class ChatMessage {
  final String text;
  final bool isUser;
  final DateTime timestamp;
  final int? emotionCategory;  // ← 새로 추가 (봇 메시지의 감정)

  ChatMessage({
    required this.text,
    required this.isUser,
    required this.timestamp,
    this.emotionCategory,
  });

  // JSON에서 ChatMessage로 변환
  factory ChatMessage.fromJson(Map<String, dynamic> json) {
    return ChatMessage(
      text: json['text'] as String,
      isUser: json['isUser'] as bool,
      timestamp: DateTime.parse(json['timestamp'] as String),
      emotionCategory: json['emotionCategory'] as int?,
    );
  }

  // ChatMessage를 JSON으로 변환
  Map<String, dynamic> toJson() {
    return {
      'text': text,
      'isUser': isUser,
      'timestamp': timestamp.toIso8601String(),
      'emotionCategory': emotionCategory,
    };
  }
}