// lib/metadata/metadata_model.dart
import 'dart:typed_data';

/// 从音频文件读取的原始元数据
class RawMetadata {
  final String title;
  final String artist;
  final String album;
  final List<String> genres;
  final List<String> performers;
  final int year;
  final int trackNumber;
  final int trackTotal;
  final int discNumber;
  final int totalDisc;
  final Duration? duration;
  final Uint8List? artwork;

  const RawMetadata({
    this.title = '',
    this.artist = '',
    this.album = '',
    this.genres = const [],
    this.performers = const [],
    this.year = 0,
    this.trackNumber = 0,
    this.trackTotal = 0,
    this.discNumber = 0,
    this.totalDisc = 0,
    this.duration,
    this.artwork,
  });

  bool get isEmpty =>
      title.isEmpty &&
      artist.isEmpty &&
      album.isEmpty &&
      genres.isEmpty &&
      performers.isEmpty &&
      year == 0;

  bool get isNotEmpty => !isEmpty;
}

/// 标准化后的元数据
class NormalizedMetadata {
  final String title;
  final String artist;
  final String album;
  final List<String> genres;
  final List<String> performers;
  final int year;
  final int trackNumber;
  final int trackTotal;
  final int discNumber;
  final int totalDisc;
  final Duration? duration;
  final Uint8List? artwork;

  /// 字段来源：true 表示来自标签，false 表示从文件名/路径推断。
  /// 置信度模型需要区分这两者——"标签里的标题"和"文件名当标题"价值完全不同。
  final bool titleFromTag;
  final bool artistFromTag;
  final bool albumFromTag;

  const NormalizedMetadata({
    this.title = '',
    this.artist = '',
    this.album = '',
    this.genres = const [],
    this.performers = const [],
    this.year = 0,
    this.trackNumber = 0,
    this.trackTotal = 0,
    this.discNumber = 0,
    this.totalDisc = 0,
    this.duration,
    this.artwork,
    this.titleFromTag = false,
    this.artistFromTag = false,
    this.albumFromTag = false,
  });

  bool get isEmpty =>
      title.isEmpty &&
      artist.isEmpty &&
      album.isEmpty &&
      genres.isEmpty &&
      performers.isEmpty &&
      year == 0;

  bool get isNotEmpty => !isEmpty;
}

/// 候选元数据
class CandidateMetadata {
  final NormalizedMetadata metadata;
  final double confidence;
  final Map<String, double> evidence;

  const CandidateMetadata({
    required this.metadata,
    required this.confidence,
    this.evidence = const {},
  });
}

/// 最终确认的元数据
class FinalMetadata {
  final String title;
  final String artist;
  final String album;
  final String genre;
  final List<String> genres;
  final List<String> performers;
  final int year;
  final int trackNumber;
  final int trackTotal;
  final int discNumber;
  final int totalDisc;
  final Duration? duration;
  final Uint8List? artwork;
  final String source;

  const FinalMetadata({
    this.title = '',
    this.artist = '',
    this.album = '',
    this.genre = '',
    this.genres = const [],
    this.performers = const [],
    this.year = 0,
    this.trackNumber = 0,
    this.trackTotal = 0,
    this.discNumber = 0,
    this.totalDisc = 0,
    this.duration,
    this.artwork,
    this.source = 'unknown',
  });

  bool get isEmpty =>
      title.isEmpty &&
      artist.isEmpty &&
      album.isEmpty &&
      genre.isEmpty &&
      genres.isEmpty &&
      performers.isEmpty &&
      year == 0;

  bool get isNotEmpty => !isEmpty;
}