feat: lazily load sqlite media artwork

lib/core/storage/media_library_store.dart

@@ -1,5 +1,6 @@
 import 'dart:convert';
 import 'dart:io';
+import 'dart:typed_data';
 
 import 'package:path/path.dart' as path;
 import 'package:sqflite/sqflite.dart';
@@ -95,6 +96,7 @@ class MediaLibraryStore {
   Future<List<MediaLibraryItem>> items({String? libraryID}) async {
     final rows = await (await _db).query(
       'media_items',
+      columns: _itemMetadataColumns,
       where: libraryID == null ? null : 'library_id = ?',
       whereArgs: libraryID == null ? null : [libraryID],
       orderBy: 'title COLLATE NOCASE',
@@ -102,6 +104,18 @@ class MediaLibraryStore {
     return rows.map(_itemFromRow).toList();
   }
 
+  Future<Uint8List?> posterBytes(String libraryID, String fileID) async {
+    final rows = await (await _db).query(
+      'media_items',
+      columns: const ['poster'],
+      where: 'library_id = ? AND file_id = ?',
+      whereArgs: [libraryID, fileID],
+      limit: 1,
+    );
+    final value = rows.isEmpty ? null : rows.first['poster'];
+    return value is Uint8List ? value : null;
+  }
+
   Future<void> saveLibraries(List<MediaLibraryDefinition> libraries) async {
     final db = await _db;
     await db.transaction((txn) async {
@@ -467,5 +481,25 @@ class MediaLibraryStore {
   }
 
   static const _rootFolderID = '@root';
+  static const _itemMetadataColumns = [
+    'library_id',
+    'file_id',
+    'resource_path',
+    'cloud_name',
+    'file_size',
+    'gcid',
+    'file_type',
+    'tmdb_id',
+    'media_kind',
+    'title',
+    'original_title',
+    'release_date',
+    'overview',
+    'has_chinese_audio',
+    'has_chinese_subtitle',
+    'collection_id',
+    'collection_name',
+    'updated_at',
+  ];
   static String _folderID(String? folderID) => folderID ?? _rootFolderID;
 }

lib/pages/media_library_page.dart

@@ -1,3 +1,5 @@
+import 'dart:typed_data';
+
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:file_picker/file_picker.dart';
@@ -1221,13 +1223,13 @@ class _LibraryRow extends StatelessWidget {
   }
 }
 
-class _MediaItemTile extends StatelessWidget {
+class _MediaItemTile extends ConsumerWidget {
   final MediaLibraryItem item;
 
   const _MediaItemTile({required this.item});
 
   @override
-  Widget build(BuildContext context) {
+  Widget build(BuildContext context, WidgetRef ref) {
     final cs = ShadTheme.of(context).colorScheme;
     final posterURL = item.posterPath == null || item.posterPath!.isEmpty
         ? null
@@ -1250,13 +1252,14 @@ class _MediaItemTile extends StatelessWidget {
               borderRadius: BorderRadius.circular(6),
             ),
             clipBehavior: Clip.antiAlias,
-            child: posterURL == null
-                ? Icon(
-                    isSeries ? Icons.tv_rounded : Icons.movie_rounded,
-                    size: 24,
-                    color: cs.mutedForeground,
-                  )
-                : Image.network(
+            child: FutureBuilder<Uint8List?>(
+              future: ref.read(mediaLibraryProvider.notifier).posterBytes(item),
+              builder: (context, snapshot) {
+                if (snapshot.data != null) {
+                  return Image.memory(snapshot.data!, fit: BoxFit.cover);
+                }
+                if (posterURL != null) {
+                  return Image.network(
                     posterURL,
                     fit: BoxFit.cover,
                     errorBuilder: (_, _, _) => Icon(
@@ -1264,7 +1267,15 @@ class _MediaItemTile extends StatelessWidget {
                       size: 24,
                       color: cs.mutedForeground,
                     ),
-                  ),
+                  );
+                }
+                return Icon(
+                  isSeries ? Icons.tv_rounded : Icons.movie_rounded,
+                  size: 24,
+                  color: cs.mutedForeground,
+                );
+              },
+            ),
           ),
           const SizedBox(width: 10),
           Expanded(

lib/providers/media_library_provider.dart

@@ -1,4 +1,5 @@
 import 'dart:async';
+import 'dart:typed_data';
 
 import 'package:flutter_riverpod/legacy.dart';
 
@@ -85,6 +86,7 @@ class MediaLibraryState {
 class MediaLibraryNotifier extends StateNotifier<MediaLibraryState> {
   GuangyaAPI? _api;
   final _store = MediaLibraryStore();
+  final _posterRequests = <String, Future<Uint8List?>>{};
   bool _loaded = false;
   bool _cancelScan = false;
 
@@ -385,6 +387,17 @@ class MediaLibraryNotifier extends StateNotifier<MediaLibraryState> {
       ..sort((a, b) => a.title.toLowerCase().compareTo(b.title.toLowerCase()));
   }
 
+  Future<Uint8List?> posterBytes(MediaLibraryItem item) {
+    final key = '${item.libraryID}:${item.file.id}';
+    return _posterRequests.putIfAbsent(key, () async {
+      final bytes = await _store.posterBytes(item.libraryID, item.file.id);
+      if (_posterRequests.length > 48) {
+        _posterRequests.remove(_posterRequests.keys.first);
+      }
+      return bytes;
+    });
+  }
+
   void clearError() {
     state = state.copyWith(clearError: true);
   }