Finishes the scrapper implementation

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

@@ -7,10 +7,12 @@ import net.knarcraft.blacksmith.config.Settings;
 import net.knarcraft.blacksmith.config.TraitSettings;
 import net.knarcraft.blacksmith.formatting.TimeFormatter;
 import net.knarcraft.blacksmith.manager.EconomyManager;
+import net.knarcraft.blacksmith.util.ItemHelper;
 import net.knarcraft.knarlib.formatting.StringFormatter;
 import org.bukkit.entity.LivingEntity;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.PlayerInventory;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -174,9 +176,17 @@ public abstract class CustomTrait<K extends Setting> extends Trait {
      */
     private void startMainAction(@NotNull NPC npc, @NotNull Player player) {
         sendNPCMessage(this.npc, player, config.getStartWorkingMessage());
-        // TODO: Differentiate between blacksmiths and scrappers when withdrawing money
-        EconomyManager.withdraw(player);
+
+        boolean isBlacksmith = this instanceof BlacksmithTrait;
+
+        if (isBlacksmith) {
+            EconomyManager.withdrawBlacksmith(player);
+        } else {
+            EconomyManager.withdrawScrapper(player);
+        }
+
         session.scheduleAction();
+        PlayerInventory playerInventory = player.getInventory();
         ItemStack heldItem = player.getInventory().getItemInMainHand();
 
         //Display the item in the NPC's hand
@@ -186,9 +196,16 @@ public abstract class CustomTrait<K extends Setting> extends Trait {
             Objects.requireNonNull(((LivingEntity) npc.getEntity()).getEquipment()).setItemInMainHand(heldItem);
         }
         //Remove the item from the player's inventory
-        // TODO: For a scrapper with extended salvaging enabled, the item needs to be reduced with the amount specified
-        //  in the recipe, or removed as normal in the case where the player has exactly enough items to run the salvage. 
-        player.getInventory().setItemInMainHand(null);
+        if (!isBlacksmith) {
+            // For scrappers, just reduce the amounts of items, unless the remaining stack is salvaged
+            int amount = ItemHelper.getRequiredAmountForSalvage(player.getServer(), heldItem);
+            if (amount != heldItem.getAmount()) {
+                heldItem.setAmount(heldItem.getAmount() - amount);
+                playerInventory.setItemInMainHand(heldItem);
+                return;
+            }
+        }
+        playerInventory.setItemInMainHand(null);
     }
 
 }