From 596b1db6a5e10475c0bc5c0f0d91fa43821c1d6e 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/server/EnchantmentManager.java b/src/main/java/net/minecraft/server/EnchantmentManager.java
index 98300d0a..f714dc32 100644
--- a/src/main/java/net/minecraft/server/EnchantmentManager.java
+++ b/src/main/java/net/minecraft/server/EnchantmentManager.java
@@ -226,6 +226,7 @@ public class EnchantmentManager {
         return getEnchantmentLevel(Enchantments.D, itemstack) > 0;
     }
 
+    public static ItemStack getRandomEquippedItemWithEnchant(Enchantment enchantment, EntityLiving entityliving) { return b(enchantment, entityliving); } // Paper - OBFHELPER
     public static ItemStack b(Enchantment enchantment, EntityLiving entityliving) {
         List list = enchantment.a(entityliving);
 
diff --git a/src/main/java/net/minecraft/server/Enchantments.java b/src/main/java/net/minecraft/server/Enchantments.java
index 35e87eb1..74a6a4f6 100644
--- a/src/main/java/net/minecraft/server/Enchantments.java
+++ b/src/main/java/net/minecraft/server/Enchantments.java
@@ -32,7 +32,7 @@ public class Enchantments {
     public static final Enchantment ARROW_INFINITE = a("infinity");
     public static final Enchantment LUCK = a("luck_of_the_sea");
     public static final Enchantment LURE = a("lure");
-    public static final Enchantment C = a("mending");
+    public static final Enchantment C = a("mending"); public static final Enchantment MENDING = C; // Paper - OBFHELPER
     public static final Enchantment D = a("vanishing_curse");
 
     @Nullable
diff --git a/src/main/java/net/minecraft/server/EntityExperienceOrb.java b/src/main/java/net/minecraft/server/EntityExperienceOrb.java
index ff5cc74b..1c59fd96 100644
--- a/src/main/java/net/minecraft/server/EntityExperienceOrb.java
+++ b/src/main/java/net/minecraft/server/EntityExperienceOrb.java
@@ -234,10 +234,12 @@ public class EntityExperienceOrb extends Entity {
         }
     }
 
+    public int durToXp(int i) { return c(i); } // Paper OBFHELPER
     private int c(int i) {
         return i / 2;
     }
 
+    public int xpToDur(int i) { return d(i); } // Paper OBFHELPER
     private int d(int i) {
         return i * 2;
     }
diff --git a/src/main/java/net/minecraft/server/ItemStack.java b/src/main/java/net/minecraft/server/ItemStack.java
index 52cb34ab..d1ff97a9 100644
--- a/src/main/java/net/minecraft/server/ItemStack.java
+++ b/src/main/java/net/minecraft/server/ItemStack.java
@@ -28,7 +28,7 @@ public final class ItemStack {
     private Item item;
     private NBTTagCompound tag;
     private boolean g;
-    private int damage;
+    private int damage; public void setDamage(int i) { this.damage = i; } // Paper - OBFHELPER
     private EntityItemFrame i;
     private Block j;
     private boolean k;
@@ -349,10 +349,12 @@ public final class ItemStack {
         return this.getItem().k();
     }
 
+    public boolean hasDamage() { return h(); } // Paper OBFHELPER
     public boolean h() {
         return this.f() && this.damage > 0;
     }
 
+    public int getDamage() { return i(); } // Paper OBFHELPER
     public int i() {
         return this.damage;
     }
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index 428b208a..21631c58 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -923,8 +923,39 @@ 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
+        ItemStack itemstack = EnchantmentManager.getRandomEquippedItemWithEnchant(Enchantments.MENDING, handle);
+        if (!itemstack.isEmpty() && itemstack.hasDamage()) {
+
+            EntityExperienceOrb orb = new EntityExperienceOrb(handle.world);
+            orb.value = amount;
+            orb.spawnReason = org.bukkit.entity.ExperienceOrb.SpawnReason.CUSTOM;
+            orb.locX = handle.locX;
+            orb.locY = handle.locY;
+            orb.locZ = 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);
     }
 
-- 
2.14.3