优化

client/flutter/lib/models/invite.dart

@@ -0,0 +1,166 @@
+class Invite {
+  final String id;
+  final String code;
+  final String salesId;
+  final String groupId;
+  final String? link;
+  final String? qrCodeUrl;
+  final DateTime? createdAt;
+  final DateTime? expiresAt;
+  final int clickCount;
+  final int scanCount;
+  final int joinCount;
+  final String status;
+
+  Invite({
+    required this.id,
+    required this.code,
+    required this.salesId,
+    required this.groupId,
+    this.link,
+    this.qrCodeUrl,
+    this.createdAt,
+    this.expiresAt,
+    this.clickCount = 0,
+    this.scanCount = 0,
+    this.joinCount = 0,
+    this.status = 'active',
+  });
+
+  factory Invite.fromJson(Map<String, dynamic> json) {
+    return Invite(
+      id: (json['_id'] ?? json['id'] ?? '').toString(),
+      code: json['code'] ?? '',
+      salesId: (json['salesId'] ?? '').toString(),
+      groupId: (json['groupId'] ?? '').toString(),
+      link: json['link'],
+      qrCodeUrl: json['qrCodeUrl'],
+      createdAt: json['createdAt'] != null
+          ? DateTime.parse(json['createdAt'].toString())
+          : null,
+      expiresAt: json['expiresAt'] != null
+          ? DateTime.parse(json['expiresAt'].toString())
+          : null,
+      clickCount: json['clickCount'] ?? 0,
+      scanCount: json['scanCount'] ?? 0,
+      joinCount: json['joinCount'] ?? 0,
+      status: json['status'] ?? 'active',
+    );
+  }
+
+  Map<String, dynamic> toJson() {
+    return {
+      '_id': id,
+      'code': code,
+      'salesId': salesId,
+      'groupId': groupId,
+      'link': link,
+      'qrCodeUrl': qrCodeUrl,
+      'createdAt': createdAt?.toIso8601String(),
+      'expiresAt': expiresAt?.toIso8601String(),
+      'clickCount': clickCount,
+      'scanCount': scanCount,
+      'joinCount': joinCount,
+      'status': status,
+    };
+  }
+
+  bool get isExpired =>
+      expiresAt != null && DateTime.now().isAfter(expiresAt!);
+  bool get isActive => status == 'active' && !isExpired;
+  bool get isValid => isActive;
+}
+
+/// 单个邀请的统计数据，由 invite.getStats 返回
+class InviteStats {
+  final String code;
+  final String? link;
+  final DateTime? createdAt;
+  final DateTime? expiresAt;
+  final InviteStatsDetail stats;
+  final List<AccessLog> recentAccess;
+
+  InviteStats({
+    required this.code,
+    this.link,
+    this.createdAt,
+    this.expiresAt,
+    required this.stats,
+    this.recentAccess = const [],
+  });
+
+  factory InviteStats.fromJson(Map<String, dynamic> json) {
+    return InviteStats(
+      code: json['code'] ?? '',
+      link: json['link'],
+      createdAt: json['createdAt'] != null
+          ? DateTime.parse(json['createdAt'].toString())
+          : null,
+      expiresAt: json['expiresAt'] != null
+          ? DateTime.parse(json['expiresAt'].toString())
+          : null,
+      stats: InviteStatsDetail.fromJson(json['stats'] ?? {}),
+      recentAccess: (json['recentAccess'] as List?)
+              ?.map((e) => AccessLog.fromJson(e))
+              .toList() ??
+          [],
+    );
+  }
+}
+
+class InviteStatsDetail {
+  final int clicks;
+  final int scans;
+  final int joins;
+  final String conversionRate;
+
+  InviteStatsDetail({
+    this.clicks = 0,
+    this.scans = 0,
+    this.joins = 0,
+    this.conversionRate = '0',
+  });
+
+  factory InviteStatsDetail.fromJson(Map<String, dynamic> json) {
+    return InviteStatsDetail(
+      clicks: json['clicks'] ?? 0,
+      scans: json['scans'] ?? 0,
+      joins: json['joins'] ?? 0,
+      conversionRate: json['conversionRate']?.toString() ?? '0',
+    );
+  }
+
+  double get conversionRateDouble => double.tryParse(conversionRate) ?? 0.0;
+}
+
+/// 来自后端的访问日志条目
+class AccessLog {
+  final String? id;
+  final String inviteCode;
+  final String? visitorId;
+  final String accessType;
+  final DateTime? timestamp;
+  final String? ipAddress;
+
+  AccessLog({
+    this.id,
+    required this.inviteCode,
+    this.visitorId,
+    required this.accessType,
+    this.timestamp,
+    this.ipAddress,
+  });
+
+  factory AccessLog.fromJson(Map<String, dynamic> json) {
+    return AccessLog(
+      id: (json['_id'] ?? json['id'])?.toString(),
+      inviteCode: json['inviteCode'] ?? '',
+      visitorId: json['visitorId']?.toString(),
+      accessType: json['accessType'] ?? '',
+      timestamp: json['timestamp'] != null
+          ? DateTime.parse(json['timestamp'].toString())
+          : null,
+      ipAddress: json['ipAddress'],
+    );
+  }
+}