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.

paper-api/src/main/java/org/bukkit/entity/Player.java

@@ -1588,6 +1588,15 @@ public interface Player extends HumanEntity, Conversable, OfflinePlayer, PluginM
      */
     public void resetPlayerWeather();
 
+    // Paper start
+    /**
+     * Gives the player the amount of experience specified.
+     *
+     * @param amount Exp amount to give
+     */
+    public default void giveExp(int amount) {
+        giveExp(amount, false);
+    }
     /**
      * Gets the player's cooldown between picking up experience orbs.
      *
@@ -1613,8 +1622,20 @@ public interface Player extends HumanEntity, Conversable, OfflinePlayer, PluginM
      * Gives the player the amount of experience specified.
      *
      * @param amount Exp amount to give
+     * @param applyMending Mend players items with mending, with same behavior as picking up orbs. calls {@link #applyMending(int)}
      */
-    public void giveExp(int amount);
+    public void giveExp(int amount, boolean applyMending);
+
+    /**
+     * Applies the mending effect to any items just as picking up an orb would.
+     *
+     * Can also be called with {@link #giveExp(int, boolean)} by passing true to applyMending
+     *
+     * @param amount Exp to apply
+     * @return the remaining experience
+     */
+    public int applyMending(int amount);
+    // Paper end
 
     /**
      * Gives the player the amount of experience levels specified. Levels can