Fixes some savage fail problems

Fixes item not being returned when salvage fails
Removes some redundancy when giving back items
Makes extended salvage return 50% of the salvage (no items if only one item would be returned)
Adds a better message when failing to salvage extended salvage items
Fixes a bug in the caching of smith presets

src/main/java/net/knarcraft/blacksmith/trait/Session.java

@@ -1,15 +1,22 @@
 package net.knarcraft.blacksmith.trait;
 
+import net.citizensnpcs.api.npc.NPC;
 import net.knarcraft.blacksmith.BlacksmithPlugin;
+import net.knarcraft.blacksmith.util.ItemHelper;
 import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
 import org.bukkit.scheduler.BukkitScheduler;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.Random;
+import java.util.logging.Level;
+
 /**
  * A runnable session for performing a reforging/salvage task
  */
 public abstract class Session implements Runnable {
 
+    protected static final Random random = new Random();
     protected final Player player;
     protected long finishTime;
     protected int taskId;
@@ -85,6 +92,47 @@ public abstract class Session implements Runnable {
         taskId = scheduler.scheduleSyncDelayedTask(BlacksmithPlugin.getInstance(), this, actionDelay * 20L);
     }
 
+    /**
+     * Gives the resulting item to the player
+     *
+     * @param hasDelay     <p>Whether the session was delayed, or if the item was processed instantly</p>
+     * @param dropItem     <p>Whether the item should be dropped on the ground</p>
+     * @param npc          <p>The NPC holding the item</p>
+     * @param itemToReturn <p>The item to return to the player</p>
+     */
+    protected void giveResultingItem(boolean hasDelay, boolean dropItem, @NotNull NPC npc, @NotNull ItemStack itemToReturn) {
+        if (hasDelay) {
+            //If the player isn't online, or the player cannot fit the item, drop the item to prevent it from disappearing
+            if (dropItem || !this.player.isOnline() || !ItemHelper.canFitItem(this.player.getInventory(), itemToReturn)) {
+                this.player.getWorld().dropItemNaturally(npc.getEntity().getLocation(), itemToReturn);
+            } else {
+                this.player.getInventory().addItem(itemToReturn);
+            }
+        } else {
+            //It can be assumed as this happens instantly, that the player still has the item's previous slot selected
+            this.player.getInventory().setItemInMainHand(itemToReturn);
+        }
+    }
+
+    /**
+     * Randomly damages the given item
+     *
+     * @param item <p>The item to damage</p>
+     */
+    protected void damageItemRandomly(@NotNull ItemStack item) {
+        short currentItemDurability = ItemHelper.getDurability(item);
+        short newDurability = (short) (currentItemDurability + (currentItemDurability * random.nextInt(8)));
+        short maxDurability = item.getType().getMaxDurability();
+        if (newDurability <= 0) {
+            newDurability = (short) (maxDurability / 3);
+        } else if (currentItemDurability + newDurability > maxDurability) {
+            newDurability = (short) (maxDurability - random.nextInt(maxDurability - 25));
+        }
+        if (ItemHelper.updateDamage(item, maxDurability - newDurability)) {
+            BlacksmithPlugin.getInstance().getLogger().log(Level.WARNING, "Unable to update damage for " + item);
+        }
+    }
+
     /**
      * Gets the delay for this session's action to finish
      *