import json
import math
import re
import tempfile
from pathlib import Path
from graphify.build import build_from_json
from graphify.cluster import cluster
from graphify.export import to_json, to_cypher, to_graphml, to_html, to_canvas, to_obsidian

FIXTURES = Path(__file__).parent / "fixtures"

def make_graph():
    return build_from_json(json.loads((FIXTURES / "extraction.json").read_text()))

def test_to_json_creates_file():
    G = make_graph()
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.json"
        to_json(G, communities, str(out))
        assert out.exists()

def test_to_json_valid_json():
    G = make_graph()
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.json"
        to_json(G, communities, str(out))
        data = json.loads(out.read_text())
        assert "nodes" in data
        assert "links" in data

def test_to_json_nodes_have_community():
    G = make_graph()
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.json"
        to_json(G, communities, str(out))
        data = json.loads(out.read_text())
        for node in data["nodes"]:
            assert "community" in node

def test_to_cypher_creates_file():
    G = make_graph()
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "cypher.txt"
        to_cypher(G, str(out))
        assert out.exists()

def test_to_cypher_contains_merge_statements():
    G = make_graph()
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "cypher.txt"
        to_cypher(G, str(out))
        content = out.read_text()
        assert "MERGE" in content

def test_to_graphml_creates_file():
    G = make_graph()
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.graphml"
        to_graphml(G, communities, str(out))
        assert out.exists()

def test_to_graphml_valid_xml():
    G = make_graph()
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.graphml"
        to_graphml(G, communities, str(out))
        content = out.read_text()
        assert "<graphml" in content
        assert "<node" in content

def test_to_graphml_has_community_attribute():
    G = make_graph()
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.graphml"
        to_graphml(G, communities, str(out))
        content = out.read_text()
        assert "community" in content

def test_to_graphml_tolerates_none_attribute_values():
    """nx.write_graphml raises ValueError on a None attribute value; to_graphml
    must coerce None -> "" so a node/edge with a null field still exports (#1502)."""
    G = make_graph()
    communities = cluster(G)
    # Inject a None-valued attribute on one node and one edge.
    a_node = next(iter(G.nodes()))
    G.nodes[a_node]["nullable_field"] = None
    if G.number_of_edges():
        u, v = next(iter(G.edges()))
        G.edges[u, v]["nullable_field"] = None
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.graphml"
        to_graphml(G, communities, str(out))  # must not raise
        content = out.read_text()
        assert "<graphml" in content

def test_to_html_creates_file():
    G = make_graph()
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.html"
        to_html(G, communities, str(out))
        assert out.exists()

def test_to_html_contains_visjs():
    G = make_graph()
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.html"
        to_html(G, communities, str(out))
        content = out.read_text()
        assert "vis-network" in content


def test_to_html_pins_visjs_version_with_sri():
    """vis-network script tag must use a pinned versioned URL with a sha384
    Subresource Integrity hash and crossorigin=anonymous. Without this,
    a compromised CDN could ship arbitrary JavaScript into every rendered
    graph viewer. The hash was verified against the upstream file at
    https://unpkg.com/vis-network@9.1.6/standalone/umd/vis-network.min.js
    (sha384-Ux6phic9PEHJ38YtrijhkzyJ8yQlH8i/+buBR8s3mAZOJrP1gwyvAcIYl3GWtpX1).
    Bumping the vis-network version MUST update both the URL and the hash.
    """
    G = make_graph()
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.html"
        to_html(G, communities, str(out))
        content = out.read_text()

    # Versioned URL — unversioned `vis-network/standalone/...` is rejected.
    assert "vis-network@9.1.6/standalone/umd/vis-network.min.js" in content
    assert "https://unpkg.com/vis-network/standalone" not in content

    # SRI integrity attribute pinning the known-good hash.
    assert 'integrity="sha384-Ux6phic9PEHJ38YtrijhkzyJ8yQlH8i/+buBR8s3mAZOJrP1gwyvAcIYl3GWtpX1"' in content

    # crossorigin="anonymous" is required for SRI on cross-origin scripts.
    assert 'crossorigin="anonymous"' in content

def test_to_html_contains_search():
    G = make_graph()
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.html"
        to_html(G, communities, str(out))
        content = out.read_text()
        assert "search" in content.lower()

def test_to_html_contains_legend_with_labels():
    G = make_graph()
    communities = cluster(G)
    labels = {cid: f"Group {cid}" for cid in communities}
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.html"
        to_html(G, communities, str(out), community_labels=labels)
        content = out.read_text()
        assert "Group 0" in content

def test_to_html_contains_nodes_and_edges():
    G = make_graph()
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.html"
        to_html(G, communities, str(out))
        content = out.read_text()
        assert "RAW_NODES" in content
        assert "RAW_EDGES" in content


def test_to_html_member_counts_accepted():
    """to_html accepts member_counts without raising."""
    G = make_graph()
    communities = cluster(G)
    member_counts = {cid: len(members) for cid, members in communities.items()}
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.html"
        to_html(G, communities, str(out), member_counts=member_counts)
        assert out.exists()


def _vis_nodes_from_html(content: str) -> list:
    """Extract the RAW_NODES JSON array embedded in the generated HTML."""
    m = re.search(r"const RAW_NODES = (\[.*?\]);", content, re.DOTALL)
    assert m, "RAW_NODES not found in HTML"
    return json.loads(m.group(1).replace("<\\/", "</"))


def test_to_html_annotated_node_gets_learning_status_and_ring():
    """A node with an overlay entry gets learning_status + learning_stale fields,
    a status-colored ring (border), and a Lesson line in its hover title."""
    G = make_graph()
    communities = cluster(G)
    overlay = {
        "n_transformer": {"status": "preferred", "uses": 3, "score": 2.4,
                          "stale": False, "neg": 0},
    }
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.html"
        to_html(G, communities, str(out), learning_overlay=overlay)
        content = out.read_text()
    nodes = {n["id"]: n for n in _vis_nodes_from_html(content)}
    ann = nodes["n_transformer"]
    assert ann["learning_status"] == "preferred"
    assert ann["learning_stale"] is False
    assert ann["color"]["border"] == "#22c55e"  # green ring for preferred
    assert ann.get("borderWidth") == 3
    assert "Lesson: preferred source" in ann["title"]
    # An un-annotated node carries no learning fields.
    other = next(n for nid, n in nodes.items() if nid != "n_transformer")
    assert "learning_status" not in other
    assert "learning_stale" not in other


def test_to_html_contested_stale_node_gets_dashed_desaturated_ring():
    G = make_graph()
    communities = cluster(G)
    overlay = {
        "n_transformer": {"status": "contested", "uses": 2, "neg": 1,
                          "verdict": "dead end", "stale": True},
    }
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.html"
        to_html(G, communities, str(out), learning_overlay=overlay)
        content = out.read_text()
    ann = {n["id"]: n for n in _vis_nodes_from_html(content)}["n_transformer"]
    assert ann["learning_status"] == "contested"
    assert ann["learning_stale"] is True
    assert ann["color"]["border"] == "#9ca3af"  # desaturated when stale
    assert ann["shapeProperties"]["borderDashes"] == [4, 4]
    assert "code changed" in ann["title"]


def test_to_html_unannotated_identical_to_pre_feature():
    """With no overlay, the HTML is byte-identical whether learning_overlay is
    omitted or passed empty — no learning fields leak into the un-annotated render."""
    G = make_graph()
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        a = Path(tmp) / "a.html"
        b = Path(tmp) / "b.html"
        to_html(G, communities, str(a))
        to_html(G, communities, str(b), learning_overlay={})
        # Output path appears in the title, so compare with paths normalized out.
        ca = a.read_text().replace("a.html", "X.html")
        cb = b.read_text().replace("b.html", "X.html")
    assert ca == cb
    assert "learning_status" not in ca


def test_to_canvas_file_paths_relative_to_vault():
    """Node file paths in canvas must be vault-root-relative (just fname.md), not hardcoded."""
    G = make_graph()
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.canvas"
        to_canvas(G, communities, str(out))
        data = json.loads(out.read_text())
        file_nodes = [n for n in data["nodes"] if n.get("type") == "file"]
        assert file_nodes, "canvas should contain file nodes"
        for node in file_nodes:
            assert "/" not in node["file"], f"file path should not contain '/': {node['file']}"
            assert node["file"].endswith(".md")


def test_to_canvas_no_communities_still_populates():
    """#1324: empty communities (e.g. --no-cluster builds) on a populated graph
    must NOT produce the 32-byte empty `{"nodes": [], "edges": []}` shell."""
    G = make_graph()
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.canvas"
        to_canvas(G, {}, str(out))  # no community data — the bug condition
        data = json.loads(out.read_text())
        assert len(data["nodes"]) >= G.number_of_nodes()
        assert len(data["edges"]) >= 1
        assert out.stat().st_size > 32


def test_to_canvas_node_grid_matches_box_columns():
    """#1452: a community's node cards are laid out in the same ceil(sqrt(n))-column
    grid the group box is sized for. Previously the box width assumed sqrt(n)
    columns while the placement loop hardcoded 3, so any community bigger than ~9
    rendered as a cramped 3-wide strip filling only part of an over-wide box.
    Covers a perfect square (25 -> 5x5) and a non-square count (10 -> 4 cols, a
    partial last row) so both the column count and the row count are pinned."""
    for n in (10, 25):
        G = build_from_json({
            "nodes": [
                {"id": f"n{i}", "label": f"sym_{i:02d}", "file_type": "code", "source_file": "a.py"}
                for i in range(n)
            ],
            "edges": [],
        })
        communities = {0: [f"n{i}" for i in range(n)]}
        with tempfile.TemporaryDirectory() as tmp:
            out = Path(tmp) / "graph.canvas"
            to_canvas(G, communities, str(out))
            data = json.loads(out.read_text())

        group = next(g for g in data["nodes"] if g.get("type") == "group")
        cards = [c for c in data["nodes"] if c.get("type") == "file"]
        assert len(cards) == n, f"n={n}"

        # Cards occupy the ceil(sqrt(n))-column / ceil(n/cols)-row grid the box is
        # sized for — not the old fixed 3 columns, which spread cards across far
        # more rows (the load-bearing checks: distinct column/row positions).
        expected_cols = math.ceil(math.sqrt(n))
        expected_rows = math.ceil(n / expected_cols)
        distinct_x = len({c["x"] for c in cards})
        distinct_y = len({c["y"] for c in cards})
        assert distinct_x == expected_cols, f"n={n}: expected {expected_cols} cols, got {distinct_x}"
        assert distinct_y == expected_rows, f"n={n}: expected {expected_rows} rows, got {distinct_y}"

        # And every card sits fully inside its group box on both axes.
        gx, gy, gw, gh = group["x"], group["y"], group["width"], group["height"]
        for c in cards:
            assert gx <= c["x"] and c["x"] + c["width"] <= gx + gw, (n, c)
            assert gy <= c["y"] and c["y"] + c["height"] <= gy + gh, (n, c)


# ── Issue #1409: punctuation-only Obsidian/Canvas filenames ───────────────────

def _punct_graph(label: str):
    """A 2-node graph where one node's label is all-punctuation (e.g. a `@/*`
    tsconfig paths key) and the other is a normal symbol."""
    return build_from_json({
        "nodes": [
            {"id": "n1", "label": label, "file_type": "code", "source_file": "tsconfig.json"},
            {"id": "n2", "label": "AuthHandler", "file_type": "code", "source_file": "auth.ts"},
        ],
        "edges": [],
    })


def test_to_obsidian_never_emits_punctuation_only_filenames():
    """#1409: an all-punctuation label (e.g. `@/*`) must not produce a `@.md`-style
    filename — valid on disk but empty once a downstream tool re-slugs on word chars
    (crashes `qmd update`). It falls back to `unnamed`."""
    G = _punct_graph("@/*")
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        to_obsidian(G, communities, tmp)
        stems = [p.stem for p in Path(tmp).rglob("*.md")]
        assert stems, "to_obsidian wrote no notes"
        bad = [s for s in stems if not re.search(r"\w", s, flags=re.UNICODE)]
        assert not bad, f"punctuation-only filenames emitted: {bad}"
        assert any(s == "unnamed" or s.startswith("unnamed") for s in stems), stems


def test_to_canvas_never_emits_punctuation_only_filenames():
    """#1409: same guard on the canvas exporter's file-node names."""
    G = _punct_graph("@")
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.canvas"
        to_canvas(G, communities, str(out))
        data = json.loads(out.read_text())
        file_nodes = [n for n in data["nodes"] if n.get("type") == "file"]
        assert file_nodes, "canvas has no file nodes"
        bad = [n["file"] for n in file_nodes if not re.search(r"\w", Path(n["file"]).stem, flags=re.UNICODE)]
        assert not bad, f"punctuation-only canvas filenames: {bad}"


# ── Existing-vault safety: graphify must not clobber user notes / .obsidian (#1506) ──

def _two_node_graph():
    import networkx as nx
    G = nx.Graph()
    G.add_node("n1", label="Database", community=0, source_file="app/db.py", type="code")
    G.add_node("n2", label="Server", community=0, source_file="app/srv.py", type="code")
    G.add_edge("n1", "n2")
    return G, {0: ["n1", "n2"]}


def test_to_obsidian_preserves_existing_user_notes_and_obsidian_config():
    """#1506: exporting into an existing vault must not overwrite a user's note that
    collides with a graphify node name, nor their .obsidian/ graph settings."""
    G, communities = _two_node_graph()
    with tempfile.TemporaryDirectory() as tmp:
        vault = Path(tmp)
        (vault / "Database.md").write_text("# MY NOTES\nkeep me\n", encoding="utf-8")
        (vault / ".obsidian").mkdir()
        (vault / ".obsidian" / "graph.json").write_text('{"USER":"settings"}', encoding="utf-8")
        to_obsidian(G, communities, str(vault), community_labels={0: "Backend"})
        # user content untouched
        assert "MY NOTES" in (vault / "Database.md").read_text()
        assert json.loads((vault / ".obsidian" / "graph.json").read_text()) == {"USER": "settings"}
        # non-colliding graphify note still written
        assert (vault / "Server.md").exists()


def test_to_obsidian_empty_dir_writes_full_vault():
    """No regression: a fresh/empty dir still gets every note + .obsidian/graph.json."""
    G, communities = _two_node_graph()
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "obsidian"
        n = to_obsidian(G, communities, str(out), community_labels={0: "Backend"})
        assert (out / "Database.md").exists() and (out / "Server.md").exists()
        assert (out / ".obsidian" / "graph.json").exists()
        assert n == 3  # 2 nodes + 1 community note


def test_to_obsidian_rerun_updates_own_notes_but_not_user_files():
    """A re-run overwrites graphify's own prior notes (via the manifest) but leaves a
    user-added note in the same dir alone."""
    G, communities = _two_node_graph()
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "obsidian"
        to_obsidian(G, communities, str(out), community_labels={0: "Backend"})
        (out / "UserNote.md").write_text("mine\n", encoding="utf-8")
        to_obsidian(G, communities, str(out), community_labels={0: "Backend2"})
        assert (out / "Database.md").exists()  # graphify re-wrote its own
        assert (out / "UserNote.md").read_text().strip() == "mine"  # user's untouched


# ── Case-only-distinct labels must not collide on case-insensitive filesystems ──

def _case_collision_graph():
    """Two nodes whose labels differ only by case - on macOS/APFS and Windows/NTFS
    their notes resolve to the same path unless the dedup map folds case."""
    return build_from_json({
        "nodes": [
            {"id": "n1", "label": "References", "file_type": "code", "source_file": "a.py"},
            {"id": "n2", "label": "references", "file_type": "document", "source_file": "b.md"},
        ],
        "edges": [],
    })


def test_to_obsidian_case_only_distinct_labels_dont_overwrite():
    """Both notes must survive as separate files. On a case-insensitive filesystem
    a missing suffix silently overwrites the first note (fewer files than nodes);
    on a case-sensitive one it writes two stems equal under .lower(). Assert both:
    every node note is on disk, and no two stems collide case-insensitively."""
    G = _case_collision_graph()
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        to_obsidian(G, communities, tmp)
        notes = [p for p in Path(tmp).rglob("*.md") if not p.name.startswith("_COMMUNITY")]
        assert len(notes) == G.number_of_nodes(), [p.name for p in notes]
        lowered = [p.stem.lower() for p in notes]
        assert len(set(lowered)) == len(lowered), [p.name for p in notes]
        # the suffixed name must be the expected one, not merely distinct
        assert sorted(p.stem for p in notes) == ["References", "references_1"], [p.name for p in notes]


def test_to_obsidian_generated_suffix_doesnt_overwrite_literal():
    """A generated `_1` suffix must not collide with a node whose literal label is
    already that suffixed name. With labels [dup, dup, dup_1] the second `dup`
    becomes `dup_1`, which would clobber the third node unless the candidate is
    re-checked. This collides on case-sensitive filesystems too, so it guards the
    dedup loop independently of case-folding."""
    G = build_from_json({
        "nodes": [
            {"id": "a", "label": "dup", "file_type": "code", "source_file": "a.py"},
            {"id": "b", "label": "dup", "file_type": "code", "source_file": "b.py"},
            {"id": "c", "label": "dup_1", "file_type": "code", "source_file": "c.py"},
        ],
        "edges": [],
    })
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        to_obsidian(G, communities, tmp)
        notes = [p for p in Path(tmp).rglob("*.md") if not p.name.startswith("_COMMUNITY")]
        assert len(notes) == 3, [p.name for p in notes]
        assert len({p.stem.lower() for p in notes}) == 3, [p.name for p in notes]


def test_to_canvas_case_only_distinct_labels_get_distinct_files():
    """Canvas file-node references for case-only-distinct labels must be distinct
    case-insensitively, else both cards point at one overwritten note."""
    G = _case_collision_graph()
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        out = Path(tmp) / "graph.canvas"
        to_canvas(G, communities, str(out))
        data = json.loads(out.read_text())
        files = [n["file"] for n in data["nodes"] if n.get("type") == "file"]
        lowered = [f.lower() for f in files]
        assert len(set(lowered)) == len(lowered), files


def test_obsidian_canvas_filenames_agree():
    """The CLI calls to_obsidian and to_canvas separately with no shared map, so
    they must independently produce the same node->filename mapping - otherwise a
    canvas card points at a note file that doesn't exist on disk."""
    G = _case_collision_graph()
    communities = cluster(G)
    with tempfile.TemporaryDirectory() as tmp:
        to_obsidian(G, communities, tmp)
        note_stems = {p.stem for p in Path(tmp).rglob("*.md") if not p.name.startswith("_COMMUNITY")}
        out = Path(tmp) / "graph.canvas"
        to_canvas(G, communities, str(out))
        data = json.loads(out.read_text())
        canvas_stems = {Path(n["file"]).stem for n in data["nodes"] if n.get("type") == "file"}
        assert canvas_stems <= note_stems, (sorted(canvas_stems), sorted(note_stems))


def test_to_obsidian_community_notes_case_collision():
    """Two community labels differing only by case must each get their own
    `_COMMUNITY_*.md` overview note. This path had no dedup at all, so even
    same-case duplicate labels previously overwrote silently."""
    G = build_from_json({
        "nodes": [
            {"id": "n1", "label": "alpha", "file_type": "code", "source_file": "a.py"},
            {"id": "n2", "label": "beta", "file_type": "code", "source_file": "b.py"},
        ],
        "edges": [],
    })
    communities = {0: ["n1"], 1: ["n2"]}
    labels = {0: "API", 1: "Api"}
    with tempfile.TemporaryDirectory() as tmp:
        to_obsidian(G, communities, tmp, community_labels=labels)
        comm = [p for p in Path(tmp).rglob("_COMMUNITY_*.md")]
        assert len(comm) == 2, [p.name for p in comm]
        lowered = [p.stem.lower() for p in comm]
        assert len(set(lowered)) == len(lowered), [p.name for p in comm]


# ── Issue #834: backup_if_protected ──────────────────────────────────────────

def test_backup_no_graph_json(tmp_path):
    """No graph.json → no backup."""
    from graphify.export import backup_if_protected
    assert backup_if_protected(tmp_path) is None


def test_backup_no_markers(tmp_path):
    """graph.json present but no sentinel and no curated labels → no backup."""
    from graphify.export import backup_if_protected
    (tmp_path / "graph.json").write_text('{"nodes":[],"links":[]}')
    assert backup_if_protected(tmp_path) is None


def test_backup_semantic_marker(tmp_path):
    """graph.json + .graphify_semantic_marker → backup taken."""
    from graphify.export import backup_if_protected
    (tmp_path / "graph.json").write_text('{"nodes":[],"links":[]}')
    (tmp_path / "GRAPH_REPORT.md").write_text("# Report")
    (tmp_path / ".graphify_semantic_marker").write_text('{"output_tokens": 1234}')
    result = backup_if_protected(tmp_path)
    assert result is not None
    assert result.is_dir()
    assert (result / "graph.json").exists()
    assert (result / "GRAPH_REPORT.md").exists()
    assert (result / ".graphify_semantic_marker").exists()


def test_backup_curated_labels(tmp_path):
    """graph.json + non-default label in .graphify_labels.json → backup taken."""
    import json
    from graphify.export import backup_if_protected
    (tmp_path / "graph.json").write_text('{"nodes":[],"links":[]}')
    (tmp_path / ".graphify_labels.json").write_text(json.dumps({"0": "Auth Pipeline", "1": "Community 1"}))
    result = backup_if_protected(tmp_path)
    assert result is not None


def test_backup_default_labels_only(tmp_path):
    """All-default labels → no backup (not curated)."""
    import json
    from graphify.export import backup_if_protected
    (tmp_path / "graph.json").write_text('{"nodes":[],"links":[]}')
    (tmp_path / ".graphify_labels.json").write_text(json.dumps({"0": "Community 0", "1": "Community 1"}))
    assert backup_if_protected(tmp_path) is None


def test_backup_same_day_no_accumulation(tmp_path):
    """Same content on same day returns existing backup dir without re-copying."""
    from graphify.export import backup_if_protected
    from datetime import date
    (tmp_path / "graph.json").write_text('{"nodes":[],"links":[]}')
    (tmp_path / ".graphify_semantic_marker").write_text("{}")
    b1 = backup_if_protected(tmp_path)
    b2 = backup_if_protected(tmp_path)
    assert b1 is not None and b2 is not None
    assert b1 == b2  # same dir, no _2 accumulation
    assert b1.name == date.today().isoformat()


def test_backup_same_day_changed_content(tmp_path):
    """Changed graph.json on same day overwrites the existing backup in place."""
    from graphify.export import backup_if_protected
    from datetime import date
    (tmp_path / "graph.json").write_text('{"nodes":[],"links":[]}')
    (tmp_path / ".graphify_semantic_marker").write_text("{}")
    b1 = backup_if_protected(tmp_path)
    (tmp_path / "graph.json").write_text('{"nodes":[{"id":"x"}],"links":[]}')
    b2 = backup_if_protected(tmp_path)
    assert b1 == b2  # still one folder per day
    assert (b2 / "graph.json").read_text() == '{"nodes":[{"id":"x"}],"links":[]}'


def test_backup_env_disable(tmp_path, monkeypatch):
    """GRAPHIFY_NO_BACKUP=1 disables backup entirely."""
    from graphify.export import backup_if_protected
    monkeypatch.setenv("GRAPHIFY_NO_BACKUP", "1")
    (tmp_path / "graph.json").write_text('{"nodes":[],"links":[]}')
    (tmp_path / ".graphify_semantic_marker").write_text("{}")
    assert backup_if_protected(tmp_path) is None