Paper/Spigot-Server-Patches/0184-Ability-to-apply-mending-to-XP-API.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Wed, 20 Dec 2017 17:36:49 -0500
Subject: [PATCH] Ability to apply mending to XP API

This allows plugins that give players the ability to apply the experience
points to the Item Mending formula, which will repair an item instead
of giving the player experience points.

Both an API To standalone mend, and apply mending logic to .giveExp has been added.

diff --git a/src/main/java/net/minecraft/world/entity/EntityExperienceOrb.java b/src/main/java/net/minecraft/world/entity/EntityExperienceOrb.java
index 1fd4bd03463a76e838d1aaa8e6f16f7a42f96fa7..dc257a7cafc4b728aa5c99ca332143bb05896d7e 100644
--- a/src/main/java/net/minecraft/world/entity/EntityExperienceOrb.java
+++ b/src/main/java/net/minecraft/world/entity/EntityExperienceOrb.java
@@ -264,10 +264,12 @@ public class EntityExperienceOrb extends Entity {
         }
     }
 
+    public final int durToXp(int i) { return b(i); } // Paper OBFHELPER
     private int b(int i) {
         return i / 2;
     }
 
+    public final int xpToDur(int i) { return c(i); } // Paper OBFHELPER
     private int c(int i) {
         return i * 2;
     }
diff --git a/src/main/java/net/minecraft/world/item/enchantment/EnchantmentManager.java b/src/main/java/net/minecraft/world/item/enchantment/EnchantmentManager.java
index d313b02f41e4f4a90676cbb37afce4e92dd4d664..72afbf8f537770540e90a2880ea81de137ea10f5 100644
--- a/src/main/java/net/minecraft/world/item/enchantment/EnchantmentManager.java
+++ b/src/main/java/net/minecraft/world/item/enchantment/EnchantmentManager.java
@@ -269,8 +269,8 @@ public class EnchantmentManager {
         return getEnchantmentLevel(Enchantments.CHANNELING, itemstack) > 0;
     }
 
-    @Nullable
-    public static Entry<EnumItemSlot, ItemStack> b(Enchantment enchantment, EntityLiving entityliving) {
+    public static @javax.annotation.Nonnull ItemStack getRandomEquippedItemWithEnchant(Enchantment enchantment, EntityLiving entityliving) { Entry<EnumItemSlot, ItemStack> entry = b(enchantment, entityliving); return entry != null ? entry.getValue() : ItemStack.NULL_ITEM; } // Paper - OBFHELPER
+    @Nullable public static Entry<EnumItemSlot, ItemStack> b(Enchantment enchantment, EntityLiving entityliving) {
         return a(enchantment, entityliving, (itemstack) -> {
             return true;
         });
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index cf9ae60db30ef09bb4c89935a42632e562b6d61e..f8780db8f376ee71a35ebe1c2ab84a6117d0d74e 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -1180,8 +1180,37 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
         return GameMode.getByValue(getHandle().playerInteractManager.getGameMode().getId());
     }
 
+    // Paper start
     @Override
-    public void giveExp(int exp) {
+    public int applyMending(int amount) {
+        EntityPlayer handle = getHandle();
+        // Logic copied from EntityExperienceOrb and remapped to unobfuscated methods/properties
+        net.minecraft.server.ItemStack itemstack = net.minecraft.server.EnchantmentManager.getRandomEquippedItemWithEnchant(net.minecraft.server.Enchantments.MENDING, handle);
+        if (!itemstack.isEmpty() && itemstack.getItem().usesDurability()) {
+
+            net.minecraft.server.EntityExperienceOrb orb = net.minecraft.server.EntityTypes.EXPERIENCE_ORB.create(handle.world);
+            orb.value = amount;
+            orb.spawnReason = org.bukkit.entity.ExperienceOrb.SpawnReason.CUSTOM;
+            orb.setPositionRaw(handle.locX(), handle.locY(), handle.locZ());
+
+            int i = Math.min(orb.xpToDur(amount), itemstack.getDamage());
+            org.bukkit.event.player.PlayerItemMendEvent event = org.bukkit.craftbukkit.event.CraftEventFactory.callPlayerItemMendEvent(handle, orb, itemstack, i);
+            i = event.getRepairAmount();
+            orb.dead = true;
+            if (!event.isCancelled()) {
+                amount -= orb.durToXp(i);
+                itemstack.setDamage(itemstack.getDamage() - i);
+            }
+        }
+        return amount;
+    }
+
+    @Override
+    public void giveExp(int exp, boolean applyMending) {
+        if (applyMending) {
+            exp = this.applyMending(exp);
+        }
+        // Paper end
         getHandle().giveExp(exp);
     }