feat(playback): restart before previous episode

close #979

lib/screens/video_player/parts/build.dart

@@ -146,7 +146,8 @@ extension _VideoPlayerBuildMethods on VideoPlayerScreenState {
                     if (widget.isLive) {
                       onPrevious = _hasPreviousChannel ? () => _switchLiveChannel(-1) : null;
                     } else {
-                      onPrevious = (_previousEpisode != null && _canNavigateEpisodes()) ? _playPrevious : null;
+                      final canRestartOrPrevious = _currentMetadata.isEpisode || _previousEpisode != null;
+                      onPrevious = (canRestartOrPrevious && _canNavigateEpisodes()) ? _restartOrPlayPrevious : null;
                     }
 
                     return Video(
@@ -172,19 +173,7 @@ extension _VideoPlayerBuildMethods on VideoPlayerScreenState {
                         onAudioTrackChanged: _onAudioTrackChanged,
                         onSubtitleTrackChanged: _onSubtitleTrackChanged,
                         onSecondarySubtitleTrackChanged: _onSecondarySubtitleTrackChanged,
-                        onSeekCompleted: (position) {
-                          // Notify Watch Together of seek for sync
-                          // Note: canControl() check is done in sync manager, not here
-                          // This matches play/pause behavior and avoids timing issues
-                          try {
-                            final watchTogether = this.context.read<WatchTogetherProvider>();
-                            if (watchTogether.isInSession) {
-                              watchTogether.onLocalSeek(position);
-                            }
-                          } catch (e) {
-                            // Watch Together not available, ignore
-                          }
-                        },
+                        onSeekCompleted: _notifyWatchTogetherSeek,
                         onBack: _handleBackButton,
                         onReachedEnd: ({skipAutoPlayCountdown = false}) =>
                             _onVideoCompleted(true, skipAutoPlayCountdown: skipAutoPlayCountdown),

lib/screens/video_player/parts/companion_remote.dart

@@ -10,7 +10,7 @@ extension _VideoPlayerCompanionRemoteMethods on VideoPlayerScreenState {
       if (mounted && _nextEpisode != null) _playNext();
     };
     receiver.onPreviousTrack = () {
-      if (mounted && _previousEpisode != null) _playPrevious();
+      if (mounted) unawaited(_restartOrPlayPrevious());
     };
     receiver.onSeekForward = () async {
       if (player == null) return;

lib/screens/video_player/parts/episode_navigation.dart

@@ -29,6 +29,31 @@ extension _VideoPlayerEpisodeNavigationMethods on VideoPlayerScreenState {
     await _navigateToEpisode(_previousEpisode!);
   }
 
+  Future<void> _restartOrPlayPrevious() async {
+    final currentPlayer = player;
+    if (!mounted || currentPlayer == null || _isLoadingPrevious) return;
+
+    if (!shouldRestartBeforePreviousItem(currentPlayer.state.position) && _previousEpisode != null) {
+      await _playPrevious();
+      return;
+    }
+
+    _autoPlayTimer?.cancel();
+    _dismissStillWatching();
+
+    _setPlayerState(() {
+      _showPlayNextDialog = false;
+      _completionTriggered = false;
+    });
+
+    final target = clampSeekPosition(currentPlayer, Duration.zero);
+    await currentPlayer.seek(target);
+    if (!mounted || currentPlayer != player) return;
+
+    _notifyWatchTogetherSeek(target);
+    _updateMediaControlsPlaybackState();
+  }
+
   /// Navigates to a new episode, preserving playback state and track selections.
   /// When PiP is active, swaps the media source in-place to keep the PiP window alive.
   Future<void> _navigateToEpisode(MediaItem episodeMetadata) async {

lib/screens/video_player/parts/playback_services.dart

@@ -123,7 +123,7 @@ extension _VideoPlayerPlaybackServiceMethods on VideoPlayerScreenState {
         if (_nextEpisode != null) _playNext();
       } else if (event is PreviousTrackEvent) {
         appLogger.d('Media control: Previous track event received');
-        if (_previousEpisode != null) _playPrevious();
+        unawaited(_restartOrPlayPrevious());
       }
     });
 

lib/screens/video_player/parts/watch_together.dart

@@ -63,6 +63,18 @@ extension _VideoPlayerWatchTogetherMethods on VideoPlayerScreenState {
     }
   }
 
+  void _notifyWatchTogetherSeek(Duration position) {
+    try {
+      final watchTogether = context.read<WatchTogetherProvider>();
+      if (watchTogether.isInSession) {
+        // Sync manager applies canControl checks; matching play/pause avoids timing gaps.
+        watchTogether.onLocalSeek(position);
+      }
+    } catch (e) {
+      appLogger.d('Could not notify watch together of seek', error: e);
+    }
+  }
+
   /// Handle media switch from host (guest only)
   /// Uses VideoPlayerScreen's context for proper navigation (pushReplacement)
   Future<void> _handlePlayerMediaSwitch(String ratingKey, String serverId, String title) async {

lib/utils/player_utils.dart

@@ -1,5 +1,11 @@
 import '../mpv/mpv.dart';
 
+const restartBeforePreviousItemThreshold = Duration(seconds: 3);
+
+bool shouldRestartBeforePreviousItem(Duration position) {
+  return position > restartBeforePreviousItemThreshold;
+}
+
 Duration clampSeekPosition(Player player, Duration position) {
   final duration = player.state.duration;
   if (position.isNegative) return Duration.zero;

test/utils/player_utils_test.dart

@@ -0,0 +1,15 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:plezy/utils/player_utils.dart';
+
+void main() {
+  group('shouldRestartBeforePreviousItem', () {
+    test('keeps previous item behavior within the restart threshold', () {
+      expect(shouldRestartBeforePreviousItem(Duration.zero), isFalse);
+      expect(shouldRestartBeforePreviousItem(const Duration(seconds: 3)), isFalse);
+    });
+
+    test('restarts the current item after the threshold', () {
+      expect(shouldRestartBeforePreviousItem(const Duration(milliseconds: 3001)), isTrue);
+    });
+  });
+}