsed_url.query else '&'
 
-            apobj.add(url)
+                # THIS IS THE TRICK HOW TO DISABLE APPRISE DOING WEIRD AUTO-CONVERSION WITH BREAKING BR TAGS ETC
+                if 'html' in requested_output_format:
+                    url = f"{url}{prefix_add_to_url}format={NotifyFormat.HTML.value}"
+                    apprise_input_format = NotifyFormat.HTML.value
+                elif 'text' in requested_output_format:
+                    url = f"{url}{prefix_add_to_url}format={NotifyFormat.TEXT.value}"
+                    apprise_input_format = NotifyFormat.TEXT.value
 
+                elif requested_output_format == NotifyFormat.MARKDOWN.value:
+                    # Convert markdown to HTML ourselves since not all plugins do this
+                    from apprise.conversion import markdown_to_html
+                    # Make sure there are paragraph breaks around horizontal rules
+                    n_body = n_body.replace('---', '\n\n---\n\n')
+                    n_body = markdown_to_html(n_body)
+                    url = f"{url}{prefix_add_to_url}format={NotifyFormat.HTML.value}"
+                    requested_output_format = NotifyFormat.HTML.value
+                    apprise_input_format = NotifyFormat.HTML.value  # Changed from MARKDOWN to HTML
+
+            else:
+                # ?format was IN the apprise URL, they are kind of on their own here, we will try our best
+                if 'format=html' in url:
+                    n_body = newline_re.sub('<br>\r\n', n_body)
+                    # This will also prevent apprise from doing conversion
+                    apprise_input_format = NotifyFormat.HTML.value
+                    requested_output_format = NotifyFormat.HTML.value
+                elif 'format=text' in url:
+                    apprise_input_format = NotifyFormat.TEXT.value
+                    requested_output_format = NotifyFormat.TEXT.value
+
+#@todo on null:// (only if its a 1 url with null) probably doesnt need to actually .add/setup/etc
             sent_objs.append({'title': n_title,
                               'body': n_body,
                               'url': url,
-                              'body_format': n_format})
+                              # So that we can do a null:// call and get back exactly what would have been sent
+                              'original_context': n_object })
 
-        # Blast off the notifications tht are set in .add()
-        apobj.notify(
-            title=n_title,
-            body=n_body,
-            body_format=n_format,
-            # False is not an option for AppRise, must be type None
-            attach=n_object.get('screenshot', None)
-        )
+            if not url.startswith('null://'):
+                apobj.add(url)
 
+            # Since the output is always based on the plaintext of the 'diff' engine, wrap it nicely.
+            # It should always be similar to the 'history' part of the UI.
+            if url.startswith('mail') and 'html' in requested_output_format:
+                if not '<pre' in n_body and not '<body' in n_body: # No custom HTML-ish body was setup already
+                    n_body = as_monospaced_html_email(content=n_body, title=n_title)
+
+        if not url.startswith('null://'):
+            apobj.notify(
+                title=n_title,
+                body=n_body,
+                # `body_format` Tell apprise what format the INPUT is in, specify a wrong/bad type and it will force skip conversion in apprise
+                # &format= in URL Tell apprise what format the OUTPUT should be in (it can convert between)
+                body_format=apprise_input_format,
+                # False is not an option for AppRise, must be type None
+                attach=n_object.get('screenshot', None)
+            )
 
         # Returns empty string if nothing found, multi-line string otherwise
         log_value = logs.getvalue()
 
-        if log_value and 'WARNING' in log_value or 'ERROR' in log_value:
+        if log_value and ('WARNING' in log_value or 'ERROR' in log_value):
             logger.critical(log_value)
             raise Exception(log_value)
 
@@ -141,17 +467,17 @@ def process_notification(n_object, datastore):
 
 # Notification title + body content parameters get created here.
 # ( Where we prepare the tokens in the notification to be replaced with actual values )
-def create_notification_parameters(n_object, datastore):
-    from copy import deepcopy
-    from . import valid_tokens
+def create_notification_parameters(n_object: NotificationContextData, datastore):
+    if not isinstance(n_object, NotificationContextData):
+        raise TypeError(f"Expected NotificationContextData, got {type(n_object)}")
 
-    # in the case we send a test notification from the main settings, there is no UUID.
-    uuid = n_object['uuid'] if 'uuid' in n_object else ''
+    ext_base_url = datastore.data['settings']['application'].get('active_base_url').strip('/')+'/'
 
-    if uuid:
-        watch_title = datastore.data['watching'][uuid].label
+    watch = datastore.data['watching'].get(n_object['uuid'])
+    if watch:
+        watch_title = datastore.data['watching'][n_object['uuid']].label
         tag_list = []
-        tags = datastore.get_all_tags_for_watch(uuid)
+        tags = datastore.get_all_tags_for_watch(n_object['uuid'])
         if tags:
             for tag_uuid, tag in tags.items():
                 tag_list.append(tag.get('title'))
@@ -160,34 +486,36 @@ def create_notification_parameters(n_object, datastore):
         watch_title = 'Change Detection'
         watch_tag = ''
 
-    # Create URLs to customise the notification with
-    # active_base_url - set in store.py data property
-    base_url = datastore.data['settings']['application'].get('active_base_url')
-
     watch_url = n_object['watch_url']
 
-    diff_url = "{}/diff/{}".format(base_url, uuid)
-    preview_url = "{}/preview/{}".format(base_url, uuid)
+    # Build URLs manually instead of using url_for() to avoid requiring a request context
+    # This allows notifications to be processed in background threads
+    uuid = n_object['uuid']
 
-    # Not sure deepcopy is needed here, but why not
-    tokens = deepcopy(valid_tokens)
+    if n_object.get('timestamp_from') and n_object.get('timestamp_to'):
+        # Include a link to the diff page with specific versions
+        diff_url = f"{ext_base_url}diff/{uuid}?from_version={n_object['timestamp_from']}&to_version={n_object['timestamp_to']}"
+    else:
+        diff_url = f"{ext_base_url}diff/{uuid}"
 
-    # Valid_tokens also used as a field validator
-    tokens.update(
+    preview_url = f"{ext_base_url}preview/{uuid}"
+    edit_url = f"{ext_base_url}edit/{uuid}"
+
+    # @todo test that preview_url is correct when running in not-null mode?
+    # if not, first time app loads i think it can set a flask context
+    n_object.update(
         {
-            'base_url': base_url,
+            'base_url': ext_base_url,
             'diff_url': diff_url,
-            'preview_url': preview_url,
+            'preview_url': preview_url, #@todo include 'version='
+            'edit_url': edit_url, #@todo also pause, also mute link
             'watch_tag': watch_tag if watch_tag is not None else '',
             'watch_title': watch_title if watch_title is not None else '',
             'watch_url': watch_url,
-            'watch_uuid': uuid,
+            'watch_uuid': n_object['uuid'],
         })
 
-    # n_object will contain diff, diff_added etc etc
-    tokens.update(n_object)
+    if watch:
+        n_object.update(datastore.data['watching'].get(n_object['uuid']).extra_notification_token_values())
 
-    if uuid:
-        tokens.update(datastore.data['watching'].get(uuid).extra_notification_token_values())
-
-    return tokens
+    return n_object

changedetectionio/notification_service.py

@@ -5,10 +5,213 @@ Notification Service Module
 Extracted from update_worker.py to provide standalone notification functionality
 for both sync and async workers
 """
+import datetime
 
-import time
+import pytz
 from loguru import logger
+import time
 
+from changedetectionio.notification import default_notification_format, valid_notification_formats
+
+
+def _check_cascading_vars(datastore, var_name, watch):
+    """
+    Check notification variables in cascading priority:
+    Individual watch settings > Tag settings > Global settings
+    """
+    from changedetectionio.notification import (
+        USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH,
+        default_notification_body,
+        default_notification_title
+    )
+
+    # Would be better if this was some kind of Object where Watch can reference the parent datastore etc
+    v = watch.get(var_name)
+    if v and not watch.get('notification_muted'):
+        if var_name == 'notification_format' and v == USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH:
+            return datastore.data['settings']['application'].get('notification_format')
+
+        return v
+
+    tags = datastore.get_all_tags_for_watch(uuid=watch.get('uuid'))
+    if tags:
+        for tag_uuid, tag in tags.items():
+            v = tag.get(var_name)
+            if v and not tag.get('notification_muted'):
+                return v
+
+    if datastore.data['settings']['application'].get(var_name):
+        return datastore.data['settings']['application'].get(var_name)
+
+    # Otherwise could be defaults
+    if var_name == 'notification_format':
+        return USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH
+    if var_name == 'notification_body':
+        return default_notification_body
+    if var_name == 'notification_title':
+        return default_notification_title
+
+    return None
+
+
+# What is passed around as notification context, also used as the complete list of valid {{ tokens }}
+class NotificationContextData(dict):
+    def __init__(self, initial_data=None, **kwargs):
+        super().__init__({
+            'base_url': None,
+            'current_snapshot': None,
+            'diff': None,
+            'diff_clean': None,
+            'diff_added': None,
+            'diff_added_clean': None,
+            'diff_full': None,
+            'diff_full_clean': None,
+            'diff_patch': None,
+            'diff_removed': None,
+            'diff_removed_clean': None,
+            'diff_url': None,
+            'markup_text_links_to_html_links': False, # If automatic conversion of plaintext to HTML should happen
+            'notification_timestamp': time.time(),
+            'preview_url': None,
+            'screenshot': None,
+            'triggered_text': None,
+            'timestamp_from': None,
+            'timestamp_to': None,
+            'uuid': 'XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX',  # Converted to 'watch_uuid' in create_notification_parameters
+            'watch_mime_type': None,
+            'watch_tag': None,
+            'watch_title': None,
+            'watch_url': 'https://WATCH-PLACE-HOLDER/',
+        })
+
+        # Apply any initial data passed in
+        self.update({'watch_uuid': self.get('uuid')})
+        if initial_data:
+            self.update(initial_data)
+
+        # Apply any keyword arguments
+        if kwargs:
+            self.update(kwargs)
+
+        n_format = self.get('notification_format')
+        if n_format and not valid_notification_formats.get(n_format):
+            raise ValueError(f'Invalid notification format: "{n_format}"')
+
+    def set_random_for_validation(self):
+        import random, string
+        """Randomly fills all dict keys with random strings (for validation/testing). 
+        So we can test the output in the notification body
+        """
+        for key in self.keys():
+            if key in ['uuid', 'time', 'watch_uuid']:
+                continue
+            rand_str = 'RANDOM-PLACEHOLDER-'+''.join(random.choices(string.ascii_letters + string.digits, k=12))
+            self[key] = rand_str
+
+    def __setitem__(self, key, value):
+        if key == 'notification_format' and isinstance(value, str) and not value.startswith('RANDOM-PLACEHOLDER-'):
+            if not valid_notification_formats.get(value):
+                raise ValueError(f'Invalid notification format: "{value}"')
+
+        super().__setitem__(key, value)
+
+def timestamp_to_localtime(timestamp):
+    # Format the date using locale-aware formatting with timezone
+    dt = datetime.datetime.fromtimestamp(int(timestamp))
+    dt = dt.replace(tzinfo=pytz.UTC)
+
+    # Get local timezone-aware datetime
+    local_tz = datetime.datetime.now().astimezone().tzinfo
+    local_dt = dt.astimezone(local_tz)
+
+    # Format date with timezone - using strftime for locale awareness
+    try:
+        formatted_date = local_dt.strftime('%Y-%m-%d %H:%M:%S %Z')
+    except:
+        # Fallback if locale issues
+        formatted_date = local_dt.isoformat()
+
+    return formatted_date
+
+def add_rendered_diff_to_notification_vars(notification_scan_text:str, prev_snapshot:str, current_snapshot:str, word_diff:bool):
+    """
+    Efficiently renders only the diff placeholders that are actually used in the notification text.
+
+    Scans the notification template for diff placeholder usage (diff, diff_added, diff_clean, etc.)
+    and only renders those specific variants, avoiding expensive render_diff() calls for unused placeholders.
+    Uses LRU caching to avoid duplicate renders when multiple placeholders share the same arguments.
+
+    Args:
+        notification_scan_text: The notification template text to scan for placeholders
+        prev_snapshot: Previous version of content for diff comparison
+        current_snapshot: Current version of content for diff comparison
+        word_diff: Whether to use word-level (True) or line-level (False) diffing
+
+    Returns:
+        dict: Only the diff placeholders that were found in notification_scan_text, with rendered content
+    """
+    from changedetectionio import diff
+    import re
+    from functools import lru_cache
+
+    now = time.time()
+
+    # Define specifications for each diff variant
+    diff_specs = {
+        'diff': {'word_diff': word_diff},
+        'diff_clean': {'word_diff': word_diff, 'include_change_type_prefix': False},
+        'diff_added': {'word_diff': word_diff, 'include_removed': False},
+        'diff_added_clean': {'word_diff': word_diff, 'include_removed': False, 'include_change_type_prefix': False},
+        'diff_full': {'word_diff': word_diff, 'include_equal': True},
+        'diff_full_clean': {'word_diff': word_diff, 'include_equal': True, 'include_change_type_prefix': False},
+        'diff_patch': {'word_diff': word_diff, 'patch_format': True},
+        'diff_removed': {'word_diff': word_diff, 'include_added': False},
+        'diff_removed_clean': {'word_diff': word_diff, 'include_added': False, 'include_change_type_prefix': False},
+    }
+
+    # Memoize render_diff to avoid duplicate renders with same kwargs
+    @lru_cache(maxsize=4)
+    def cached_render(kwargs_tuple):
+        return diff.render_diff(prev_snapshot, current_snapshot, **dict(kwargs_tuple))
+
+    ret = {}
+    rendered_count = 0
+    # Only check and render diff keys that exist in NotificationContextData
+    for key in NotificationContextData().keys():
+        if key.startswith('diff') and key in diff_specs:
+            # Check if this placeholder is actually used in the notification text
+            pattern = rf"(?<![A-Za-z0-9_]){re.escape(key)}(?![A-Za-z0-9_])"
+            if re.search(pattern, notification_scan_text, re.IGNORECASE):
+                kwargs = diff_specs[key]
+                # Convert dict to sorted tuple for cache key (handles duplicate kwarg combinations)
+                ret[key] = cached_render(tuple(sorted(kwargs.items())))
+                rendered_count += 1
+
+    if rendered_count:
+        logger.trace(f"Rendered {rendered_count} diff placeholder(s) {sorted(ret.keys())} in {time.time() - now:.3f}s")
+
+    return ret
+
+def set_basic_notification_vars(current_snapshot, prev_snapshot, watch, triggered_text, timestamp_changed=None):
+
+    n_object = {
+        'current_snapshot': current_snapshot,
+        'prev_snapshot': prev_snapshot,
+        'screenshot': watch.get_screenshot() if watch and watch.get('notification_screenshot') else None,
+        'change_datetime': timestamp_to_localtime(timestamp_changed) if timestamp_changed else None,
+        'triggered_text': triggered_text,
+        'uuid': watch.get('uuid') if watch else None,
+        'watch_url': watch.get('url') if watch else None,
+        'watch_uuid': watch.get('uuid') if watch else None,
+        'watch_mime_type': watch.get('content-type')
+    }
+
+    # The \n's in the content from the above will get converted to <br> etc depending on the notification format
+
+    if watch:
+        n_object.update(watch.extra_notification_token_values())
+
+    return n_object
 
 class NotificationService:
     """
@@ -20,18 +223,18 @@ class NotificationService:
         self.datastore = datastore
         self.notification_q = notification_q
     
-    def queue_notification_for_watch(self, n_object, watch):
+    def queue_notification_for_watch(self, n_object: NotificationContextData, watch, date_index_from=-2, date_index_to=-1):
         """
         Queue a notification for a watch with full diff rendering and template variables
         """
-        from changedetectionio import diff
-        from changedetectionio.notification import default_notification_format_for_watch
+        from changedetectionio.notification import USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH
+
+        if not isinstance(n_object, NotificationContextData):
+            raise TypeError(f"Expected NotificationContextData, got {type(n_object)}")
 
         dates = []
         trigger_text = ''
 
-        now = time.time()
-
         if watch:
             watch_history = watch.history
             dates = list(watch_history.keys())
@@ -39,108 +242,49 @@ class NotificationService:
 
         # Add text that was triggered
         if len(dates):
-            snapshot_contents = watch.get_history_snapshot(dates[-1])
+            snapshot_contents = watch.get_history_snapshot(timestamp=dates[-1])
         else:
             snapshot_contents = "No snapshot/history available, the watch should fetch atleast once."
 
         # If we ended up here with "System default"
-        if n_object.get('notification_format') == default_notification_format_for_watch:
+        if n_object.get('notification_format') == USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH:
             n_object['notification_format'] = self.datastore.data['settings']['application'].get('notification_format')
 
-        html_colour_enable = False
-        # HTML needs linebreak, but MarkDown and Text can use a linefeed
-        if n_object.get('notification_format') == 'HTML':
-            line_feed_sep = "<br>"
-            # Snapshot will be plaintext on the disk, convert to some kind of HTML
-            snapshot_contents = snapshot_contents.replace('\n', line_feed_sep)
-        elif n_object.get('notification_format') == 'HTML Color':
-            line_feed_sep = "<br>"
-            # Snapshot will be plaintext on the disk, convert to some kind of HTML
-            snapshot_contents = snapshot_contents.replace('\n', line_feed_sep)
-            html_colour_enable = True
-        else:
-            line_feed_sep = "\n"
 
         triggered_text = ''
         if len(trigger_text):
             from . import html_tools
             triggered_text = html_tools.get_triggered_text(content=snapshot_contents, trigger_text=trigger_text)
             if triggered_text:
-                triggered_text = line_feed_sep.join(triggered_text)
+                triggered_text = '\n'.join(triggered_text)
 
         # Could be called as a 'test notification' with only 1 snapshot available
         prev_snapshot = "Example text: example test\nExample text: change detection is cool\nExample text: some more examples\n"
         current_snapshot = "Example text: example test\nExample text: change detection is fantastic\nExample text: even more examples\nExample text: a lot more examples"
 
         if len(dates) > 1:
-            prev_snapshot = watch.get_history_snapshot(dates[-2])
-            current_snapshot = watch.get_history_snapshot(dates[-1])
+            prev_snapshot = watch.get_history_snapshot(timestamp=dates[date_index_from])
+            current_snapshot = watch.get_history_snapshot(timestamp=dates[date_index_to])
 
-        n_object.update({
-            'current_snapshot': snapshot_contents,
-            'diff': diff.render_diff(prev_snapshot, current_snapshot, line_feed_sep=line_feed_sep, html_colour=html_colour_enable),
-            'diff_added': diff.render_diff(prev_snapshot, current_snapshot, include_removed=False, line_feed_sep=line_feed_sep),
-            'diff_full': diff.render_diff(prev_snapshot, current_snapshot, include_equal=True, line_feed_sep=line_feed_sep, html_colour=html_colour_enable),
-            'diff_patch': diff.render_diff(prev_snapshot, current_snapshot, line_feed_sep=line_feed_sep, patch_format=True),
-            'diff_removed': diff.render_diff(prev_snapshot, current_snapshot, include_added=False, line_feed_sep=line_feed_sep),
-            'notification_timestamp': now,
-            'screenshot': watch.get_screenshot() if watch and watch.get('notification_screenshot') else None,
-            'triggered_text': triggered_text,
-            'uuid': watch.get('uuid') if watch else None,
-            'watch_url': watch.get('url') if watch else None,
-        })
 
-        if watch:
-            n_object.update(watch.extra_notification_token_values())
+        n_object.update(set_basic_notification_vars(current_snapshot=current_snapshot,
+                                                    prev_snapshot=prev_snapshot,
+                                                    watch=watch,
+                                                    triggered_text=triggered_text,
+                                                    timestamp_changed=dates[date_index_to]))
 
-        logger.trace(f"Main rendered notification placeholders (diff_added etc) calculated in {time.time()-now:.3f}s")
-        logger.debug("Queued notification for sending")
-        self.notification_q.put(n_object)
-
-    def _check_cascading_vars(self, var_name, watch):
-        """
-        Check notification variables in cascading priority:
-        Individual watch settings > Tag settings > Global settings
-        """
-        from changedetectionio.notification import (
-            default_notification_format_for_watch,
-            default_notification_body,
-            default_notification_title
-        )
-
-        # Would be better if this was some kind of Object where Watch can reference the parent datastore etc
-        v = watch.get(var_name)
-        if v and not watch.get('notification_muted'):
-            if var_name == 'notification_format' and v == default_notification_format_for_watch:
-                return self.datastore.data['settings']['application'].get('notification_format')
-
-            return v
-
-        tags = self.datastore.get_all_tags_for_watch(uuid=watch.get('uuid'))
-        if tags:
-            for tag_uuid, tag in tags.items():
-                v = tag.get(var_name)
-                if v and not tag.get('notification_muted'):
-                    return v
-
-        if self.datastore.data['settings']['application'].get(var_name):
-            return self.datastore.data['settings']['application'].get(var_name)
-
-        # Otherwise could be defaults
-        if var_name == 'notification_format':
-            return default_notification_format_for_watch
-        if var_name == 'notification_body':
-            return default_notification_body
-        if var_name == 'notification_title':
-            return default_notification_title
-
-        return None
+        if self.notification_q:
+            logger.debug("Queued notification for sending")
+            self.notification_q.put(n_object)
+        else:
+            logger.debug("Not queued, no queue defined. Just returning processed data")
+            return n_object
 
     def send_content_changed_notification(self, watch_uuid):
         """
         Send notification when content changes are detected
         """
-        n_object = {}
+        n_object = NotificationContextData()
         watch = self.datastore.data['watching'].get(watch_uuid)
         if not watch:
             return
@@ -157,10 +301,11 @@ class NotificationService:
         # Should be a better parent getter in the model object
 
         # Prefer - Individual watch settings > Tag settings >  Global settings (in that order)
-        n_object['notification_urls'] = self._check_cascading_vars('notification_urls', watch)
-        n_object['notification_title'] = self._check_cascading_vars('notification_title', watch)
-        n_object['notification_body'] = self._check_cascading_vars('notification_body', watch)
-        n_object['notification_format'] = self._check_cascading_vars('notification_format', watch)
+        # this change probably not needed?
+        n_object['notification_urls'] = _check_cascading_vars(self.datastore, 'notification_urls', watch)
+        n_object['notification_title'] = _check_cascading_vars(self.datastore,'notification_title', watch)
+        n_object['notification_body'] = _check_cascading_vars(self.datastore,'notification_body', watch)
+        n_object['notification_format'] = _check_cascading_vars(self.datastore,'notification_format', watch)
 
         # (Individual watch) Only prepare to notify if the rules above matched
         queued = False
@@ -183,11 +328,25 @@ class NotificationService:
         if not watch:
             return
 
-        n_object = {'notification_title': 'Changedetection.io - Alert - CSS/xPath filter was not present in the page',
-                    'notification_body': "Your configured CSS/xPath filters of '{}' for {{{{watch_url}}}} did not appear on the page after {} attempts, did the page change layout?\n\nLink: {{{{base_url}}}}/edit/{{{{watch_uuid}}}}\n\nThanks - Your omniscient changedetection.io installation :)\n".format(
-                        ", ".join(watch['include_filters']),
-                        threshold),
-                    'notification_format': 'text'}
+        filter_list = ", ".join(watch['include_filters'])
+        # @todo - This could be a markdown template on the disk, apprise will convert the markdown to HTML+Plaintext parts in the email, and then 'markup_text_links_to_html_links' is not needed
+        body = f"""Hello,
+
+Your configured CSS/xPath filters of '{filter_list}' for {{{{watch_url}}}} did not appear on the page after {threshold} attempts.
+
+It's possible the page changed layout and the filter needs updating ( Try the 'Visual Selector' tab )
+
+Edit link: {{{{base_url}}}}/edit/{{{{watch_uuid}}}}
+
+Thanks - Your omniscient changedetection.io installation.
+"""
+
+        n_object = NotificationContextData({
+            'notification_title': 'Changedetection.io - Alert - CSS/xPath filter was not present in the page',
+            'notification_body': body,
+            'notification_format': _check_cascading_vars(self.datastore, 'notification_format', watch),
+        })
+        n_object['markup_text_links_to_html_links'] = n_object.get('notification_format').startswith('html')
 
         if len(watch['notification_urls']):
             n_object['notification_urls'] = watch['notification_urls']
@@ -215,12 +374,28 @@ class NotificationService:
         if not watch:
             return
         threshold = self.datastore.data['settings']['application'].get('filter_failure_notification_threshold_attempts')
-        n_object = {'notification_title': "Changedetection.io - Alert - Browser step at position {} could not be run".format(step_n+1),
-                    'notification_body': "Your configured browser step at position {} for {{{{watch_url}}}} "
-                                         "did not appear on the page after {} attempts, did the page change layout? "
-                                         "Does it need a delay added?\n\nLink: {{{{base_url}}}}/edit/{{{{watch_uuid}}}}\n\n"
-                                         "Thanks - Your omniscient changedetection.io installation :)\n".format(step_n+1, threshold),
-                    'notification_format': 'text'}
+
+        step = step_n + 1
+        # @todo - This could be a markdown template on the disk, apprise will convert the markdown to HTML+Plaintext parts in the email, and then 'markup_text_links_to_html_links' is not needed
+
+        # {{{{ }}}} because this will be Jinja2 {{ }} tokens
+        body = f"""Hello,
+        
+Your configured browser step at position {step} for the web page watch {{{{watch_url}}}} did not appear on the page after {threshold} attempts, did the page change layout?
+
+The element may have moved and needs editing, or does it need a delay added?
+
+Edit link: {{{{base_url}}}}/edit/{{{{watch_uuid}}}}
+
+Thanks - Your omniscient changedetection.io installation.
+"""
+
+        n_object = NotificationContextData({
+            'notification_title': f"Changedetection.io - Alert - Browser step at position {step} could not be run",
+            'notification_body': body,
+            'notification_format': self._check_cascading_vars('notification_format', watch),
+        })
+        n_object['markup_text_links_to_html_links'] = n_object.get('notification_format').startswith('html')
 
         if len(watch['notification_urls']):
             n_object['notification_urls'] = watch['notification_urls']

changedetectionio/pluggy_interface.py

@@ -2,6 +2,7 @@ import pluggy
 import os
 import importlib
 import sys
+from loguru import logger
 
 # Global plugin namespace for changedetection.io
 PLUGIN_NAMESPACE = "changedetectionio"
@@ -16,15 +17,94 @@ class ChangeDetectionSpec:
     @hookspec
     def ui_edit_stats_extras(watch):
         """Return HTML content to add to the stats tab in the edit view.
-        
+
         Args:
             watch: The watch object being edited
-            
+
         Returns:
             str: HTML content to be inserted in the stats tab
         """
         pass
 
+    @hookspec
+    def register_content_fetcher(self):
+        """Return a tuple of (fetcher_name, fetcher_class) for content fetcher plugins.
+
+        The fetcher_name should start with 'html_' and the fetcher_class
+        should inherit from changedetectionio.content_fetchers.base.Fetcher
+
+        Returns:
+            tuple: (str: fetcher_name, class: fetcher_class)
+        """
+        pass
+
+    @hookspec
+    def fetcher_status_icon(fetcher_name):
+        """Return status icon HTML attributes for a content fetcher.
+
+        Args:
+            fetcher_name: The name of the fetcher (e.g., 'html_webdriver', 'html_js_zyte')
+
+        Returns:
+            str: HTML string containing <img> tags or other status icon elements
+                 Empty string if no custom status icon is needed
+        """
+        pass
+
+    @hookspec
+    def plugin_static_path(self):
+        """Return the path to the plugin's static files directory.
+
+        Returns:
+            str: Absolute path to the plugin's static directory, or None if no static files
+        """
+        pass
+
+    @hookspec
+    def get_itemprop_availability_override(self, content, fetcher_name, fetcher_instance, url):
+        """Provide custom implementation of get_itemprop_availability for a specific fetcher.
+
+        This hook allows plugins to provide their own product availability detection
+        when their fetcher is being used. This is called as a fallback when the built-in
+        method doesn't find good data.
+
+        Args:
+            content: The HTML/text content to parse
+            fetcher_name: The name of the fetcher being used (e.g., 'html_js_zyte')
+            fetcher_instance: The fetcher instance that generated the content
+            url: The URL being watched/checked
+
+        Returns:
+            dict or None: Dictionary with availability data:
+                {
+                    'price': float or None,
+                    'availability': str or None,  # e.g., 'in stock', 'out of stock'
+                    'currency': str or None,      # e.g., 'USD', 'EUR'
+                }
+                Or None if this plugin doesn't handle this fetcher or couldn't extract data
+        """
+        pass
+
+    @hookspec
+    def plugin_settings_tab(self):
+        """Return settings tab information for this plugin.
+
+        This hook allows plugins to add their own settings tab to the settings page.
+        Settings will be saved to a separate JSON file in the datastore directory.
+
+        Returns:
+            dict or None: Dictionary with settings tab information:
+                {
+                    'plugin_id': str,           # Unique identifier (e.g., 'zyte_fetcher')
+                    'tab_label': str,           # Display name for tab (e.g., 'Zyte Fetcher')
+                    'form_class': Form,         # WTForms Form class for the settings
+                    'template_path': str,       # Optional: path to Jinja2 template (relative to plugin)
+                                                # If not provided, a default form renderer will be used
+                }
+                Or None if this plugin doesn't provide settings
+        """
+        pass
+
 
 # Set up Plugin Manager
 plugin_manager = pluggy.PluginManager(PLUGIN_NAMESPACE)
@@ -65,18 +145,334 @@ load_plugins_from_directories()
 # Discover installed plugins from external packages (if any)
 plugin_manager.load_setuptools_entrypoints(PLUGIN_NAMESPACE)
 
+# Function to inject datastore into plugins that need it
+def inject_datastore_into_plugins(datastore):
+    """Inject the global datastore into plugins that need access to settings.
+
+    This should be called after plugins are loaded and datastore is initialized.
+
+    Args:
+        datastore: The global ChangeDetectionStore instance
+    """
+    for plugin_name, plugin_obj in plugin_manager.list_name_plugin():
+        # Check if plugin has datastore attribute and it's not set
+        if hasattr(plugin_obj, 'datastore'):
+            if plugin_obj.datastore is None:
+                plugin_obj.datastore = datastore
+                logger.debug(f"Injected datastore into plugin: {plugin_name}")
+
+# Function to register built-in fetchers - called later from content_fetchers/__init__.py
+def register_builtin_fetchers():
+    """Register built-in content fetchers as internal plugins
+
+    This is called from content_fetchers/__init__.py after all fetchers are imported
+    to avoid circular import issues.
+    """
+    from changedetectionio.content_fetchers import requests, playwright, puppeteer, webdriver_selenium
+
+    # Register each built-in fetcher plugin
+    if hasattr(requests, 'requests_plugin'):
+        plugin_manager.register(requests.requests_plugin, 'builtin_requests')
+
+    if hasattr(playwright, 'playwright_plugin'):
+        plugin_manager.register(playwright.playwright_plugin, 'builtin_playwright')
+
+    if hasattr(puppeteer, 'puppeteer_plugin'):
+        plugin_manager.register(puppeteer.puppeteer_plugin, 'builtin_puppeteer')
+
+    if hasattr(webdriver_selenium, 'webdriver_selenium_plugin'):
+        plugin_manager.register(webdriver_selenium.webdriver_selenium_plugin, 'builtin_webdriver_selenium')
+
 # Helper function to collect UI stats extras from all plugins
 def collect_ui_edit_stats_extras(watch):
     """Collect and combine HTML content from all plugins that implement ui_edit_stats_extras"""
     extras_content = []
-    
+
     # Get all plugins that implement the ui_edit_stats_extras hook
     results = plugin_manager.hook.ui_edit_stats_extras(watch=watch)
-    
+
     # If we have results, add them to our content
     if results:
         for result in results:
             if result:  # Skip empty results
                 extras_content.append(result)
-            
-    return "\n".join(extras_content) if extras_content else ""
+
+    return "\n".join(extras_content) if extras_content else ""
+
+def collect_fetcher_status_icons(fetcher_name):
+    """Collect status icon data from all plugins
+
+    Args:
+        fetcher_name: The name of the fetcher (e.g., 'html_webdriver', 'html_js_zyte')
+
+    Returns:
+        dict or None: Icon data dictionary from first matching plugin, or None
+    """
+    # Get status icon data from plugins
+    results = plugin_manager.hook.fetcher_status_icon(fetcher_name=fetcher_name)
+
+    # Return first non-None result
+    if results:
+        for result in results:
+            if result and isinstance(result, dict):
+                return result
+
+    return None
+
+def get_itemprop_availability_from_plugin(content, fetcher_name, fetcher_instance, url):
+    """Get itemprop availability data from plugins as a fallback.
+
+    This is called when the built-in get_itemprop_availability doesn't find good data.
+
+    Args:
+        content: The HTML/text content to parse
+        fetcher_name: The name of the fetcher being used (e.g., 'html_js_zyte')
+        fetcher_instance: The fetcher instance that generated the content
+        url: The URL being watched (watch.link - includes Jinja2 evaluation)
+
+    Returns:
+        dict or None: Availability data dictionary from first matching plugin, or None
+    """
+    # Get availability data from plugins
+    results = plugin_manager.hook.get_itemprop_availability_override(
+        content=content,
+        fetcher_name=fetcher_name,
+        fetcher_instance=fetcher_instance,
+        url=url
+    )
+
+    # Return first non-None result with actual data
+    if results:
+        for result in results:
+            if result and isinstance(result, dict):
+                # Check if the result has any meaningful data
+                if result.get('price') is not None or result.get('availability'):
+                    return result
+
+    return None
+
+
+def get_active_plugins():
+    """Get a list of active plugins with their descriptions.
+
+    Returns:
+        list: List of dictionaries with plugin information:
+            [
+                {'name': 'plugin_name', 'description': 'Plugin description'},
+                ...
+            ]
+    """
+    active_plugins = []
+
+    # Get all registered plugins
+    for plugin_name, plugin_obj in plugin_manager.list_name_plugin():
+        # Skip built-in plugins (they start with 'builtin_')
+        if plugin_name.startswith('builtin_'):
+            continue
+
+        # Get plugin description if available
+        description = None
+        if hasattr(plugin_obj, '__doc__') and plugin_obj.__doc__:
+            description = plugin_obj.__doc__.strip().split('\n')[0]  # First line only
+        elif hasattr(plugin_obj, 'description'):
+            description = plugin_obj.description
+
+        # Try to get a friendly name from the plugin
+        friendly_name = plugin_name
+        if hasattr(plugin_obj, 'name'):
+            friendly_name = plugin_obj.name
+
+        active_plugins.append({
+            'name': friendly_name,
+            'description': description or 'No description available'
+        })
+
+    return active_plugins
+
+
+def get_fetcher_capabilities(watch, datastore):
+    """Get capability flags for a watch's fetcher.
+
+    Args:
+        watch: The watch object/dict
+        datastore: The datastore to resolve 'system' fetcher
+
+    Returns:
+        dict: Dictionary with capability flags:
+            {
+                'supports_browser_steps': bool,
+                'supports_screenshots': bool,
+                'supports_xpath_element_data': bool
+            }
+    """
+    # Get the fetcher name from watch
+    fetcher_name = watch.get('fetch_backend', 'system')
+
+    # Resolve 'system' to actual fetcher
+    if fetcher_name == 'system':
+        fetcher_name = datastore.data['settings']['application'].get('fetch_backend', 'html_requests')
+
+    # Get the fetcher class
+    from changedetectionio import content_fetchers
+
+    # Try to get from built-in fetchers first
+    if hasattr(content_fetchers, fetcher_name):
+        fetcher_class = getattr(content_fetchers, fetcher_name)
+        return {
+            'supports_browser_steps': getattr(fetcher_class, 'supports_browser_steps', False),
+            'supports_screenshots': getattr(fetcher_class, 'supports_screenshots', False),
+            'supports_xpath_element_data': getattr(fetcher_class, 'supports_xpath_element_data', False)
+        }
+
+    # Try to get from plugin-provided fetchers
+    # Query all plugins for registered fetchers
+    plugin_fetchers = plugin_manager.hook.register_content_fetcher()
+    for fetcher_registration in plugin_fetchers:
+        if fetcher_registration:
+            name, fetcher_class = fetcher_registration
+            if name == fetcher_name:
+                return {
+                    'supports_browser_steps': getattr(fetcher_class, 'supports_browser_steps', False),
+                    'supports_screenshots': getattr(fetcher_class, 'supports_screenshots', False),
+                    'supports_xpath_element_data': getattr(fetcher_class, 'supports_xpath_element_data', False)
+                }
+
+    # Default: no capabilities
+    return {
+        'supports_browser_steps': False,
+        'supports_screenshots': False,
+        'supports_xpath_element_data': False
+    }
+
+
+def get_plugin_settings_tabs():
+    """Get all plugin settings tabs.
+
+    Returns:
+        list: List of dictionaries with plugin settings tab information:
+            [
+                {
+                    'plugin_id': str,
+                    'tab_label': str,
+                    'form_class': Form,
+                    'description': str
+                },
+                ...
+            ]
+    """
+    tabs = []
+    results = plugin_manager.hook.plugin_settings_tab()
+
+    for result in results:
+        if result and isinstance(result, dict):
+            # Validate required fields
+            if 'plugin_id' in result and 'tab_label' in result and 'form_class' in result:
+                tabs.append(result)
+            else:
+                logger.warning(f"Invalid plugin settings tab spec: {result}")
+
+    return tabs
+
+
+def load_plugin_settings(datastore_path, plugin_id):
+    """Load settings for a specific plugin from JSON file.
+
+    Args:
+        datastore_path: Path to the datastore directory
+        plugin_id: Unique identifier for the plugin (e.g., 'zyte_fetcher')
+
+    Returns:
+        dict: Plugin settings, or empty dict if file doesn't exist
+    """
+    import json
+    settings_file = os.path.join(datastore_path, f"{plugin_id}.json")
+
+    if not os.path.exists(settings_file):
+        return {}
+
+    try:
+        with open(settings_file, 'r', encoding='utf-8') as f:
+            return json.load(f)
+    except Exception as e:
+        logger.error(f"Failed to load settings for plugin '{plugin_id}': {e}")
+        return {}
+
+
+def save_plugin_settings(datastore_path, plugin_id, settings):
+    """Save settings for a specific plugin to JSON file.
+
+    Args:
+        datastore_path: Path to the datastore directory
+        plugin_id: Unique identifier for the plugin (e.g., 'zyte_fetcher')
+        settings: Dictionary of settings to save
+
+    Returns:
+        bool: True if save was successful, False otherwise
+    """
+    import json
+    settings_file = os.path.join(datastore_path, f"{plugin_id}.json")
+
+    try:
+        with open(settings_file, 'w', encoding='utf-8') as f:
+            json.dump(settings, f, indent=2, ensure_ascii=False)
+        logger.info(f"Saved settings for plugin '{plugin_id}' to {settings_file}")
+        return True
+    except Exception as e:
+        logger.error(f"Failed to save settings for plugin '{plugin_id}': {e}")
+        return False
+
+
+def get_plugin_template_paths():
+    """Get list of plugin template directories for Jinja2 loader.
+
+    Scans both external pluggy plugins and built-in processor plugins.
+
+    Returns:
+        list: List of absolute paths to plugin template directories
+    """
+    template_paths = []
+
+    # Add the base processors/templates directory (as absolute path)
+    processors_templates_dir = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'processors', 'templates')
+    if os.path.isdir(processors_templates_dir):
+        template_paths.append(processors_templates_dir)
+        logger.debug(f"Added base processors template path: {processors_templates_dir}")
+
+    # Scan built-in processor plugins
+    from changedetectionio.processors import find_processors
+    processor_list = find_processors()
+    for processor_module, processor_name in processor_list:
+        # Each processor is a module, check if it has a templates directory
+        if hasattr(processor_module, '__file__'):
+            processor_file = processor_module.__file__
+            if processor_file:
+                # Get the processor directory (e.g., processors/image_ssim_diff/)
+                processor_dir = os.path.dirname(os.path.abspath(processor_file))
+                templates_dir = os.path.join(processor_dir, 'templates')
+                if os.path.isdir(templates_dir):
+                    template_paths.append(templates_dir)
+                    logger.debug(f"Added processor template path: {templates_dir}")
+
+    # Get all registered external pluggy plugins
+    for plugin_name, plugin_obj in plugin_manager.list_name_plugin():
+        # Check if plugin has a templates directory
+        if hasattr(plugin_obj, '__file__'):
+            plugin_file = plugin_obj.__file__
+        elif hasattr(plugin_obj, '__module__'):
+            # Get the module file
+            module = sys.modules.get(plugin_obj.__module__)
+            if module and hasattr(module, '__file__'):
+                plugin_file = module.__file__
+            else:
+                continue
+        else:
+            continue
+
+        if plugin_file:
+            plugin_dir = os.path.dirname(os.path.abspath(plugin_file))
+            templates_dir = os.path.join(plugin_dir, 'templates')
+            if os.path.isdir(templates_dir):
+                template_paths.append(templates_dir)
+                logger.debug(f"Added plugin template path: {templates_dir}")
+
+    return template_paths

changedetectionio/processors/__init__.py

@@ -1,178 +1,10 @@
-from abc import abstractmethod
-from changedetectionio.content_fetchers.base import Fetcher
-from changedetectionio.strtobool import strtobool
-from copy import deepcopy
+from functools import lru_cache
 from loguru import logger
-import hashlib
+from flask_babel import gettext
 import importlib
 import inspect
 import os
 import pkgutil
-import re
-
-class difference_detection_processor():
-
-    browser_steps = None
-    datastore = None
-    fetcher = None
-    screenshot = None
-    watch = None
-    xpath_data = None
-    preferred_proxy = None
-
-    def __init__(self, *args, datastore, watch_uuid, **kwargs):
-        super().__init__(*args, **kwargs)
-        self.datastore = datastore
-        self.watch = deepcopy(self.datastore.data['watching'].get(watch_uuid))
-        # Generic fetcher that should be extended (requests, playwright etc)
-        self.fetcher = Fetcher()
-
-    async def call_browser(self, preferred_proxy_id=None):
-
-        from requests.structures import CaseInsensitiveDict
-
-        url = self.watch.link
-
-        # Protect against file:, file:/, file:// access, check the real "link" without any meta "source:" etc prepended.
-        if re.search(r'^file:', url.strip(), re.IGNORECASE):
-            if not strtobool(os.getenv('ALLOW_FILE_URI', 'false')):
-                raise Exception(
-                    "file:// type access is denied for security reasons."
-                )
-
-        # Requests, playwright, other browser via wss:// etc, fetch_extra_something
-        prefer_fetch_backend = self.watch.get('fetch_backend', 'system')
-
-        # Proxy ID "key"
-        preferred_proxy_id = preferred_proxy_id if preferred_proxy_id else self.datastore.get_preferred_proxy_for_watch(uuid=self.watch.get('uuid'))
-
-        # Pluggable content self.fetcher
-        if not prefer_fetch_backend or prefer_fetch_backend == 'system':
-            prefer_fetch_backend = self.datastore.data['settings']['application'].get('fetch_backend')
-
-        # In the case that the preferred fetcher was a browser config with custom connection URL..
-        # @todo - on save watch, if its extra_browser_ then it should be obvious it will use playwright (like if its requests now..)
-        custom_browser_connection_url = None
-        if prefer_fetch_backend.startswith('extra_browser_'):
-            (t, key) = prefer_fetch_backend.split('extra_browser_')
-            connection = list(
-                filter(lambda s: (s['browser_name'] == key), self.datastore.data['settings']['requests'].get('extra_browsers', [])))
-            if connection:
-                prefer_fetch_backend = 'html_webdriver'
-                custom_browser_connection_url = connection[0].get('browser_connection_url')
-
-        # PDF should be html_requests because playwright will serve it up (so far) in a embedded page
-        # @todo https://github.com/dgtlmoon/changedetection.io/issues/2019
-        # @todo needs test to or a fix
-        if self.watch.is_pdf:
-           prefer_fetch_backend = "html_requests"
-
-        # Grab the right kind of 'fetcher', (playwright, requests, etc)
-        from changedetectionio import content_fetchers
-        if hasattr(content_fetchers, prefer_fetch_backend):
-            # @todo TEMPORARY HACK - SWITCH BACK TO PLAYWRIGHT FOR BROWSERSTEPS
-            if prefer_fetch_backend == 'html_webdriver' and self.watch.has_browser_steps:
-                # This is never supported in selenium anyway
-                logger.warning("Using playwright fetcher override for possible puppeteer request in browsersteps, because puppetteer:browser steps is incomplete.")
-                from changedetectionio.content_fetchers.playwright import fetcher as playwright_fetcher
-                fetcher_obj = playwright_fetcher
-            else:
-                fetcher_obj = getattr(content_fetchers, prefer_fetch_backend)
-        else:
-            # What it referenced doesnt exist, Just use a default
-            fetcher_obj = getattr(content_fetchers, "html_requests")
-
-        proxy_url = None
-        if preferred_proxy_id:
-            # Custom browser endpoints should NOT have a proxy added
-            if not prefer_fetch_backend.startswith('extra_browser_'):
-                proxy_url = self.datastore.proxy_list.get(preferred_proxy_id).get('url')
-                logger.debug(f"Selected proxy key '{preferred_proxy_id}' as proxy URL '{proxy_url}' for {url}")
-            else:
-                logger.debug("Skipping adding proxy data when custom Browser endpoint is specified. ")
-
-        # Now call the fetcher (playwright/requests/etc) with arguments that only a fetcher would need.
-        # When browser_connection_url is None, it method should default to working out whats the best defaults (os env vars etc)
-        self.fetcher = fetcher_obj(proxy_override=proxy_url,
-                                   custom_browser_connection_url=custom_browser_connection_url
-                                   )
-
-        if self.watch.has_browser_steps:
-            self.fetcher.browser_steps = self.watch.get('browser_steps', [])
-            self.fetcher.browser_steps_screenshot_path = os.path.join(self.datastore.datastore_path, self.watch.get('uuid'))
-
-        # Tweak the base config with the per-watch ones
-        from changedetectionio.safe_jinja import render as jinja_render
-        request_headers = CaseInsensitiveDict()
-
-        ua = self.datastore.data['settings']['requests'].get('default_ua')
-        if ua and ua.get(prefer_fetch_backend):
-            request_headers.update({'User-Agent': ua.get(prefer_fetch_backend)})
-
-        request_headers.update(self.watch.get('headers', {}))
-        request_headers.update(self.datastore.get_all_base_headers())
-        request_headers.update(self.datastore.get_all_headers_in_textfile_for_watch(uuid=self.watch.get('uuid')))
-
-        # https://github.com/psf/requests/issues/4525
-        # Requests doesnt yet support brotli encoding, so don't put 'br' here, be totally sure that the user cannot
-        # do this by accident.
-        if 'Accept-Encoding' in request_headers and "br" in request_headers['Accept-Encoding']:
-            request_headers['Accept-Encoding'] = request_headers['Accept-Encoding'].replace(', br', '')
-
-        for header_name in request_headers:
-            request_headers.update({header_name: jinja_render(template_str=request_headers.get(header_name))})
-
-        timeout = self.datastore.data['settings']['requests'].get('timeout')
-
-        request_body = self.watch.get('body')
-        if request_body:
-            request_body = jinja_render(template_str=self.watch.get('body'))
-        
-        request_method = self.watch.get('method')
-        ignore_status_codes = self.watch.get('ignore_status_codes', False)
-
-        # Configurable per-watch or global extra delay before extracting text (for webDriver types)
-        system_webdriver_delay = self.datastore.data['settings']['application'].get('webdriver_delay', None)
-        if self.watch.get('webdriver_delay'):
-            self.fetcher.render_extract_delay = self.watch.get('webdriver_delay')
-        elif system_webdriver_delay is not None:
-            self.fetcher.render_extract_delay = system_webdriver_delay
-
-        if self.watch.get('webdriver_js_execute_code') is not None and self.watch.get('webdriver_js_execute_code').strip():
-            self.fetcher.webdriver_js_execute_code = self.watch.get('webdriver_js_execute_code')
-
-        # Requests for PDF's, images etc should be passwd the is_binary flag
-        is_binary = self.watch.is_pdf
-
-        # And here we go! call the right browser with browser-specific settings
-        empty_pages_are_a_change = self.datastore.data['settings']['application'].get('empty_pages_are_a_change', False)
-        # All fetchers are now async
-        await self.fetcher.run(
-            current_include_filters=self.watch.get('include_filters'),
-            empty_pages_are_a_change=empty_pages_are_a_change,
-            fetch_favicon=self.watch.favicon_is_expired(),
-            ignore_status_codes=ignore_status_codes,
-            is_binary=is_binary,
-            request_body=request_body,
-            request_headers=request_headers,
-            request_method=request_method,
-            timeout=timeout,
-            url=url,
-       )
-
-        #@todo .quit here could go on close object, so we can run JS if change-detected
-        self.fetcher.quit(watch=self.watch)
-
-        # After init, call run_changedetection() which will do the actual change-detection
-
-    @abstractmethod
-    def run_changedetection(self, watch):
-        update_obj = {'last_notification_error': False, 'last_error': False}
-        some_data = 'xxxxx'
-        update_obj["previous_md5"] = hashlib.md5(some_data.encode('utf-8')).hexdigest()
-        changed_detected = False
-        return changed_detected, update_obj, ''.encode('utf-8')
-
 
 def find_sub_packages(package_name):
     """
@@ -196,6 +28,7 @@ def find_processors():
 
     processors = []
     sub_packages = find_sub_packages(package_name)
+    from changedetectionio.processors.base import difference_detection_processor
 
     for sub_package in sub_packages:
         module_name = f"{package_name}.{sub_package}.processor"
@@ -204,8 +37,12 @@ def find_processors():
 
             # Iterate through all classes in the module
             for name, obj in inspect.getmembers(module, inspect.isclass):
-                if issubclass(obj, difference_detection_processor) and obj is not difference_detection_processor:
+                # Only register classes that are actually defined in this module (not imported)
+                if (issubclass(obj, difference_detection_processor) and
+                    obj is not difference_detection_processor and
+                    obj.__module__ == module.__name__):
                     processors.append((module, sub_package))
+                    break  # Only need one processor per module
         except (ModuleNotFoundError, ImportError) as e:
             logger.warning(f"Failed to import module {module_name}: {e} (find_processors())")
 
@@ -240,17 +77,205 @@ def get_custom_watch_obj_for_processor(processor_name):
     return watch_class
 
 
+def find_processor_module(processor_name):
+    """
+    Find the processor module by name.
+
+    Args:
+        processor_name: Processor machine name (e.g., 'image_ssim_diff')
+
+    Returns:
+        module: The processor's parent module, or None if not found
+    """
+    processor_classes = find_processors()
+    processor_tuple = next((tpl for tpl in processor_classes if tpl[1] == processor_name), None)
+
+    if processor_tuple:
+        # Return the parent module (the package containing processor.py)
+        return get_parent_module(processor_tuple[0])
+
+    return None
+
+
 def available_processors():
     """
-    Get a list of processors by name and description for the UI elements
+    Get a list of processors by name and description for the UI elements.
+    Can be filtered via ALLOWED_PROCESSORS environment variable (comma-separated list).
     :return: A list :)
     """
 
     processor_classes = find_processors()
 
+    # Check if ALLOWED_PROCESSORS env var is set
+    # For now we disable it, need to make a deploy with lots of new code and this will be an overload
+    allowed_processors_env = os.getenv('ALLOWED_PROCESSORS', 'text_json_diff, restock_diff').strip()
+    allowed_processors = None
+    if allowed_processors_env:
+        # Parse comma-separated list and strip whitespace
+        allowed_processors = [p.strip() for p in allowed_processors_env.split(',') if p.strip()]
+        logger.info(f"ALLOWED_PROCESSORS set, filtering to: {allowed_processors}")
+
     available = []
-    for package, processor_class in processor_classes:
-        available.append((processor_class, package.name))
+    for module, sub_package_name in processor_classes:
+        # Filter by allowed processors if set
+        if allowed_processors and sub_package_name not in allowed_processors:
+            logger.debug(f"Skipping processor '{sub_package_name}' (not in ALLOWED_PROCESSORS)")
+            continue
 
-    return available
+        # Try to get the 'name' attribute from the processor module first
+        if hasattr(module, 'name'):
+            description = gettext(module.name)
+        else:
+            # Fall back to processor_description from parent module's __init__.py
+            parent_module = get_parent_module(module)
+            if parent_module and hasattr(parent_module, 'processor_description'):
+                description = gettext(parent_module.processor_description)
+            else:
+                # Final fallback to a readable name
+                description = sub_package_name.replace('_', ' ').title()
+
+        # Get weight for sorting (lower weight = higher in list)
+        weight = 0  # Default weight for processors without explicit weight
+
+        # Check processor module itself first
+        if hasattr(module, 'processor_weight'):
+            weight = module.processor_weight
+        else:
+            # Fall back to parent module (package __init__.py)
+            parent_module = get_parent_module(module)
+            if parent_module and hasattr(parent_module, 'processor_weight'):
+                weight = parent_module.processor_weight
+
+        available.append((sub_package_name, description, weight))
+
+    # Sort by weight (lower weight = appears first)
+    available.sort(key=lambda x: x[2])
+
+    # Return as tuples without weight (for backwards compatibility)
+    return [(name, desc) for name, desc, weight in available]
+
+
+def get_processor_badge_texts():
+    """
+    Get a dictionary mapping processor names to their list_badge_text values.
+    Translations are applied based on the current request locale.
+
+    :return: A dict mapping processor name to badge text (e.g., {'text_json_diff': 'Text', 'restock_diff': 'Restock'})
+    """
+    processor_classes = find_processors()
+    badge_texts = {}
+
+    for module, sub_package_name in processor_classes:
+        # Try to get the 'list_badge_text' attribute from the processor module
+        if hasattr(module, 'list_badge_text'):
+            badge_texts[sub_package_name] = gettext(module.list_badge_text)
+        else:
+            # Fall back to parent module's __init__.py
+            parent_module = get_parent_module(module)
+            if parent_module and hasattr(parent_module, 'list_badge_text'):
+                badge_texts[sub_package_name] = gettext(parent_module.list_badge_text)
+
+    return badge_texts
+
+
+def get_processor_descriptions():
+    """
+    Get a dictionary mapping processor names to their description/name values.
+    Translations are applied based on the current request locale.
+
+    :return: A dict mapping processor name to description (e.g., {'text_json_diff': 'Webpage Text/HTML, JSON and PDF changes'})
+    """
+    processor_classes = find_processors()
+    descriptions = {}
+
+    for module, sub_package_name in processor_classes:
+        # Try to get the 'name' or 'description' attribute from the processor module first
+        if hasattr(module, 'name'):
+            descriptions[sub_package_name] = gettext(module.name)
+        elif hasattr(module, 'description'):
+            descriptions[sub_package_name] = gettext(module.description)
+        else:
+            # Fall back to parent module's __init__.py
+            parent_module = get_parent_module(module)
+            if parent_module and hasattr(parent_module, 'processor_description'):
+                descriptions[sub_package_name] = gettext(parent_module.processor_description)
+            elif parent_module and hasattr(parent_module, 'name'):
+                descriptions[sub_package_name] = gettext(parent_module.name)
+            else:
+                # Final fallback to a readable name
+                descriptions[sub_package_name] = sub_package_name.replace('_', ' ').title()
+
+    return descriptions
+
+
+def generate_processor_badge_colors(processor_name):
+    """
+    Generate consistent colors for a processor badge based on its name.
+    Uses a hash of the processor name to generate pleasing, accessible colors
+    for both light and dark modes.
+
+    :param processor_name: The processor name (e.g., 'text_json_diff')
+    :return: A dict with 'light' and 'dark' color schemes, each containing 'bg' and 'color'
+    """
+    import hashlib
+
+    # Generate a consistent hash from the processor name
+    hash_obj = hashlib.md5(processor_name.encode('utf-8'))
+    hash_int = int(hash_obj.hexdigest()[:8], 16)
+
+    # Generate hue from hash (0-360)
+    hue = hash_int % 360
+
+    # Light mode: pastel background with darker text
+    light_saturation = 60 + (hash_int % 25)  # 60-85%
+    light_lightness = 85 + (hash_int % 10)   # 85-95% - very light
+    text_lightness = 25 + (hash_int % 15)    # 25-40% - dark
+
+    # Dark mode: solid, vibrant colors with white text
+    dark_saturation = 55 + (hash_int % 20)   # 55-75%
+    dark_lightness = 45 + (hash_int % 15)    # 45-60%
+
+    return {
+        'light': {
+            'bg': f'hsl({hue}, {light_saturation}%, {light_lightness}%)',
+            'color': f'hsl({hue}, 50%, {text_lightness}%)'
+        },
+        'dark': {
+            'bg': f'hsl({hue}, {dark_saturation}%, {dark_lightness}%)',
+            'color': '#fff'
+        }
+    }
+
+
+@lru_cache(maxsize=1)
+def get_processor_badge_css():
+    """
+    Generate CSS for all processor badges with auto-generated colors.
+    This creates CSS rules for both light and dark modes for each processor.
+
+    :return: A string containing CSS rules for all processor badges
+    """
+    processor_classes = find_processors()
+    css_rules = []
+
+    for module, sub_package_name in processor_classes:
+        colors = generate_processor_badge_colors(sub_package_name)
+
+        # Light mode rule
+        css_rules.append(
+            f".processor-badge-{sub_package_name} {{\n"
+            f"  background-color: {colors['light']['bg']};\n"
+            f"  color: {colors['light']['color']};\n"
+            f"}}"
+        )
+
+        # Dark mode rule
+        css_rules.append(
+            f"html[data-darkmode=\"true\"] .processor-badge-{sub_package_name} {{\n"
+            f"  background-color: {colors['dark']['bg']};\n"
+            f"  color: {colors['dark']['color']};\n"
+            f"}}"
+        )
+
+    return '\n\n'.join(css_rules)
 

changedetectionio/processors/base.py

@@ -0,0 +1,259 @@
+import re
+import hashlib
+from changedetectionio.content_fetchers.base import Fetcher
+from changedetectionio.strtobool import strtobool
+from copy import deepcopy
+from abc import abstractmethod
+import os
+from loguru import logger
+
+SCREENSHOT_FORMAT_JPEG = 'JPEG'
+SCREENSHOT_FORMAT_PNG = 'PNG'
+
+class difference_detection_processor():
+    browser_steps = None
+    datastore = None
+    fetcher = None
+    screenshot = None
+    watch = None
+    xpath_data = None
+    preferred_proxy = None
+    screenshot_format = SCREENSHOT_FORMAT_JPEG
+
+    def __init__(self, datastore, watch_uuid):
+        self.datastore = datastore
+        self.watch_uuid = watch_uuid
+        self.watch = deepcopy(self.datastore.data['watching'].get(watch_uuid))
+        # Generic fetcher that should be extended (requests, playwright etc)
+        self.fetcher = Fetcher()
+
+    async def call_browser(self, preferred_proxy_id=None):
+
+        from requests.structures import CaseInsensitiveDict
+
+        url = self.watch.link
+
+        # Protect against file:, file:/, file:// access, check the real "link" without any meta "source:" etc prepended.
+        if re.search(r'^file:', url.strip(), re.IGNORECASE):
+            if not strtobool(os.getenv('ALLOW_FILE_URI', 'false')):
+                raise Exception(
+                    "file:// type access is denied for security reasons."
+                )
+
+        # Requests, playwright, other browser via wss:// etc, fetch_extra_something
+        prefer_fetch_backend = self.watch.get('fetch_backend', 'system')
+
+        # Proxy ID "key"
+        preferred_proxy_id = preferred_proxy_id if preferred_proxy_id else self.datastore.get_preferred_proxy_for_watch(
+            uuid=self.watch.get('uuid'))
+
+        # Pluggable content self.fetcher
+        if not prefer_fetch_backend or prefer_fetch_backend == 'system':
+            prefer_fetch_backend = self.datastore.data['settings']['application'].get('fetch_backend')
+
+        # In the case that the preferred fetcher was a browser config with custom connection URL..
+        # @todo - on save watch, if its extra_browser_ then it should be obvious it will use playwright (like if its requests now..)
+        custom_browser_connection_url = None
+        if prefer_fetch_backend.startswith('extra_browser_'):
+            (t, key) = prefer_fetch_backend.split('extra_browser_')
+            connection = list(
+                filter(lambda s: (s['browser_name'] == key), self.datastore.data['settings']['requests'].get('extra_browsers', [])))
+            if connection:
+                prefer_fetch_backend = 'html_webdriver'
+                custom_browser_connection_url = connection[0].get('browser_connection_url')
+
+        # PDF should be html_requests because playwright will serve it up (so far) in a embedded page
+        # @todo https://github.com/dgtlmoon/changedetection.io/issues/2019
+        # @todo needs test to or a fix
+        if self.watch.is_pdf:
+            prefer_fetch_backend = "html_requests"
+
+        # Grab the right kind of 'fetcher', (playwright, requests, etc)
+        from changedetectionio import content_fetchers
+        if hasattr(content_fetchers, prefer_fetch_backend):
+            # @todo TEMPORARY HACK - SWITCH BACK TO PLAYWRIGHT FOR BROWSERSTEPS
+            if prefer_fetch_backend == 'html_webdriver' and self.watch.has_browser_steps:
+                # This is never supported in selenium anyway
+                logger.warning(
+                    "Using playwright fetcher override for possible puppeteer request in browsersteps, because puppetteer:browser steps is incomplete.")
+                from changedetectionio.content_fetchers.playwright import fetcher as playwright_fetcher
+                fetcher_obj = playwright_fetcher
+            else:
+                fetcher_obj = getattr(content_fetchers, prefer_fetch_backend)
+        else:
+            # What it referenced doesnt exist, Just use a default
+            fetcher_obj = getattr(content_fetchers, "html_requests")
+
+        proxy_url = None
+        if preferred_proxy_id:
+            # Custom browser endpoints should NOT have a proxy added
+            if not prefer_fetch_backend.startswith('extra_browser_'):
+                proxy_url = self.datastore.proxy_list.get(preferred_proxy_id).get('url')
+                logger.debug(f"Selected proxy key '{preferred_proxy_id}' as proxy URL '{proxy_url}' for {url}")
+            else:
+                logger.debug("Skipping adding proxy data when custom Browser endpoint is specified. ")
+
+        logger.debug(f"Using proxy '{proxy_url}' for {self.watch['uuid']}")
+
+        # Now call the fetcher (playwright/requests/etc) with arguments that only a fetcher would need.
+        # When browser_connection_url is None, it method should default to working out whats the best defaults (os env vars etc)
+        self.fetcher = fetcher_obj(proxy_override=proxy_url,
+                                   custom_browser_connection_url=custom_browser_connection_url,
+                                   screenshot_format=self.screenshot_format
+                                   )
+
+        if self.watch.has_browser_steps:
+            self.fetcher.browser_steps = self.watch.get('browser_steps', [])
+            self.fetcher.browser_steps_screenshot_path = os.path.join(self.datastore.datastore_path, self.watch.get('uuid'))
+
+        # Tweak the base config with the per-watch ones
+        from changedetectionio.jinja2_custom import render as jinja_render
+        request_headers = CaseInsensitiveDict()
+
+        ua = self.datastore.data['settings']['requests'].get('default_ua')
+        if ua and ua.get(prefer_fetch_backend):
+            request_headers.update({'User-Agent': ua.get(prefer_fetch_backend)})
+
+        request_headers.update(self.watch.get('headers', {}))
+        request_headers.update(self.datastore.get_all_base_headers())
+        request_headers.update(self.datastore.get_all_headers_in_textfile_for_watch(uuid=self.watch.get('uuid')))
+
+        # https://github.com/psf/requests/issues/4525
+        # Requests doesnt yet support brotli encoding, so don't put 'br' here, be totally sure that the user cannot
+        # do this by accident.
+        if 'Accept-Encoding' in request_headers and "br" in request_headers['Accept-Encoding']:
+            request_headers['Accept-Encoding'] = request_headers['Accept-Encoding'].replace(', br', '')
+
+        for header_name in request_headers:
+            request_headers.update({header_name: jinja_render(template_str=request_headers.get(header_name))})
+
+        timeout = self.datastore.data['settings']['requests'].get('timeout')
+
+        request_body = self.watch.get('body')
+        if request_body:
+            request_body = jinja_render(template_str=self.watch.get('body'))
+
+        request_method = self.watch.get('method')
+        ignore_status_codes = self.watch.get('ignore_status_codes', False)
+
+        # Configurable per-watch or global extra delay before extracting text (for webDriver types)
+        system_webdriver_delay = self.datastore.data['settings']['application'].get('webdriver_delay', None)
+        if self.watch.get('webdriver_delay'):
+            self.fetcher.render_extract_delay = self.watch.get('webdriver_delay')
+        elif system_webdriver_delay is not None:
+            self.fetcher.render_extract_delay = system_webdriver_delay
+
+        if self.watch.get('webdriver_js_execute_code') is not None and self.watch.get('webdriver_js_execute_code').strip():
+            self.fetcher.webdriver_js_execute_code = self.watch.get('webdriver_js_execute_code')
+
+        # Requests for PDF's, images etc should be passwd the is_binary flag
+        is_binary = self.watch.is_pdf
+
+        # And here we go! call the right browser with browser-specific settings
+        empty_pages_are_a_change = self.datastore.data['settings']['application'].get('empty_pages_are_a_change', False)
+        # All fetchers are now async
+        await self.fetcher.run(
+            current_include_filters=self.watch.get('include_filters'),
+            empty_pages_are_a_change=empty_pages_are_a_change,
+            fetch_favicon=self.watch.favicon_is_expired(),
+            ignore_status_codes=ignore_status_codes,
+            is_binary=is_binary,
+            request_body=request_body,
+            request_headers=request_headers,
+            request_method=request_method,
+            screenshot_format=self.screenshot_format,
+            timeout=timeout,
+            url=url,
+            watch_uuid=self.watch_uuid,
+        )
+
+        # @todo .quit here could go on close object, so we can run JS if change-detected
+        await self.fetcher.quit(watch=self.watch)
+
+        # After init, call run_changedetection() which will do the actual change-detection
+
+    def get_extra_watch_config(self, filename):
+        """
+        Read processor-specific JSON config file from watch data directory.
+
+        Args:
+            filename: Name of JSON file (e.g., "visual_ssim_score.json")
+
+        Returns:
+            dict: Parsed JSON data, or empty dict if file doesn't exist
+        """
+        import json
+        import os
+
+        watch = self.datastore.data['watching'].get(self.watch_uuid)
+        watch_data_dir = watch.watch_data_dir
+
+        if not watch_data_dir:
+            return {}
+
+        filepath = os.path.join(watch_data_dir, filename)
+
+        if not os.path.isfile(filepath):
+            return {}
+
+        try:
+            with open(filepath, 'r', encoding='utf-8') as f:
+                return json.load(f)
+        except (json.JSONDecodeError, IOError) as e:
+            logger.warning(f"Failed to read extra watch config {filename}: {e}")
+            return {}
+
+    def update_extra_watch_config(self, filename, data, merge=True):
+        """
+        Write processor-specific JSON config file to watch data directory.
+
+        Args:
+            filename: Name of JSON file (e.g., "visual_ssim_score.json")
+            data: Dictionary to serialize as JSON
+            merge: If True, merge with existing data; if False, overwrite completely
+        """
+        import json
+        import os
+
+        watch = self.datastore.data['watching'].get(self.watch_uuid)
+        watch_data_dir = watch.watch_data_dir
+
+        if not watch_data_dir:
+            logger.warning(f"Cannot save extra watch config {filename}: no watch_data_dir")
+            return
+
+        # Ensure directory exists
+        watch.ensure_data_dir_exists()
+
+        filepath = os.path.join(watch_data_dir, filename)
+
+        try:
+            # If merge is enabled, read existing data first
+            existing_data = {}
+            if merge and os.path.isfile(filepath):
+                try:
+                    with open(filepath, 'r', encoding='utf-8') as f:
+                        existing_data = json.load(f)
+                except (json.JSONDecodeError, IOError) as e:
+                    logger.warning(f"Failed to read existing config for merge: {e}")
+
+            # Merge new data with existing
+            if merge:
+                existing_data.update(data)
+                data_to_save = existing_data
+            else:
+                data_to_save = data
+
+            # Write the data
+            with open(filepath, 'w', encoding='utf-8') as f:
+                json.dump(data_to_save, f, indent=2)
+        except IOError as e:
+            logger.error(f"Failed to write extra watch config {filename}: {e}")
+
+    @abstractmethod
+    def run_changedetection(self, watch):
+        update_obj = {'last_notification_error': False, 'last_error': False}
+        some_data = 'xxxxx'
+        update_obj["previous_md5"] = hashlib.md5(some_data.encode('utf-8')).hexdigest()
+        changed_detected = False
+        return changed_detected, update_obj, ''.encode('utf-8')

changedetectionio/processors/extract.py

@@ -0,0 +1,132 @@
+"""
+Base data extraction module for all processors.
+
+This module handles extracting data from watch history using regex patterns
+and exporting to CSV format. This is the default extractor that all processors
+(text_json_diff, restock_diff, etc.) can use by default or override.
+"""
+
+import os
+from flask_babel import gettext
+from loguru import logger
+
+
+def render_form(watch, datastore, request, url_for, render_template, flash, redirect, extract_form=None):
+    """
+    Render the data extraction form.
+
+    Args:
+        watch: The watch object
+        datastore: The ChangeDetectionStore instance
+        request: Flask request object
+        url_for: Flask url_for function
+        render_template: Flask render_template function
+        flash: Flask flash function
+        redirect: Flask redirect function
+        extract_form: Optional pre-built extract form (for error cases)
+
+    Returns:
+        Rendered HTML response with the extraction form
+    """
+    from changedetectionio import forms
+
+    uuid = watch.get('uuid')
+
+    # Use provided form or create a new one
+    if extract_form is None:
+        extract_form = forms.extractDataForm(
+            formdata=request.form,
+            data={'extract_regex': request.form.get('extract_regex', '')}
+        )
+
+    # Get error information for the template
+    screenshot_url = watch.get_screenshot()
+
+    system_uses_webdriver = datastore.data['settings']['application']['fetch_backend'] == 'html_webdriver'
+    is_html_webdriver = False
+    if (watch.get('fetch_backend') == 'system' and system_uses_webdriver) or watch.get('fetch_backend') == 'html_webdriver' or watch.get('fetch_backend', '').startswith('extra_browser_'):
+        is_html_webdriver = True
+
+    password_enabled_and_share_is_off = False
+    if datastore.data['settings']['application'].get('password') or os.getenv("SALTED_PASS", False):
+        password_enabled_and_share_is_off = not datastore.data['settings']['application'].get('shared_diff_access')
+
+    # Use the shared default template from processors/templates/
+    # Processors can override this by creating their own extract.py with custom template logic
+    output = render_template(
+        "extract.html",
+        uuid=uuid,
+        extract_form=extract_form,
+        watch_a=watch,
+        last_error=watch['last_error'],
+        last_error_screenshot=watch.get_error_snapshot(),
+        last_error_text=watch.get_error_text(),
+        screenshot=screenshot_url,
+        is_html_webdriver=is_html_webdriver,
+        password_enabled_and_share_is_off=password_enabled_and_share_is_off,
+        extra_title=f" - {watch.label} - Extract Data",
+        extra_stylesheets=[url_for('static_content', group='styles', filename='diff.css')],
+        pure_menu_fixed=False
+    )
+
+    return output
+
+
+def process_extraction(watch, datastore, request, url_for, make_response, send_from_directory, flash, redirect, extract_form=None):
+    """
+    Process the data extraction request and return CSV file.
+
+    Args:
+        watch: The watch object
+        datastore: The ChangeDetectionStore instance
+        request: Flask request object
+        url_for: Flask url_for function
+        make_response: Flask make_response function
+        send_from_directory: Flask send_from_directory function
+        flash: Flask flash function
+        redirect: Flask redirect function
+        extract_form: Optional pre-built extract form
+
+    Returns:
+        CSV file download response or redirect to form on error
+    """
+    from changedetectionio import forms
+
+    uuid = watch.get('uuid')
+
+    # Use provided form or create a new one
+    if extract_form is None:
+        extract_form = forms.extractDataForm(
+            formdata=request.form,
+            data={'extract_regex': request.form.get('extract_regex', '')}
+        )
+
+    if not extract_form.validate():
+        flash(gettext("An error occurred, please see below."), "error")
+        # render_template needs to be imported from Flask for this to work
+        from flask import render_template as flask_render_template
+        return render_form(
+            watch=watch,
+            datastore=datastore,
+            request=request,
+            url_for=url_for,
+            render_template=flask_render_template,
+            flash=flash,
+            redirect=redirect,
+            extract_form=extract_form
+        )
+
+    extract_regex = request.form.get('extract_regex', '').strip()
+    output = watch.extract_regex_from_all_history(extract_regex)
+
+    if output:
+        watch_dir = os.path.join(datastore.datastore_path, uuid)
+        response = make_response(send_from_directory(directory=watch_dir, path=output, as_attachment=True))
+        response.headers['Content-type'] = 'text/csv'
+        response.headers['Cache-Control'] = 'no-cache, no-store, must-revalidate'
+        response.headers['Pragma'] = 'no-cache'
+        response.headers['Expires'] = "0"
+        return response
+
+    flash(gettext('No matches found while scanning all of the watch history for that RegEx.'), 'error')
+    return redirect(url_for('ui.ui_diff.diff_history_page_extract_GET', uuid=uuid))

changedetectionio/processors/image_ssim_diff/README.md

@@ -0,0 +1,210 @@
+# Fast Screenshot Comparison Processor
+
+Visual/screenshot change detection using ultra-fast image comparison algorithms.
+
+## Overview
+
+This processor uses **OpenCV** by default for screenshot comparison, providing **50-100x faster** performance compared to the previous SSIM implementation while still detecting meaningful visual changes.
+
+## Current Features
+
+- **Ultra-fast OpenCV comparison**: cv2.absdiff with Gaussian blur for noise reduction
+- **MD5 pre-check**: Fast identical image detection before expensive comparison
+- **Configurable sensitivity**: Threshold-based change detection
+- **Three-panel diff view**: Previous | Current | Difference (with red highlights)
+- **Direct image support**: Works with browser screenshots AND direct image URLs
+- **Visual selector support**: Compare specific page regions using CSS/XPath selectors
+- **Download images**: Download any of the three comparison images directly from the diff view
+
+## Performance
+
+- **OpenCV (default)**: 50-100x faster than SSIM
+- **Large screenshots**: Automatic downscaling for diff visualization (configurable via `MAX_DIFF_HEIGHT`/`MAX_DIFF_WIDTH`)
+- **Memory efficient**: Explicit cleanup of large objects for long-running processes
+- **JPEG diff images**: Smaller file sizes, faster rendering
+
+## How It Works
+
+1. **Fetch**: Screenshot captured via browser OR direct image URL fetched
+2. **MD5 Check**: Quick hash comparison - if identical, skip comparison
+3. **Region Selection** (optional): Crop to specific page region if visual selector is configured
+4. **OpenCV Comparison**: Fast pixel-level difference detection with Gaussian blur
+5. **Change Detection**: Percentage of changed pixels above threshold = change detected
+6. **Visualization**: Generate diff image with red-highlighted changed regions
+
+## Architecture
+
+### Default Method: OpenCV
+
+The processor uses OpenCV's `cv2.absdiff()` for ultra-fast pixel-level comparison:
+
+```python
+# Convert to grayscale
+gray_from = cv2.cvtColor(image_from, cv2.COLOR_RGB2GRAY)
+gray_to = cv2.cvtColor(image_to, cv2.COLOR_RGB2GRAY)
+
+# Apply Gaussian blur (reduces noise, controlled by OPENCV_BLUR_SIGMA env var)
+gray_from = cv2.GaussianBlur(gray_from, (0, 0), sigma=0.8)
+gray_to = cv2.GaussianBlur(gray_to, (0, 0), sigma=0.8)
+
+# Calculate absolute difference
+diff = cv2.absdiff(gray_from, gray_to)
+
+# Apply threshold (default: 30)
+_, thresh = cv2.threshold(diff, threshold, 255, cv2.THRESH_BINARY)
+
+# Count changed pixels
+change_percentage = (changed_pixels / total_pixels) * 100
+```
+
+### Optional: Pixelmatch
+
+For users who need better anti-aliasing detection (especially for text-heavy screenshots), **pixelmatch** can be optionally installed:
+
+```bash
+pip install pybind11-pixelmatch>=0.1.3
+```
+
+**Note**: Pixelmatch uses a C++17 implementation via pybind11 and may have build issues on some platforms (particularly Alpine/musl systems with symbolic link security restrictions). The application will automatically fall back to OpenCV if pixelmatch is not available.
+
+To use pixelmatch instead of OpenCV, set the environment variable:
+```bash
+COMPARISON_METHOD=pixelmatch
+```
+
+#### When to use pixelmatch:
+- Screenshots with lots of text and anti-aliasing
+- Need to ignore minor font rendering differences between browser versions
+- 10-20x faster than SSIM (but slower than OpenCV)
+
+#### When to stick with OpenCV (default):
+- General webpage monitoring
+- Maximum performance (50-100x faster than SSIM)
+- Simple pixel-level change detection
+- Avoid build dependencies (Alpine/musl systems)
+
+## Configuration
+
+### Environment Variables
+
+```bash
+# Comparison method (opencv or pixelmatch)
+COMPARISON_METHOD=opencv  # Default
+
+# OpenCV threshold (0-255, lower = more sensitive)
+COMPARISON_THRESHOLD_OPENCV=30  # Default
+
+# Pixelmatch threshold (0-100, mapped to 0-1 scale)
+COMPARISON_THRESHOLD_PIXELMATCH=10  # Default
+
+# Gaussian blur sigma for OpenCV (0 = no blur, higher = more blur)
+OPENCV_BLUR_SIGMA=0.8  # Default
+
+# Minimum change percentage to trigger detection
+OPENCV_MIN_CHANGE_PERCENT=0.1  # Default (0.1%)
+PIXELMATCH_MIN_CHANGE_PERCENT=0.1  # Default
+
+# Diff visualization image size limits (pixels)
+MAX_DIFF_HEIGHT=8000  # Default
+MAX_DIFF_WIDTH=900  # Default
+```
+
+### Per-Watch Configuration
+
+- **Comparison Threshold**: Can be configured per-watch in the edit form
+  - Very low sensitivity (10) - Only major changes
+  - Low sensitivity (20) - Significant changes
+  - Medium sensitivity (30) - Moderate changes (default)
+  - High sensitivity (50) - Small changes
+  - Very high sensitivity (75) - Any visible change
+
+### Visual Selector (Region Comparison)
+
+Use the "Include filters" field with CSS selectors or XPath to compare only specific page regions:
+
+```
+.content-area
+//div[@id='main']
+```
+
+The processor will automatically crop both screenshots to the bounding box of the first matched element.
+
+## Dependencies
+
+### Required
+- `opencv-python-headless>=4.8.0.76` - Fast image comparison
+- `Pillow (PIL)` - Image loading and manipulation
+- `numpy` - Array operations
+
+### Optional
+- `pybind11-pixelmatch>=0.1.3` - Alternative comparison method with anti-aliasing detection
+
+## Change Detection Interpretation
+
+- **0%** = Identical images (or below minimum change threshold)
+- **0.1-1%** = Minor differences (anti-aliasing, slight rendering differences)
+- **1-5%** = Noticeable changes (text updates, small content changes)
+- **5-20%** = Significant changes (layout shifts, content additions)
+- **>20%** = Major differences (page redesign, large content changes)
+
+## Technical Notes
+
+### Memory Management
+```python
+# Explicit cleanup for long-running processes
+img.close()  # Close PIL Images
+buffer.close()  # Close BytesIO buffers
+del large_array  # Mark numpy arrays for GC
+```
+
+### Diff Image Generation
+- Format: JPEG (quality=85, optimized)
+- Highlight: Red overlay (50% blend with original)
+- Auto-downscaling: Large screenshots downscaled for faster rendering
+- Base64 embedded: For direct template rendering
+
+### OpenCV Blur Parameters
+The Gaussian blur reduces sensitivity to:
+- Font rendering differences
+- Anti-aliasing variations
+- JPEG compression artifacts
+- Minor pixel shifts (1-2 pixels)
+
+Increase `OPENCV_BLUR_SIGMA` to make comparison more tolerant of these differences.
+
+## Comparison: OpenCV vs Pixelmatch vs SSIM
+
+| Feature | OpenCV | Pixelmatch | SSIM (old) |
+|---------|--------|------------|------------|
+| **Speed** | 50-100x faster | 10-20x faster | Baseline |
+| **Anti-aliasing** | Via blur | Built-in detection | Built-in |
+| **Text sensitivity** | High | Medium (AA-aware) | Medium |
+| **Dependencies** | opencv-python-headless | pybind11-pixelmatch + C++ compiler | scikit-image |
+| **Alpine/musl support** | ✅ Yes | ⚠️ Build issues | ✅ Yes |
+| **Memory usage** | Low | Low | High |
+| **Best for** | General use, max speed | Text-heavy screenshots | Deprecated |
+
+## Migration from SSIM
+
+If you're upgrading from the old SSIM-based processor:
+
+1. **Thresholds are different**: SSIM used 0-1 scale (higher = more similar), OpenCV uses 0-255 pixel difference (lower = more similar)
+2. **Default threshold**: Start with 30 for OpenCV, adjust based on your needs
+3. **Performance**: Expect dramatically faster comparisons, especially for large screenshots
+4. **Accuracy**: OpenCV is more sensitive to pixel-level changes; increase `OPENCV_BLUR_SIGMA` if you're getting false positives
+
+## Future Enhancements
+
+Potential features for future consideration:
+
+- **Change region detection**: Highlight specific areas that changed with bounding boxes
+- **Perceptual hashing**: Pre-screening filter for even faster checks
+- **Ignore regions**: Exclude specific page areas (ads, timestamps) from comparison
+- **Text extraction**: OCR-based text comparison for semantic changes
+- **Adaptive thresholds**: Different sensitivity for different page regions
+
+## Resources
+
+- [OpenCV Documentation](https://docs.opencv.org/)
+- [pybind11-pixelmatch GitHub](https://github.com/whtsky/pybind11-pixelmatch)
+- [Pixelmatch (original JS library)](https://github.com/mapbox/pixelmatch)

changedetectionio/processors/image_ssim_diff/__init__.py

@@ -0,0 +1,32 @@
+"""
+Visual/screenshot change detection using fast image comparison algorithms.
+
+This processor compares screenshots using OpenCV (cv2.absdiff),
+which is 10-100x faster than SSIM while still detecting meaningful visual changes.
+"""
+
+import os
+from pathlib import Path
+
+processor_description = "Visual/Screenshot change detection (Fast)"
+processor_name = "image_ssim_diff"
+processor_weight = 2  # Lower weight = appears at top, heavier weight = appears lower (bottom)
+
+PROCESSOR_CONFIG_NAME = f"{Path(__file__).parent.name}.json"
+
+# Subprocess timeout settings
+# Maximum time to wait for subprocess operations (seconds)
+POLL_TIMEOUT_ABSOLUTE = int(os.getenv('OPENCV_SUBPROCESS_TIMEOUT', '20'))
+
+# Template tracking filename
+CROPPED_IMAGE_TEMPLATE_FILENAME = 'cropped_image_template.png'
+
+SCREENSHOT_COMPARISON_THRESHOLD_OPTIONS = [
+    ('200', 'Low sensitivity (only major changes)'),
+    ('80', 'Medium sensitivity (moderate changes - recommended)'),
+    ('20', 'High sensitivity (small changes)'),
+    ('0', 'Very high sensitivity (any change)')
+]
+
+SCREENSHOT_COMPARISON_THRESHOLD_OPTIONS_DEFAULT=0.999
+OPENCV_BLUR_SIGMA=float(os.getenv("OPENCV_BLUR_SIGMA", "3.0"))

changedetectionio/processors/image_ssim_diff/difference.py

@@ -0,0 +1,441 @@
+"""
+Screenshot diff visualization for fast image comparison processor.
+
+All image operations now use ImageDiffHandler abstraction for clean separation
+of concerns and easy backend swapping (LibVIPS, OpenCV, PIL, etc.).
+"""
+
+import os
+import json
+import time
+from flask_babel import gettext
+from loguru import logger
+
+from changedetectionio.processors.image_ssim_diff import SCREENSHOT_COMPARISON_THRESHOLD_OPTIONS_DEFAULT, PROCESSOR_CONFIG_NAME, \
+    OPENCV_BLUR_SIGMA
+
+# All image operations now use OpenCV via isolated_opencv subprocess handler
+# No direct handler imports needed - subprocess isolation handles everything
+
+# Maximum dimensions for diff visualization (can be overridden via environment variable)
+# Large screenshots don't need full resolution for visual inspection
+# Reduced defaults to minimize memory usage - 2000px height is plenty for diff viewing
+MAX_DIFF_HEIGHT = int(os.getenv('MAX_DIFF_HEIGHT', '8000'))
+MAX_DIFF_WIDTH = int(os.getenv('MAX_DIFF_WIDTH', '900'))
+
+
+def get_asset(asset_name, watch, datastore, request):
+    """
+    Get processor-specific binary assets for streaming.
+
+    Uses ImageDiffHandler for all image operations - no more multiprocessing needed
+    as LibVIPS handles threading/memory internally.
+
+    Supported assets:
+    - 'before': The previous/from screenshot
+    - 'after': The current/to screenshot
+    - 'rendered_diff': The generated diff visualization with red highlights
+
+    Args:
+        asset_name: Name of the asset to retrieve ('before', 'after', 'rendered_diff')
+        watch: Watch object
+        datastore: Datastore object
+        request: Flask request (for from_version/to_version query params)
+
+    Returns:
+        tuple: (binary_data, content_type, cache_control_header) or None if not found
+    """
+    # Get version parameters from query string
+    versions = list(watch.history.keys())
+
+    if len(versions) < 2:
+        return None
+
+    from_version = request.args.get('from_version', versions[-2] if len(versions) >= 2 else versions[0])
+    to_version = request.args.get('to_version', versions[-1])
+
+    # Validate versions exist
+    if from_version not in versions:
+        from_version = versions[-2] if len(versions) >= 2 else versions[0]
+    if to_version not in versions:
+        to_version = versions[-1]
+
+    try:
+        if asset_name == 'before':
+            # Return the 'from' screenshot with bounding box if configured
+            img_bytes = watch.get_history_snapshot(timestamp=from_version)
+            img_bytes = _draw_bounding_box_if_configured(img_bytes, watch, datastore)
+            mime_type = _detect_mime_type(img_bytes)
+            return (img_bytes, mime_type, 'public, max-age=3600')
+
+        elif asset_name == 'after':
+            # Return the 'to' screenshot with bounding box if configured
+            img_bytes = watch.get_history_snapshot(timestamp=to_version)
+            img_bytes = _draw_bounding_box_if_configured(img_bytes, watch, datastore)
+            mime_type = _detect_mime_type(img_bytes)
+            return (img_bytes, mime_type, 'public, max-age=3600')
+
+        elif asset_name == 'rendered_diff':
+            # Generate diff in isolated subprocess to prevent memory leaks
+            # Subprocess provides complete memory isolation
+            from .image_handler import isolated_opencv as process_screenshot_handler
+
+            img_bytes_from = watch.get_history_snapshot(timestamp=from_version)
+            img_bytes_to = watch.get_history_snapshot(timestamp=to_version)
+
+            # Get pixel difference threshold sensitivity (per-watch > global)
+            # This controls how different a pixel must be (0-255 scale) to count as "changed"
+            from changedetectionio import processors
+            processor_instance = processors.difference_detection_processor(datastore, watch.get('uuid'))
+            processor_config = processor_instance.get_extra_watch_config(PROCESSOR_CONFIG_NAME)
+
+            pixel_difference_threshold_sensitivity = processor_config.get('pixel_difference_threshold_sensitivity')
+            if not pixel_difference_threshold_sensitivity:
+                pixel_difference_threshold_sensitivity = datastore.data['settings']['application'].get(
+                    'pixel_difference_threshold_sensitivity', SCREENSHOT_COMPARISON_THRESHOLD_OPTIONS_DEFAULT)
+            try:
+                pixel_difference_threshold_sensitivity = int(pixel_difference_threshold_sensitivity)
+            except (ValueError, TypeError):
+                logger.warning(
+                    f"Invalid pixel_difference_threshold_sensitivity value '{pixel_difference_threshold_sensitivity}', using default")
+                pixel_difference_threshold_sensitivity = SCREENSHOT_COMPARISON_THRESHOLD_OPTIONS_DEFAULT
+
+            logger.debug(f"Pixel difference threshold sensitivity is {pixel_difference_threshold_sensitivity}")
+
+
+            # Generate diff in isolated subprocess (async-safe)
+            import asyncio
+            import threading
+
+            # Async-safe wrapper: runs coroutine in new thread with its own event loop
+            def run_async_in_thread():
+                return asyncio.run(
+                    process_screenshot_handler.generate_diff_isolated(
+                        img_bytes_from,
+                        img_bytes_to,
+                        pixel_difference_threshold=int(pixel_difference_threshold_sensitivity),
+                        blur_sigma=OPENCV_BLUR_SIGMA,
+                        max_width=MAX_DIFF_WIDTH,
+                        max_height=MAX_DIFF_HEIGHT
+                    )
+                )
+
+            # Run in thread to avoid blocking event loop if called from async context
+            result_container = [None]
+            exception_container = [None]
+
+            def thread_target():
+                try:
+                    result_container[0] = run_async_in_thread()
+                except Exception as e:
+                    exception_container[0] = e
+
+            thread = threading.Thread(target=thread_target)
+            thread.start()
+            thread.join(timeout=60)
+
+            if exception_container[0]:
+                raise exception_container[0]
+
+            diff_image_bytes = result_container[0]
+
+            if diff_image_bytes:
+                # Note: Bounding box drawing on diff not yet implemented
+                return (diff_image_bytes, 'image/jpeg', 'public, max-age=300')
+            else:
+                logger.error("Failed to generate diff in subprocess")
+                return None
+
+        else:
+            # Unknown asset
+            return None
+
+    except Exception as e:
+        logger.error(f"Failed to get asset '{asset_name}': {e}")
+        import traceback
+        logger.error(traceback.format_exc())
+        return None
+
+
+def _detect_mime_type(img_bytes):
+    """
+    Detect MIME type using puremagic (same as Watch.py).
+
+    Args:
+        img_bytes: Image bytes
+
+    Returns:
+        str: MIME type (e.g., 'image/png', 'image/jpeg')
+    """
+    try:
+        import puremagic
+        detections = puremagic.magic_string(img_bytes[:2048])
+        if detections:
+            mime_type = detections[0].mime_type
+            logger.trace(f"Detected MIME type: {mime_type}")
+            return mime_type
+        else:
+            logger.trace("No MIME type detected, using 'image/png' fallback")
+            return 'image/png'
+    except Exception as e:
+        logger.warning(f"puremagic detection failed: {e}, using 'image/png' fallback")
+        return 'image/png'
+
+
+def _draw_bounding_box_if_configured(img_bytes, watch, datastore):
+    """
+    Draw blue bounding box on image if configured in processor settings.
+    Uses isolated subprocess to prevent memory leaks from large images.
+
+    Supports two modes:
+    - "Select by element": Use include_filter to find xpath element bbox
+    - "Draw area": Use manually drawn bounding_box from config
+
+    Args:
+        img_bytes: Image bytes (PNG)
+        watch: Watch object
+        datastore: Datastore object
+
+    Returns:
+        Image bytes (possibly with bounding box drawn)
+    """
+    try:
+        # Get processor configuration
+        from changedetectionio import processors
+        processor_instance = processors.difference_detection_processor(datastore, watch.get('uuid'))
+        processor_name = watch.get('processor', 'default')
+        config_filename = f'{processor_name}.json'
+        processor_config = processor_instance.get_extra_watch_config(config_filename)
+
+        if not processor_config:
+            return img_bytes
+
+        selection_mode = processor_config.get('selection_mode', 'draw')
+        x, y, width, height = None, None, None, None
+
+        # Mode 1: Select by element (use include_filter + xpath_data)
+        if selection_mode == 'element':
+            include_filters = watch.get('include_filters', [])
+
+            if include_filters and len(include_filters) > 0:
+                first_filter = include_filters[0].strip()
+
+                # Get xpath_data from watch history
+                history_keys = list(watch.history.keys())
+                if history_keys:
+                    latest_snapshot = watch.get_history_snapshot(timestamp=history_keys[-1])
+                    xpath_data_path = watch.get_xpath_data_filepath(timestamp=history_keys[-1])
+
+                    try:
+                        import gzip
+                        with gzip.open(xpath_data_path, 'rt') as f:
+                            xpath_data = json.load(f)
+
+                        # Find matching element
+                        for element in xpath_data.get('size_pos', []):
+                            if element.get('xpath') == first_filter and element.get('highlight_as_custom_filter'):
+                                x = element.get('left', 0)
+                                y = element.get('top', 0)
+                                width = element.get('width', 0)
+                                height = element.get('height', 0)
+                                logger.debug(f"Found element bbox for filter '{first_filter}': x={x}, y={y}, w={width}, h={height}")
+                                break
+                    except Exception as e:
+                        logger.warning(f"Failed to load xpath_data for element selection: {e}")
+
+        # Mode 2: Draw area (use manually configured bbox)
+        else:
+            bounding_box = processor_config.get('bounding_box')
+            if bounding_box:
+                # Parse bounding box: "x,y,width,height"
+                parts = [int(p.strip()) for p in bounding_box.split(',')]
+                if len(parts) == 4:
+                    x, y, width, height = parts
+                else:
+                    logger.warning(f"Invalid bounding box format: {bounding_box}")
+
+        # If no bbox found, return original image
+        if x is None or y is None or width is None or height is None:
+            return img_bytes
+
+        # Use isolated subprocess to prevent memory leaks from large images
+        from .image_handler import isolated_opencv
+        import asyncio
+        import threading
+
+        # Async-safe wrapper: runs coroutine in new thread with its own event loop
+        # This prevents blocking when called from async context (update worker)
+        def run_async_in_thread():
+            return asyncio.run(
+                isolated_opencv.draw_bounding_box_isolated(
+                    img_bytes, x, y, width, height,
+                    color=(255, 0, 0),  # Blue in BGR format
+                    thickness=3
+                )
+            )
+
+        # Always run in thread to avoid blocking event loop if called from async context
+        result_container = [None]
+        exception_container = [None]
+
+        def thread_target():
+            try:
+                result_container[0] = run_async_in_thread()
+            except Exception as e:
+                exception_container[0] = e
+
+        thread = threading.Thread(target=thread_target)
+        thread.start()
+        thread.join(timeout=15)
+
+        if exception_container[0]:
+            raise exception_container[0]
+
+        result = result_container[0]
+
+        # Return result or original if subprocess failed
+        return result if result else img_bytes
+
+    except Exception as e:
+        logger.warning(f"Failed to draw bounding box: {e}")
+        import traceback
+        logger.debug(traceback.format_exc())
+        return img_bytes
+
+
+def render(watch, datastore, request, url_for, render_template, flash, redirect):
+    """
+    Render the screenshot comparison diff page.
+
+    Uses ImageDiffHandler for all image operations.
+
+    Args:
+        watch: Watch object
+        datastore: Datastore object
+        request: Flask request
+        url_for: Flask url_for function
+        render_template: Flask render_template function
+        flash: Flask flash function
+        redirect: Flask redirect function
+
+    Returns:
+        Rendered template or redirect
+    """
+    # Get version parameters (from_version, to_version)
+    versions = list(watch.history.keys())
+
+    if len(versions) < 2:
+        flash(gettext("Not enough history to compare. Need at least 2 snapshots."), "error")
+        return redirect(url_for('watchlist.index'))
+
+    # Default: compare latest two versions
+    from_version = request.args.get('from_version', versions[-2] if len(versions) >= 2 else versions[0])
+    to_version = request.args.get('to_version', versions[-1])
+
+    # Validate versions exist
+    if from_version not in versions:
+        from_version = versions[-2] if len(versions) >= 2 else versions[0]
+    if to_version not in versions:
+        to_version = versions[-1]
+
+    # Get pixel difference threshold sensitivity (per-watch > global > env default)
+    pixel_difference_threshold_sensitivity = watch.get('pixel_difference_threshold_sensitivity')
+    if not pixel_difference_threshold_sensitivity or pixel_difference_threshold_sensitivity == '':
+        pixel_difference_threshold_sensitivity = datastore.data['settings']['application'].get('pixel_difference_threshold_sensitivity', SCREENSHOT_COMPARISON_THRESHOLD_OPTIONS_DEFAULT)
+
+    # Convert to appropriate type
+    try:
+        pixel_difference_threshold_sensitivity = float(pixel_difference_threshold_sensitivity)
+    except (ValueError, TypeError):
+        logger.warning(f"Invalid pixel_difference_threshold_sensitivity value '{pixel_difference_threshold_sensitivity}', using default")
+        pixel_difference_threshold_sensitivity = 30.0
+
+    # Get blur sigma
+    blur_sigma = OPENCV_BLUR_SIGMA
+
+    # Load screenshots from history
+    try:
+        img_bytes_from = watch.get_history_snapshot(timestamp=from_version)
+        img_bytes_to = watch.get_history_snapshot(timestamp=to_version)
+
+    except Exception as e:
+        logger.error(f"Failed to load screenshots: {e}")
+        flash(gettext("Failed to load screenshots: {}").format(e), "error")
+        return redirect(url_for('watchlist.index'))
+
+    # Calculate change percentage using isolated subprocess to prevent memory leaks (async-safe)
+    now = time.time()
+    try:
+        from .image_handler import isolated_opencv as process_screenshot_handler
+        import asyncio
+        import threading
+
+        # Async-safe wrapper: runs coroutine in new thread with its own event loop
+        def run_async_in_thread():
+            return asyncio.run(
+                process_screenshot_handler.calculate_change_percentage_isolated(
+                    img_bytes_from,
+                    img_bytes_to,
+                    pixel_difference_threshold=int(pixel_difference_threshold_sensitivity),
+                    blur_sigma=blur_sigma,
+                    max_width=MAX_DIFF_WIDTH,
+                    max_height=MAX_DIFF_HEIGHT
+                )
+            )
+
+        # Run in thread to avoid blocking event loop if called from async context
+        result_container = [None]
+        exception_container = [None]
+
+        def thread_target():
+            try:
+                result_container[0] = run_async_in_thread()
+            except Exception as e:
+                exception_container[0] = e
+
+        thread = threading.Thread(target=thread_target)
+        thread.start()
+        thread.join(timeout=60)
+
+        if exception_container[0]:
+            raise exception_container[0]
+
+        change_percentage = result_container[0]
+
+        method_display = f"{process_screenshot_handler.IMPLEMENTATION_NAME} (pixel_diff_threshold: {pixel_difference_threshold_sensitivity:.0f})"
+        logger.debug(f"Done change percentage calculation in {time.time() - now:.2f}s")
+
+    except Exception as e:
+        logger.error(f"Failed to calculate change percentage: {e}")
+        import traceback
+        logger.error(traceback.format_exc())
+        flash(gettext("Failed to calculate diff: {}").format(e), "error")
+        return redirect(url_for('watchlist.index'))
+
+    # Load historical data if available (for charts/visualization)
+    comparison_data = {}
+    comparison_config_path = os.path.join(watch.watch_data_dir, "visual_comparison_data.json")
+    if os.path.isfile(comparison_config_path):
+        try:
+            with open(comparison_config_path, 'r') as f:
+                comparison_data = json.load(f)
+        except Exception as e:
+            logger.warning(f"Failed to load comparison history data: {e}")
+
+    # Render custom template
+    # Template path is namespaced to avoid conflicts with other processors
+    # Images are now served via separate /processor-asset/ endpoints instead of base64
+    return render_template(
+        'image_ssim_diff/diff.html',
+        change_percentage=change_percentage,
+        comparison_data=comparison_data,  # Full history for charts/visualization
+        comparison_method=method_display,
+        current_diff_url=watch['url'],
+        from_version=from_version,
+        percentage_different=change_percentage,
+        threshold=pixel_difference_threshold_sensitivity,
+        to_version=to_version,
+        uuid=watch.get('uuid'),
+        versions=versions,
+        watch=watch,
+    )

changedetectionio/processors/image_ssim_diff/edit_hook.py

@@ -0,0 +1,151 @@
+"""
+Optional hook called when processor settings are saved in edit page.
+
+This hook analyzes the selected region to determine if template matching
+should be enabled for tracking content movement.
+
+Template matching is controlled via ENABLE_TEMPLATE_TRACKING env var (default: False).
+"""
+
+import io
+import os
+from loguru import logger
+from changedetectionio import strtobool
+from . import CROPPED_IMAGE_TEMPLATE_FILENAME
+
+# Template matching controlled via environment variable (default: disabled)
+# Set ENABLE_TEMPLATE_TRACKING=True to enable
+TEMPLATE_MATCHING_ENABLED = strtobool(os.getenv('ENABLE_TEMPLATE_TRACKING', 'False'))
+IMPORT_ERROR = "Template matching disabled (set ENABLE_TEMPLATE_TRACKING=True to enable)"
+
+
+def on_config_save(watch, processor_config, datastore):
+    """
+    Called after processor config is saved in edit page.
+
+    Analyzes the bounding box region to determine if it has enough
+    visual features (texture/edges) to enable template matching for
+    tracking content movement when page layout shifts.
+
+    Args:
+        watch: Watch object
+        processor_config: Dict of processor-specific config
+        datastore: Datastore object
+
+    Returns:
+        dict: Updated processor_config with auto_track_region setting
+    """
+    # Check if template matching is globally enabled via ENV var
+    if not TEMPLATE_MATCHING_ENABLED:
+        logger.debug("Template tracking disabled via ENABLE_TEMPLATE_TRACKING env var")
+        processor_config['auto_track_region'] = False
+        return processor_config
+
+    bounding_box = processor_config.get('bounding_box')
+
+    if not bounding_box:
+        # No bounding box, disable tracking
+        processor_config['auto_track_region'] = False
+        logger.debug("No bounding box set, disabled auto-tracking")
+        return processor_config
+
+    try:
+        # Get the latest screenshot from watch history
+        history_keys = list(watch.history.keys())
+        if len(history_keys) == 0:
+            logger.warning("No screenshot history available yet, cannot analyze for tracking")
+            processor_config['auto_track_region'] = False
+            return processor_config
+
+        # Get latest screenshot
+        latest_timestamp = history_keys[-1]
+        screenshot_bytes = watch.get_history_snapshot(timestamp=latest_timestamp)
+
+        if not screenshot_bytes:
+            logger.warning("Could not load screenshot for analysis")
+            processor_config['auto_track_region'] = False
+            return processor_config
+
+        # Parse bounding box
+        parts = [int(p.strip()) for p in bounding_box.split(',')]
+        if len(parts) != 4:
+            logger.warning("Invalid bounding box format")
+            processor_config['auto_track_region'] = False
+            return processor_config
+
+        x, y, width, height = parts
+
+        # Analyze the region for features/texture
+        has_enough_features = analyze_region_features(screenshot_bytes, x, y, width, height)
+
+        if has_enough_features:
+            logger.info(f"Region has sufficient features for tracking - enabling auto_track_region")
+            processor_config['auto_track_region'] = True
+
+            # Save the template as cropped.jpg in watch data directory
+            save_template_to_file(watch, screenshot_bytes, x, y, width, height)
+
+        else:
+            logger.info(f"Region lacks distinctive features - disabling auto_track_region")
+            processor_config['auto_track_region'] = False
+
+            # Remove old template file if exists
+            template_path = os.path.join(watch.watch_data_dir, CROPPED_IMAGE_TEMPLATE_FILENAME)
+            if os.path.exists(template_path):
+                os.remove(template_path)
+                logger.debug(f"Removed old template file: {template_path}")
+
+        return processor_config
+
+    except Exception as e:
+        logger.error(f"Error analyzing region for tracking: {e}")
+        processor_config['auto_track_region'] = False
+        return processor_config
+
+
+def analyze_region_features(screenshot_bytes, x, y, width, height):
+    """
+    Analyze if a region has enough visual features for template matching.
+
+    Uses OpenCV to detect corners/edges. If the region has distinctive
+    features, template matching can reliably track it when it moves.
+
+    Args:
+        screenshot_bytes: Full screenshot as bytes
+        x, y, width, height: Bounding box coordinates
+
+    Returns:
+        bool: True if region has enough features, False otherwise
+    """
+    # Template matching disabled - would need OpenCV implementation for region analysis
+    if not TEMPLATE_MATCHING_ENABLED:
+        logger.warning(f"Cannot analyze region features: {IMPORT_ERROR}")
+        return False
+
+    # Note: Original implementation used LibVIPS handler to crop region, then OpenCV
+    # for feature detection (goodFeaturesToTrack, Canny edge detection, variance).
+    # If re-implementing, use OpenCV directly for both cropping and analysis.
+    # Feature detection would use: cv2.goodFeaturesToTrack, cv2.Canny, np.var
+    return False
+
+
+def save_template_to_file(watch, screenshot_bytes, x, y, width, height):
+    """
+    Extract the template region and save as cropped_image_template.png in watch data directory.
+
+    This is a convenience wrapper around handler.save_template() that handles
+    watch directory setup and path construction.
+
+    Args:
+        watch: Watch object
+        screenshot_bytes: Full screenshot as bytes
+        x, y, width, height: Bounding box coordinates
+    """
+    # Template matching disabled - would need OpenCV implementation for template saving
+    if not TEMPLATE_MATCHING_ENABLED:
+        logger.warning(f"Cannot save template: {IMPORT_ERROR}")
+        return
+
+    # Note: Original implementation used LibVIPS handler to crop and save region.
+    # If re-implementing, use OpenCV (cv2.imdecode, crop with array slicing, cv2.imwrite).
+    return

changedetectionio/processors/image_ssim_diff/forms.py

@@ -0,0 +1,120 @@
+"""
+Configuration forms for fast screenshot comparison processor.
+"""
+
+from wtforms import SelectField, StringField, validators, ValidationError, IntegerField
+from flask_babel import lazy_gettext as _l
+from changedetectionio.forms import processor_text_json_diff_form
+import re
+
+from changedetectionio.processors.image_ssim_diff import SCREENSHOT_COMPARISON_THRESHOLD_OPTIONS
+
+
+def validate_bounding_box(form, field):
+    """Validate bounding box format: x,y,width,height with integers."""
+    if not field.data:
+        return  # Optional field
+
+    if len(field.data) > 100:
+        raise ValidationError(_l('Bounding box value is too long'))
+
+    # Should be comma-separated integers
+    if not re.match(r'^\d+,\d+,\d+,\d+$', field.data):
+        raise ValidationError(_l('Bounding box must be in format: x,y,width,height (integers only)'))
+
+    # Validate values are reasonable (not negative, not ridiculously large)
+    parts = [int(p) for p in field.data.split(',')]
+    for part in parts:
+        if part < 0:
+            raise ValidationError(_l('Bounding box values must be non-negative'))
+        if part > 10000:  # Reasonable max screen dimension
+            raise ValidationError(_l('Bounding box values are too large'))
+
+
+def validate_selection_mode(form, field):
+    """Validate selection mode value."""
+    if not field.data:
+        return  # Optional field
+
+    if field.data not in ['element', 'draw']:
+        raise ValidationError(_l('Selection mode must be either "element" or "draw"'))
+
+
+class processor_settings_form(processor_text_json_diff_form):
+    """Form for fast image comparison processor settings."""
+
+    processor_config_min_change_percentage = IntegerField(
+        _l('Minimum Change Percentage'),
+        validators=[
+            validators.Optional(),
+            validators.NumberRange(min=1, max=100, message=_l('Must be between 0 and 100'))
+        ],
+        render_kw={"placeholder": "Use global default (0.1)"}
+    )
+
+    processor_config_pixel_difference_threshold_sensitivity = SelectField(
+        _l('Pixel Difference Sensitivity'),
+        choices=[
+                    ('', _l('Use global default'))
+                ] + SCREENSHOT_COMPARISON_THRESHOLD_OPTIONS,
+        validators=[validators.Optional()],
+        default=''
+    )
+
+    # Processor-specific config fields (stored in separate JSON file)
+    processor_config_bounding_box = StringField(
+        _l('Bounding Box'),
+        validators=[
+            validators.Optional(),
+            validators.Length(max=100, message=_l('Bounding box value is too long')),
+            validate_bounding_box
+        ],
+        render_kw={"style": "display: none;", "id": "bounding_box"}
+    )
+
+    processor_config_selection_mode = StringField(
+        _l('Selection Mode'),
+        validators=[
+            validators.Optional(),
+            validators.Length(max=20, message=_l('Selection mode value is too long')),
+            validate_selection_mode
+        ],
+        render_kw={"style": "display: none;", "id": "selection_mode"}
+    )
+
+    def extra_tab_content(self):
+        """Tab label for processor-specific settings."""
+        return _l('Screenshot Comparison')
+
+    def extra_form_content(self):
+        """Render processor-specific form fields.
+        @NOTE: prepend processor_config_* to the field name so it will save into its own datadir/uuid/image_ssim_diff.json and be read at process time
+        """
+        return '''
+        {% from '_helpers.html' import render_field %}
+        <fieldset>
+            <legend>Screenshot Comparison Settings</legend>
+
+            <div class="pure-control-group">
+                {{ render_field(form.processor_config_min_change_percentage) }}
+                <span class="pure-form-message-inline">
+                    <strong>What percentage of pixels must change to trigger a detection?</strong><br>
+                    For example, <strong>0.1%</strong> means if 0.1% or more of the pixels change, it counts as a change.<br>
+                    Lower values = more sensitive (detect smaller changes).<br>
+                    Higher values = less sensitive (only detect larger changes).<br>
+                    Leave blank to use global default (0.1%).
+                </span>
+            </div>
+
+            <div class="pure-control-group">
+                {{ render_field(form.processor_config_pixel_difference_threshold_sensitivity) }}
+                <span class="pure-form-message-inline">
+                    <strong>How different must an individual pixel be to count as "changed"?</strong><br>
+                    <strong>Low sensitivity (75)</strong> = Only count pixels that changed significantly (0-255 scale).<br>
+                    <strong>High sensitivity (20)</strong> = Count pixels with small changes as different.<br>
+                    <strong>Very high (0)</strong> = Any pixel change counts.<br>
+                    Select "Use global default" to inherit the system-wide setting.
+                </span>
+            </div>
+        </fieldset>
+        '''

changedetectionio/processors/image_ssim_diff/image_handler/__init__.py

@@ -0,0 +1,242 @@
+"""
+Abstract base class for image processing operations.
+
+All image operations for the image_ssim_diff processor must be implemented
+through this interface to allow different backends (libvips, OpenCV, PIL, etc.).
+"""
+
+from abc import ABC, abstractmethod
+from typing import Tuple, Optional, Any
+
+
+class ImageDiffHandler(ABC):
+    """
+    Abstract base class for image processing operations.
+
+    Implementations must handle all image operations needed for screenshot
+    comparison including loading, cropping, resizing, diffing, and overlays.
+    """
+
+    @abstractmethod
+    def load_from_bytes(self, img_bytes: bytes) -> Any:
+        """
+        Load image from bytes.
+
+        Args:
+            img_bytes: Image data as bytes (PNG, JPEG, etc.)
+
+        Returns:
+            Handler-specific image object
+        """
+        pass
+
+    @abstractmethod
+    def save_to_bytes(self, img: Any, format: str = 'png', quality: int = 85) -> bytes:
+        """
+        Save image to bytes.
+
+        Args:
+            img: Handler-specific image object
+            format: Output format ('png' or 'jpeg')
+            quality: Quality for JPEG (1-100)
+
+        Returns:
+            Image data as bytes
+        """
+        pass
+
+    @abstractmethod
+    def crop(self, img: Any, left: int, top: int, right: int, bottom: int) -> Any:
+        """
+        Crop image to specified region.
+
+        Args:
+            img: Handler-specific image object
+            left: Left coordinate
+            top: Top coordinate
+            right: Right coordinate
+            bottom: Bottom coordinate
+
+        Returns:
+            Cropped image object
+        """
+        pass
+
+    @abstractmethod
+    def resize(self, img: Any, max_width: int, max_height: int) -> Any:
+        """
+        Resize image maintaining aspect ratio.
+
+        Args:
+            img: Handler-specific image object
+            max_width: Maximum width in pixels
+            max_height: Maximum height in pixels
+
+        Returns:
+            Resized image object
+        """
+        pass
+
+    @abstractmethod
+    def get_dimensions(self, img: Any) -> Tuple[int, int]:
+        """
+        Get image dimensions.
+
+        Args:
+            img: Handler-specific image object
+
+        Returns:
+            Tuple of (width, height)
+        """
+        pass
+
+    @abstractmethod
+    def to_grayscale(self, img: Any) -> Any:
+        """
+        Convert image to grayscale.
+
+        Args:
+            img: Handler-specific image object
+
+        Returns:
+            Grayscale image object
+        """
+        pass
+
+    @abstractmethod
+    def gaussian_blur(self, img: Any, sigma: float) -> Any:
+        """
+        Apply Gaussian blur to image.
+
+        Args:
+            img: Handler-specific image object
+            sigma: Blur sigma value (0 = no blur)
+
+        Returns:
+            Blurred image object
+        """
+        pass
+
+    @abstractmethod
+    def absolute_difference(self, img1: Any, img2: Any) -> Any:
+        """
+        Calculate absolute difference between two images.
+
+        Args:
+            img1: First image (handler-specific object)
+            img2: Second image (handler-specific object)
+
+        Returns:
+            Difference image object
+        """
+        pass
+
+    @abstractmethod
+    def threshold(self, img: Any, threshold_value: int) -> Tuple[float, Any]:
+        """
+        Apply threshold to image and calculate change percentage.
+
+        Args:
+            img: Handler-specific image object (typically grayscale difference)
+            threshold_value: Threshold value (0-255)
+
+        Returns:
+            Tuple of (change_percentage, binary_mask)
+            - change_percentage: Percentage of pixels above threshold (0-100)
+            - binary_mask: Handler-specific binary mask object
+        """
+        pass
+
+    @abstractmethod
+    def apply_red_overlay(self, img: Any, mask: Any) -> bytes:
+        """
+        Apply red overlay to image where mask is True.
+
+        Args:
+            img: Handler-specific image object (color)
+            mask: Handler-specific binary mask object
+
+        Returns:
+            JPEG bytes with red overlay applied
+        """
+        pass
+
+    @abstractmethod
+    def close(self, img: Any) -> None:
+        """
+        Clean up image resources if needed.
+
+        Args:
+            img: Handler-specific image object
+        """
+        pass
+
+    @abstractmethod
+    def find_template(
+        self,
+        img: Any,
+        template_img: Any,
+        original_bbox: Tuple[int, int, int, int],
+        search_tolerance: float = 0.2
+    ) -> Optional[Tuple[int, int, int, int]]:
+        """
+        Find template in image using template matching.
+
+        Args:
+            img: Handler-specific image object to search in
+            template_img: Handler-specific template image object to find
+            original_bbox: Original bounding box (left, top, right, bottom)
+            search_tolerance: How far to search (0.2 = ±20% of region size)
+
+        Returns:
+            New bounding box (left, top, right, bottom) or None if not found
+        """
+        pass
+
+    @abstractmethod
+    def save_template(
+        self,
+        img: Any,
+        bbox: Tuple[int, int, int, int],
+        output_path: str
+    ) -> bool:
+        """
+        Save a cropped region as a template file.
+
+        Args:
+            img: Handler-specific image object
+            bbox: Bounding box to crop (left, top, right, bottom)
+            output_path: Where to save the template PNG
+
+        Returns:
+            True if successful, False otherwise
+        """
+        pass
+
+    @abstractmethod
+    def draw_bounding_box(
+        self,
+        img_bytes: bytes,
+        x: int,
+        y: int,
+        width: int,
+        height: int,
+        color: Tuple[int, int, int] = (255, 0, 0),
+        thickness: int = 3
+    ) -> bytes:
+        """
+        Draw a bounding box rectangle on image.
+
+        Args:
+            img_bytes: Image data as bytes
+            x: Left coordinate
+            y: Top coordinate
+            width: Box width
+            height: Box height
+            color: BGR color tuple (default: blue)
+            thickness: Line thickness in pixels
+
+        Returns:
+            Image bytes with bounding box drawn
+        """
+        pass

changedetectionio/processors/image_ssim_diff/image_handler/isolated_libvips.py

@@ -0,0 +1,353 @@
+"""
+Subprocess-isolated image operations for memory leak prevention.
+
+LibVIPS accumulates C-level memory in long-running processes that cannot be
+reclaimed by Python's GC or libvips cache management. Using subprocess isolation
+ensures complete memory cleanup when the process exits.
+
+This module wraps LibvipsImageDiffHandler operations in multiprocessing for
+complete memory isolation without code duplication.
+
+Research: https://github.com/libvips/pyvips/issues/234
+"""
+
+import multiprocessing
+
+# CRITICAL: Use 'spawn' instead of 'fork' to avoid inheriting parent's
+# LibVIPS threading state which can cause hangs in gaussblur operations
+# https://docs.python.org/3/library/multiprocessing.html#contexts-and-start-methods
+try:
+    multiprocessing.set_start_method('spawn', force=False)
+except RuntimeError:
+    # Already set, ignore
+    pass
+
+
+def _worker_generate_diff(conn, img_bytes_from, img_bytes_to, threshold, blur_sigma, max_width, max_height):
+    """
+    Worker: Generate diff visualization using LibvipsImageDiffHandler in isolated subprocess.
+
+    This runs in a separate process for complete memory isolation.
+    Uses print() instead of loguru to avoid forking issues.
+    """
+    try:
+        # Import handler inside worker
+        from .libvips_handler import LibvipsImageDiffHandler
+
+        print(f"[Worker] Initializing handler", flush=True)
+        handler = LibvipsImageDiffHandler()
+
+        # Load images using handler
+        img_from = handler.load_from_bytes(img_bytes_from)
+        img_to = handler.load_from_bytes(img_bytes_to)
+
+        # Ensure same size
+        w1, h1 = handler.get_dimensions(img_from)
+        w2, h2 = handler.get_dimensions(img_to)
+        if (w1, h1) != (w2, h2):
+            img_from = handler.resize(img_from, w2, h2)
+
+        # Downscale for faster diff visualization
+        img_from = handler.resize(img_from, max_width, max_height)
+        img_to = handler.resize(img_to, max_width, max_height)
+
+        # Convert to grayscale
+        gray_from = handler.to_grayscale(img_from)
+        gray_to = handler.to_grayscale(img_to)
+
+        # Optional blur - DISABLED due to LibVIPS threading issues in fork
+        # gray_from = handler.gaussian_blur(gray_from, blur_sigma)
+        # gray_to = handler.gaussian_blur(gray_to, blur_sigma)
+
+        # Calculate difference
+        diff = handler.absolute_difference(gray_from, gray_to)
+
+        # Threshold to get mask
+        _, diff_mask = handler.threshold(diff, int(threshold))
+
+        # Generate diff image with red overlay
+        diff_image_bytes = handler.apply_red_overlay(img_to, diff_mask)
+
+        print(f"[Worker] Generated diff ({len(diff_image_bytes)} bytes)", flush=True)
+        conn.send(diff_image_bytes)
+
+    except Exception as e:
+        print(f"[Worker] Error: {e}", flush=True)
+        import traceback
+        traceback.print_exc()
+        conn.send(None)
+    finally:
+        conn.close()
+
+
+def generate_diff_isolated(img_bytes_from, img_bytes_to, threshold, blur_sigma, max_width, max_height):
+    """
+    Generate diff visualization in isolated subprocess for memory leak prevention.
+
+    Args:
+        img_bytes_from: Previous screenshot bytes
+        img_bytes_to: Current screenshot bytes
+        threshold: Pixel difference threshold
+        blur_sigma: Gaussian blur sigma
+        max_width: Maximum width for diff
+        max_height: Maximum height for diff
+
+    Returns:
+        bytes: JPEG diff image or None on failure
+    """
+    parent_conn, child_conn = multiprocessing.Pipe()
+
+    p = multiprocessing.Process(
+        target=_worker_generate_diff,
+        args=(child_conn, img_bytes_from, img_bytes_to, threshold, blur_sigma, max_width, max_height)
+    )
+    p.start()
+
+    result = None
+    try:
+        # Wait for result (30 second timeout)
+        if parent_conn.poll(30):
+            result = parent_conn.recv()
+    except Exception as e:
+        print(f"[Parent] Error receiving result: {e}", flush=True)
+    finally:
+        # Always close pipe first
+        try:
+            parent_conn.close()
+        except:
+            pass
+
+        # Try graceful shutdown
+        p.join(timeout=5)
+        if p.is_alive():
+            print("[Parent] Process didn't exit gracefully, terminating", flush=True)
+            p.terminate()
+            p.join(timeout=3)
+
+        # Force kill if still alive
+        if p.is_alive():
+            print("[Parent] Process didn't terminate, killing", flush=True)
+            p.kill()
+            p.join(timeout=1)
+
+    return result
+
+
+def calculate_change_percentage_isolated(img_bytes_from, img_bytes_to, threshold, blur_sigma, max_width, max_height):
+    """
+    Calculate change percentage in isolated subprocess using handler.
+
+    Returns:
+        float: Change percentage
+    """
+    parent_conn, child_conn = multiprocessing.Pipe()
+
+    def _worker_calculate(conn):
+        try:
+            # Import handler inside worker
+            from .libvips_handler import LibvipsImageDiffHandler
+
+            handler = LibvipsImageDiffHandler()
+
+            # Load images
+            img_from = handler.load_from_bytes(img_bytes_from)
+            img_to = handler.load_from_bytes(img_bytes_to)
+
+            # Ensure same size
+            w1, h1 = handler.get_dimensions(img_from)
+            w2, h2 = handler.get_dimensions(img_to)
+            if (w1, h1) != (w2, h2):
+                img_from = handler.resize(img_from, w2, h2)
+
+            # Downscale
+            img_from = handler.resize(img_from, max_width, max_height)
+            img_to = handler.resize(img_to, max_width, max_height)
+
+            # Convert to grayscale
+            gray_from = handler.to_grayscale(img_from)
+            gray_to = handler.to_grayscale(img_to)
+
+            # Optional blur
+            gray_from = handler.gaussian_blur(gray_from, blur_sigma)
+            gray_to = handler.gaussian_blur(gray_to, blur_sigma)
+
+            # Calculate difference
+            diff = handler.absolute_difference(gray_from, gray_to)
+
+            # Threshold and get percentage
+            change_percentage, _ = handler.threshold(diff, int(threshold))
+
+            conn.send(float(change_percentage))
+
+        except Exception as e:
+            print(f"[Worker] Calculate error: {e}", flush=True)
+            conn.send(0.0)
+        finally:
+            conn.close()
+
+    p = multiprocessing.Process(target=_worker_calculate, args=(child_conn,))
+    p.start()
+
+    result = 0.0
+    try:
+        if parent_conn.poll(30):
+            result = parent_conn.recv()
+    except Exception as e:
+        print(f"[Parent] Calculate error receiving result: {e}", flush=True)
+    finally:
+        # Always close pipe first
+        try:
+            parent_conn.close()
+        except:
+            pass
+
+        # Try graceful shutdown
+        p.join(timeout=5)
+        if p.is_alive():
+            print("[Parent] Calculate process didn't exit gracefully, terminating", flush=True)
+            p.terminate()
+            p.join(timeout=3)
+
+        # Force kill if still alive
+        if p.is_alive():
+            print("[Parent] Calculate process didn't terminate, killing", flush=True)
+            p.kill()
+            p.join(timeout=1)
+
+    return result
+
+
+def compare_images_isolated(img_bytes_from, img_bytes_to, threshold, blur_sigma, min_change_percentage, crop_region=None):
+    """
+    Compare images in isolated subprocess for change detection.
+
+    Args:
+        img_bytes_from: Previous screenshot bytes
+        img_bytes_to: Current screenshot bytes
+        threshold: Pixel difference threshold
+        blur_sigma: Gaussian blur sigma
+        min_change_percentage: Minimum percentage to trigger change detection
+        crop_region: Optional tuple (left, top, right, bottom) for cropping both images
+
+    Returns:
+        tuple: (changed_detected, change_percentage)
+    """
+    print(f"[Parent] Starting compare_images_isolated subprocess", flush=True)
+    parent_conn, child_conn = multiprocessing.Pipe()
+
+    def _worker_compare(conn):
+        try:
+            print(f"[Worker] Compare worker starting", flush=True)
+            # Import handler inside worker
+            from .libvips_handler import LibvipsImageDiffHandler
+
+            print(f"[Worker] Initializing handler", flush=True)
+            handler = LibvipsImageDiffHandler()
+
+            # Load images
+            print(f"[Worker] Loading images (from={len(img_bytes_from)} bytes, to={len(img_bytes_to)} bytes)", flush=True)
+            img_from = handler.load_from_bytes(img_bytes_from)
+            img_to = handler.load_from_bytes(img_bytes_to)
+            print(f"[Worker] Images loaded", flush=True)
+
+            # Crop if region specified
+            if crop_region:
+                print(f"[Worker] Cropping to region {crop_region}", flush=True)
+                left, top, right, bottom = crop_region
+                img_from = handler.crop(img_from, left, top, right, bottom)
+                img_to = handler.crop(img_to, left, top, right, bottom)
+                print(f"[Worker] Cropping completed", flush=True)
+
+            # Ensure same size
+            w1, h1 = handler.get_dimensions(img_from)
+            w2, h2 = handler.get_dimensions(img_to)
+            print(f"[Worker] Image dimensions: from={w1}x{h1}, to={w2}x{h2}", flush=True)
+            if (w1, h1) != (w2, h2):
+                print(f"[Worker] Resizing to match dimensions", flush=True)
+                img_from = handler.resize(img_from, w2, h2)
+
+            # Convert to grayscale
+            print(f"[Worker] Converting to grayscale", flush=True)
+            gray_from = handler.to_grayscale(img_from)
+            gray_to = handler.to_grayscale(img_to)
+
+            # Optional blur
+            # NOTE: gaussblur can hang in forked subprocesses due to LibVIPS threading
+            # Skip blur as a workaround - sigma=0.8 is subtle and comparison works without it
+            if blur_sigma > 0:
+                print(f"[Worker] Skipping blur (sigma={blur_sigma}) due to LibVIPS threading issues in fork", flush=True)
+                # gray_from = handler.gaussian_blur(gray_from, blur_sigma)
+                # gray_to = handler.gaussian_blur(gray_to, blur_sigma)
+
+            # Calculate difference
+            print(f"[Worker] Calculating difference", flush=True)
+            diff = handler.absolute_difference(gray_from, gray_to)
+
+            # Threshold and get percentage
+            print(f"[Worker] Applying threshold ({threshold})", flush=True)
+            change_percentage, _ = handler.threshold(diff, int(threshold))
+
+            # Determine if change detected
+            changed_detected = change_percentage > min_change_percentage
+
+            print(f"[Worker] Comparison complete: changed={changed_detected}, percentage={change_percentage:.2f}%", flush=True)
+            conn.send((changed_detected, float(change_percentage)))
+
+        except Exception as e:
+            print(f"[Worker] Compare error: {e}", flush=True)
+            import traceback
+            traceback.print_exc()
+            conn.send((False, 0.0))
+        finally:
+            conn.close()
+
+    p = multiprocessing.Process(target=_worker_compare, args=(child_conn,))
+    print(f"[Parent] Starting subprocess (pid will be assigned)", flush=True)
+    p.start()
+    print(f"[Parent] Subprocess started (pid={p.pid}), waiting for result (30s timeout)", flush=True)
+
+    result = (False, 0.0)
+    try:
+        if parent_conn.poll(30):
+            print(f"[Parent] Result available, receiving", flush=True)
+            result = parent_conn.recv()
+            print(f"[Parent] Result received: {result}", flush=True)
+        else:
+            print(f"[Parent] Timeout waiting for result after 30s", flush=True)
+    except Exception as e:
+        print(f"[Parent] Compare error receiving result: {e}", flush=True)
+    finally:
+        # Always close pipe first
+        try:
+            parent_conn.close()
+        except:
+            pass
+
+        # Try graceful shutdown
+        import time
+        print(f"[Parent] Waiting for subprocess to exit (5s timeout)", flush=True)
+        join_start = time.time()
+        p.join(timeout=5)
+        join_elapsed = time.time() - join_start
+        print(f"[Parent] First join took {join_elapsed:.2f}s", flush=True)
+
+        if p.is_alive():
+            print("[Parent] Compare process didn't exit gracefully, terminating", flush=True)
+            term_start = time.time()
+            p.terminate()
+            p.join(timeout=3)
+            term_elapsed = time.time() - term_start
+            print(f"[Parent] Terminate+join took {term_elapsed:.2f}s", flush=True)
+
+        # Force kill if still alive
+        if p.is_alive():
+            print("[Parent] Compare process didn't terminate, killing", flush=True)
+            kill_start = time.time()
+            p.kill()
+            p.join(timeout=1)
+            kill_elapsed = time.time() - kill_start
+            print(f"[Parent] Kill+join took {kill_elapsed:.2f}s", flush=True)
+
+        print(f"[Parent] Subprocess cleanup complete, returning result", flush=True)
+
+    return result

changedetectionio/processors/image_ssim_diff/image_handler/isolated_opencv.py

@@ -0,0 +1,627 @@
+"""
+OpenCV-based subprocess isolation for image comparison.
+
+OpenCV is much more stable in multiprocessing contexts than LibVIPS.
+No threading issues, no fork problems, picklable functions.
+"""
+
+import multiprocessing
+import numpy as np
+from .. import POLL_TIMEOUT_ABSOLUTE
+
+# Public implementation name for logging
+IMPLEMENTATION_NAME = "OpenCV"
+
+
+def _worker_compare(conn, img_bytes_from, img_bytes_to, pixel_difference_threshold, blur_sigma, crop_region):
+    """
+    Worker function for image comparison (must be top-level for pickling with spawn).
+
+    Args:
+        conn: Pipe connection for sending results
+        img_bytes_from: Previous screenshot bytes
+        img_bytes_to: Current screenshot bytes
+        pixel_difference_threshold: Pixel-level sensitivity (0-255) - how different must a pixel be to count as changed
+        blur_sigma: Gaussian blur sigma
+        crop_region: Optional (left, top, right, bottom) crop coordinates
+    """
+    import time
+    try:
+        import cv2
+
+        # CRITICAL: Disable OpenCV threading to prevent thread explosion
+        # With multiprocessing, each subprocess would otherwise spawn threads equal to CPU cores
+        # This causes excessive thread counts and memory overhead
+        # Research: https://medium.com/@rachittayal7/a-note-on-opencv-threads-performance-in-prod-d10180716fba
+        cv2.setNumThreads(1)
+
+        print(f"[{time.time():.3f}] [Worker] Compare worker starting (threads=1 for memory optimization)", flush=True)
+
+        # Decode images from bytes
+        print(f"[{time.time():.3f}] [Worker] Loading images (from={len(img_bytes_from)} bytes, to={len(img_bytes_to)} bytes)", flush=True)
+        img_from = cv2.imdecode(np.frombuffer(img_bytes_from, np.uint8), cv2.IMREAD_COLOR)
+        img_to = cv2.imdecode(np.frombuffer(img_bytes_to, np.uint8), cv2.IMREAD_COLOR)
+
+        # Check if decoding succeeded
+        if img_from is None:
+            raise ValueError("Failed to decode 'from' image - may be corrupt or unsupported format")
+        if img_to is None:
+            raise ValueError("Failed to decode 'to' image - may be corrupt or unsupported format")
+
+        print(f"[{time.time():.3f}] [Worker] Images loaded: from={img_from.shape}, to={img_to.shape}", flush=True)
+
+        # Crop if region specified
+        if crop_region:
+            print(f"[{time.time():.3f}] [Worker] Cropping to region {crop_region}", flush=True)
+            left, top, right, bottom = crop_region
+            img_from = img_from[top:bottom, left:right]
+            img_to = img_to[top:bottom, left:right]
+            print(f"[{time.time():.3f}] [Worker] Cropped: from={img_from.shape}, to={img_to.shape}", flush=True)
+
+        # Resize if dimensions don't match
+        if img_from.shape != img_to.shape:
+            print(f"[{time.time():.3f}] [Worker] Resizing to match dimensions", flush=True)
+            img_from = cv2.resize(img_from, (img_to.shape[1], img_to.shape[0]))
+
+        # Convert to grayscale
+        print(f"[{time.time():.3f}] [Worker] Converting to grayscale", flush=True)
+        gray_from = cv2.cvtColor(img_from, cv2.COLOR_BGR2GRAY)
+        gray_to = cv2.cvtColor(img_to, cv2.COLOR_BGR2GRAY)
+
+        # Optional Gaussian blur
+        if blur_sigma > 0:
+            print(f"[{time.time():.3f}] [Worker] Applying Gaussian blur (sigma={blur_sigma})", flush=True)
+            # OpenCV uses kernel size, convert sigma to kernel size: size = 2 * round(3*sigma) + 1
+            ksize = int(2 * round(3 * blur_sigma)) + 1
+            if ksize % 2 == 0:  # Must be odd
+                ksize += 1
+            gray_from = cv2.GaussianBlur(gray_from, (ksize, ksize), blur_sigma)
+            gray_to = cv2.GaussianBlur(gray_to, (ksize, ksize), blur_sigma)
+            print(f"[{time.time():.3f}] [Worker] Blur applied (kernel={ksize}x{ksize})", flush=True)
+
+        # Calculate absolute difference
+        print(f"[{time.time():.3f}] [Worker] Calculating absolute difference", flush=True)
+        diff = cv2.absdiff(gray_from, gray_to)
+
+        # Apply threshold
+        print(f"[{time.time():.3f}] [Worker] Applying pixel difference threshold ({pixel_difference_threshold})", flush=True)
+        _, thresholded = cv2.threshold(diff, int(pixel_difference_threshold), 255, cv2.THRESH_BINARY)
+
+        # Calculate change percentage
+        total_pixels = thresholded.size
+        changed_pixels = np.count_nonzero(thresholded)
+        change_percentage = (changed_pixels / total_pixels) * 100.0
+
+        print(f"[{time.time():.3f}] [Worker] Comparison complete: percentage={change_percentage:.2f}%", flush=True)
+        # Return only the score - let the caller decide if it's a "change"
+        conn.send(float(change_percentage))
+
+    except Exception as e:
+        print(f"[{time.time():.3f}] [Worker] Error: {e}", flush=True)
+        import traceback
+        traceback.print_exc()
+        # Send error info as dict so parent can re-raise
+        conn.send({'error': str(e), 'traceback': traceback.format_exc()})
+    finally:
+        conn.close()
+
+
+async def compare_images_isolated(img_bytes_from, img_bytes_to, pixel_difference_threshold, blur_sigma, crop_region=None):
+    """
+    Compare images in isolated subprocess using OpenCV (async-safe).
+
+    Args:
+        img_bytes_from: Previous screenshot bytes
+        img_bytes_to: Current screenshot bytes
+        pixel_difference_threshold: Pixel-level sensitivity (0-255) - how different must a pixel be to count as changed
+        blur_sigma: Gaussian blur sigma
+        crop_region: Optional (left, top, right, bottom) crop coordinates
+
+    Returns:
+        float: Change percentage (0-100)
+    """
+    import time
+    import asyncio
+    print(f"[{time.time():.3f}] [Parent] Starting OpenCV comparison subprocess", flush=True)
+
+    # Use spawn method for clean process (no fork issues)
+    ctx = multiprocessing.get_context('spawn')
+    parent_conn, child_conn = ctx.Pipe()
+
+    p = ctx.Process(
+        target=_worker_compare,
+        args=(child_conn, img_bytes_from, img_bytes_to, pixel_difference_threshold, blur_sigma, crop_region)
+    )
+
+    print(f"[{time.time():.3f}] [Parent] Starting subprocess", flush=True)
+    p.start()
+    print(f"[{time.time():.3f}] [Parent] Subprocess started (pid={p.pid}), waiting for result ({POLL_TIMEOUT_ABSOLUTE}s timeout)", flush=True)
+
+    result = 0.0
+    try:
+        # Async-friendly polling: check in small intervals without blocking event loop
+        deadline = time.time() + POLL_TIMEOUT_ABSOLUTE
+        while time.time() < deadline:
+            # Run poll() in thread to avoid blocking event loop
+            has_data = await asyncio.to_thread(parent_conn.poll, 0.1)
+            if has_data:
+                print(f"[{time.time():.3f}] [Parent] Result available, receiving", flush=True)
+                result = await asyncio.to_thread(parent_conn.recv)
+                # Check if result is an error dict
+                if isinstance(result, dict) and 'error' in result:
+                    raise RuntimeError(f"Image comparison failed: {result['error']}")
+                print(f"[{time.time():.3f}] [Parent] Result received: {result:.2f}%", flush=True)
+                break
+            await asyncio.sleep(0)  # Yield control to event loop
+        else:
+            from loguru import logger
+            logger.critical(f"[OpenCV subprocess] Timeout waiting for compare_images result after {POLL_TIMEOUT_ABSOLUTE}s (subprocess may be hung)")
+            print(f"[{time.time():.3f}] [Parent] Timeout waiting for result after {POLL_TIMEOUT_ABSOLUTE}s", flush=True)
+            raise TimeoutError(f"Image comparison subprocess timeout after {POLL_TIMEOUT_ABSOLUTE}s")
+    except Exception as e:
+        print(f"[{time.time():.3f}] [Parent] Error receiving result: {e}", flush=True)
+        raise
+    finally:
+        # Always close pipe first
+        try:
+            parent_conn.close()
+        except:
+            pass
+
+        # Try graceful shutdown (async-safe)
+        print(f"[{time.time():.3f}] [Parent] Waiting for subprocess to exit (5s timeout)", flush=True)
+        join_start = time.time()
+        await asyncio.to_thread(p.join, 5)
+        join_elapsed = time.time() - join_start
+        print(f"[{time.time():.3f}] [Parent] First join took {join_elapsed:.2f}s", flush=True)
+
+        if p.is_alive():
+            print(f"[{time.time():.3f}] [Parent] Process didn't exit gracefully, terminating", flush=True)
+            term_start = time.time()
+            p.terminate()
+            await asyncio.to_thread(p.join, 3)
+            term_elapsed = time.time() - term_start
+            print(f"[{time.time():.3f}] [Parent] Terminate+join took {term_elapsed:.2f}s", flush=True)
+
+        # Force kill if still alive
+        if p.is_alive():
+            print(f"[{time.time():.3f}] [Parent] Process didn't terminate, killing", flush=True)
+            kill_start = time.time()
+            p.kill()
+            await asyncio.to_thread(p.join, 1)
+            kill_elapsed = time.time() - kill_start
+            print(f"[{time.time():.3f}] [Parent] Kill+join took {kill_elapsed:.2f}s", flush=True)
+
+        print(f"[{time.time():.3f}] [Parent] Subprocess cleanup complete, returning result", flush=True)
+
+    return result
+
+
+def _worker_generate_diff(conn, img_bytes_from, img_bytes_to, pixel_difference_threshold, blur_sigma, max_width, max_height):
+    """
+    Worker function for generating visual diff with red overlay.
+    """
+    import time
+    try:
+        import cv2
+
+        cv2.setNumThreads(1)
+        print(f"[{time.time():.3f}] [Worker] Generate diff worker starting", flush=True)
+
+        # Decode images
+        img_from = cv2.imdecode(np.frombuffer(img_bytes_from, np.uint8), cv2.IMREAD_COLOR)
+        img_to = cv2.imdecode(np.frombuffer(img_bytes_to, np.uint8), cv2.IMREAD_COLOR)
+
+        # Resize if needed to match dimensions
+        if img_from.shape != img_to.shape:
+            img_from = cv2.resize(img_from, (img_to.shape[1], img_to.shape[0]))
+
+        # Downscale to max dimensions for faster processing
+        h, w = img_to.shape[:2]
+        if w > max_width or h > max_height:
+            scale = min(max_width / w, max_height / h)
+            new_w = int(w * scale)
+            new_h = int(h * scale)
+            img_from = cv2.resize(img_from, (new_w, new_h))
+            img_to = cv2.resize(img_to, (new_w, new_h))
+
+        # Convert to grayscale
+        gray_from = cv2.cvtColor(img_from, cv2.COLOR_BGR2GRAY)
+        gray_to = cv2.cvtColor(img_to, cv2.COLOR_BGR2GRAY)
+
+        # Optional blur
+        if blur_sigma > 0:
+            ksize = int(2 * round(3 * blur_sigma)) + 1
+            if ksize % 2 == 0:
+                ksize += 1
+            gray_from = cv2.GaussianBlur(gray_from, (ksize, ksize), blur_sigma)
+            gray_to = cv2.GaussianBlur(gray_to, (ksize, ksize), blur_sigma)
+
+        # Calculate difference
+        diff = cv2.absdiff(gray_from, gray_to)
+
+        # Apply threshold to get mask
+        _, mask = cv2.threshold(diff, int(pixel_difference_threshold), 255, cv2.THRESH_BINARY)
+
+        # Create red overlay on original 'to' image
+        # Where mask is 255 (changed), blend 50% red
+        overlay = img_to.copy()
+        overlay[:, :, 2] = np.where(mask > 0,
+                                     np.clip(overlay[:, :, 2] * 0.5 + 127, 0, 255).astype(np.uint8),
+                                     overlay[:, :, 2])
+        overlay[:, :, 0:2] = np.where(mask[:, :, np.newaxis] > 0,
+                                       (overlay[:, :, 0:2] * 0.5).astype(np.uint8),
+                                       overlay[:, :, 0:2])
+
+        # Encode as JPEG
+        _, encoded = cv2.imencode('.jpg', overlay, [cv2.IMWRITE_JPEG_QUALITY, 85])
+        diff_bytes = encoded.tobytes()
+
+        print(f"[{time.time():.3f}] [Worker] Generated diff ({len(diff_bytes)} bytes)", flush=True)
+        conn.send(diff_bytes)
+
+    except Exception as e:
+        print(f"[{time.time():.3f}] [Worker] Generate diff error: {e}", flush=True)
+        import traceback
+        traceback.print_exc()
+        # Send error info as dict so parent can re-raise
+        conn.send({'error': str(e), 'traceback': traceback.format_exc()})
+    finally:
+        conn.close()
+
+
+async def generate_diff_isolated(img_bytes_from, img_bytes_to, pixel_difference_threshold, blur_sigma, max_width, max_height):
+    """
+    Generate visual diff with red overlay in isolated subprocess (async-safe).
+
+    Returns:
+        bytes: JPEG diff image or None on failure
+    """
+    import time
+    import asyncio
+    print(f"[{time.time():.3f}] [Parent] Starting generate_diff subprocess", flush=True)
+
+    ctx = multiprocessing.get_context('spawn')
+    parent_conn, child_conn = ctx.Pipe()
+
+    p = ctx.Process(
+        target=_worker_generate_diff,
+        args=(child_conn, img_bytes_from, img_bytes_to, pixel_difference_threshold, blur_sigma, max_width, max_height)
+    )
+
+    print(f"[{time.time():.3f}] [Parent] Starting subprocess", flush=True)
+    p.start()
+    print(f"[{time.time():.3f}] [Parent] Subprocess started (pid={p.pid}), waiting for result ({POLL_TIMEOUT_ABSOLUTE}s timeout)", flush=True)
+
+    result = None
+    try:
+        # Async-friendly polling: check in small intervals without blocking event loop
+        deadline = time.time() + POLL_TIMEOUT_ABSOLUTE
+        while time.time() < deadline:
+            # Run poll() in thread to avoid blocking event loop
+            has_data = await asyncio.to_thread(parent_conn.poll, 0.1)
+            if has_data:
+                print(f"[{time.time():.3f}] [Parent] Result available, receiving", flush=True)
+                result = await asyncio.to_thread(parent_conn.recv)
+                # Check if result is an error dict
+                if isinstance(result, dict) and 'error' in result:
+                    raise RuntimeError(f"Generate diff failed: {result['error']}")
+                print(f"[{time.time():.3f}] [Parent] Result received ({len(result) if result else 0} bytes)", flush=True)
+                break
+            await asyncio.sleep(0)  # Yield control to event loop
+        else:
+            from loguru import logger
+            logger.critical(f"[OpenCV subprocess] Timeout waiting for generate_diff result after {POLL_TIMEOUT_ABSOLUTE}s (subprocess may be hung)")
+            print(f"[{time.time():.3f}] [Parent] Timeout waiting for result after {POLL_TIMEOUT_ABSOLUTE}s", flush=True)
+            raise TimeoutError(f"Generate diff subprocess timeout after {POLL_TIMEOUT_ABSOLUTE}s")
+    except Exception as e:
+        print(f"[{time.time():.3f}] [Parent] Error receiving diff: {e}", flush=True)
+        raise
+    finally:
+        # Always close pipe first
+        try:
+            parent_conn.close()
+        except:
+            pass
+
+        # Try graceful shutdown (async-safe)
+        print(f"[{time.time():.3f}] [Parent] Waiting for subprocess to exit (5s timeout)", flush=True)
+        join_start = time.time()
+        await asyncio.to_thread(p.join, 5)
+        join_elapsed = time.time() - join_start
+        print(f"[{time.time():.3f}] [Parent] First join took {join_elapsed:.2f}s", flush=True)
+
+        if p.is_alive():
+            print(f"[{time.time():.3f}] [Parent] Process didn't exit gracefully, terminating", flush=True)
+            term_start = time.time()
+            p.terminate()
+            await asyncio.to_thread(p.join, 3)
+            term_elapsed = time.time() - term_start
+            print(f"[{time.time():.3f}] [Parent] Terminate+join took {term_elapsed:.2f}s", flush=True)
+
+        if p.is_alive():
+            print(f"[{time.time():.3f}] [Parent] Process didn't terminate, killing", flush=True)
+            kill_start = time.time()
+            p.kill()
+            await asyncio.to_thread(p.join, 1)
+            kill_elapsed = time.time() - kill_start
+            print(f"[{time.time():.3f}] [Parent] Kill+join took {kill_elapsed:.2f}s", flush=True)
+
+        print(f"[{time.time():.3f}] [Parent] Subprocess cleanup complete, returning result", flush=True)
+
+    return result
+
+
+def _worker_draw_bounding_box(conn, img_bytes, x, y, width, height, color, thickness):
+    """
+    Worker function for drawing bounding box on image.
+    """
+    import time
+    try:
+        import cv2
+
+        cv2.setNumThreads(1)
+        print(f"[{time.time():.3f}] [Worker] Draw bounding box worker starting", flush=True)
+
+        # Decode image
+        img = cv2.imdecode(np.frombuffer(img_bytes, np.uint8), cv2.IMREAD_COLOR)
+        if img is None:
+            print(f"[{time.time():.3f}] [Worker] Failed to decode image", flush=True)
+            conn.send(None)
+            return
+
+        # Draw rectangle (BGR format)
+        cv2.rectangle(img, (x, y), (x + width, y + height), color, thickness)
+
+        # Encode back to PNG
+        _, encoded = cv2.imencode('.png', img)
+        result_bytes = encoded.tobytes()
+
+        print(f"[{time.time():.3f}] [Worker] Bounding box drawn ({len(result_bytes)} bytes)", flush=True)
+        conn.send(result_bytes)
+
+    except Exception as e:
+        print(f"[{time.time():.3f}] [Worker] Draw bounding box error: {e}", flush=True)
+        import traceback
+        traceback.print_exc()
+        # Send error info as dict so parent can re-raise
+        conn.send({'error': str(e), 'traceback': traceback.format_exc()})
+    finally:
+        conn.close()
+
+
+async def draw_bounding_box_isolated(img_bytes, x, y, width, height, color=(255, 0, 0), thickness=3):
+    """
+    Draw bounding box on image in isolated subprocess (async-safe).
+
+    Args:
+        img_bytes: Image data as bytes
+        x: Left coordinate
+        y: Top coordinate
+        width: Box width
+        height: Box height
+        color: BGR color tuple (default: blue)
+        thickness: Line thickness in pixels
+
+    Returns:
+        bytes: PNG image with bounding box or None on failure
+    """
+    import time
+    import asyncio
+    print(f"[{time.time():.3f}] [Parent] Starting draw_bounding_box subprocess", flush=True)
+
+    ctx = multiprocessing.get_context('spawn')
+    parent_conn, child_conn = ctx.Pipe()
+
+    p = ctx.Process(
+        target=_worker_draw_bounding_box,
+        args=(child_conn, img_bytes, x, y, width, height, color, thickness)
+    )
+
+    print(f"[{time.time():.3f}] [Parent] Starting subprocess", flush=True)
+    p.start()
+    print(f"[{time.time():.3f}] [Parent] Subprocess started (pid={p.pid}), waiting for result ({POLL_TIMEOUT_ABSOLUTE}s timeout)", flush=True)
+
+    result = None
+    try:
+        # Async-friendly polling: check in small intervals without blocking event loop
+        deadline = time.time() + POLL_TIMEOUT_ABSOLUTE
+        while time.time() < deadline:
+            # Run poll() in thread to avoid blocking event loop
+            has_data = await asyncio.to_thread(parent_conn.poll, 0.1)
+            if has_data:
+                print(f"[{time.time():.3f}] [Parent] Result available, receiving", flush=True)
+                # Run recv() in thread too
+                result = await asyncio.to_thread(parent_conn.recv)
+                # Check if result is an error dict
+                if isinstance(result, dict) and 'error' in result:
+                    raise RuntimeError(f"Draw bounding box failed: {result['error']}")
+                print(f"[{time.time():.3f}] [Parent] Result received ({len(result) if result else 0} bytes)", flush=True)
+                break
+            # Yield control to event loop
+            await asyncio.sleep(0)
+        else:
+            from loguru import logger
+            logger.critical(f"[OpenCV subprocess] Timeout waiting for draw_bounding_box result after {POLL_TIMEOUT_ABSOLUTE}s (subprocess may be hung)")
+            print(f"[{time.time():.3f}] [Parent] Timeout waiting for result after {POLL_TIMEOUT_ABSOLUTE}s", flush=True)
+            raise TimeoutError(f"Draw bounding box subprocess timeout after {POLL_TIMEOUT_ABSOLUTE}s")
+    except Exception as e:
+        print(f"[{time.time():.3f}] [Parent] Error receiving result: {e}", flush=True)
+        raise
+    finally:
+        # Always close pipe first
+        try:
+            parent_conn.close()
+        except:
+            pass
+
+        # Try graceful shutdown (run join in thread to avoid blocking)
+        print(f"[{time.time():.3f}] [Parent] Waiting for subprocess to exit (3s timeout)", flush=True)
+        join_start = time.time()
+        await asyncio.to_thread(p.join, 3)
+        join_elapsed = time.time() - join_start
+        print(f"[{time.time():.3f}] [Parent] First join took {join_elapsed:.2f}s", flush=True)
+
+        if p.is_alive():
+            print(f"[{time.time():.3f}] [Parent] Process didn't exit gracefully, terminating", flush=True)
+            term_start = time.time()
+            p.terminate()
+            await asyncio.to_thread(p.join, 2)
+            term_elapsed = time.time() - term_start
+            print(f"[{time.time():.3f}] [Parent] Terminate+join took {term_elapsed:.2f}s", flush=True)
+
+        if p.is_alive():
+            print(f"[{time.time():.3f}] [Parent] Process didn't terminate, killing", flush=True)
+            kill_start = time.time()
+            p.kill()
+            await asyncio.to_thread(p.join, 1)
+            kill_elapsed = time.time() - kill_start
+            print(f"[{time.time():.3f}] [Parent] Kill+join took {kill_elapsed:.2f}s", flush=True)
+
+        print(f"[{time.time():.3f}] [Parent] Subprocess cleanup complete, returning result", flush=True)
+
+    return result
+
+
+def _worker_calculate_percentage(conn, img_bytes_from, img_bytes_to, pixel_difference_threshold, blur_sigma, max_width, max_height):
+    """
+    Worker function for calculating change percentage.
+    """
+    import time
+    try:
+        import cv2
+
+        cv2.setNumThreads(1)
+
+        # Decode images
+        img_from = cv2.imdecode(np.frombuffer(img_bytes_from, np.uint8), cv2.IMREAD_COLOR)
+        img_to = cv2.imdecode(np.frombuffer(img_bytes_to, np.uint8), cv2.IMREAD_COLOR)
+
+        # Resize if needed
+        if img_from.shape != img_to.shape:
+            img_from = cv2.resize(img_from, (img_to.shape[1], img_to.shape[0]))
+
+        # Downscale to max dimensions
+        h, w = img_to.shape[:2]
+        if w > max_width or h > max_height:
+            scale = min(max_width / w, max_height / h)
+            new_w = int(w * scale)
+            new_h = int(h * scale)
+            img_from = cv2.resize(img_from, (new_w, new_h))
+            img_to = cv2.resize(img_to, (new_w, new_h))
+
+        # Convert to grayscale
+        gray_from = cv2.cvtColor(img_from, cv2.COLOR_BGR2GRAY)
+        gray_to = cv2.cvtColor(img_to, cv2.COLOR_BGR2GRAY)
+
+        # Optional blur
+        if blur_sigma > 0:
+            ksize = int(2 * round(3 * blur_sigma)) + 1
+            if ksize % 2 == 0:
+                ksize += 1
+            gray_from = cv2.GaussianBlur(gray_from, (ksize, ksize), blur_sigma)
+            gray_to = cv2.GaussianBlur(gray_to, (ksize, ksize), blur_sigma)
+
+        # Calculate difference
+        diff = cv2.absdiff(gray_from, gray_to)
+
+        # Apply threshold
+        _, thresholded = cv2.threshold(diff, int(pixel_difference_threshold), 255, cv2.THRESH_BINARY)
+
+        # Calculate percentage
+        total_pixels = thresholded.size
+        changed_pixels = np.count_nonzero(thresholded)
+        change_percentage = (changed_pixels / total_pixels) * 100.0
+
+        conn.send(float(change_percentage))
+
+    except Exception as e:
+        print(f"[{time.time():.3f}] [Worker] Calculate percentage error: {e}", flush=True)
+        import traceback
+        traceback.print_exc()
+        # Send error info as dict so parent can re-raise
+        conn.send({'error': str(e), 'traceback': traceback.format_exc()})
+    finally:
+        conn.close()
+
+
+async def calculate_change_percentage_isolated(img_bytes_from, img_bytes_to, pixel_difference_threshold, blur_sigma, max_width, max_height):
+    """
+    Calculate change percentage in isolated subprocess (async-safe).
+
+    Returns:
+        float: Change percentage
+    """
+    import time
+    import asyncio
+    print(f"[{time.time():.3f}] [Parent] Starting calculate_percentage subprocess", flush=True)
+
+    ctx = multiprocessing.get_context('spawn')
+    parent_conn, child_conn = ctx.Pipe()
+
+    p = ctx.Process(
+        target=_worker_calculate_percentage,
+        args=(child_conn, img_bytes_from, img_bytes_to, pixel_difference_threshold, blur_sigma, max_width, max_height)
+    )
+
+    print(f"[{time.time():.3f}] [Parent] Starting subprocess", flush=True)
+    p.start()
+    print(f"[{time.time():.3f}] [Parent] Subprocess started (pid={p.pid}), waiting for result ({POLL_TIMEOUT_ABSOLUTE}s timeout)", flush=True)
+
+    result = 0.0
+    try:
+        # Async-friendly polling: check in small intervals without blocking event loop
+        deadline = time.time() + POLL_TIMEOUT_ABSOLUTE
+        while time.time() < deadline:
+            # Run poll() in thread to avoid blocking event loop
+            has_data = await asyncio.to_thread(parent_conn.poll, 0.1)
+            if has_data:
+                print(f"[{time.time():.3f}] [Parent] Result available, receiving", flush=True)
+                result = await asyncio.to_thread(parent_conn.recv)
+                # Check if result is an error dict
+                if isinstance(result, dict) and 'error' in result:
+                    raise RuntimeError(f"Calculate change percentage failed: {result['error']}")
+                print(f"[{time.time():.3f}] [Parent] Result received: {result:.2f}%", flush=True)
+                break
+            await asyncio.sleep(0)  # Yield control to event loop
+        else:
+            from loguru import logger
+            logger.critical(f"[OpenCV subprocess] Timeout waiting for calculate_change_percentage result after {POLL_TIMEOUT_ABSOLUTE}s (subprocess may be hung)")
+            print(f"[{time.time():.3f}] [Parent] Timeout waiting for result after {POLL_TIMEOUT_ABSOLUTE}s", flush=True)
+            raise TimeoutError(f"Calculate change percentage subprocess timeout after {POLL_TIMEOUT_ABSOLUTE}s")
+    except Exception as e:
+        print(f"[{time.time():.3f}] [Parent] Error receiving percentage: {e}", flush=True)
+        raise
+    finally:
+        # Always close pipe first
+        try:
+            parent_conn.close()
+        except:
+            pass
+
+        # Try graceful shutdown (async-safe)
+        print(f"[{time.time():.3f}] [Parent] Waiting for subprocess to exit (5s timeout)", flush=True)
+        join_start = time.time()
+        await asyncio.to_thread(p.join, 5)
+        join_elapsed = time.time() - join_start
+        print(f"[{time.time():.3f}] [Parent] First join took {join_elapsed:.2f}s", flush=True)
+
+        if p.is_alive():
+            print(f"[{time.time():.3f}] [Parent] Process didn't exit gracefully, terminating", flush=True)
+            term_start = time.time()
+            p.terminate()
+            await asyncio.to_thread(p.join, 3)
+            term_elapsed = time.time() - term_start
+            print(f"[{time.time():.3f}] [Parent] Terminate+join took {term_elapsed:.2f}s", flush=True)
+
+        if p.is_alive():
+            print(f"[{time.time():.3f}] [Parent] Process didn't terminate, killing", flush=True)
+            kill_start = time.time()
+            p.kill()
+            await asyncio.to_thread(p.join, 1)
+            kill_elapsed = time.time() - kill_start
+            print(f"[{time.time():.3f}] [Parent] Kill+join took {kill_elapsed:.2f}s", flush=True)
+
+        print(f"[{time.time():.3f}] [Parent] Subprocess cleanup complete, returning result", flush=True)
+
+    return result

changedetectionio/processors/image_ssim_diff/image_handler/libvips_handler.py

@@ -0,0 +1,340 @@
+"""
+LibVIPS implementation of ImageDiffHandler.
+
+Uses pyvips for high-performance image processing with streaming architecture
+and low memory footprint. Ideal for large screenshots (8000px+).
+"""
+
+from __future__ import annotations
+import os
+from typing import Tuple, Any, TYPE_CHECKING
+from loguru import logger
+
+if TYPE_CHECKING:
+    import pyvips
+
+try:
+    import pyvips
+    PYVIPS_AVAILABLE = True
+except ImportError:
+    PYVIPS_AVAILABLE = False
+    logger.warning("pyvips not available - install with: pip install pyvips")
+
+from . import ImageDiffHandler
+
+
+class LibvipsImageDiffHandler(ImageDiffHandler):
+    """
+    LibVIPS implementation using streaming architecture.
+
+    Benefits:
+    - 3x faster than ImageMagick
+    - 5x less memory than PIL
+    - Automatic multi-threading
+    - Streaming - processes images in chunks
+    """
+
+    def __init__(self):
+        if not PYVIPS_AVAILABLE:
+            raise ImportError("pyvips is not installed. Install with: pip install pyvips")
+
+    def load_from_bytes(self, img_bytes: bytes) -> pyvips.Image:
+        """Load image from bytes using libvips streaming."""
+        return pyvips.Image.new_from_buffer(img_bytes, '')
+
+    def save_to_bytes(self, img: pyvips.Image, format: str = 'png', quality: int = 85) -> bytes:
+        """
+        Save image to bytes using temp file.
+
+        Note: Uses temp file instead of write_to_buffer() to avoid C memory leak.
+        See: https://github.com/libvips/pyvips/issues/234
+        """
+        import tempfile
+
+        format = format.lower()
+
+        try:
+            if format == 'png':
+                suffix = '.png'
+                write_args = {'compression': 6}
+            elif format in ['jpg', 'jpeg']:
+                suffix = '.jpg'
+                write_args = {'Q': quality}
+            else:
+                raise ValueError(f"Unsupported format: {format}")
+
+            # Use temp file to avoid write_to_buffer() memory leak
+            with tempfile.NamedTemporaryFile(suffix=suffix, delete=False) as tmp:
+                temp_path = tmp.name
+
+            # Write to file
+            img.write_to_file(temp_path, **write_args)
+
+            # Read bytes and clean up
+            with open(temp_path, 'rb') as f:
+                image_bytes = f.read()
+
+            os.unlink(temp_path)
+            return image_bytes
+
+        except Exception as e:
+            logger.error(f"Failed to save via temp file: {e}")
+            # Fallback to write_to_buffer if temp file fails
+            if format == 'png':
+                return img.write_to_buffer('.png', compression=6)
+            else:
+                return img.write_to_buffer('.jpg', Q=quality)
+
+    def crop(self, img: pyvips.Image, left: int, top: int, right: int, bottom: int) -> pyvips.Image:
+        """Crop image using libvips."""
+        width = right - left
+        height = bottom - top
+        return img.crop(left, top, width, height)
+
+    def resize(self, img: pyvips.Image, max_width: int, max_height: int) -> pyvips.Image:
+        """
+        Resize image maintaining aspect ratio.
+
+        Uses thumbnail_image for efficient downscaling with streaming.
+        """
+        width, height = img.width, img.height
+
+        if width <= max_width and height <= max_height:
+            return img
+
+        # Calculate scaling to fit within max dimensions
+        width_ratio = max_width / width if width > max_width else 1.0
+        height_ratio = max_height / height if height > max_height else 1.0
+        ratio = min(width_ratio, height_ratio)
+
+        new_width = int(width * ratio)
+        new_height = int(height * ratio)
+
+        logger.debug(f"Resizing image: {width}x{height} -> {new_width}x{new_height}")
+
+        # thumbnail_image is faster than resize for downscaling
+        return img.thumbnail_image(new_width, height=new_height)
+
+    def get_dimensions(self, img: pyvips.Image) -> Tuple[int, int]:
+        """Get image dimensions."""
+        return (img.width, img.height)
+
+    def to_grayscale(self, img: pyvips.Image) -> pyvips.Image:
+        """Convert to grayscale using 'b-w' colorspace."""
+        return img.colourspace('b-w')
+
+    def gaussian_blur(self, img: pyvips.Image, sigma: float) -> pyvips.Image:
+        """Apply Gaussian blur."""
+        if sigma > 0:
+            return img.gaussblur(sigma)
+        return img
+
+    def absolute_difference(self, img1: pyvips.Image, img2: pyvips.Image) -> pyvips.Image:
+        """
+        Calculate absolute difference using operator overloading.
+
+        LibVIPS supports arithmetic operations between images.
+        """
+        return (img1 - img2).abs()
+
+    def threshold(self, img: pyvips.Image, threshold_value: int) -> Tuple[float, pyvips.Image]:
+        """
+        Apply threshold and calculate change percentage.
+
+        Uses ifthenelse for efficient thresholding.
+        """
+        # Create binary mask: pixels above threshold = 255, others = 0
+        mask = (img > threshold_value).ifthenelse(255, 0)
+
+        # Calculate percentage by averaging mask values
+        # avg() returns mean pixel value (0-255)
+        # Divide by 255 to get proportion, multiply by 100 for percentage
+        mean_value = mask.avg()
+        change_percentage = (mean_value / 255.0) * 100.0
+
+        return float(change_percentage), mask
+
+    def apply_red_overlay(self, img: pyvips.Image, mask: pyvips.Image) -> bytes:
+        """
+        Apply red overlay where mask is True (50% blend).
+
+        Args:
+            img: Color image (will be converted to RGB if needed)
+            mask: Binary mask (255 where changed, 0 elsewhere)
+
+        Returns:
+            JPEG bytes with red overlay
+        """
+        import tempfile
+
+        # Ensure RGB colorspace
+        if img.bands == 1:
+            img = img.colourspace('srgb')
+
+        # Normalize mask to 0-1 range for blending
+        mask_normalized = mask / 255.0
+
+        # Split into R, G, B channels
+        channels = img.bandsplit()
+        r, g, b = channels[0], channels[1], channels[2]
+
+        # Apply red overlay (50% blend):
+        # Where mask is 1: blend 50% original with 50% red (255)
+        # Where mask is 0: keep original
+        r = r * (1 - mask_normalized * 0.5) + 127.5 * mask_normalized
+        g = g * (1 - mask_normalized * 0.5)
+        b = b * (1 - mask_normalized * 0.5)
+
+        # Recombine channels
+        result = r.bandjoin([g, b])
+
+        # CRITICAL: Use temp file instead of write_to_buffer()
+        # write_to_buffer() leaks C memory that isn't returned to OS
+        # See: https://github.com/libvips/pyvips/issues/234
+        try:
+            with tempfile.NamedTemporaryFile(suffix='.jpg', delete=False) as tmp:
+                temp_path = tmp.name
+
+            # Write to file (doesn't leak like write_to_buffer)
+            result.write_to_file(temp_path, Q=85)
+
+            # Read bytes and clean up
+            with open(temp_path, 'rb') as f:
+                image_bytes = f.read()
+
+            os.unlink(temp_path)
+            return image_bytes
+
+        except Exception as e:
+            logger.error(f"Failed to write image via temp file: {e}")
+            # Fallback to write_to_buffer if temp file fails
+            return result.write_to_buffer('.jpg', Q=85)
+
+    def close(self, img: pyvips.Image) -> None:
+        """
+        LibVIPS uses automatic reference counting.
+
+        No explicit cleanup needed - memory freed when references drop to zero.
+        """
+        pass
+
+    def find_template(
+        self,
+        img: pyvips.Image,
+        template_img: pyvips.Image,
+        original_bbox: Tuple[int, int, int, int],
+        search_tolerance: float = 0.2
+    ) -> Tuple[int, int, int, int]:
+        """
+        Find template in image using OpenCV template matching.
+
+        Note: This temporarily converts to numpy for OpenCV operations since
+        libvips doesn't have template matching built-in.
+        """
+        import cv2
+        import numpy as np
+
+        try:
+            left, top, right, bottom = original_bbox
+            width = right - left
+            height = bottom - top
+
+            # Calculate search region
+            margin_x = int(width * search_tolerance)
+            margin_y = int(height * search_tolerance)
+
+            search_left = max(0, left - margin_x)
+            search_top = max(0, top - margin_y)
+            search_right = min(img.width, right + margin_x)
+            search_bottom = min(img.height, bottom + margin_y)
+
+            # Crop search region
+            search_region = self.crop(img, search_left, search_top, search_right, search_bottom)
+
+            # Convert to numpy arrays for OpenCV
+            search_array = np.ndarray(
+                buffer=search_region.write_to_memory(),
+                dtype=np.uint8,
+                shape=[search_region.height, search_region.width, search_region.bands]
+            )
+            template_array = np.ndarray(
+                buffer=template_img.write_to_memory(),
+                dtype=np.uint8,
+                shape=[template_img.height, template_img.width, template_img.bands]
+            )
+
+            # Convert to grayscale
+            if len(search_array.shape) == 3:
+                search_gray = cv2.cvtColor(search_array, cv2.COLOR_RGB2GRAY)
+            else:
+                search_gray = search_array
+
+            if len(template_array.shape) == 3:
+                template_gray = cv2.cvtColor(template_array, cv2.COLOR_RGB2GRAY)
+            else:
+                template_gray = template_array
+
+            logger.debug(f"Searching for template in region: ({search_left}, {search_top}) to ({search_right}, {search_bottom})")
+
+            # Perform template matching
+            result = cv2.matchTemplate(search_gray, template_gray, cv2.TM_CCOEFF_NORMED)
+            min_val, max_val, min_loc, max_loc = cv2.minMaxLoc(result)
+
+            logger.debug(f"Template matching confidence: {max_val:.2%}")
+
+            # Check if match is good enough (80% confidence threshold)
+            if max_val >= 0.8:
+                # Calculate new bounding box in original image coordinates
+                match_x = search_left + max_loc[0]
+                match_y = search_top + max_loc[1]
+
+                new_bbox = (match_x, match_y, match_x + width, match_y + height)
+
+                # Calculate movement distance
+                move_x = abs(match_x - left)
+                move_y = abs(match_y - top)
+
+                logger.info(f"Template found at ({match_x}, {match_y}), "
+                           f"moved {move_x}px horizontally, {move_y}px vertically, "
+                           f"confidence: {max_val:.2%}")
+
+                return new_bbox
+            else:
+                logger.warning(f"Template match confidence too low: {max_val:.2%} (need 80%)")
+                return None
+
+        except Exception as e:
+            logger.error(f"Template matching error: {e}")
+            return None
+
+    def save_template(
+        self,
+        img: pyvips.Image,
+        bbox: Tuple[int, int, int, int],
+        output_path: str
+    ) -> bool:
+        """
+        Save a cropped region as a template file.
+        """
+        import os
+
+        try:
+            left, top, right, bottom = bbox
+            width = right - left
+            height = bottom - top
+
+            # Ensure output directory exists
+            os.makedirs(os.path.dirname(output_path), exist_ok=True)
+
+            # Crop template region
+            template = self.crop(img, left, top, right, bottom)
+
+            # Save as PNG
+            template.write_to_file(output_path, compression=6)
+
+            logger.info(f"Saved template: {output_path} ({width}x{height}px)")
+            return True
+
+        except Exception as e:
+            logger.error(f"Failed to save template: {e}")
+            return False