enum QuizMode { kanjiToEnglish, englishToKanji, reading, vocabToEnglish, englishToVocab, audioToEnglish }

class SrsItem {
  final int subjectId;
  final QuizMode quizMode;
  final String? readingType;
  int srsStage;
  DateTime lastAsked;

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