some work on anvil

src/block/anvil/AnvilAction.php

@@ -26,6 +26,7 @@ namespace pocketmine\block\anvil;
 use pocketmine\item\Item;
 
 abstract class AnvilAction{
+	/** @phpstan-var int<0, max>  */
 	protected int $xpCost = 0;
 
 	final public function __construct(
@@ -34,6 +35,12 @@ abstract class AnvilAction{
 		protected ?string $customName
 	){ }
 
+	/**
+	 * Returns the XP cost requested for this action.
+	 * This XP cost will be summed up to the total XP cost of the anvil operation.
+	 *
+	 * @phpstan-return int<0, max>
+	 */
 	final public function getXpCost() : int{
 		return $this->xpCost;
 	}
@@ -46,7 +53,14 @@ abstract class AnvilAction{
 		return false;
 	}
 
+	/**
+	 * Processing an action means applying the changes to the result item
+	 * and updating the XP cost property of the action.
+	 */
 	abstract public function process(Item $resultItem) : void;
 
+	/**
+	 * Returns whether this action is valid and can be applied.
+	 */
 	abstract public function canBeApplied() : bool;
 }

src/block/anvil/CombineEnchantmentsAction.php

@@ -29,6 +29,7 @@ use pocketmine\item\enchantment\AvailableEnchantmentRegistry;
 use pocketmine\item\enchantment\EnchantmentInstance;
 use pocketmine\item\enchantment\Rarity;
 use pocketmine\item\Item;
+use function floor;
 use function max;
 use function min;
 
@@ -74,7 +75,7 @@ final class CombineEnchantmentsAction extends AnvilAction{
 				$costAddition = max(1, $costAddition / 2);
 			}
 			$levelDifference = $instance->getLevel() - $this->base->getEnchantmentLevel($instance->getType());
-			$this->xpCost += $costAddition * $levelDifference;
+			$this->xpCost += (int) floor($costAddition * $levelDifference);
 			$resultItem->addEnchantment($instance);
 		}
 	}

src/block/anvil/RepairWithMaterialAction.php

@@ -53,6 +53,6 @@ final class RepairWithMaterialAction extends AnvilAction{
 		}
 		$resultItem->setDamage(max(0, $damage));
 
-		$this->xpCost = $numberRepair * self::COST;
+		$this->xpCost = (int) floor($numberRepair * self::COST);
 	}
 }

src/block/utils/AnvilHelper.php

@@ -51,10 +51,10 @@ final class AnvilHelper{
 			$xpCost += $action->getXpCost();
 		}
 
-		$xpCost += 2 ** $resultItem->getRepairCost() - 1;
+		$xpCost += 2 ** $resultItem->getAnvilRepairCost() - 1;
-		$xpCost += 2 ** $material->getRepairCost() - 1;
+		$xpCost += 2 ** $material->getAnvilRepairCost() - 1;
-		$resultItem->setRepairCost(
+		$resultItem->setAnvilRepairCost(
-			max($resultItem->getRepairCost(), $material->getRepairCost()) + $additionnalRepairCost
+			max($resultItem->getAnvilRepairCost(), $material->getAnvilRepairCost()) + $additionnalRepairCost
 		);
 
 		if($xpCost <= 0 || ($xpCost > self::COST_LIMIT && !$player->isCreative())){

src/item/Item.php

@@ -85,7 +85,7 @@ class Item implements \JsonSerializable{
 	protected string $customName = "";
 	/** @var string[] */
 	protected array $lore = [];
-	protected int $repairCost = 0;
+	protected int $anvilRepairCost = 0;
 	/** TODO: this needs to die in a fire */
 	protected ?CompoundTag $blockEntityTag = null;
 
@@ -285,19 +285,26 @@ class Item implements \JsonSerializable{
 	}
 
 	/**
-	 * Returns the repair cost of the item.
+	 * Returns the anvil repair cost of the item.
+	 * This value is used in anvil to determine the XP cost of repairing the item.
+	 *
+	 * In vanilla, this value is stored in the "RepairCost" tag.
 	 */
-	public function getRepairCost() : int{
+	public function getAnvilRepairCost() : int{
-		return $this->repairCost;
+		return $this->anvilRepairCost;
 	}
 
 	/**
-	 * Sets the repair cost of the item.
+	 * Sets the anvil repair cost value of the item.
+	 * This value is used in anvil to determine the XP cost of repairing the item.
+	 * Higher cost means more XP is required to repair the item.
+	 *
+	 * In vanilla, this value is stored in the "RepairCost" tag.
 	 *
 	 * @return $this
 	 */
-	public function setRepairCost(int $cost) : self{
+	public function setAnvilRepairCost(int $cost) : self{
-		$this->repairCost = $cost;
+		$this->anvilRepairCost = $cost;
 		return $this;
 	}
 
@@ -357,7 +364,7 @@ class Item implements \JsonSerializable{
 		}
 
 		$this->keepOnDeath = $tag->getByte(self::TAG_KEEP_ON_DEATH, 0) !== 0;
-		$this->repairCost = $tag->getInt(self::TAG_REPAIR_COST, 0);
+		$this->anvilRepairCost = $tag->getInt(self::TAG_REPAIR_COST, 0);
 	}
 
 	protected function serializeCompoundTag(CompoundTag $tag) : void{
@@ -427,8 +434,8 @@ class Item implements \JsonSerializable{
 			$tag->removeTag(self::TAG_KEEP_ON_DEATH);
 		}
 
-		if($this->repairCost > 0){
+		if($this->anvilRepairCost > 0){
-			$tag->setInt(self::TAG_REPAIR_COST, $this->repairCost);
+			$tag->setInt(self::TAG_REPAIR_COST, $this->anvilRepairCost);
 		}else{
 			$tag->removeTag(self::TAG_REPAIR_COST);
 		}