japp_flutter/lib/core/models/challenge_model.dart

class ChallengeModel {
  final String id;
  final String title;
  final String description;
  final DateTime startDate;
  final DateTime endDate;
  final int participants;
  final bool completed;
  final String difficulty;

  ChallengeModel({
    required this.id,
    required this.title,
    required this.description,
    required this.startDate,
    required this.endDate,
    required this.participants,
    required this.completed,
    required this.difficulty,
  });

  // 获取剩余天数
  int get remainingDays {
    return endDate.difference(DateTime.now()).inDays;
  }
}