fix(player): 修复详情往返播放位置丢失

lib/pages/player/player_binding.dart

@@ -4,6 +4,7 @@ import '../../core/data/repositories/watch_history_repository.dart';
 import '../../core/data/repositories/playback_repository.dart';
 import '../../core/data/services/android_picture_in_picture.dart';
 import '../../core/data/services/download_controller.dart';
+import '../../core/data/services/playback_position_cache.dart';
 import '../../core/data/services/wallet_controller.dart';
 import 'player_logic.dart';
 
@@ -11,11 +12,13 @@ class PlayerBinding {
   PlayerLogic create({
     required WatchHistoryRepository history,
     required PlaybackRepository playback,
+    required PlaybackPositionCache positionCache,
     WalletController? wallet,
     DownloadController? downloads,
   }) => PlayerLogic(
     history: history,
     playback: playback,
+    positionCache: positionCache,
     pictureInPicture: AndroidPictureInPicture(),
     wallet: wallet,
     downloads: downloads,

lib/pages/player/player_logic.dart

@@ -17,6 +17,7 @@ import '../../core/data/services/android_picture_in_picture.dart';
 import '../../core/data/services/catalog_controller.dart';
 import '../../core/data/services/download_controller.dart';
 import '../../core/data/services/platform_share_service.dart';
+import '../../core/data/services/playback_position_cache.dart';
 import '../../core/data/services/playback_queue.dart';
 import '../../core/data/services/playback_session.dart';
 import '../../core/data/services/video_player_port.dart';
@@ -40,8 +41,10 @@ class PlayerLogic extends ChangeNotifier {
     required this.pictureInPicture,
     this.wallet,
     this.downloads,
+    PlaybackPositionCache? positionCache,
     Future<void> Function()? waitForFrame,
-  }) : _waitForFrame =
+  }) : positionCache = positionCache ?? PlaybackPositionCache(),
+       _waitForFrame =
            waitForFrame ?? (() => WidgetsBinding.instance.endOfFrame);
 
   final WatchHistoryRepository history;
@@ -49,6 +52,7 @@ class PlayerLogic extends ChangeNotifier {
   final AndroidPictureInPicture pictureInPicture;
   final WalletController? wallet;
   final DownloadController? downloads;
+  final PlaybackPositionCache positionCache;
   final Future<void> Function() _waitForFrame;
 
   late PageController pages;
@@ -351,9 +355,22 @@ class PlayerLogic extends ChangeNotifier {
 
   /// 服务端续看位置：进播放页时取一次，用于"定位到上次那一集的那一秒"。
   Future<void> loadResumePoint() async {
-    final dramaId = queue.entryAt(initialIndex).drama.id;
+    final entry = queue.entryAt(initialIndex);
+    final cached = positionCache.read(
+      entry.episode.id,
+      dramaId: entry.drama.id,
+    );
+    if (cached != null) {
+      resumePoint = ResumePoint(
+        episodeId: cached.episodeId,
+        position: cached.position,
+      );
+      resumeLoaded = true;
+      if (isMounted()) notify();
+      return;
+    }
     try {
-      resumePoint = await history.resumePointFor(dramaId);
+      resumePoint = await history.resumePointFor(entry.drama.id);
     } catch (_) {
       // 拿不到续看位置不影响播放：从当前集开头看
       resumePoint = null;
@@ -639,6 +656,18 @@ class PlayerLogic extends ChangeNotifier {
       await pendingWrite;
       // 服务端每剧只记一条：只有"记录里的那一集"才定位，其它集从头播
       if (resumePoint == null) await loadResumePoint();
+      if (resumePositionFor(episode.id) == null) {
+        final dramaId = _dramaIdForEpisode(episode.id);
+        final cached = dramaId == null
+            ? null
+            : positionCache.read(episode.id, dramaId: dramaId);
+        if (cached != null) {
+          resumePoint = ResumePoint(
+            episodeId: cached.episodeId,
+            position: cached.position,
+          );
+        }
+      }
       final saved = resumePositionFor(episode.id);
       if (saved != null) {
         await player.controller.seekTo(
@@ -667,6 +696,12 @@ class PlayerLogic extends ChangeNotifier {
       if (session.active != player || !player.controller.value.isInitialized) {
         return;
       }
+      positionCache.save(
+        episodeId: episode.id,
+        dramaId: drama.id,
+        position: player.controller.value.position,
+        duration: player.controller.value.duration,
+      );
       if (player.controller.value.isCompleted && !completionProgressSaved) {
         completionProgressSaved = true;
         unawaited(
@@ -750,6 +785,12 @@ class PlayerLogic extends ChangeNotifier {
         !player.controller.value.isInitialized) {
       return pendingWrite;
     }
+    positionCache.save(
+      episodeId: episode.id,
+      dramaId: drama.id,
+      position: player.controller.value.position,
+      duration: player.controller.value.duration,
+    );
     return queueProgress(
       drama,
       episode,
@@ -851,6 +892,7 @@ class PlayerLogic extends ChangeNotifier {
 
   Future<void> openDetail(BuildContext context) async {
     session.setOverlayOpen(true);
+    await saveCurrentProgress();
     try {
       if (!context.mounted) return;
       await Navigator.of(context).push(
@@ -865,6 +907,13 @@ class PlayerLogic extends ChangeNotifier {
     await saveCurrentProgress();
   }
 
+  String? _dramaIdForEpisode(String episodeId) {
+    for (final entry in queue.entries) {
+      if (entry.episode.id == episodeId) return entry.drama.id;
+    }
+    return null;
+  }
+
   Future<void> openSeriesAt(
     BuildContext context,
     Drama drama,

lib/pages/player/player_view.dart

@@ -11,6 +11,7 @@ import '../../core/data/repositories/comment_repository.dart';
 import '../../core/data/services/favorite_controller.dart';
 import '../../core/data/services/download_controller.dart';
 import '../../core/data/services/interaction_controller.dart';
+import '../../core/data/services/playback_position_cache.dart';
 import '../../core/data/services/playback_session.dart';
 import '../../core/data/services/video_player_port.dart';
 import '../../core/data/services/wallet_controller.dart';
@@ -119,6 +120,7 @@ class _PlayerPageState extends State<PlayerPage>
     logic = PlayerBinding().create(
       history: context.read<WatchHistoryRepository>(),
       playback: context.read<PlaybackRepository>(),
+      positionCache: context.read<PlaybackPositionCache>(),
       wallet: widget.wallet,
       downloads: widget.downloads,
     );