Push more utilities and UUID stuff

lib/nbt/NbtUtils.dart

@@ -1,11 +1,13 @@
 import 'package:libac_flutter/nbt/impl/ByteTag.dart';
 import 'package:libac_flutter/nbt/impl/CompoundTag.dart';
 import 'package:libac_flutter/nbt/impl/DoubleTag.dart';
+import 'package:libac_flutter/nbt/impl/IntArrayTag.dart';
 import 'package:libac_flutter/nbt/impl/IntTag.dart';
 import 'package:libac_flutter/nbt/impl/ListTag.dart';
 import 'package:libac_flutter/utils/Vector3.dart';
 
 import '../utils/Vector2.dart';
+import '../utils/uuid/UUID.dart';
 
 class NbtUtils {
   static void writeBoolean(CompoundTag tag, String name, bool b) {
@@ -89,4 +91,29 @@ class NbtUtils {
       return Vector3i.ZERO;
     }
   }
+
+  static List<int> _msbLsbToIntArray(int msb, int lsb) {
+    return [msb >> 32, msb, lsb >> 32, lsb];
+  }
+
+  static List<int> _uuidToIntArray(UUID ID) {
+    return _msbLsbToIntArray(
+        ID.getMostSignificantBits(), ID.getLeastSignificantBits());
+  }
+
+  static UUID _uuidFromIntArray(List<int> values) {
+    return UUID((values[0] << 32 | values[1] & 4294967295),
+        (values[2] << 32 | values[3] & 4294967295));
+  }
+
+  static void writeUUID(CompoundTag tag, String name, UUID ID) {
+    tag.put(name, IntArrayTag.valueOf(_uuidToIntArray(ID)));
+  }
+
+  static UUID readUUID(CompoundTag tag, String name) {
+    if (!tag.contains(name))
+      return UUID.ZERO;
+    else
+      return _uuidFromIntArray(tag.get(name)!.asIntArray());
+  }
 }

lib/nbt/Stream.dart

@@ -283,4 +283,74 @@ class ByteLayer {
     int value = readLong();
     return (value >> 1) ^ (-(value & 1));
   }
+
+  void writeBytes(Iterable<int> bytes) {
+    for (int byte in bytes) {
+      writeByte(byte);
+    }
+  }
+
+  List<int> readBytes(int num) {
+    List<int> lst = [];
+    for (int i = 0; i < num; i++) {
+      lst.add(readByte());
+    }
+
+    return lst;
+  }
+
+  void setBit(int position, int maskToSet) {
+    if (position < _byteBuffer.length) {
+      // Set the value now
+      seek(position);
+      int current = readByte();
+      seek(position);
+      current |= maskToSet;
+      writeByte(current);
+    }
+  }
+
+  void clearBit(int position, int maskToClear) {
+    if (position < _byteBuffer.length) {
+      // Lets clear the bit
+      seek(position);
+      int current = readByte();
+      current &= maskToClear;
+      seek(position);
+      writeByte(current);
+    }
+  }
+
+  bool checkBit(int position, int mask) {
+    if (position < _byteBuffer.length) {
+      seek(position);
+      int current = readByte();
+      return (current & mask) == mask;
+    } else
+      return false;
+  }
+
+  int getBit(int position) {
+    if (position < _byteBuffer.length) {
+      seek(position);
+      return readByte();
+    } else
+      return 0;
+  }
+
+  void seek(int position) {
+    _position = 0;
+    _ensureCapacity(position);
+    _position = position;
+  }
+
+  void waitSetBit(int position, int maskToClear, int maskToSet) {
+    clearBit(position, maskToClear);
+    setBit(position, maskToSet);
+
+    while (!checkBit(position, maskToSet)) {
+      clearBit(position, maskToClear);
+      setBit(position, maskToSet);
+    }
+  }
 }

lib/nbt/impl/IntArrayTag.dart

@@ -9,6 +9,10 @@ class IntArrayTag extends Tag {
     this.value.addAll(value);
   }
 
+  static IntArrayTag valueOf(List<int> value) {
+    return IntArrayTag._(value);
+  }
+
   @override
   void readValue(ByteLayer data) {
     int count = data.readInt();

lib/utils/uuid/UUID.dart

@@ -0,0 +1,161 @@
+import 'dart:convert';
+import 'dart:math';
+
+import 'package:crypto/crypto.dart';
+import 'package:libac_flutter/nbt/Stream.dart';
+
+class UUID {
+  late final int LSB;
+  late final int MSB;
+
+  UUID(int msb, int lsb) {
+    if (msb < 0)
+      MSB = -msb;
+    else
+      MSB = msb;
+
+    if (lsb < 0)
+      LSB = -lsb;
+    else
+      LSB = lsb;
+  }
+
+  static final UUID ZERO = UUID.generate(0);
+
+  /// Validates whether the given [uuid] is a valid UUID.
+  static bool validate(String uuid) {
+    try {
+      parse(uuid);
+      return true;
+    } catch (e) {
+      return false;
+    }
+  }
+
+  /// Parses the given [uuid] string and returns a UUID object.
+  static UUID parse(String uuid) {
+    if (validate(uuid)) {
+      final segments = uuid.split('-');
+      if (segments.length != 5) {
+        throw const FormatException('Invalid UUID format');
+      }
+
+      final msbString = segments.sublist(0, 3).join('');
+      final lsbString = segments.sublist(3, 5).join('');
+
+      final msb = int.parse(msbString, radix: 16);
+      final lsb = int.parse(lsbString, radix: 16);
+
+      return UUID(msb, lsb);
+    } else
+      return UUID.ZERO;
+  }
+
+  @override
+  String toString() {
+    final msbHex = MSB.toRadixString(16).padLeft(16, '0');
+    final lsbHex = LSB.toRadixString(16).padLeft(16, '0');
+    return '${msbHex.substring(0, 8)}-${msbHex.substring(8, 12)}-${msbHex.substring(12, 16)}-${lsbHex.substring(0, 4)}-${lsbHex.substring(4, 16)}';
+  }
+
+  /// Returns the Most Significant Bits (MSB) long value of the UUID.
+  int getMostSignificantBits() => MSB;
+
+  /// Returns the Least Significant Bits (LSB) long value of the UUID.
+  int getLeastSignificantBits() => LSB;
+
+  /// Factory method to generate UUID of the specific version.
+  factory UUID.generate(int version, {List<Object>? parameters}) {
+    List<Object> params = [];
+    if (parameters == null) {
+      if (version != 4) {
+        return UUID.generate(4);
+      }
+    } else
+      params = parameters!;
+    switch (version) {
+      case 0:
+        return UUID(0, 0);
+      case 3:
+        {
+          if (params.length != 2)
+            throw Exception(
+                "UUID v3 requires two parameters, [namespace,name]");
+          String namespace = params[0] as String;
+          String name = params[1] as String;
+
+          ByteLayer layer = ByteLayer();
+
+          if (!namespace.isEmpty) {
+            final namespaceBytes = utf8.encode(namespace);
+            layer.writeBytes(namespaceBytes);
+          }
+
+          if (!name.isEmpty) {
+            final nameBytes = utf8.encode(name);
+            layer.writeBytes(nameBytes);
+          }
+
+          var bytes = md5.convert(List.from(layer.bytes)).bytes;
+          layer.clear();
+          layer.writeBytes(bytes);
+
+          layer.waitSetBit(6, 0x0F, 0x30);
+          layer.waitSetBit(8, 0x3F, 0x80);
+
+          layer.resetPosition();
+
+          return UUID(layer.readLong(), layer.readLong());
+        }
+      case 4:
+        {
+          ByteLayer layer = ByteLayer();
+          final random = Random.secure();
+
+          layer.writeLong(
+              (random.nextInt(0xFFFFFFFF) << 32) | random.nextInt(0xFFFFFFFF));
+          layer.writeLong(
+              (random.nextInt(0xFFFFFFFF) << 32) | random.nextInt(0xFFFFFFFF));
+
+          layer.waitSetBit(6, 0x0F, 0x40);
+          layer.waitSetBit(8, 0x3F, 0x80);
+
+          layer.resetPosition();
+
+          return UUID(layer.readLong(), layer.readLong());
+        }
+      case 5:
+        {
+          ByteLayer layer = ByteLayer();
+          if (params.length != 2)
+            throw Exception(
+                "UUID v5 requires two parameters, [namespace,name]");
+          String namespace = params[0] as String;
+          String name = params[1] as String;
+
+          if (!namespace.isEmpty) {
+            final namespaceBytes = utf8.encode(namespace);
+            layer.writeBytes(namespaceBytes);
+          }
+
+          if (!name.isEmpty) {
+            final nameBytes = utf8.encode(name);
+            layer.writeBytes(nameBytes);
+          }
+
+          final hashBytes = sha1.convert(List.from(layer.bytes)).bytes;
+          layer.clear();
+          layer.writeBytes(hashBytes);
+
+          layer.waitSetBit(6, 0x0F, 0x50);
+          layer.waitSetBit(8, 0x3F, 0x80);
+
+          layer.resetPosition();
+
+          return UUID(layer.readLong(), layer.readLong());
+        }
+      default:
+        throw ArgumentError('Unsupported UUID version: $version');
+    }
+  }
+}

pubspec.yaml

@@ -8,6 +8,7 @@ environment:
   flutter: ">=1.17.0"
 
 dependencies:
+  crypto: ^3.0.3
   flutter:
     sdk: flutter
 

test/nbt_test.dart

@@ -2,8 +2,10 @@ import 'dart:io';
 
 import 'package:flutter_test/flutter_test.dart';
 import 'package:libac_flutter/nbt/NbtIo.dart';
+import 'package:libac_flutter/nbt/NbtUtils.dart';
 import 'package:libac_flutter/nbt/impl/CompoundTag.dart';
 import 'package:libac_flutter/nbt/impl/StringTag.dart';
+import 'package:libac_flutter/utils/uuid/UUID.dart';
 
 void main() {
   test('read non-compressed helloworld NBT', () async {
@@ -44,4 +46,13 @@ void main() {
     expect(tag.get("doubleTest")!.asDouble(), 0.4931287132182315);
     expect(tag.get("floatTest")!.asFloat(), 0.49823147);
   });
+
+  test("Generate a UUID v4, save to NBT, and read it back again", () async {
+    var id = UUID.generate(4);
+    CompoundTag tag = CompoundTag();
+    NbtUtils.writeUUID(tag, "test", id);
+
+    var newID = NbtUtils.readUUID(tag, "test");
+    expect(id.toString(), newID.toString());
+  });
 }

test/uuid_test.dart

@@ -0,0 +1,51 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:libac_flutter/nbt/Stream.dart';
+import 'package:libac_flutter/utils/uuid/UUID.dart';
+
+void main() {
+  test("Generate a UUID v4", () {
+    var ID = UUID.generate(4);
+    expect(UUID.validate(ID.toString()), true);
+  });
+
+  test("Generate 10 UUIDv4", () {
+    List<UUID> ID = [];
+    for (int i = 0; i < 10; i++) {
+      ID.add(UUID.generate(4));
+    }
+
+    for (UUID sID in ID) {
+      print("ID : ${sID}}");
+    }
+  });
+
+  test("Check UUIDv4 for validity", () {
+    var ID = UUID.generate(4);
+    ByteLayer layer = ByteLayer();
+    layer.writeLong(ID.getMostSignificantBits());
+    layer.writeLong(ID.getLeastSignificantBits());
+
+    print(
+        "Checking version bit: ${layer.checkBit(6, 0x40)} - ${layer.getBit(6)}");
+    expect(layer.checkBit(6, 0x40), true);
+  });
+
+  test("Generate and check a UUIDv3", () {
+    var ID3 = UUID.generate(3, parameters: ["Test", "Test2"]);
+    ByteLayer layer = ByteLayer();
+    layer.writeLong(ID3.getMostSignificantBits());
+    layer.writeLong(ID3.getLeastSignificantBits());
+
+    print(
+        "Checking version bit: ${layer.checkBit(6, 0x30)} - ${layer.getBit(6)}");
+    expect(layer.checkBit(6, 0x30), true);
+  });
+
+  test("Test v3 implementation", () {
+    var expected =
+        "3e1b8c8a-efab-381b-ab57-4764c45b0889"; // Minecraft offline UUID : zontreck
+    var ID3 = UUID.generate(3, parameters: ["OfflinePlayer:zontreck", ""]);
+
+    expect(ID3.toString(), expected);
+  });
+}