Add a wrapper type for blockstate NBT

src/data/bedrock/blockstate/BlockStateData.php

@@ -0,0 +1,88 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+declare(strict_types=1);
+
+namespace pocketmine\data\bedrock\blockstate;
+
+use pocketmine\nbt\NbtException;
+use pocketmine\nbt\tag\CompoundTag;
+use function array_keys;
+use function count;
+use function implode;
+
+/**
+ * Contains the common information found in a serialized blockstate.
+ */
+final class BlockStateData{
+	/**
+	 * Bedrock version of the most recent backwards-incompatible change to blockstates.
+	 */
+	public const CURRENT_VERSION =
+		(1 << 24) | //major
+		(16 << 16) | //minor
+		(210 << 8) | //patch
+		(3); //revision
+
+	public const TAG_NAME = "name";
+	public const TAG_STATES = "states";
+	public const TAG_VERSION = "version";
+
+	public function __construct(
+		private string $name,
+		private CompoundTag $states,
+		private int $version
+	){}
+
+	public function getName() : string{ return $this->name; }
+
+	public function getStates() : CompoundTag{ return $this->states; }
+
+	public function getVersion() : int{ return $this->version; }
+
+	/**
+	 * @throws BlockStateDeserializeException
+	 */
+	public static function fromNbt(CompoundTag $nbt) : self{
+		try{
+			$name = $nbt->getString(self::TAG_NAME);
+			$states = $nbt->getCompoundTag(self::TAG_STATES) ?? throw new BlockStateDeserializeException("Missing tag \"" . self::TAG_STATES . "\"");
+			$version = $nbt->getInt(self::TAG_VERSION, 0);
+		}catch(NbtException $e){
+			throw new BlockStateDeserializeException($e->getMessage(), 0, $e);
+		}
+
+		$allKeys = $nbt->getValue();
+		unset($allKeys[self::TAG_NAME], $allKeys[self::TAG_STATES], $allKeys[self::TAG_VERSION]);
+		if(count($allKeys) !== 0){
+			throw new BlockStateDeserializeException("Unexpected extra keys: " . implode(", ", array_keys($allKeys)));
+		}
+
+		return new self($name, $states, $version);
+	}
+
+	public function toNbt() : CompoundTag{
+		return CompoundTag::create()
+			->setString(self::TAG_NAME, $this->name)
+			->setInt(self::TAG_VERSION, $this->version)
+			->setTag(self::TAG_STATES, $this->states);
+	}
+}

src/data/bedrock/blockstate/BlockStateDeserializer.php

@@ -37,7 +37,6 @@ use pocketmine\data\bedrock\blockstate\BlockStateStringValues as StringValues;
 use pocketmine\data\bedrock\blockstate\BlockTypeNames as Ids;
 use pocketmine\math\Axis;
 use pocketmine\math\Facing;
-use pocketmine\nbt\NbtException;
 use pocketmine\nbt\tag\CompoundTag;
 use function array_key_exists;
 use function min;
@@ -2501,20 +2500,12 @@ final class BlockStateDeserializer{
 
 	/** @throws BlockStateDeserializeException */
 	public function deserialize(CompoundTag $blockState) : Block{
-		try{
+		$blockStateData = BlockStateData::fromNbt($blockState);
-			$id = $blockState->getString("name");
-			$states = $blockState->getCompoundTag("states");
-		}catch(NbtException $e){
-			throw new BlockStateDeserializeException("Error reading blockstate NBT: " . $e->getMessage(), 0, $e);
-		}
-
-		if($states === null){
-			throw new BlockStateDeserializeException("\"states\" tag must always be present, even if it has no data");
-		}
 
+		$id = $blockStateData->getName();
 		if(!array_key_exists($id, $this->deserializeFuncs)){
 			throw new BlockStateDeserializeException("Unknown block ID \"$id\"");
 		}
-		return $this->deserializeFuncs[$id](new BlockStateReader($states));
+		return $this->deserializeFuncs[$id](new BlockStateReader($blockStateData));
 	}
 }

src/data/bedrock/blockstate/BlockStateReader.php

@@ -31,7 +31,6 @@ use pocketmine\data\bedrock\blockstate\BlockStateStringValues as StringValues;
 use pocketmine\math\Axis;
 use pocketmine\math\Facing;
 use pocketmine\nbt\tag\ByteTag;
-use pocketmine\nbt\tag\CompoundTag;
 use pocketmine\nbt\tag\IntTag;
 use pocketmine\nbt\tag\StringTag;
 use pocketmine\nbt\tag\Tag;
@@ -39,13 +38,9 @@ use function get_class;
 
 final class BlockStateReader{
 
-	private CompoundTag $nbt;
+	public function __construct(
-
+		private BlockStateData $data
-	public function __construct(CompoundTag $nbt){
+	){}
-		$this->nbt = $nbt;
-	}
-
-	public function getNbt() : CompoundTag{ return $this->nbt; }
 
 	public function missingOrWrongTypeException(string $name, ?Tag $tag) : BlockStateDeserializeException{
 		return new BlockStateDeserializeException("Property \"$name\" " . ($tag !== null ? "has unexpected type " . get_class($tag) : "is missing"));
@@ -60,7 +55,7 @@ final class BlockStateReader{
 
 	/** @throws BlockStateDeserializeException */
 	public function readBool(string $name) : bool{
-		$tag = $this->nbt->getTag($name);
+		$tag = $this->data->getStates()->getTag($name);
 		if($tag instanceof ByteTag){
 			switch($tag->getValue()){
 				case 0: return false;
@@ -73,7 +68,7 @@ final class BlockStateReader{
 
 	/** @throws BlockStateDeserializeException */
 	public function readInt(string $name) : int{
-		$tag = $this->nbt->getTag($name);
+		$tag = $this->data->getStates()->getTag($name);
 		if($tag instanceof IntTag){
 			return $tag->getValue();
 		}
@@ -92,7 +87,7 @@ final class BlockStateReader{
 	/** @throws BlockStateDeserializeException */
 	public function readString(string $name) : string{
 		//TODO: only allow a specific set of values (strings are primarily used for enums)
-		$tag = $this->nbt->getTag($name);
+		$tag = $this->data->getStates()->getTag($name);
 		if($tag instanceof StringTag){
 			return $tag->getValue();
 		}

src/data/bedrock/blockstate/BlockStateSerializer.php

@@ -143,7 +143,6 @@ use pocketmine\data\bedrock\blockstate\BlockStateWriter as Writer;
 use pocketmine\data\bedrock\blockstate\BlockTypeNames as Ids;
 use pocketmine\math\Axis;
 use pocketmine\math\Facing;
-use pocketmine\nbt\tag\CompoundTag;
 use pocketmine\utils\AssumptionFailedError;
 use function class_parents;
 use function get_class;
@@ -175,7 +174,7 @@ final class BlockStateSerializer{
 	 * @phpstan-template TBlockType of Block
 	 * @phpstan-param TBlockType $blockState
 	 */
-	public function serialize(Block $blockState) : CompoundTag{
+	public function serialize(Block $blockState) : BlockStateData{
 		$typeId = $blockState->getTypeId();
 
 		$locatedSerializer = $this->serializers[$typeId][get_class($blockState)] ?? null;
@@ -204,7 +203,7 @@ final class BlockStateSerializer{
 
 		/** @var Writer $writer */
 		$writer = $serializer($blockState);
-		return $writer->writeBlockStateNbt();
+		return $writer->getBlockStateData();
 	}
 
 	public function __construct(){

src/data/bedrock/blockstate/BlockStateWriter.php

@@ -246,10 +246,7 @@ final class BlockStateWriter{
 		return $this;
 	}
 
-	public function writeBlockStateNbt() : CompoundTag{
+	public function getBlockStateData() : BlockStateData{
-		//TODO: add `version` field
+		return new BlockStateData($this->id, $this->states, BlockStateData::CURRENT_VERSION);
-		return CompoundTag::create()
-			->setString("name", $this->id)
-			->setTag("states", $this->states);
 	}
 }