defmodule WandererApp.DataCase do
  @moduledoc """
  This module defines the setup for tests requiring
  access to the application's data layer.

  You may define functions here to be used as helpers in
  your tests.

  Finally, if the test case interacts with the database,
  we enable the SQL sandbox, so changes done to the database
  are reverted at the end of every test. If you are using
  PostgreSQL, you can even run database tests asynchronously
  by setting `use WandererApp.DataCase, async: true`, although
  this option is not recommended for other databases.
  """

  use ExUnit.CaseTemplate

  using do
    quote do
      alias WandererApp.Repo

      import Ecto
      import Ecto.Changeset
      import Ecto.Query
      import WandererApp.DataCase

      # Import Ash test helpers
      import WandererAppWeb.Factory

      # Import test utilities
      import WandererApp.TestHelpers
    end
  end

  setup tags do
    WandererApp.DataCase.setup_sandbox(tags)

    # Set up mocks for this test process
    WandererApp.Test.Mocks.setup_test_mocks()

    # Set up integration test environment
    WandererApp.Test.IntegrationConfig.setup_integration_environment()
    WandererApp.Test.IntegrationConfig.setup_test_reliability_configs()

    # Cleanup after test
    on_exit(fn ->
      WandererApp.Test.IntegrationConfig.cleanup_integration_environment()
    end)

    :ok
  end

  @doc """
  Sets up the sandbox based on the test tags.
  """
  def setup_sandbox(tags) do
    # Ensure the repo is started before setting up sandbox
    unless Process.whereis(WandererApp.Repo) do
      {:ok, _} = WandererApp.Repo.start_link()
    end

    # Use shared mode if requested or if running as a ConnCase test (to avoid ownership issues)
    # Otherwise use non-shared mode for proper test isolation
    shared = (tags[:shared] || tags[:conn_case] || not tags[:async]) and not tags[:async]

    # Start the sandbox owner and link it to the test process
    pid = Ecto.Adapters.SQL.Sandbox.start_owner!(WandererApp.Repo, shared: shared)

    # Store the sandbox owner pid BEFORE registering on_exit
    # This ensures it's available for use in setup callbacks
    Process.put(:sandbox_owner_pid, pid)

    # Register cleanup - this will be called last (LIFO order)
    on_exit(fn ->
      # Only stop if the owner is still alive
      if Process.alive?(pid) do
        Ecto.Adapters.SQL.Sandbox.stop_owner(pid)
      end
    end)

    # Allow critical system processes to access the database
    allow_system_processes_database_access()

    # Set $callers to enable automatic allowance propagation to child processes
    # This makes child processes inherit database access from the test process
    Process.put(:"$callers", [pid])
  end

  @doc """
  Allows a process to access the database by granting it sandbox access.
  This is necessary for background processes like map servers that need database access.
  """
  def allow_database_access(pid) when is_pid(pid) do
    owner_pid = Process.get(:sandbox_owner_pid)

    if owner_pid do
      Ecto.Adapters.SQL.Sandbox.allow(WandererApp.Repo, owner_pid, pid)
    end
  end

  @doc """
  Allows a process to access the database by granting it sandbox access with monitoring.
  This version provides enhanced monitoring for child processes.
  """
  def allow_database_access(pid, owner_pid) when is_pid(pid) and is_pid(owner_pid) do
    Ecto.Adapters.SQL.Sandbox.allow(WandererApp.Repo, owner_pid, pid)
    # Note: Skip the manager call to avoid recursion
  end

  @doc """
  Allows critical system processes to access the database during tests.
  This prevents DBConnection.OwnershipError for processes that are started
  during application boot and need database access.
  """
  def allow_system_processes_database_access do
    # List of system processes that may need database access during tests
    system_processes = [
      WandererApp.Map.Manager,
      WandererApp.Character.TrackerManager,
      WandererApp.Server.TheraDataFetcher,
      WandererApp.ExternalEvents.MapEventRelay,
      WandererApp.ExternalEvents.WebhookDispatcher,
      WandererApp.ExternalEvents.SseStreamManager,
      # Task.Supervisor for Task.async_stream calls (e.g., from MapPool background tasks)
      Task.Supervisor
    ]

    Enum.each(system_processes, fn process_name ->
      case GenServer.whereis(process_name) do
        pid when is_pid(pid) ->
          allow_database_access(pid)

        _ ->
          :ok
      end
    end)

    # Grant database access to MapPoolSupervisor and MapPoolDynamicSupervisor
    # This must be done early and repeatedly to catch dynamically spawned children
    owner_pid = Process.get(:sandbox_owner_pid) || self()

    case Process.whereis(WandererApp.Map.MapPoolSupervisor) do
      pid when is_pid(pid) ->
        WandererApp.Test.DatabaseAccessManager.grant_supervision_tree_access(pid, owner_pid)
        WandererApp.Test.MockOwnership.allow_supervision_tree(pid, owner_pid)

      _ ->
        :ok
    end

    # Also grant to MapPoolDynamicSupervisor which actually spawns MapPool processes
    case Process.whereis(WandererApp.Map.MapPoolDynamicSupervisor) do
      pid when is_pid(pid) ->
        WandererApp.Test.DatabaseAccessManager.grant_supervision_tree_access(pid, owner_pid)
        WandererApp.Test.MockOwnership.allow_supervision_tree(pid, owner_pid)

      _ ->
        :ok
    end
  end

  @doc """
  Grants database access to a GenServer and all its child processes.
  """
  def allow_genserver_database_access(genserver_pid, owner_pid \\ self()) do
    WandererApp.Test.DatabaseAccessManager.grant_genserver_database_access(
      genserver_pid,
      owner_pid
    )
  end

  @doc """
  A helper that transforms changeset errors into a map of messages.

      assert {:error, changeset} = Accounts.create_user(%{password: "short"})
      assert "password is too short" in errors_on(changeset).password
      assert %{password: ["password is too short"]} = errors_on(changeset)

  """
  def errors_on(changeset) do
    Ecto.Changeset.traverse_errors(changeset, fn {message, opts} ->
      Regex.replace(~r"%{(\w+)}", message, fn _, key ->
        opts |> Keyword.get(String.to_existing_atom(key), key) |> to_string()
      end)
    end)
  end

  @doc """
  Truncates all tables in the test database.
  Use with caution - this will delete all test data.
  """
  def truncate_all_tables do
    Ecto.Adapters.SQL.query!(
      WandererApp.Repo,
      "TRUNCATE #{tables_to_truncate()} RESTART IDENTITY CASCADE",
      []
    )
  end

  @doc """
  Resets the database to a clean state.
  """
  def reset_database do
    # Use checkout and checkin to reset sandbox mode
    Ecto.Adapters.SQL.Sandbox.checkout(WandererApp.Repo)
    Ecto.Adapters.SQL.Sandbox.checkin(WandererApp.Repo)
  end

  @doc """
  Waits for async operations to complete using polling.
  Useful when testing async processes.
  """
  # Backward compatibility - accepts just timeout
  def wait_for_async(timeout) when is_integer(timeout) do
    :timer.sleep(timeout)
  end

  def wait_for_async(condition_fn) when is_function(condition_fn) do
    wait_for_async(condition_fn, 1000)
  end

  def wait_for_async(condition_fn, timeout) when is_function(condition_fn) do
    wait_for_async_poll(condition_fn, timeout, 50)
  end

  defp wait_for_async_poll(condition_fn, timeout, interval) when timeout > 0 do
    if condition_fn.() do
      :ok
    else
      :timer.sleep(interval)
      wait_for_async_poll(condition_fn, timeout - interval, interval)
    end
  end

  defp wait_for_async_poll(_condition_fn, _timeout, _interval) do
    raise "Timeout waiting for async condition"
  end

  @doc """
  Asserts that an Ash action succeeds and returns the result.
  """
  def assert_ash_success({:ok, result}), do: result

  def assert_ash_success({:error, error}) do
    flunk("Expected Ash action to succeed, but got error: #{inspect(error)}")
  end

  @doc """
  Asserts that an Ash action fails with expected error.
  """
  def assert_ash_error({:error, _error} = result), do: result

  def assert_ash_error({:ok, result}) do
    flunk("Expected Ash action to fail, but got success: #{inspect(result)}")
  end

  @doc """
  Asserts that an Ash action fails with a specific error message.
  """
  def assert_ash_error({:error, error}, expected_message) when is_binary(expected_message) do
    error_string = inspect(error)

    assert error_string =~ expected_message,
           "Expected error to contain '#{expected_message}', but got: #{error_string}"

    {:error, error}
  end

  # Private helpers

  defp tables_to_truncate do
    "users, characters, maps, map_systems, map_connections, access_lists, access_list_members"
  end
end