class Message {
  final String id;
  final String content;
  final String? author;
  final String? groupId;
  final String converseId;
  final bool hasRecall;
  final Map<String, dynamic>? meta;
  final DateTime? createdAt;
  final DateTime? updatedAt;

  Message({
    required this.id,
    required this.content,
    this.author,
    this.groupId,
    required this.converseId,
    this.hasRecall = false,
    this.meta,
    this.createdAt,
    this.updatedAt,
  });

  factory Message.fromJson(Map<String, dynamic> json) {
    return Message(
      id: (json['_id'] ?? json['id'] ?? '').toString(),
      content: json['content'] ?? '',
      author: json['author']?.toString(),
      groupId: json['groupId']?.toString(),
      converseId: (json['converseId'] ?? '').toString(),
      hasRecall: json['hasRecall'] ?? false,
      meta: json['meta'],
      createdAt: json['createdAt'] != null
          ? DateTime.parse(json['createdAt'].toString())
          : null,
      updatedAt: json['updatedAt'] != null
          ? DateTime.parse(json['updatedAt'].toString())
          : null,
    );
  }

  Map<String, dynamic> toJson() {
    return {
      '_id': id,
      'content': content,
      'author': author,
      'groupId': groupId,
      'converseId': converseId,
      'hasRecall': hasRecall,
      'meta': meta,
      'createdAt': createdAt?.toIso8601String(),
      'updatedAt': updatedAt?.toIso8601String(),
    };
  }

  /// Determine message type from meta
  MessageType get type {
    if (hasRecall) return MessageType.recalled;
    final metaType = meta?['type'];
    if (metaType == 'image' || metaType == 'file') {
      return MessageType.file;
    }
    if (metaType == 'system') {
      return MessageType.system;
    }
    return MessageType.text;
  }

  /// Convenience alias for author (sender ID)
  String get senderId => author ?? '';

  /// For display purposes - get sender name from meta if available
  String get senderName => meta?['nickname']?.toString() ?? '';
}

enum MessageType {
  text,
  file,
  system,
  recalled,
}