first look at anvil

src/block/inventory/AnvilInventory.php

@@ -25,6 +25,7 @@ namespace pocketmine\block\inventory;
 
 use pocketmine\inventory\SimpleInventory;
 use pocketmine\inventory\TemporaryInventory;
+use pocketmine\item\Item;
 use pocketmine\world\Position;
 
 class AnvilInventory extends SimpleInventory implements BlockInventory, TemporaryInventory{
@@ -37,4 +38,12 @@ class AnvilInventory extends SimpleInventory implements BlockInventory, Temporar
 		$this->holder = $holder;
 		parent::__construct(2);
 	}
+
+	public function getInput() : Item {
+		return $this->getItem(self::SLOT_INPUT);
+	}
+
+	public function getMaterial() : Item {
+		return $this->getItem(self::SLOT_MATERIAL);
+	}
 }

src/block/utils/AnvilHelper.php

@@ -0,0 +1,187 @@
+<?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\block\utils;
+
+use pocketmine\inventory\transaction\TransactionValidationException;
+use pocketmine\item\Durable;
+use pocketmine\item\EnchantedBook;
+use pocketmine\item\enchantment\AvailableEnchantmentRegistry;
+use pocketmine\item\enchantment\Enchantment;
+use pocketmine\item\enchantment\EnchantmentInstance;
+use pocketmine\item\enchantment\Rarity;
+use pocketmine\item\Item;
+use pocketmine\player\Player;
+use function ceil;
+use function floor;
+use function max;
+use function min;
+use function strlen;
+
+class AnvilHelper{
+	private const COST_REPAIR_MATERIAL = 1;
+	private const COST_REPAIR_SACRIFICE = 2;
+	private const COST_RENAME = 1;
+	private const COST_LIMIT = 39;
+
+	/**
+	 * Attempts to calculate the result of an anvil operation.
+	 *
+	 * Returns null if the operation can't do anything.
+	 */
+	public static function calculateResult(Player $player, Item $base, Item $material, ?string $customName = null) : ?AnvilResult {
+		$resultCost = 0;
+		$resultItem = clone $base;
+
+		if($resultItem instanceof Durable && $resultItem->isValidRepairMaterial($material) && $resultItem->getDamage() > 0){
+			$resultCost += self::repairWithMaterial($resultItem, $material);
+		}else{
+			if($resultItem->getTypeId() === $material->getTypeId() && $resultItem instanceof Durable && $material instanceof Durable){
+				$resultCost += self::repairWithSacrifice($resultItem, $material);
+			}
+			if($material->hasEnchantments()){
+				$resultCost += self::combineEnchantments($resultItem, $material);
+			}
+		}
+
+		// Repair cost increment if the item has been processed, the rename is free of penalty
+		$additionnalRepairCost = $resultCost > 0 ? 1 : 0;
+		$resultCost += self::renameItem($resultItem, $customName);
+
+		$resultCost += 2 ** $resultItem->getRepairCost() - 1;
+		$resultCost += 2 ** $material->getRepairCost() - 1;
+		$resultItem->setRepairCost(
+			max($resultItem->getRepairCost(), $material->getRepairCost()) + $additionnalRepairCost
+		);
+
+		if($resultCost <= 0 || ($resultCost > self::COST_LIMIT && !$player->isCreative())){
+			return null;
+		}
+
+		return new AnvilResult($resultCost, $resultItem);
+	}
+
+	/**
+	 * @return int The XP cost of repairing the item
+	 */
+	private static function repairWithMaterial(Durable $result, Item $material) : int {
+		$damage = $result->getDamage();
+		$quarter = min($damage, (int) floor($result->getMaxDurability() / 4));
+		$numberRepair = min($material->getCount(), (int) ceil($damage / $quarter));
+		if($numberRepair > 0){
+			$material->pop($numberRepair);
+			$damage -= $quarter * $numberRepair;
+		}
+		$result->setDamage(max(0, $damage));
+
+		return $numberRepair * self::COST_REPAIR_MATERIAL;
+	}
+
+	/**
+	 * @return int The XP cost of repairing the item
+	 */
+	private static function repairWithSacrifice(Durable $result, Durable $sacrifice) : int{
+		if($result->getDamage() === 0){
+			return 0;
+		}
+		$baseDurability = $result->getMaxDurability() - $result->getDamage();
+		$materialDurability = $sacrifice->getMaxDurability() - $sacrifice->getDamage();
+		$addDurability = (int) ($result->getMaxDurability() * 12 / 100);
+
+		$newDurability = min($result->getMaxDurability(), $baseDurability + $materialDurability + $addDurability);
+
+		$result->setDamage($result->getMaxDurability() - $newDurability);
+
+		return self::COST_REPAIR_SACRIFICE;
+	}
+
+	/**
+	 * @return int The XP cost of combining the enchantments
+	 */
+	private static function combineEnchantments(Item $base, Item $sacrifice) : int{
+		$cost = 0;
+		foreach($sacrifice->getEnchantments() as $instance){
+			$enchantment = $instance->getType();
+			$level = $instance->getLevel();
+			if(!AvailableEnchantmentRegistry::getInstance()->isAvailableForItem($enchantment, $base)){
+				continue;
+			}
+			if(($targetEnchantment = $base->getEnchantment($enchantment)) !== null){
+				// Enchant already present on the target item
+				$targetLevel = $targetEnchantment->getLevel();
+				$newLevel = ($targetLevel === $level ? $targetLevel + 1 : max($targetLevel, $level));
+				$level = min($newLevel, $enchantment->getMaxLevel());
+				$instance = new EnchantmentInstance($enchantment, $level);
+			}else{
+				// Check if the enchantment is compatible with the existing enchantments
+				foreach($base->getEnchantments() as $testedInstance){
+					$testedEnchantment = $testedInstance->getType();
+					if(!$testedEnchantment->isCompatibleWith($enchantment)){
+						$cost++;
+						continue 2;
+					}
+				}
+			}
+
+			$costAddition = self::getCostAddition($enchantment);
+
+			if($sacrifice instanceof EnchantedBook){
+				// Enchanted books are half as expensive to combine
+				$costAddition = max(1, $costAddition / 2);
+			}
+			$levelDifference = $instance->getLevel() - $base->getEnchantmentLevel($instance->getType());
+			$cost += $costAddition * $levelDifference;
+			$base->addEnchantment($instance);
+		}
+
+		return (int) $cost;
+	}
+
+	/**
+	 * @return int The XP cost of renaming the item
+	 */
+	private static function renameItem(Item $item, ?string $customName) : int{
+		$resultCost = 0;
+		if($customName === null || strlen($customName) === 0){
+			if($item->hasCustomName()){
+				$resultCost += self::COST_RENAME;
+				$item->clearCustomName();
+			}
+		}else{
+			$resultCost += self::COST_RENAME;
+			$item->setCustomName($customName);
+		}
+
+		return $resultCost;
+	}
+
+	private static function getCostAddition(Enchantment $enchantment) : int {
+		return match($enchantment->getRarity()){
+			Rarity::COMMON => 1,
+			Rarity::UNCOMMON => 2,
+			Rarity::RARE => 4,
+			Rarity::MYTHIC => 8,
+			default => throw new TransactionValidationException("Invalid rarity " . $enchantment->getRarity() . " found")
+		};
+	}
+}

src/block/utils/AnvilResult.php

@@ -0,0 +1,41 @@
+<?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\block\utils;
+
+use pocketmine\item\Item;
+
+class AnvilResult{
+	public function __construct(
+		private int $repairCost,
+		private ?Item $result,
+	){}
+
+	public function getRepairCost() : int{
+		return $this->repairCost;
+	}
+
+	public function getResult() : ?Item{
+		return $this->result;
+	}
+}

src/inventory/transaction/AnvilTransaction.php

@@ -0,0 +1,60 @@
+<?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\inventory\transaction;
+
+use pocketmine\block\utils\AnvilResult;
+use pocketmine\item\Item;
+use pocketmine\player\Player;
+use function count;
+
+class AnvilTransaction extends InventoryTransaction{
+	public function __construct(
+		Player $source,
+		private AnvilResult $anvilResult
+	) {
+		parent::__construct($source);
+	}
+
+	public function validate() : void{
+		if(count($this->actions) < 1){
+			throw new TransactionValidationException("Transaction must have at least one action to be executable");
+		}
+
+		/** @var Item[] $inputs */
+		$inputs = [];
+		/** @var Item[] $outputs */
+		$outputs = [];
+		$this->matchItems($outputs, $inputs);
+
+		//TODO
+	}
+
+	public function execute() : void{
+		parent::execute();
+
+		if($this->source->hasFiniteResources()){
+			$this->source->getXpManager()->subtractXpLevels($this->anvilResult->getRepairCost());
+		}
+	}
+}

src/item/Armor.php

@@ -33,6 +33,7 @@ use pocketmine\nbt\tag\CompoundTag;
 use pocketmine\nbt\tag\IntTag;
 use pocketmine\player\Player;
 use pocketmine\utils\Binary;
+use function in_array;
 use function lcg_value;
 use function mt_rand;
 
@@ -172,4 +173,8 @@ class Armor extends Durable{
 			$tag->setInt(self::TAG_CUSTOM_COLOR, Binary::signInt($this->customColor->toARGB())) :
 			$tag->removeTag(self::TAG_CUSTOM_COLOR);
 	}
+
+	public function isValidRepairMaterial(Item $material) : bool{
+		return in_array($material->getTypeId(), $this->armorInfo->getMaterial()->getRepairMaterials(), true);
+	}
 }

src/item/ArmorMaterial.php

@@ -27,9 +27,13 @@ use pocketmine\world\sound\Sound;
 
 class ArmorMaterial{
 
+	/**
+	 * @param int[] $repairMaterials
+	 */
 	public function __construct(
 		private readonly int $enchantability,
-		private readonly ?Sound $equipSound = null
+		private readonly ?Sound $equipSound = null,
+		private readonly array $repairMaterials = []
 	){
 	}
 
@@ -49,4 +53,11 @@ class ArmorMaterial{
 	public function getEquipSound() : ?Sound{
 		return $this->equipSound;
 	}
+
+	/**
+	 * Returns the items that can be used to repair the armor
+	 */
+	public function getRepairMaterials() : array{
+		return $this->repairMaterials;
+	}
 }

src/item/Durable.php

@@ -118,6 +118,10 @@ abstract class Durable extends Item{
 		return $this->damage >= $this->getMaxDurability() || $this->isNull();
 	}
 
+	public function isValidRepairMaterial(Item $material) : bool {
+		return false;
+	}
+
 	protected function deserializeCompoundTag(CompoundTag $tag) : void{
 		parent::deserializeCompoundTag($tag);
 		$this->unbreakable = $tag->getByte("Unbreakable", 0) !== 0;

src/item/Item.php

@@ -69,6 +69,7 @@ class Item implements \JsonSerializable{
 
 	public const TAG_DISPLAY_NAME = "Name";
 	public const TAG_DISPLAY_LORE = "Lore";
+	public const TAG_REPAIR_COST = "RepairCost";
 
 	public const TAG_KEEP_ON_DEATH = "minecraft:keep_on_death";
 
@@ -84,6 +85,7 @@ class Item implements \JsonSerializable{
 	protected string $customName = "";
 	/** @var string[] */
 	protected array $lore = [];
+	protected int $repairCost = 0;
 	/** TODO: this needs to die in a fire */
 	protected ?CompoundTag $blockEntityTag = null;
 
@@ -282,6 +284,23 @@ class Item implements \JsonSerializable{
 		return $this;
 	}
 
+	/**
+	 * Returns the repair cost of the item.
+	 */
+	public function getRepairCost() : int{
+		return $this->repairCost;
+	}
+
+	/**
+	 * Sets the repair cost of the item.
+	 *
+	 * @return $this
+	 */
+	public function setRepairCost(int $cost) : self{
+		$this->repairCost = $cost;
+		return $this;
+	}
+
 	/**
 	 * @throws NbtException
 	 */
@@ -338,6 +357,7 @@ class Item implements \JsonSerializable{
 		}
 
 		$this->keepOnDeath = $tag->getByte(self::TAG_KEEP_ON_DEATH, 0) !== 0;
+		$this->repairCost = $tag->getInt(self::TAG_REPAIR_COST, 0);
 	}
 
 	protected function serializeCompoundTag(CompoundTag $tag) : void{
@@ -406,6 +426,12 @@ class Item implements \JsonSerializable{
 		}else{
 			$tag->removeTag(self::TAG_KEEP_ON_DEATH);
 		}
+
+		if($this->repairCost){
+			$tag->setInt(self::TAG_REPAIR_COST, $this->repairCost);
+		}else{
+			$tag->removeTag(self::TAG_REPAIR_COST);
+		}
 	}
 
 	public function getCount() : int{

src/item/TieredTool.php

@@ -23,6 +23,8 @@ declare(strict_types=1);
 
 namespace pocketmine\item;
 
+use function in_array;
+
 abstract class TieredTool extends Tool{
 	protected ToolTier $tier;
 
@@ -61,4 +63,8 @@ abstract class TieredTool extends Tool{
 	public function isFireProof() : bool{
 		return $this->tier === ToolTier::NETHERITE;
 	}
+
+	public function isValidRepairMaterial(Item $material) : bool{
+		return in_array($material->getTypeId(), $this->tier->getRepairMaterials(), true);
+	}
 }

src/item/ToolTier.php

@@ -23,6 +23,7 @@ declare(strict_types=1);
 
 namespace pocketmine\item;
 
+use pocketmine\block\BlockTypeIds;
 use pocketmine\utils\LegacyEnumShimTrait;
 
 /**
@@ -36,7 +37,7 @@ use pocketmine\utils\LegacyEnumShimTrait;
  * @method static ToolTier STONE()
  * @method static ToolTier WOOD()
  *
- * @phpstan-type TMetadata array{0: int, 1: int, 2: int, 3: int, 4: int}
+ * @phpstan-type TMetadata array{0: int, 1: int, 2: int, 3: int, 4: int, 5: int[]}
  */
 enum ToolTier{
 	use LegacyEnumShimTrait;
@@ -52,8 +53,8 @@ enum ToolTier{
 	 * This function exists only to permit the use of named arguments and to make the code easier to read in PhpStorm.
 	 * @phpstan-return TMetadata
 	 */
-	private static function meta(int $harvestLevel, int $maxDurability, int $baseAttackPoints, int $baseEfficiency, int $enchantability) : array{
-		return [$harvestLevel, $maxDurability, $baseAttackPoints, $baseEfficiency, $enchantability];
+	private static function meta(int $harvestLevel, int $maxDurability, int $baseAttackPoints, int $baseEfficiency, int $enchantability, array $repairMaterials = []) : array{
+		return [$harvestLevel, $maxDurability, $baseAttackPoints, $baseEfficiency, $enchantability, $repairMaterials];
 	}
 
 	/**
@@ -61,12 +62,26 @@ enum ToolTier{
 	 */
 	private function getMetadata() : array{
 		return match($this){
-			self::WOOD => self::meta(1, 60, 5, 2, 15),
-			self::GOLD => self::meta(2, 33, 5, 12, 22),
-			self::STONE => self::meta(3, 132, 6, 4, 5),
-			self::IRON => self::meta(4, 251, 7, 6, 14),
-			self::DIAMOND => self::meta(5, 1562, 8, 8, 10),
-			self::NETHERITE => self::meta(6, 2032, 9, 9, 15)
+			self::WOOD => self::meta(1, 60, 5, 2, 15, [
+				ItemTypeIds::fromBlockTypeId(BlockTypeIds::OAK_PLANKS),
+				ItemTypeIds::fromBlockTypeId(BlockTypeIds::SPRUCE_PLANKS),
+				ItemTypeIds::fromBlockTypeId(BlockTypeIds::BIRCH_PLANKS),
+				ItemTypeIds::fromBlockTypeId(BlockTypeIds::JUNGLE_PLANKS),
+				ItemTypeIds::fromBlockTypeId(BlockTypeIds::ACACIA_PLANKS),
+				ItemTypeIds::fromBlockTypeId(BlockTypeIds::DARK_OAK_PLANKS),
+				ItemTypeIds::fromBlockTypeId(BlockTypeIds::CRIMSON_PLANKS),
+				ItemTypeIds::fromBlockTypeId(BlockTypeIds::WARPED_PLANKS),
+				ItemTypeIds::fromBlockTypeId(BlockTypeIds::CHERRY_PLANKS),
+				ItemTypeIds::fromBlockTypeId(BlockTypeIds::MANGROVE_PLANKS)
+			]),
+			self::GOLD => self::meta(2, 33, 5, 12, 22, [ItemTypeIds::GOLD_INGOT]),
+			self::STONE => self::meta(3, 132, 6, 4, 5, [
+				ItemTypeIds::fromBlockTypeId(BlockTypeIds::COBBLESTONE),
+				ItemTypeIds::fromBlockTypeId(BlockTypeIds::COBBLED_DEEPSLATE)
+			]),
+			self::IRON => self::meta(4, 251, 7, 6, 14, [ItemTypeIds::IRON_INGOT]),
+			self::DIAMOND => self::meta(5, 1562, 8, 8, 10, [ItemTypeIds::DIAMOND]),
+			self::NETHERITE => self::meta(6, 2032, 9, 9, 15, [ItemTypeIds::NETHERITE_INGOT])
 		};
 	}
 
@@ -95,4 +110,13 @@ enum ToolTier{
 	public function getEnchantability() : int{
 		return $this->getMetadata()[4];
 	}
+
+	/**
+	 * Returns the list of items that can be used to repair this tool.
+	 *
+	 * @return int[]
+	 */
+	public function getRepairMaterials() : array{
+		return $this->getMetadata()[5];
+	}
 }

src/item/TurtleHelmet.php

@@ -38,4 +38,8 @@ class TurtleHelmet extends Armor{
 
 		return false;
 	}
+
+	public function isValidRepairMaterial(Item $material) : bool{
+		return $material->getTypeId() === ItemTypeIds::SCUTE;
+	}
 }

src/item/VanillaArmorMaterials.php

@@ -69,12 +69,12 @@ final class VanillaArmorMaterials{
 	}
 
 	protected static function setup() : void{
-		self::register("leather", new ArmorMaterial(15, new ArmorEquipLeatherSound()));
+		self::register("leather", new ArmorMaterial(15, new ArmorEquipLeatherSound(), [ItemTypeIds::LEATHER]));
 		self::register("chainmail", new ArmorMaterial(12, new ArmorEquipChainSound()));
-		self::register("iron", new ArmorMaterial(9, new ArmorEquipIronSound()));
-		self::register("turtle", new ArmorMaterial(9, new ArmorEquipGenericSound()));
-		self::register("gold", new ArmorMaterial(25, new ArmorEquipGoldSound()));
-		self::register("diamond", new ArmorMaterial(10, new ArmorEquipDiamondSound()));
-		self::register("netherite", new ArmorMaterial(15, new ArmorEquipNetheriteSound()));
+		self::register("iron", new ArmorMaterial(9, new ArmorEquipIronSound(), [ItemTypeIds::IRON_INGOT]));
+		self::register("turtle", new ArmorMaterial(9, new ArmorEquipGenericSound(), [ItemTypeIds::SCUTE]));
+		self::register("gold", new ArmorMaterial(25, new ArmorEquipGoldSound(), [ItemTypeIds::GOLD_INGOT]));
+		self::register("diamond", new ArmorMaterial(10, new ArmorEquipDiamondSound(), [ItemTypeIds::DIAMOND]));
+		self::register("netherite", new ArmorMaterial(15, new ArmorEquipNetheriteSound(), [ItemTypeIds::NETHERITE_INGOT]));
 	}
 }

src/network/mcpe/handler/ItemStackRequestExecutor.php

@@ -23,11 +23,14 @@ declare(strict_types=1);
 
 namespace pocketmine\network\mcpe\handler;
 
+use pocketmine\block\inventory\AnvilInventory;
 use pocketmine\block\inventory\EnchantInventory;
+use pocketmine\block\utils\AnvilHelper;
 use pocketmine\inventory\Inventory;
 use pocketmine\inventory\transaction\action\CreateItemAction;
 use pocketmine\inventory\transaction\action\DestroyItemAction;
 use pocketmine\inventory\transaction\action\DropItemAction;
+use pocketmine\inventory\transaction\AnvilTransaction;
 use pocketmine\inventory\transaction\CraftingTransaction;
 use pocketmine\inventory\transaction\EnchantingTransaction;
 use pocketmine\inventory\transaction\InventoryTransaction;
@@ -39,6 +42,7 @@ use pocketmine\network\mcpe\protocol\types\inventory\ContainerUIIds;
 use pocketmine\network\mcpe\protocol\types\inventory\stackrequest\CraftingConsumeInputStackRequestAction;
 use pocketmine\network\mcpe\protocol\types\inventory\stackrequest\CraftingCreateSpecificResultStackRequestAction;
 use pocketmine\network\mcpe\protocol\types\inventory\stackrequest\CraftRecipeAutoStackRequestAction;
+use pocketmine\network\mcpe\protocol\types\inventory\stackrequest\CraftRecipeOptionalStackRequestAction;
 use pocketmine\network\mcpe\protocol\types\inventory\stackrequest\CraftRecipeStackRequestAction;
 use pocketmine\network\mcpe\protocol\types\inventory\stackrequest\CreativeCreateStackRequestAction;
 use pocketmine\network\mcpe\protocol\types\inventory\stackrequest\DeprecatedCraftingResultsStackRequestAction;
@@ -289,7 +293,7 @@ class ItemStackRequestExecutor{
 	 * @throws ItemStackRequestProcessException
 	 */
 	private function assertDoingCrafting() : void{
-		if(!$this->specialTransaction instanceof CraftingTransaction && !$this->specialTransaction instanceof EnchantingTransaction){
+		if(!$this->specialTransaction instanceof CraftingTransaction && !$this->specialTransaction instanceof EnchantingTransaction && !$this->specialTransaction instanceof AnvilTransaction){
 			if($this->specialTransaction === null){
 				throw new ItemStackRequestProcessException("Expected CraftRecipe or CraftRecipeAuto action to precede this action");
 			}else{
@@ -347,6 +351,15 @@ class ItemStackRequestExecutor{
 			}
 		}elseif($action instanceof CraftRecipeAutoStackRequestAction){
 			$this->beginCrafting($action->getRecipeId(), $action->getRepetitions());
+		}elseif($action instanceof CraftRecipeOptionalStackRequestAction){
+			$window = $this->player->getCurrentWindow();
+			if($window instanceof AnvilInventory){
+				$result = AnvilHelper::calculateResult($this->player, $window->getInput(), $window->getMaterial(), $this->request->getFilterStrings()[0] ?? null);
+				if($result !== null){
+					$this->specialTransaction = new AnvilTransaction($this->player, $result);
+					$this->setNextCreatedItem($result->getResult());
+				}
+			}
 		}elseif($action instanceof CraftingConsumeInputStackRequestAction){
 			$this->assertDoingCrafting();
 			$this->removeItemFromSlot($action->getSource(), $action->getCount()); //output discarded - we allow CraftingTransaction to verify the balance