import 'dart:convert';

enum ImMessageType {
  chatPrivate('CHAT_PRIVATE'),
  chatGroup('CHAT_GROUP'),
  online('ONLINE'),
  heartbeat('HEARTBEAT'),
  system('SYSTEM'),
  notice('NOTICE');

  final String value;

  const ImMessageType(this.value);
}

class ImMessage {
  final ImMessageType type;
  final String title;
  final String from;
  final String to;
  final String content;

  ImMessage({
    required this.type,
    required this.title,
    required this.from,
    required this.to,
    required this.content,
  });

  factory ImMessage.fromJsonString(String json) {
    return ImMessage.fromJson(jsonDecode(json));
  }

  factory ImMessage.fromJson(Map<String, dynamic> json) {
    return ImMessage(
      type: ImMessageType.values.firstWhere((e) => e.value == json['type']),
      title: json['title'],
      from: json['from'],
      to: json['to'],
      content: json['content'],
    );
  }

  Map<String, dynamic> toJson() => {
    'type': type.value,
    'title': title,
    'from': from,
    'to': to,
    'content': content,
  };

  String toJsonString() {
    return jsonEncode(toJson());
  }

  static ImMessage online(int userId) {
    return ImMessage(
      type: ImMessageType.online,
      title: '',
      from: userId.toString(),
      to: 'SYSTEM',
      content: '',
    );
  }
}