class Habit {
  const Habit({
    required this.id,
    required this.title,
    required this.createdAt,
    required this.completedDates,
  });

  final String id;
  final String title;
  final DateTime createdAt;
  final Set<String> completedDates;

  Habit copyWith({String? title, Set<String>? completedDates}) {
    return Habit(
      id: id,
      title: title ?? this.title,
      createdAt: createdAt,
      completedDates: completedDates ?? this.completedDates,
    );
  }

  Map<String, dynamic> toJson() {
    return {
      'id': id,
      'title': title,
      'createdAt': createdAt.toIso8601String(),
      'completedDates': completedDates.toList()..sort(),
    };
  }

  static Habit fromJson(Map<String, dynamic> json) {
    return Habit(
      id: json['id'] as String,
      title: json['title'] as String,
      createdAt: DateTime.parse(json['createdAt'] as String),
      completedDates:
          ((json['completedDates'] as List?) ?? const [])
              .map((value) => value.toString())
              .toSet(),
    );
  }
}