class MessageModel {
  final String id;
  final String body;
  final bool fromMe;
  final int timestamp;
  final String type; // "chat"|"image"|"video"|"audio"|"document"|"sticker"
  final bool hasMedia;
  final bool isForwarded;
  final String? author;
  final int ack; // 0=error/none 1=pending 2=sent 3=delivered 4=read

  MessageModel({
    required this.id,
    required this.body,
    required this.fromMe,
    required this.timestamp,
    required this.type,
    required this.hasMedia,
    required this.isForwarded,
    this.author,
    required this.ack,
  });

  factory MessageModel.fromJson(Map<String, dynamic> json) {
    return MessageModel(
      id: json['id'] ?? '',
      body: json['body'] ?? '',
      fromMe: json['fromMe'] ?? false,
      timestamp: json['timestamp'] ?? 0,
      type: json['type'] ?? 'chat',
      hasMedia: json['hasMedia'] ?? false,
      isForwarded: json['isForwarded'] ?? false,
      author: json['author'],
      ack: json['ack'] ?? 0,
    );
  }

  Map<String, dynamic> toJson() {
    return {
      'id': id,
      'body': body,
      'fromMe': fromMe,
      'timestamp': timestamp,
      'type': type,
      'hasMedia': hasMedia,
      'isForwarded': isForwarded,
      'author': author,
      'ack': ack,
    };
  }

  MessageModel copyWith({
    String? id,
    String? body,
    bool? fromMe,
    int? timestamp,
    String? type,
    bool? hasMedia,
    bool? isForwarded,
    String? author,
    int? ack,
  }) {
    return MessageModel(
      id: id ?? this.id,
      body: body ?? this.body,
      fromMe: fromMe ?? this.fromMe,
      timestamp: timestamp ?? this.timestamp,
      type: type ?? this.type,
      hasMedia: hasMedia ?? this.hasMedia,
      isForwarded: isForwarded ?? this.isForwarded,
      author: author ?? this.author,
      ack: ack ?? this.ack,
    );
  }
}