enum QuizMode { kanjiToEnglish, englishToKanji, reading }

class SrsItem {
  final int kanjiId;
  final QuizMode quizMode;
  final String? readingType; // 'onyomi' or 'kunyomi'
  int srsStage;
  DateTime lastAsked;

  SrsItem({
    required this.kanjiId,
    required this.quizMode,
    this.readingType,
    this.srsStage = 0,
    DateTime? lastAsked,
  }) : lastAsked = lastAsked ?? DateTime.now();
}

class KanjiItem {
  final int id;
  final int level;
  final String characters;
  final List<String> meanings;
  final List<String> onyomi;
  final List<String> kunyomi;
  final Map<String, SrsItem> srsItems = {};

  KanjiItem({
    required this.id,
    required this.level,
    required this.characters,
    required this.meanings,
    required this.onyomi,
    required this.kunyomi,
  });

  factory KanjiItem.fromSubject(Map<String, dynamic> subj) {
    final int id = subj['id'] as int;
    final data = subj['data'] as Map<String, dynamic>;
    final int level = data['level'] as int;
    final String characters = (data['characters'] ?? '') as String;
    final List<String> meanings = <String>[];
    final List<String> onyomi = <String>[];
    final List<String> kunyomi = <String>[];

    if (data['meanings'] != null) {
      for (final m in data['meanings'] as List) {
        meanings.add((m['meaning'] as String).toLowerCase());
      }
    }

    if (data['readings'] != null) {
      for (final r in data['readings'] as List) {
        final typ = r['type'] as String? ?? '';
        final reading = r['reading'] as String? ?? '';
        if (typ == 'onyomi') {
          onyomi.add(_katakanaToHiragana(reading));
        } else if (typ == 'kunyomi') {
          kunyomi.add(reading);
        }
      }
    }

    return KanjiItem(
      id: id,
      level: level,
      characters: characters,
      meanings: meanings,
      onyomi: onyomi,
      kunyomi: kunyomi,
    );
  }
}

String _katakanaToHiragana(String input) {
  final buf = StringBuffer();
  for (final r in input.runes) {
    if (r >= 0x30A1 && r <= 0x30FA) {
      buf.writeCharCode(r - 0x60);
    } else {
      buf.writeCharCode(r);
    }
  }
  return buf.toString();
}

enum VocabQuizMode { vocabToEnglish, englishToVocab, audioToEnglish }

class VocabSrsItem {
  final int vocabId;
  final VocabQuizMode quizMode;
  int srsStage;
  DateTime lastAsked;

  VocabSrsItem({
    required this.vocabId,
    required this.quizMode,
    this.srsStage = 0,
    DateTime? lastAsked,
  }) : lastAsked = lastAsked ?? DateTime.now();
}

class PronunciationAudio {
  final String url;
  final String gender;

  PronunciationAudio({required this.url, required this.gender});
}

class VocabularyItem {
  final int id;
  final int level;
  final String characters;
  final List<String> meanings;
  final List<String> readings;
  final List<PronunciationAudio> pronunciationAudios;
  final Map<String, VocabSrsItem> srsItems = {};

  VocabularyItem(
      {required this.id,
      required this.level,
      required this.characters,
      required this.meanings,
      required this.readings,
      required this.pronunciationAudios});

  factory VocabularyItem.fromSubject(Map<String, dynamic> subj) {
    final int id = subj['id'] as int;
    final data = subj['data'] as Map<String, dynamic>;
    final int level = data['level'] as int;
    final String characters = (data['characters'] ?? '') as String;
    final List<String> meanings = <String>[];
    final List<String> readings = <String>[];
    final List<PronunciationAudio> pronunciationAudios = <PronunciationAudio>[];

    if (data['meanings'] != null) {
      for (final m in data['meanings'] as List) {
        meanings.add((m['meaning'] as String).toLowerCase());
      }
    }

    if (data['readings'] != null) {
      for (final r in data['readings'] as List) {
        readings.add(r['reading'] as String);
      }
    }

    if (data['pronunciation_audios'] != null) {
      for (final audio in data['pronunciation_audios'] as List) {
        final url = audio['url'] as String?;
        final metadata = audio['metadata'] as Map<String, dynamic>?;
        final gender = metadata?['gender'] as String?;

        if (url != null && gender != null) {
          pronunciationAudios.add(PronunciationAudio(
            url: url,
            gender: gender,
          ));
        }
      }
    }

    return VocabularyItem(
        id: id,
        level: level,
        characters: characters,
        meanings: meanings,
        readings: readings,
        pronunciationAudios: pronunciationAudios);
  }
}