#
# Copyright (c) 2024-2026, Daily
#
# SPDX-License-Identifier: BSD 2-Clause License
#

"""Tests for LiveKit transport video stream handling.

Regression tests for issue #3116: Memory leak when video_in_enabled=False
but video tracks are subscribed. The fix ensures video stream processing
only starts when there is a consumer for the frames.
"""

import unittest
from unittest.mock import AsyncMock, MagicMock, patch

try:
    from livekit import rtc

    from pipecat.transports.livekit.transport import (
        LiveKitCallbacks,
        LiveKitParams,
        LiveKitTransportClient,
    )

    LIVEKIT_AVAILABLE = True
except ImportError:
    LIVEKIT_AVAILABLE = False


@unittest.skipUnless(LIVEKIT_AVAILABLE, "livekit package not installed")
class TestLiveKitVideoStreamMemoryLeak(unittest.IsolatedAsyncioTestCase):
    """Regression tests for video queue memory leak (#3116).

    The bug: When video_in_enabled=False, subscribing to a video track would
    start a producer that fills _video_queue, but no consumer would drain it,
    causing unbounded memory growth (~3GB/min).

    The fix: Only start video stream processing when video_in_enabled=True.
    """

    def _create_client(self, video_in_enabled: bool) -> LiveKitTransportClient:
        """Create a client with the specified video input setting."""
        params = LiveKitParams(video_in_enabled=video_in_enabled)
        callbacks = LiveKitCallbacks(
            on_connected=AsyncMock(),
            on_disconnected=AsyncMock(),
            on_before_disconnect=AsyncMock(),
            on_participant_connected=AsyncMock(),
            on_participant_disconnected=AsyncMock(),
            on_audio_track_subscribed=AsyncMock(),
            on_audio_track_unsubscribed=AsyncMock(),
            on_video_track_subscribed=AsyncMock(),
            on_video_track_unsubscribed=AsyncMock(),
            on_data_received=AsyncMock(),
            on_first_participant_joined=AsyncMock(),
        )
        client = LiveKitTransportClient(
            url="wss://test.livekit.cloud",
            token="test-token",
            room_name="test-room",
            params=params,
            callbacks=callbacks,
            transport_name="test-transport",
        )
        client._task_manager = MagicMock()
        return client

    def _create_mock_video_track(self):
        """Create a mock video track subscription event."""
        track = MagicMock()
        track.kind = rtc.TrackKind.KIND_VIDEO
        track.sid = "video-track-123"
        publication = MagicMock()
        participant = MagicMock()
        participant.sid = "participant-456"
        return track, publication, participant

    async def test_disabled_video_input_does_not_start_queue_producer(self):
        """When video input is disabled, no producer should fill the queue.

        This prevents the memory leak where frames accumulate with no consumer.
        """
        client = self._create_client(video_in_enabled=False)
        track, publication, participant = self._create_mock_video_track()

        await client._async_on_track_subscribed(track, publication, participant)

        # Verify no video processing task was started
        task_names = [call[0][1] for call in client._task_manager.create_task.call_args_list]
        video_tasks = [name for name in task_names if "video" in name.lower()]
        self.assertEqual(video_tasks, [], "No video processing task should be started")

        # Queue should remain empty
        self.assertEqual(client._video_queue.qsize(), 0)

        # Track metadata should still be recorded
        self.assertIn(participant.sid, client._video_tracks)

        # Callback should still fire for user code
        client._callbacks.on_video_track_subscribed.assert_called_once()

    async def test_enabled_video_input_starts_queue_producer(self):
        """When video input is enabled, the producer should start."""
        client = self._create_client(video_in_enabled=True)
        track, publication, participant = self._create_mock_video_track()

        with patch.object(rtc, "VideoStream"):
            await client._async_on_track_subscribed(track, publication, participant)

        # Verify video processing task was started
        task_names = [call[0][1] for call in client._task_manager.create_task.call_args_list]
        video_tasks = [name for name in task_names if "video" in name.lower()]
        self.assertEqual(len(video_tasks), 1, "Video processing task should be started")

        # Track metadata should be recorded
        self.assertIn(participant.sid, client._video_tracks)

        # Callback should fire
        client._callbacks.on_video_track_subscribed.assert_called_once()


if __name__ == "__main__":
    unittest.main()