// 功能描述：解析消息中心真实业务消息及分类计数；版本：1.0.0。
class UserMessage {
  const UserMessage({
    required this.key,
    required this.category,
    required this.title,
    required this.summary,
    required this.statusText,
    required this.target,
    required this.targetIdentity,
    required this.occurredAt,
    required this.read,
  });

  factory UserMessage.fromJson(Map<String, dynamic> json) => UserMessage(
    key: json['key']?.toString() ?? '',
    category: json['category']?.toString() ?? '',
    title: json['title']?.toString() ?? '',
    summary: json['summary']?.toString() ?? '',
    statusText: json['status_text']?.toString() ?? '',
    target: json['target']?.toString() ?? '',
    targetIdentity: json['target_identity']?.toString() ?? '',
    occurredAt:
        DateTime.tryParse(json['occurred_at']?.toString() ?? '') ??
        DateTime.fromMillisecondsSinceEpoch(0),
    read: json['read'] == true,
  );

  final String key, category, title, summary, statusText, target, targetIdentity;
  final DateTime occurredAt;
  final bool read;
}

class MessageCenterData {
  const MessageCenterData({required this.items, required this.counts});
  factory MessageCenterData.fromJson(Map<String, dynamic> json) {
    final rawItems = json['items'] is List ? json['items'] as List<dynamic> : const <dynamic>[];
    final rawCounts = json['counts'] is Map
        ? Map<String, dynamic>.from(json['counts'] as Map<dynamic, dynamic>)
        : const <String, dynamic>{};
    return MessageCenterData(
      items: List.unmodifiable(
        rawItems.whereType<Map<dynamic, dynamic>>().map(
          (item) => UserMessage.fromJson(Map<String, dynamic>.from(item)),
        ),
      ),
      counts: Map.unmodifiable(
        rawCounts.map((key, value) => MapEntry(key, value is num ? value.toInt() : 0)),
      ),
    );
  }
  final List<UserMessage> items;
  final Map<String, int> counts;
}