"""Deep coverage tests for database/thread_local_session.py.

Focuses on:
- ThreadLocalSessionManager.get_session: session reuse, invalid session recovery,
  PendingRollbackError rollback then re-execute fails -> new session
- ThreadLocalSessionManager.cleanup_all
- Module-level helpers: get_metrics_session, get_current_thread_session,
  cleanup_current_thread
- _ThreadCleanup: clear_settings_context and clear_search_context exception paths
- ThreadSessionContext: None session handling
"""

import threading
from unittest.mock import MagicMock, patch

import pytest
from sqlalchemy.exc import PendingRollbackError

MODULE = "local_deep_research.database.thread_local_session"


def _make_manager():
    from local_deep_research.database.thread_local_session import (
        ThreadLocalSessionManager,
    )

    return ThreadLocalSessionManager()


# ---------------------------------------------------------------------------
# get_session – full coverage of branches
# ---------------------------------------------------------------------------


class TestGetSessionBranches:
    def test_reuses_valid_session(self):
        """When an existing valid session is in thread-local, it is reused."""
        mgr = _make_manager()
        valid_sess = MagicMock()
        mgr._local.session = valid_sess
        mgr._local.username = "alice"

        result = mgr.get_session("alice", "pw")
        assert result is valid_sess
        valid_sess.execute.assert_called()

    def test_pending_rollback_then_re_execute_fails_creates_new(self):
        """PendingRollbackError, rollback succeeds but SELECT 1 again fails."""
        mgr = _make_manager()
        broken_sess = MagicMock()
        broken_sess.execute.side_effect = [
            PendingRollbackError("pending"),
            Exception("still broken"),  # second execute after rollback fails
        ]
        mgr._local.session = broken_sess
        mgr._local.username = "alice"

        new_sess = MagicMock()
        with patch(f"{MODULE}.db_manager") as mock_db:
            mock_db.open_user_database.return_value = MagicMock()
            mock_db.create_thread_safe_session_for_metrics.return_value = (
                new_sess
            )
            result = mgr.get_session("alice", "pw")

        assert result is new_sess

    def test_generic_exception_invalidates_session(self):
        """Any exception from execute causes cleanup and new session creation."""
        mgr = _make_manager()
        broken_sess = MagicMock()
        broken_sess.execute.side_effect = OSError("db file locked")
        mgr._local.session = broken_sess
        mgr._local.username = "alice"

        new_sess = MagicMock()
        with patch(f"{MODULE}.db_manager") as mock_db:
            mock_db.open_user_database.return_value = MagicMock()
            mock_db.create_thread_safe_session_for_metrics.return_value = (
                new_sess
            )
            result = mgr.get_session("alice", "pw")

        assert result is new_sess

    def test_credentials_tracked_after_new_session(self):
        mgr = _make_manager()
        new_sess = MagicMock()
        with patch(f"{MODULE}.db_manager") as mock_db:
            mock_db.open_user_database.return_value = MagicMock()
            mock_db.create_thread_safe_session_for_metrics.return_value = (
                new_sess
            )
            mgr.get_session("bob", "s3cr3t")

        tid = threading.get_ident()
        assert mgr._thread_credentials.get(tid) == ("bob", "s3cr3t")


# ---------------------------------------------------------------------------
# cleanup_all
# ---------------------------------------------------------------------------


class TestCleanupAll:
    def test_cleanup_all_calls_cleanup_for_all_tracked_threads(self):
        mgr = _make_manager()
        mgr._thread_credentials[111] = ("a", "pw")
        mgr._thread_credentials[222] = ("b", "pw")

        called_with = []

        def track_cleanup(tid=None):
            called_with.append(tid)

        mgr.cleanup_thread = track_cleanup
        mgr.cleanup_all()

        # Both thread IDs should have been cleaned up
        assert len(called_with) == 2


# ---------------------------------------------------------------------------
# Module-level helpers
# ---------------------------------------------------------------------------


class TestModuleLevelHelpers:
    def test_get_metrics_session_delegates_to_manager(self):
        from local_deep_research.database.thread_local_session import (
            get_metrics_session,
        )

        mock_sess = MagicMock()
        with patch(f"{MODULE}.thread_session_manager") as mock_mgr:
            mock_mgr.get_session.return_value = mock_sess
            result = get_metrics_session("alice", "pw")
        assert result is mock_sess
        mock_mgr.get_session.assert_called_once_with("alice", "pw")

    def test_get_current_thread_session_delegates(self):
        from local_deep_research.database.thread_local_session import (
            get_current_thread_session,
        )

        mock_sess = MagicMock()
        with patch(f"{MODULE}.thread_session_manager") as mock_mgr:
            mock_mgr.get_current_session.return_value = mock_sess
            result = get_current_thread_session()
        assert result is mock_sess

    def test_cleanup_current_thread_delegates(self):
        from local_deep_research.database.thread_local_session import (
            cleanup_current_thread,
        )

        with patch(f"{MODULE}.thread_session_manager") as mock_mgr:
            cleanup_current_thread()
        mock_mgr.cleanup_thread.assert_called_once_with()


# ---------------------------------------------------------------------------
# _ThreadCleanup – exception suppression paths
# ---------------------------------------------------------------------------


class TestThreadCleanupExceptionPaths:
    def test_clear_settings_context_exception_suppressed(self):
        from local_deep_research.database.thread_local_session import (
            _ThreadCleanup,
        )

        with (
            patch(f"{MODULE}.cleanup_current_thread"),
            patch(
                "local_deep_research.config.thread_settings.clear_settings_context",
                side_effect=RuntimeError("settings boom"),
                create=True,
            ),
        ):
            with _ThreadCleanup():
                pass  # Should not raise

    def test_clear_search_context_exception_suppressed(self):
        from local_deep_research.database.thread_local_session import (
            _ThreadCleanup,
        )

        with (
            patch(f"{MODULE}.cleanup_current_thread"),
            patch(
                "local_deep_research.utilities.thread_context.clear_search_context",
                side_effect=RuntimeError("search boom"),
                create=True,
            ),
        ):
            with _ThreadCleanup():
                pass  # Should not raise

    def test_returns_false_from_exit(self):
        """__exit__ returns False to propagate exceptions from the body."""
        from local_deep_research.database.thread_local_session import (
            _ThreadCleanup,
        )

        with patch(f"{MODULE}.cleanup_current_thread"):
            cm = _ThreadCleanup()
            cm.__enter__()
            result = cm.__exit__(None, None, None)
        assert result is False


# ---------------------------------------------------------------------------
# ThreadSessionContext – None session
# ---------------------------------------------------------------------------


class TestThreadSessionContextNone:
    def test_none_session_is_yielded(self):
        from local_deep_research.database.thread_local_session import (
            ThreadSessionContext,
        )

        with patch(f"{MODULE}.get_metrics_session", return_value=None):
            with ThreadSessionContext("alice", "pw") as sess:
                assert sess is None

    def test_exception_in_body_propagates(self):
        from local_deep_research.database.thread_local_session import (
            ThreadSessionContext,
        )

        mock_sess = MagicMock()
        with patch(f"{MODULE}.get_metrics_session", return_value=mock_sess):
            with pytest.raises(ValueError, match="body error"):
                with ThreadSessionContext("alice", "pw"):
                    raise ValueError("body error")
