import 'dart:convert';
import 'dart:io';

class RCONPacket {
  int id;
  int type;
  String body;

  RCONPacket(this.id, this.type, this.body);

  List<int> toBytes() {
    List<int> bodyBytes = utf8.encode(body);
    int size = 10 + bodyBytes.length;
    List<int> packet = [];
    packet.addAll(_intToBytes(size));
    packet.addAll(_intToBytes(id));
    packet.addAll(_intToBytes(type));
    packet.addAll(bodyBytes);
    packet.addAll([0, 0]);
    return packet;
  }

  static RCONPacket fromBytes(List<int> bytes) {
    int size = _bytesToInt(bytes.sublist(0, 4));
    int id = _bytesToInt(bytes.sublist(4, 8));
    int type = _bytesToInt(bytes.sublist(8, 12));
    String body =
        utf8.decode(bytes.sublist(12, size + 2).sublist(0, size - 10));
    return RCONPacket(id, type, body);
  }

  static List<int> _intToBytes(int value) {
    return [
      value & 0xFF,
      (value >> 8) & 0xFF,
      (value >> 16) & 0xFF,
      (value >> 24) & 0xFF
    ];
  }

  static int _bytesToInt(List<int> bytes) {
    return bytes[0] | (bytes[1] << 8) | (bytes[2] << 16) | (bytes[3] << 24);
  }
}

class RCONClient {
  String host;
  int port;
  String password;
  late Socket _socket;
  late int _requestId;

  RCONClient(this.host, this.port, this.password) {
    _requestId = 0;
  }

  Future<void> connect() async {
    _socket = await Socket.connect(host, port);
    if (await _authenticate()) {
      print('Authenticated successfully');
    } else {
      print('Authentication failed');
    }
  }

  Future<bool> _authenticate() async {
    RCONPacket packet = RCONPacket(_requestId++, 3, password);
    _socket.add(packet.toBytes());
    await _socket.flush();
    RCONPacket response = await _readPacket();
    return response.id == packet.id && response.type == 2;
  }

  Future<RCONPacket> _readPacket() async {
    List<int> sizeBytes = await _socket.first;
    int size = RCONPacket._bytesToInt(sizeBytes);
    List<int> dataBytes = [];
    while (dataBytes.length < size) {
      dataBytes.addAll(await _socket.first);
    }
    return RCONPacket.fromBytes(sizeBytes + dataBytes);
  }

  Future<String> sendCommand(String command) async {
    RCONPacket packet = RCONPacket(_requestId++, 2, command);
    _socket.add(packet.toBytes());
    await _socket.flush();
    RCONPacket response = await _readPacket();
    return response.body;
  }

  void close() {
    _socket.close();
  }
}