import threading
import time
from unittest.mock import MagicMock, call, patch

from deerflow.agents.memory.queue import ConversationContext, MemoryUpdateQueue
from deerflow.config.memory_config import MemoryConfig
from deerflow.trace_context import get_current_trace_id, request_trace_context


def _memory_config(**overrides: object) -> MemoryConfig:
    config = MemoryConfig()
    for key, value in overrides.items():
        setattr(config, key, value)
    return config


def test_queue_add_preserves_existing_correction_flag_for_same_thread() -> None:
    queue = MemoryUpdateQueue()

    with (
        patch("deerflow.agents.memory.queue.get_memory_config", return_value=_memory_config(enabled=True)),
        patch.object(queue, "_reset_timer"),
    ):
        queue.add(thread_id="thread-1", messages=["first"], correction_detected=True)
        queue.add(thread_id="thread-1", messages=["second"], correction_detected=False)

    assert len(queue._queue) == 1
    assert queue._queue[0].messages == ["second"]
    assert queue._queue[0].correction_detected is True


def test_process_queue_forwards_correction_flag_to_updater() -> None:
    queue = MemoryUpdateQueue()
    queue._queue = [
        ConversationContext(
            thread_id="thread-1",
            messages=["conversation"],
            agent_name="lead_agent",
            correction_detected=True,
        )
    ]
    mock_updater = MagicMock()
    mock_updater.update_memory.return_value = True

    with patch("deerflow.agents.memory.updater.MemoryUpdater", return_value=mock_updater):
        queue._process_queue()

    mock_updater.update_memory.assert_called_once_with(
        messages=["conversation"],
        thread_id="thread-1",
        agent_name="lead_agent",
        correction_detected=True,
        reinforcement_detected=False,
        user_id=None,
        deerflow_trace_id=None,
    )


def test_queue_add_preserves_existing_reinforcement_flag_for_same_thread() -> None:
    queue = MemoryUpdateQueue()

    with (
        patch("deerflow.agents.memory.queue.get_memory_config", return_value=_memory_config(enabled=True)),
        patch.object(queue, "_reset_timer"),
    ):
        queue.add(thread_id="thread-1", messages=["first"], reinforcement_detected=True)
        queue.add(thread_id="thread-1", messages=["second"], reinforcement_detected=False)

    assert len(queue._queue) == 1
    assert queue._queue[0].messages == ["second"]
    assert queue._queue[0].reinforcement_detected is True


def test_process_queue_forwards_reinforcement_flag_to_updater() -> None:
    queue = MemoryUpdateQueue()
    queue._queue = [
        ConversationContext(
            thread_id="thread-1",
            messages=["conversation"],
            agent_name="lead_agent",
            reinforcement_detected=True,
        )
    ]
    mock_updater = MagicMock()
    mock_updater.update_memory.return_value = True

    with patch("deerflow.agents.memory.updater.MemoryUpdater", return_value=mock_updater):
        queue._process_queue()

    mock_updater.update_memory.assert_called_once_with(
        messages=["conversation"],
        thread_id="thread-1",
        agent_name="lead_agent",
        correction_detected=False,
        reinforcement_detected=True,
        user_id=None,
        deerflow_trace_id=None,
    )


def test_flush_nowait_cancels_existing_timer_and_starts_immediate_timer() -> None:
    queue = MemoryUpdateQueue()
    existing_timer = MagicMock()
    queue._timer = existing_timer
    created_timer = MagicMock()

    with patch("deerflow.agents.memory.queue.threading.Timer", return_value=created_timer) as timer_cls:
        queue.flush_nowait()

    existing_timer.cancel.assert_called_once_with()
    timer_cls.assert_called_once_with(0, queue._process_queue)
    assert created_timer.daemon is True
    created_timer.start.assert_called_once_with()
    assert queue._timer is created_timer


def test_add_nowait_cancels_existing_timer_and_starts_immediate_timer() -> None:
    queue = MemoryUpdateQueue()
    existing_timer = MagicMock()
    queue._timer = existing_timer
    created_timer = MagicMock()

    with (
        patch("deerflow.agents.memory.queue.get_memory_config", return_value=_memory_config(enabled=True)),
        patch("deerflow.agents.memory.queue.threading.Timer", return_value=created_timer) as timer_cls,
    ):
        queue.add_nowait(thread_id="thread-1", messages=["conversation"], agent_name="lead-agent")

    existing_timer.cancel.assert_called_once_with()
    timer_cls.assert_called_once_with(0, queue._process_queue)
    assert queue.pending_count == 1
    assert queue._queue[0].agent_name == "lead-agent"
    assert created_timer.daemon is True
    created_timer.start.assert_called_once_with()


def test_process_queue_defers_reprocess_when_already_processing() -> None:
    """When a timer fires while a worker is active, ``_process_queue`` must set the
    deferred-rerun flag instead of spinning up a tight 0-delay Timer chain.

    The old behavior re-scheduled a 0-delay Timer on every re-entry while busy,
    burning a fresh thread each time. The fix defers a single re-run via
    ``_reprocess_pending`` that the finishing worker honors once.
    """
    queue = MemoryUpdateQueue()
    queue._processing = True

    with patch("deerflow.agents.memory.queue.threading.Timer") as timer_cls:
        queue._process_queue()

    timer_cls.assert_not_called()
    assert queue._reprocess_pending is True


def test_finishing_worker_reschedules_once_when_reprocess_pending() -> None:
    """A worker that finishes with ``_reprocess_pending`` set and work still queued
    schedules exactly one follow-up run (not a per-arrival timer spin)."""
    queue = MemoryUpdateQueue()
    queue._queue = [ConversationContext(thread_id="thread-1", messages=["first"], agent_name="lead_agent")]
    queue._reprocess_pending = True
    created_timer = MagicMock()
    mock_updater = MagicMock()

    def _enqueue_more_while_processing(**_kwargs) -> bool:
        # Simulate a new update arriving mid-processing so the finally block sees
        # remaining work and reschedules exactly once.
        queue._queue.append(ConversationContext(thread_id="thread-2", messages=["second"], agent_name="lead_agent"))
        return True

    mock_updater.update_memory.side_effect = _enqueue_more_while_processing

    with (
        patch("deerflow.agents.memory.updater.MemoryUpdater", return_value=mock_updater),
        patch("deerflow.agents.memory.queue.threading.Timer", return_value=created_timer) as timer_cls,
    ):
        queue._process_queue()

    timer_cls.assert_called_once_with(0, queue._process_queue)
    assert created_timer.daemon is True
    created_timer.start.assert_called_once_with()
    assert queue._reprocess_pending is False


def test_finishing_worker_does_not_reschedule_when_no_work_remains() -> None:
    """The deferred re-run is cleared even when nothing is left to process, so a
    stray flag never leaves a dangling ``_reprocess_pending``."""
    queue = MemoryUpdateQueue()
    queue._queue = [ConversationContext(thread_id="thread-1", messages=["only"], agent_name="lead_agent")]
    queue._reprocess_pending = True
    mock_updater = MagicMock()
    mock_updater.update_memory.return_value = True

    with (
        patch("deerflow.agents.memory.updater.MemoryUpdater", return_value=mock_updater),
        patch("deerflow.agents.memory.queue.threading.Timer") as timer_cls,
    ):
        queue._process_queue()

    timer_cls.assert_not_called()
    assert queue._reprocess_pending is False


def test_flush_nowait_is_non_blocking() -> None:
    queue = MemoryUpdateQueue()
    started = threading.Event()
    finished = threading.Event()

    def _slow_process_queue() -> None:
        started.set()
        time.sleep(0.2)
        finished.set()

    queue._process_queue = _slow_process_queue

    start = time.perf_counter()
    queue.flush_nowait()
    elapsed = time.perf_counter() - start

    assert started.wait(0.1) is True
    assert elapsed < 0.1
    assert finished.is_set() is False
    assert finished.wait(1.0) is True


def test_queue_keeps_updates_for_different_agents_in_same_thread() -> None:
    queue = MemoryUpdateQueue()

    with (
        patch("deerflow.agents.memory.queue.get_memory_config", return_value=_memory_config(enabled=True)),
        patch.object(queue, "_reset_timer"),
    ):
        queue.add(thread_id="thread-1", messages=["agent-a"], agent_name="agent-a")
        queue.add(thread_id="thread-1", messages=["agent-b"], agent_name="agent-b")

    assert queue.pending_count == 2
    assert [context.agent_name for context in queue._queue] == ["agent-a", "agent-b"]


def test_queue_still_coalesces_updates_for_same_agent_in_same_thread() -> None:
    queue = MemoryUpdateQueue()

    with (
        patch("deerflow.agents.memory.queue.get_memory_config", return_value=_memory_config(enabled=True)),
        patch.object(queue, "_reset_timer"),
    ):
        queue.add(
            thread_id="thread-1",
            messages=["first"],
            agent_name="agent-a",
            correction_detected=True,
        )
        queue.add(
            thread_id="thread-1",
            messages=["second"],
            agent_name="agent-a",
            correction_detected=False,
        )

    assert queue.pending_count == 1
    assert queue._queue[0].agent_name == "agent-a"
    assert queue._queue[0].messages == ["second"]
    assert queue._queue[0].correction_detected is True


def test_process_queue_updates_different_agents_in_same_thread_separately() -> None:
    queue = MemoryUpdateQueue()

    with (
        patch("deerflow.agents.memory.queue.get_memory_config", return_value=_memory_config(enabled=True)),
        patch.object(queue, "_reset_timer"),
    ):
        queue.add(thread_id="thread-1", messages=["agent-a"], agent_name="agent-a")
        queue.add(thread_id="thread-1", messages=["agent-b"], agent_name="agent-b")

    mock_updater = MagicMock()
    mock_updater.update_memory.return_value = True

    with (
        patch("deerflow.agents.memory.updater.MemoryUpdater", return_value=mock_updater),
        patch("deerflow.agents.memory.queue.time.sleep"),
    ):
        queue.flush()

    assert mock_updater.update_memory.call_count == 2
    mock_updater.update_memory.assert_has_calls(
        [
            call(
                messages=["agent-a"],
                thread_id="thread-1",
                agent_name="agent-a",
                correction_detected=False,
                reinforcement_detected=False,
                user_id=None,
                deerflow_trace_id=None,
            ),
            call(
                messages=["agent-b"],
                thread_id="thread-1",
                agent_name="agent-b",
                correction_detected=False,
                reinforcement_detected=False,
                user_id=None,
                deerflow_trace_id=None,
            ),
        ]
    )


def test_process_queue_forwards_deerflow_trace_id_to_updater() -> None:
    queue = MemoryUpdateQueue()
    queue._queue = [
        ConversationContext(
            thread_id="thread-1",
            messages=["conversation"],
            agent_name="lead_agent",
            deerflow_trace_id="trace-memory-1",
        )
    ]
    mock_updater = MagicMock()
    mock_updater.update_memory.return_value = True

    with patch("deerflow.agents.memory.updater.MemoryUpdater", return_value=mock_updater):
        queue._process_queue()

    mock_updater.update_memory.assert_called_once_with(
        messages=["conversation"],
        thread_id="thread-1",
        agent_name="lead_agent",
        correction_detected=False,
        reinforcement_detected=False,
        user_id=None,
        deerflow_trace_id="trace-memory-1",
    )


class TestProcessQueueBindsTraceContextVar:
    """Regression: ``_process_queue`` runs in a Timer thread where the request
    trace ContextVar is unbound. The per-context iteration must bind
    ``ConversationContext.deerflow_trace_id`` into the ContextVar so
    ``TraceContextFilter`` (which only reads the ContextVar) attaches the correct
    ``trace_id`` to log records emitted from ``queue.py`` itself (``"Updating
    memory for thread ..."``, ``"Memory updated successfully..."``, exception
    logs) — not just from the deep memory-updater stack.
    """

    @staticmethod
    def _run_process_queue_in_fresh_thread(queue: MemoryUpdateQueue, mock_updater: MagicMock) -> None:
        def _target() -> None:
            with patch("deerflow.agents.memory.updater.MemoryUpdater", return_value=mock_updater):
                queue._process_queue()

        thread = threading.Thread(target=_target)
        thread.start()
        thread.join()

    def test_process_queue_binds_deerflow_trace_id_during_iteration(self) -> None:
        queue = MemoryUpdateQueue()
        queue._queue = [
            ConversationContext(
                thread_id="thread-1",
                messages=["conversation"],
                agent_name="lead_agent",
                deerflow_trace_id="trace-queue-abc",
            )
        ]
        captured: list[str | None] = []
        mock_updater = MagicMock()

        def _capture(**_kwargs) -> bool:
            captured.append(get_current_trace_id())
            return True

        mock_updater.update_memory.side_effect = _capture

        self._run_process_queue_in_fresh_thread(queue, mock_updater)

        assert captured == ["trace-queue-abc"]

    def test_process_queue_binds_distinct_ids_per_context(self) -> None:
        """Each queued context must be scoped independently — a per-iteration bind,
        not a batch-level one — so id A's logs don't bleed into id B's iteration."""
        queue = MemoryUpdateQueue()
        queue._queue = [
            ConversationContext(
                thread_id="thread-1",
                messages=["conv-a"],
                agent_name="agent-a",
                deerflow_trace_id="trace-a",
            ),
            ConversationContext(
                thread_id="thread-2",
                messages=["conv-b"],
                agent_name="agent-b",
                deerflow_trace_id="trace-b",
            ),
        ]
        captured: list[str | None] = []
        mock_updater = MagicMock()

        def _capture(**_kwargs) -> bool:
            captured.append(get_current_trace_id())
            return True

        mock_updater.update_memory.side_effect = _capture

        with (
            patch("deerflow.agents.memory.updater.MemoryUpdater", return_value=mock_updater),
            patch("deerflow.agents.memory.queue.time.sleep"),
        ):
            queue._process_queue()

        assert captured == ["trace-a", "trace-b"]

    def test_process_queue_leaves_contextvar_unbound_when_no_trace_id(self) -> None:
        """A queued context without ``deerflow_trace_id`` must not fabricate one;
        the ContextVar stays unbound and log records fall through to '-'."""
        queue = MemoryUpdateQueue()
        queue._queue = [
            ConversationContext(
                thread_id="thread-1",
                messages=["conversation"],
                agent_name="lead_agent",
                deerflow_trace_id=None,
            )
        ]
        captured: list[str | None] = []
        mock_updater = MagicMock()

        def _capture(**_kwargs) -> bool:
            captured.append(get_current_trace_id())
            return True

        mock_updater.update_memory.side_effect = _capture

        self._run_process_queue_in_fresh_thread(queue, mock_updater)

        assert captured == [None]

    def test_process_queue_restores_outer_contextvar_after_return(self) -> None:
        queue = MemoryUpdateQueue()
        queue._queue = [
            ConversationContext(
                thread_id="thread-1",
                messages=["conversation"],
                agent_name="lead_agent",
                deerflow_trace_id="trace-inner",
            )
        ]
        mock_updater = MagicMock()
        mock_updater.update_memory.return_value = True

        with (
            request_trace_context("trace-outer"),
            patch("deerflow.agents.memory.updater.MemoryUpdater", return_value=mock_updater),
        ):
            queue._process_queue()
            assert get_current_trace_id() == "trace-outer"