引入部分缓存机制

引入封面图信息

正在进入测试阶段

lib/metadata/metadata_service.dart

@@ -1,11 +1,14 @@
 // lib/metadata/metadata_service.dart
-// ⭐ 移除未使用的 import 'dart:io';
-import 'package:flutter/foundation.dart'; // ⭐ 添加
+import 'dart:io'; // ⭐ 添加这一行
+import 'dart:typed_data'; // ⭐ 如果已经有更好
+import 'package:flutter/foundation.dart';
+import '../database/song_database.dart';
 import 'metadata_model.dart';
 import 'metadata_reader.dart';
 import 'metadata_normalizer.dart';
 import 'metadata_cache.dart';
 import 'file_provider.dart';
+import '../utils/artwork_helper.dart';
 
 class MetadataService {
   static final MetadataService _instance = MetadataService._internal();
@@ -14,7 +17,13 @@ class MetadataService {
 
   final MetadataReader _reader = MetadataReader();
   final MetadataNormalizer _normalizer = MetadataNormalizer();
-  final MetadataCache _cache = MetadataCache();
+  final MetadataCache _memoryCache = MetadataCache();
+  final SongDatabase _db = SongDatabase();
+
+  String _generateSongKey(String url, int fileSize, int modifiedTime) {
+    final raw = '$url|$fileSize|$modifiedTime';
+    return raw.hashCode.toString();
+  }
 
   FileProvider _getProvider(String url) {
     if (url.startsWith('http://') || url.startsWith('https://')) {
@@ -29,11 +38,11 @@ class MetadataService {
     required String fileId,
     bool forceRefresh = false,
   }) async {
-    // 1. 检查缓存
+    // 1. 内存缓存
     if (!forceRefresh) {
-      final cached = await _cache.get(fileId);
+      final cached = await _memoryCache.get(fileId);
       if (cached != null && cached.isNotEmpty) {
-        debugPrint('📦 [MetadataService] cache hit: ${cached.title}');
+        debugPrint('📦 [MetadataService] memory hit: ${cached.title}');
         return cached;
       }
     }
@@ -43,33 +52,96 @@ class MetadataService {
     final file = await provider.getFile(url);
 
     if (file == null || !await file.exists()) {
-      debugPrint(
-          '⚠️ [MetadataService] file not available, using filename fallback');
+      debugPrint('⚠️ [MetadataService] file not available, using fallback');
       return _fallbackFromFileName(fileName);
     }
 
-    // 3. 读取 metadata
+    final stat = await file.stat();
+    final songKey =
+        _generateSongKey(url, stat.size, stat.modified.millisecondsSinceEpoch);
+
+    // 3. SQLite 查询（高置信度直接使用）
+    if (!forceRefresh) {
+      final dbSong = await _db.getSong(songKey);
+      if (dbSong != null) {
+        final confidence = (dbSong['confidence'] as num?)?.toDouble() ?? 0.0;
+        if (confidence >= 0.6) {
+          debugPrint(
+              '📦 [MetadataService] SQLite hit: ${dbSong['title']} - ${dbSong['artist']}');
+
+          // 读取封面图
+          final artworkPath = dbSong['artwork_path'] as String?;
+          Uint8List? artwork;
+          if (artworkPath != null && artworkPath.isNotEmpty) {
+            try {
+              final artFile = File(artworkPath);
+              if (await artFile.exists()) {
+                artwork = await artFile.readAsBytes();
+              }
+            } catch (e) {
+              // ignore
+            }
+          }
+
+          final metadata = FinalMetadata(
+            title: dbSong['title'] as String? ?? '',
+            artist: dbSong['artist'] as String? ?? '',
+            album: dbSong['album'] as String? ?? '',
+            genre: dbSong['genre'] as String? ?? '',
+            artwork: artwork,
+            source: 'database',
+          );
+          await _memoryCache.put(fileId, metadata);
+          return metadata;
+        }
+      }
+    }
+
+    // 4. 读取原始 metadata
     final raw = await _reader.readRawMetadata(file);
 
-    // 4. 标准化
+    // 5. 标准化
     final normalized = _normalizer.normalize(
       raw,
       fileName: fileName,
       filePath: url,
     );
 
-    // 5. 评估（第一阶段：直接接受）
-    final history = await _cache.getHistory(normalized.artist, limit: 10);
+    // 6. 评估
+    final history = await _db.getSongsByArtist(normalized.artist, limit: 10);
     final candidate = _normalizer.evaluate(normalized, history);
     final finalMetadata = _normalizer.decide(candidate);
 
-    // 6. 缓存
-    if (finalMetadata.isNotEmpty) {
-      await _cache.put(fileId, finalMetadata);
-      debugPrint(
-          '✅ [MetadataService] metadata saved: ${finalMetadata.title} - ${finalMetadata.artist}');
+    // 7. 保存封面图到本地
+    String? artworkPath;
+    if (finalMetadata.artwork != null && finalMetadata.artwork!.isNotEmpty) {
+      artworkPath =
+          await ArtworkHelper.saveArtwork(finalMetadata.artwork!, songKey);
     }
 
+    // 8. 保存到 SQLite
+    await _db.insertSong({
+      'song_key': songKey,
+      'remote_path': url,
+      'file_size': stat.size,
+      'modified_time': stat.modified.millisecondsSinceEpoch,
+      'title': finalMetadata.title,
+      'artist': finalMetadata.artist,
+      'album': finalMetadata.album,
+      'genre': finalMetadata.genre,
+      'artwork_path': artworkPath,
+      'confidence': candidate.confidence,
+      'validation_count': 1,
+      'first_scan': DateTime.now().millisecondsSinceEpoch,
+      'last_scan': DateTime.now().millisecondsSinceEpoch,
+      'metadata_status': candidate.confidence >= 0.6 ? 'verified' : 'pending',
+    });
+
+    // 9. 内存缓存
+    await _memoryCache.put(fileId, finalMetadata);
+
+    debugPrint(
+        '✅ [MetadataService] saved: ${finalMetadata.title} - ${finalMetadata.artist} (confidence: ${candidate.confidence})');
     return finalMetadata;
   }