class MessageModel {
  final String id;
  final String title;
  final String content;
  final String msgType;
  final String? bizType;
  final String? bizId;
  final bool isRead;
  final DateTime createTime;

  const MessageModel({
    required this.id,
    required this.title,
    this.content = '',
    this.msgType = 'system',
    this.bizType,
    this.bizId,
    this.isRead = false,
    required this.createTime,
  });

  factory MessageModel.fromJson(Map<String, dynamic> json) => MessageModel(
    id: json['id'] as String,
    title: json['title'] as String,
    content: json['content'] as String? ?? '',
    msgType: json['msgType'] as String? ?? 'system',
    bizType: json['bizType'] as String?,
    bizId: json['bizId'] as String?,
    isRead: json['isRead'] as bool? ?? false,
    createTime: DateTime.parse(json['createTime'] as String),
  );

  static final mockMessages = [
    // 审批待办
    MessageModel(
      id: '1',
      title: '张三提交了差旅报销，待审批',
      content: '报销金额 ¥2,380.00',
      msgType: 'approval_notice',
      bizType: 'expense',
      bizId: 'exp-001',
      isRead: false,
      createTime: DateTime(2026, 6, 4, 9, 30),
    ),
    // 审批待办
    MessageModel(
      id: '2',
      title: '李四的加班申请待审批',
      content: '加班时长 4小时',
      msgType: 'approval_notice',
      bizType: 'overtime',
      bizId: 'ot-001',
      isRead: false,
      createTime: DateTime(2026, 6, 3, 14, 0),
    ),
    // 审批结果 — 通过
    MessageModel(
      id: '3',
      title: '您的差旅报销已通过',
      content: 'BX-20260602-001 已通过审批',
      msgType: 'approval_result',
      bizType: 'expense',
      bizId: 'exp-002',
      isRead: true,
      createTime: DateTime(2026, 6, 2, 10, 0),
    ),
    // 审批结果 — 拒绝
    MessageModel(
      id: '4',
      title: '您的加班申请已被拒绝',
      content: '原因：与部门预算冲突',
      msgType: 'approval_result',
      bizType: 'overtime',
      bizId: 'ot-002',
      isRead: false,
      createTime: DateTime(2026, 6, 2, 11, 30),
    ),
    // 撤回通知
    MessageModel(
      id: '5',
      title: '王五撤回了用车申请',
      content: 'YC-20260601-003 已撤回',
      msgType: 'withdraw_notice',
      bizType: 'vehicle',
      bizId: 'vcl-003',
      isRead: false,
      createTime: DateTime(2026, 6, 1, 16, 45),
    ),
    // 系统公告
    MessageModel(
      id: '6',
      title: '【通知公告】2026年端午放假安排',
      content: '6月8日至6月10日放假，共3天',
      msgType: 'announcement',
      bizType: 'announcement',
      bizId: 'an-001',
      isRead: false,
      createTime: DateTime(2026, 6, 1, 14, 0),
    ),
    // 系统公告（已读）
    MessageModel(
      id: '7',
      title: '关于启用新版报销流程的通知',
      content: '自2026年7月1日起全面启用新版报销系统',
      msgType: 'announcement',
      bizType: 'announcement',
      bizId: 'an-002',
      isRead: true,
      createTime: DateTime(2026, 5, 28, 9, 0),
    ),
    // 过期提醒
    MessageModel(
      id: '8',
      title: '您的差旅申请已过期，预算已释放',
      content: '申请单 BXSQ-20260501-002 有效期已截止',
      msgType: 'expiry_reminder',
      bizType: 'expense_application',
      bizId: 'ea-002',
      isRead: false,
      createTime: DateTime(2026, 6, 1, 8, 0),
    ),
  ];
}