75 lines
2.1 KiB
Dart
75 lines
2.1 KiB
Dart
// lib/metadata/metadata_service.dart
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import 'dart:io';
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import 'metadata_model.dart';
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import 'metadata_reader.dart';
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import 'metadata_normalizer.dart';
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import 'metadata_cache.dart';
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class MetadataService {
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static final MetadataService _instance = MetadataService._internal();
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factory MetadataService() => _instance;
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MetadataService._internal();
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final MetadataReader _reader = MetadataReader();
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final MetadataNormalizer _normalizer = MetadataNormalizer();
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final MetadataCache _cache = MetadataCache();
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/// 获取歌曲的最终元数据（优先缓存，否则读取文件）
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Future<FinalMetadata> getMetadata({
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required String filePath,
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required String fileName,
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required String fileId,
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bool forceRefresh = false,
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}) async {
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// 1. 尝试从缓存读取
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if (!forceRefresh) {
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final cached = await _cache.get(fileId);
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if (cached != null && cached.isNotEmpty) {
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return cached;
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}
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}
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// 2. 检查文件是否存在
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final file = File(filePath);
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if (!await file.exists()) {
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// 文件不存在，返回基于文件名的推断
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return _fallbackFromFileName(fileName);
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}
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// 3. 从文件读取原始元数据
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final raw = await _reader.readRawMetadata(file);
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// 4. 标准化
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final normalized = _normalizer.normalize(
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raw,
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fileName: fileName,
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filePath: filePath,
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);
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// 5. 评估（第一阶段直接接受）
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final history = await _cache.getHistory(normalized.artist, limit: 10);
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final candidate = _normalizer.evaluate(normalized, history);
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// 6. 决策
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final finalMetadata = _normalizer.decide(candidate);
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// 7. 写入缓存
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if (finalMetadata.isNotEmpty) {
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await _cache.put(fileId, finalMetadata);
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}
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return finalMetadata;
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}
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/// Fallback：从文件名推断
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FinalMetadata _fallbackFromFileName(String fileName) {
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final dotIndex = fileName.lastIndexOf('.');
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final title = dotIndex > 0 ? fileName.substring(0, dotIndex) : fileName;
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return FinalMetadata(
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title: title,
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artist: '未知艺术家',
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source: 'filename',
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);
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}
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}
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