Paper/patches/server/0674-Implement-enchantWithLevels-API.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jason Penilla <11360596+jpenilla@users.noreply.github.com>
Date: Wed, 16 Mar 2022 20:35:21 -0700
Subject: [PATCH] Implement enchantWithLevels API


diff --git a/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemFactory.java b/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemFactory.java
index ad86ee4372e55c82968fd4fc6a65debab0092028..d9eec6cff3c7c6515f4d61bf1063e7d609d4bcb3 100644
--- a/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemFactory.java
+++ b/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemFactory.java
@@ -305,4 +305,47 @@ public final class CraftItemFactory implements ItemFactory {
         return eggItem == null ? null : new net.minecraft.world.item.ItemStack(eggItem).asBukkitMirror();
     }
     // Paper end - old getSpawnEgg API
+    // Paper start - enchantWithLevels API
+    @Override
+    public ItemStack enchantWithLevels(ItemStack itemStack, int levels, boolean allowTreasure, java.util.Random random) {
+        return enchantWithLevels(
+            itemStack,
+            levels,
+            allowTreasure
+                ? Optional.empty()
+                // While IN_ENCHANTING_TABLE is not logically the same as all but TREASURE, the tag is defined as
+                // NON_TREASURE, which does contain all enchantments not in the treasure tag.
+                // Additionally, the allowTreasure boolean is more intended to configure this method to behave like
+                // an enchanting table.
+                : net.minecraft.server.MinecraftServer.getServer().registryAccess().lookupOrThrow(Registries.ENCHANTMENT).get(EnchantmentTags.IN_ENCHANTING_TABLE),
+            random
+        );
+    }
+
+    @SuppressWarnings("OptionalUsedAsFieldOrParameterType")
+    private ItemStack enchantWithLevels(
+        ItemStack itemStack,
+        int levels,
+        Optional<? extends net.minecraft.core.HolderSet<net.minecraft.world.item.enchantment.Enchantment>> possibleEnchantments,
+        java.util.Random random
+    ) {
+        Preconditions.checkArgument(itemStack != null, "Argument 'itemStack' must not be null");
+        Preconditions.checkArgument(!itemStack.isEmpty(), "Argument 'itemStack' cannot be empty");
+        Preconditions.checkArgument(levels > 0 && levels <= 30, "Argument 'levels' must be in range [1, 30] (attempted " + levels + ")");
+        Preconditions.checkArgument(random != null, "Argument 'random' must not be null");
+        final net.minecraft.world.item.ItemStack internalStack = CraftItemStack.asNMSCopy(itemStack);
+        if (internalStack.isEnchanted()) {
+            internalStack.set(net.minecraft.core.component.DataComponents.ENCHANTMENTS, net.minecraft.world.item.enchantment.ItemEnchantments.EMPTY);
+        }
+        final net.minecraft.core.RegistryAccess registryAccess = net.minecraft.server.MinecraftServer.getServer().registryAccess();
+        final net.minecraft.world.item.ItemStack enchanted = net.minecraft.world.item.enchantment.EnchantmentHelper.enchantItem(
+            new org.bukkit.craftbukkit.util.RandomSourceWrapper(random),
+            internalStack,
+            levels,
+            registryAccess,
+            possibleEnchantments
+        );
+        return CraftItemStack.asCraftMirror(enchanted);
+    }
+    // Paper end - enchantWithLevels API
 }