Improved MacOS support and organized screens and utils

lib/utils/packet_framer.dart

@@ -0,0 +1,98 @@
+import 'dart:typed_data';
+import 'package:msgpack_dart/msgpack_dart.dart';
+import 'package:es_compression/lz4.dart';
+
+final lz4Codec = Lz4Codec();
+
+Uint8List packPacket({
+  required int ver,
+  required int cmd,
+  required int seq,
+  required int opcode,
+  required Map<String, dynamic> payload,
+}) {
+  Uint8List payloadBytes = serialize(payload);
+  bool isCompressed = false;
+
+  if (payloadBytes.length >= 32) {
+    final uncompressedSize = ByteData(4)
+      ..setUint32(0, payloadBytes.length, Endian.big);
+
+    final compressedData = lz4Codec.encode(payloadBytes);
+
+    final builder = BytesBuilder();
+    builder.add(uncompressedSize.buffer.asUint8List());
+    builder.add(compressedData);
+    payloadBytes = builder.toBytes();
+    isCompressed = true;
+  }
+
+  final header = ByteData(10);
+  header.setUint8(0, ver);
+  header.setUint16(1, cmd, Endian.big);
+  header.setUint8(3, seq);
+  header.setUint16(4, opcode, Endian.big);
+
+  int packedLen = payloadBytes.length;
+  if (isCompressed) {
+    packedLen |= (1 << 24);
+  }
+  header.setUint32(6, packedLen, Endian.big);
+
+  final builder = BytesBuilder();
+  builder.add(header.buffer.asUint8List());
+  builder.add(payloadBytes);
+
+  return builder.toBytes();
+}
+
+Map<String, dynamic>? unpackPacket(Uint8List data) {
+  if (data.length < 10) {
+    print("Ошибка распаковки: Пакет слишком короткий для заголовка.");
+    return null;
+  }
+
+  final byteData = data.buffer.asByteData(
+    data.offsetInBytes,
+    data.lengthInBytes,
+  );
+
+  final ver = byteData.getUint8(0);
+  final cmd = byteData.getUint16(1, Endian.big);
+  final seq = byteData.getUint8(3);
+  final opcode = byteData.getUint16(4, Endian.big);
+  final packedLen = byteData.getUint32(6, Endian.big);
+
+  final compFlag = packedLen >> 24;
+  final payloadLength = packedLen & 0x00FFFFFF;
+
+  if (data.length < 10 + payloadLength) {
+    print(
+      "Ошибка распаковки: Фактическая длина пакета (${data.length}) меньше заявленной (${10 + payloadLength}).",
+    );
+    return null;
+  }
+
+  Uint8List payloadBytes = data.sublist(10, 10 + payloadLength);
+
+  if (compFlag != 0) {
+    try {
+      final compressedData = payloadBytes.sublist(4);
+
+      payloadBytes = Uint8List.fromList(lz4Codec.decode(compressedData));
+    } catch (e) {
+      print("Ошибка распаковки LZ4: $e");
+      return null;
+    }
+  }
+
+  final dynamic payload = deserialize(payloadBytes);
+
+  return {
+    "ver": ver,
+    "cmd": cmd,
+    "seq": seq,
+    "opcode": opcode,
+    "payload": payload,
+  };
+}