class Conversation {
  final String id;
  final String? title;
  final DateTime createdAt;
  final DateTime updatedAt;
  final int messageCount;

  Conversation({
    required this.id,
    this.title,
    required this.createdAt,
    required this.updatedAt,
    this.messageCount = 0,
  });

  factory Conversation.fromJson(Map<String, dynamic> json) {
    return Conversation(
      id: json['id'],
      title: json['title'],
      createdAt: DateTime.parse(json['created_at']),
      updatedAt: DateTime.parse(json['updated_at']),
      messageCount: json['message_count'] ?? 0,
    );
  }

  String get displayTitle => title ?? 'New Conversation';

  String get timeAgo {
    final now = DateTime.now();
    final diff = now.difference(updatedAt);

    if (diff.inMinutes < 1) return 'Just now';
    if (diff.inMinutes < 60) return '${diff.inMinutes}m ago';
    if (diff.inHours < 24) return '${diff.inHours}h ago';
    if (diff.inDays < 7) return '${diff.inDays}d ago';
    return '${updatedAt.day}/${updatedAt.month}/${updatedAt.year}';
  }
}