import 'dart:convert';
import 'dart:typed_data';

/// MobileIMSDK 官方 TCP 帧：4 字节大端长度 + UTF-8 JSON Protocal。
class ClientType {
  static const login = 0;
  static const keepAlive = 1;
  static const commonData = 2;
  static const logout = 3;
  static const received = 4;
  static const echo = 5;
}

class ServerType {
  static const login = 50;
  static const keepAlive = 51;
  static const error = 52;
  static const echo = 53;
  static const kickout = 54;
}

class Protocal {
  Protocal({
    required this.type,
    this.dataContent = '',
    this.from = '0',
    this.to = '0',
    this.fp,
    this.qos = false,
    this.typeu = -1,
    this.sm = -1,
  });

  int type;
  String dataContent;
  String from;
  String to;
  String? fp;
  bool qos;
  int typeu;
  int sm;

  Map<String, dynamic> toJson() => {
        'bridge': false,
        'type': type,
        'dataContent': dataContent,
        'from': from,
        'to': to,
        'fp': fp,
        'QoS': qos,
        'typeu': typeu,
        'sm': sm,
      };

  factory Protocal.fromJson(Map<String, dynamic> j) => Protocal(
        type: (j['type'] as num?)?.toInt() ?? 0,
        dataContent: '${j['dataContent'] ?? ''}',
        from: '${j['from'] ?? '0'}',
        to: '${j['to'] ?? '0'}',
        fp: j['fp']?.toString(),
        qos: j['QoS'] == true || j['qos'] == true,
        typeu: (j['typeu'] as num?)?.toInt() ?? -1,
        sm: (j['sm'] as num?)?.toInt() ?? -1,
      );
}

Uint8List encodeFrame(Protocal p) {
  final body = utf8.encode(jsonEncode(p.toJson()));
  final header = ByteData(4)..setUint32(0, body.length);
  return Uint8List.fromList([...header.buffer.asUint8List(), ...body]);
}

const maxBody = 6 * 1024;