immich/mobile/lib/pages/common/native_video_viewer.page.dart

import 'dart:async';
import 'dart:io';

import 'package:auto_route/auto_route.dart';
import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart' hide Store;
import 'package:hooks_riverpod/hooks_riverpod.dart';
import 'package:immich_mobile/domain/models/store.model.dart';
import 'package:immich_mobile/entities/asset.entity.dart';
import 'package:immich_mobile/entities/store.entity.dart';
import 'package:immich_mobile/providers/app_settings.provider.dart';
import 'package:immich_mobile/providers/asset_viewer/current_asset.provider.dart';
import 'package:immich_mobile/providers/asset_viewer/is_motion_video_playing.provider.dart';
import 'package:immich_mobile/providers/asset_viewer/video_player_controls_provider.dart';
import 'package:immich_mobile/providers/asset_viewer/video_player_value_provider.dart';
import 'package:immich_mobile/providers/cast.provider.dart';
import 'package:immich_mobile/services/api.service.dart';
import 'package:immich_mobile/services/app_settings.service.dart';
import 'package:immich_mobile/services/asset.service.dart';
import 'package:immich_mobile/utils/debounce.dart';
import 'package:immich_mobile/utils/hooks/interval_hook.dart';
import 'package:immich_mobile/widgets/asset_viewer/custom_video_player_controls.dart';
import 'package:logging/logging.dart';
import 'package:native_video_player/native_video_player.dart';
import 'package:wakelock_plus/wakelock_plus.dart';

@RoutePage()
class NativeVideoViewerPage extends HookConsumerWidget {
  static final log = Logger('NativeVideoViewer');
  final Asset asset;
  final bool showControls;
  final int playbackDelayFactor;
  final Widget image;

  const NativeVideoViewerPage({
    super.key,
    required this.asset,
    required this.image,
    this.showControls = true,
    this.playbackDelayFactor = 1,
  });

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final controller = useState<NativeVideoPlayerController?>(null);
    final lastVideoPosition = useRef(-1);
    final isBuffering = useRef(false);

    // Used to track whether the video should play when the app
    // is brought back to the foreground
    final shouldPlayOnForeground = useRef(true);

    // When a video is opened through the timeline, `isCurrent` will immediately be true.
    // When swiping from video A to video B, `isCurrent` will initially be true for video A and false for video B.
    // If the swipe is completed, `isCurrent` will be true for video B after a delay.
    // If the swipe is canceled, `currentAsset` will not have changed and video A will continue to play.
    final currentAsset = useState(ref.read(currentAssetProvider));
    final isCurrent = currentAsset.value == asset;

    // Used to show the placeholder during hero animations for remote videos to avoid a stutter
    final isVisible = useState(Platform.isIOS && asset.isLocal);

    final isCasting = ref.watch(castProvider.select((c) => c.isCasting));

    final isVideoReady = useState(false);

    Future<VideoSource?> createSource() async {
      if (!context.mounted) {
        return null;
      }

      try {
        final local = asset.local;
        if (local != null && asset.livePhotoVideoId == null) {
          final file = await local.file;
          if (file == null) {
            throw Exception('No file found for the video');
          }

          final source = await VideoSource.init(path: file.path, type: VideoSourceType.file);
          return source;
        }

        // Use a network URL for the video player controller
        final serverEndpoint = Store.get(StoreKey.serverEndpoint);
        final isOriginalVideo = ref
            .read(appSettingsServiceProvider)
            .getSetting<bool>(AppSettingsEnum.loadOriginalVideo);
        final String postfixUrl = isOriginalVideo ? 'original' : 'video/playback';
        final String videoUrl = asset.livePhotoVideoId != null
            ? '$serverEndpoint/assets/${asset.livePhotoVideoId}/$postfixUrl'
            : '$serverEndpoint/assets/${asset.remoteId}/$postfixUrl';

        final source = await VideoSource.init(
          path: videoUrl,
          type: VideoSourceType.network,
          headers: ApiService.getRequestHeaders(),
        );
        return source;
      } catch (error) {
        log.severe('Error creating video source for asset ${asset.fileName}: $error');
        return null;
      }
    }

    final videoSource = useMemoized<Future<VideoSource?>>(() => createSource());
    final aspectRatio = useState<double?>(asset.aspectRatio);
    useMemoized(() async {
      if (!context.mounted || aspectRatio.value != null) {
        return null;
      }

      try {
        aspectRatio.value = await ref.read(assetServiceProvider).getAspectRatio(asset);
      } catch (error) {
        log.severe('Error getting aspect ratio for asset ${asset.fileName}: $error');
      }
    });

    void checkIfBuffering() {
      if (!context.mounted) {
        return;
      }

      final videoPlayback = ref.read(videoPlaybackValueProvider);
      if ((isBuffering.value || videoPlayback.state == VideoPlaybackState.initializing) &&
          videoPlayback.state != VideoPlaybackState.buffering) {
        ref.read(videoPlaybackValueProvider.notifier).value = videoPlayback.copyWith(
          state: VideoPlaybackState.buffering,
        );
      }
    }

    // Timer to mark videos as buffering if the position does not change
    useInterval(const Duration(seconds: 5), checkIfBuffering);

    // When the position changes, seek to the position
    // Debounce the seek to avoid seeking too often
    // But also don't delay the seek too much to maintain visual feedback
    final seekDebouncer = useDebouncer(
      interval: const Duration(milliseconds: 100),
      maxWaitTime: const Duration(milliseconds: 200),
    );
    ref.listen(videoPlayerControlsProvider, (oldControls, newControls) {
      final playerController = controller.value;
      if (playerController == null) {
        return;
      }

      final playbackInfo = playerController.playbackInfo;
      if (playbackInfo == null) {
        return;
      }

      final oldSeek = oldControls?.position.inMilliseconds;
      final newSeek = newControls.position.inMilliseconds;
      if (oldSeek != newSeek || newControls.restarted) {
        seekDebouncer.run(() => playerController.seekTo(newSeek));
      }

      if (oldControls?.pause != newControls.pause || newControls.restarted) {
        unawaited(_onPauseChange(context, playerController, seekDebouncer, newControls.pause));
      }
    });

    void onPlaybackReady() async {
      final videoController = controller.value;
      if (videoController == null || !isCurrent || !context.mounted) {
        return;
      }

      final videoPlayback = VideoPlaybackValue.fromNativeController(videoController);
      ref.read(videoPlaybackValueProvider.notifier).value = videoPlayback;

      isVideoReady.value = true;

      try {
        final autoPlayVideo = ref.read(appSettingsServiceProvider).getSetting<bool>(AppSettingsEnum.autoPlayVideo);
        if (autoPlayVideo) {
          await videoController.play();
        }
        await videoController.setVolume(0.9);
      } catch (error) {
        log.severe('Error playing video: $error');
      }
    }

    void onPlaybackStatusChanged() {
      final videoController = controller.value;
      if (videoController == null || !context.mounted) {
        return;
      }

      final videoPlayback = VideoPlaybackValue.fromNativeController(videoController);
      if (videoPlayback.state == VideoPlaybackState.playing) {
        // Sync with the controls playing
        WakelockPlus.enable();
      } else {
        // Sync with the controls pause
        WakelockPlus.disable();
      }

      ref.read(videoPlaybackValueProvider.notifier).status = videoPlayback.state;
    }

    void onPlaybackPositionChanged() {
      // When seeking, these events sometimes move the slider to an older position
      if (seekDebouncer.isActive) {
        return;
      }

      final videoController = controller.value;
      if (videoController == null || !context.mounted) {
        return;
      }

      final playbackInfo = videoController.playbackInfo;
      if (playbackInfo == null) {
        return;
      }

      ref.read(videoPlaybackValueProvider.notifier).position = Duration(milliseconds: playbackInfo.position);

      // Check if the video is buffering
      if (playbackInfo.status == PlaybackStatus.playing) {
        isBuffering.value = lastVideoPosition.value == playbackInfo.position;
        lastVideoPosition.value = playbackInfo.position;
      } else {
        isBuffering.value = false;
        lastVideoPosition.value = -1;
      }
    }

    void onPlaybackEnded() {
      final videoController = controller.value;
      if (videoController == null || !context.mounted) {
        return;
      }

      if (videoController.playbackInfo?.status == PlaybackStatus.stopped &&
          !ref.read(appSettingsServiceProvider).getSetting<bool>(AppSettingsEnum.loopVideo)) {
        ref.read(isPlayingMotionVideoProvider.notifier).playing = false;
      }
    }

    void removeListeners(NativeVideoPlayerController controller) {
      controller.onPlaybackPositionChanged.removeListener(onPlaybackPositionChanged);
      controller.onPlaybackStatusChanged.removeListener(onPlaybackStatusChanged);
      controller.onPlaybackReady.removeListener(onPlaybackReady);
      controller.onPlaybackEnded.removeListener(onPlaybackEnded);
    }

    void initController(NativeVideoPlayerController nc) async {
      if (controller.value != null || !context.mounted) {
        return;
      }
      ref.read(videoPlayerControlsProvider.notifier).reset();
      ref.read(videoPlaybackValueProvider.notifier).reset();

      final source = await videoSource;
      if (source == null) {
        return;
      }

      nc.onPlaybackPositionChanged.addListener(onPlaybackPositionChanged);
      nc.onPlaybackStatusChanged.addListener(onPlaybackStatusChanged);
      nc.onPlaybackReady.addListener(onPlaybackReady);
      nc.onPlaybackEnded.addListener(onPlaybackEnded);

      nc.loadVideoSource(source).catchError((error) {
        log.severe('Error loading video source: $error');
      });
      final loopVideo = ref.read(appSettingsServiceProvider).getSetting<bool>(AppSettingsEnum.loopVideo);
      nc.setLoop(loopVideo);

      controller.value = nc;
      Timer(const Duration(milliseconds: 200), checkIfBuffering);
    }

    ref.listen(currentAssetProvider, (_, value) {
      final playerController = controller.value;
      if (playerController != null && value != asset) {
        removeListeners(playerController);
      }

      final curAsset = currentAsset.value;
      if (curAsset == asset) {
        return;
      }

      final imageToVideo = curAsset != null && !curAsset.isVideo;

      // No need to delay video playback when swiping from an image to a video
      if (imageToVideo && Platform.isIOS) {
        currentAsset.value = value;
        onPlaybackReady();
        return;
      }

      // Delay the video playback to avoid a stutter in the swipe animation
      // Note, in some circumstances a longer delay is needed (eg: memories),
      // the playbackDelayFactor can be used for this
      // This delay seems like a hacky way to resolve underlying bugs in video
      // playback, but other resolutions failed thus far
      Timer(
        Platform.isIOS
            ? Duration(milliseconds: 300 * playbackDelayFactor)
            : imageToVideo
            ? Duration(milliseconds: 200 * playbackDelayFactor)
            : Duration(milliseconds: 400 * playbackDelayFactor),
        () {
          if (!context.mounted) {
            return;
          }

          currentAsset.value = value;
          if (currentAsset.value == asset) {
            onPlaybackReady();
          }
        },
      );
    });

    useEffect(() {
      // If opening a remote video from a hero animation, delay visibility to avoid a stutter
      final timer = isVisible.value ? null : Timer(const Duration(milliseconds: 300), () => isVisible.value = true);

      return () {
        timer?.cancel();
        final playerController = controller.value;
        if (playerController == null) {
          return;
        }
        removeListeners(playerController);
        playerController.stop().catchError((error) {
          log.fine('Error stopping video: $error');
        });

        WakelockPlus.disable();
      };
    }, const []);

    useOnAppLifecycleStateChange((_, state) async {
      if (state == AppLifecycleState.resumed && shouldPlayOnForeground.value) {
        controller.value?.play();
      } else if (state == AppLifecycleState.paused) {
        final videoPlaying = await controller.value?.isPlaying();
        if (videoPlaying ?? true) {
          shouldPlayOnForeground.value = true;
          controller.value?.pause();
        } else {
          shouldPlayOnForeground.value = false;
        }
      }
    });

    return Stack(
      children: [
        // This remains under the video to avoid flickering
        // For motion videos, this is the image portion of the asset
        if (!isVideoReady.value || asset.isMotionPhoto) Center(key: ValueKey(asset.id), child: image),
        if (aspectRatio.value != null && !isCasting)
          Visibility.maintain(
            key: ValueKey(asset),
            visible: isVisible.value,
            child: Center(
              key: ValueKey(asset),
              child: AspectRatio(
                key: ValueKey(asset),
                aspectRatio: aspectRatio.value!,
                child: isCurrent ? NativeVideoPlayerView(key: ValueKey(asset), onViewReady: initController) : null,
              ),
            ),
          ),
        if (showControls) const Center(child: CustomVideoPlayerControls()),
      ],
    );
  }

  Future<void> _onPauseChange(
    BuildContext context,
    NativeVideoPlayerController controller,
    Debouncer seekDebouncer,
    bool isPaused,
  ) async {
    if (!context.mounted) {
      return;
    }

    // Make sure the last seek is complete before pausing or playing
    // Otherwise, `onPlaybackPositionChanged` can receive outdated events
    if (seekDebouncer.isActive) {
      await seekDebouncer.drain();
    }

    if (!context.mounted) {
      return;
    }

    try {
      if (isPaused) {
        await controller.pause();
      } else {
        await controller.play();
      }
    } catch (error) {
      log.severe('Error pausing or playing video: $error');
    }
  }
}