Rewrites a lot of scrapper code to fix actual and potential bugs

src/main/java/net/knarcraft/blacksmith/util/SalvageHelper.java

@@ -1,6 +1,7 @@
 package net.knarcraft.blacksmith.util;
 
-import org.bukkit.Bukkit;
+import net.knarcraft.blacksmith.BlacksmithPlugin;
+import net.knarcraft.blacksmith.container.RecipeResult;
 import org.bukkit.Material;
 import org.bukkit.Server;
 import org.bukkit.enchantments.Enchantment;
@@ -20,6 +21,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Random;
+import java.util.logging.Level;
 
 /**
  * A helper class for deciding the salvage returned if salvaging an item
@@ -123,23 +125,6 @@ public final class SalvageHelper {
         return false;
     }
 
-    /**
-     * Gets the amount of an item that's required to salvage that item
-     *
-     * @param server <p>The server to get recipes from</p>
-     * @param item   <p>The item to check</p>
-     * @return <p>The number of items required for salvage, or -1 if the recipe was not found</p>
-     */
-    public static int getRequiredAmountForSalvage(@NotNull Server server, @NotNull ItemStack item) {
-        for (Recipe recipe : server.getRecipesFor(new ItemStack(item.getType(), item.getAmount()))) {
-            // Only crafting recipes are allowed.
-            if (recipe instanceof ShapedRecipe || recipe instanceof ShapelessRecipe) {
-                return recipe.getResult().getAmount();
-            }
-        }
-        return 1;
-    }
-
     /**
      * Gets the sum of all enchantment levels for the given item
      *
@@ -165,28 +150,34 @@ public final class SalvageHelper {
      * @param extended     <p>Whether to enable extended salvage, ignoring the repairable restriction</p>
      * @return <p>The items to return to the user, or null if not salvageable</p>
      */
-    public static @Nullable List<ItemStack> getSalvage(@NotNull Server server, @Nullable ItemStack salvagedItem,
-                                                       @NotNull Collection<Material> trashSalvage, boolean extended) {
+    public static @Nullable RecipeResult getSalvage(@NotNull Server server, @Nullable ItemStack salvagedItem,
+                                                    @NotNull Collection<Material> trashSalvage, boolean extended) {
         if (salvagedItem == null || salvagedItem.getAmount() < 1 ||
                 (!extended && !ItemHelper.isRepairable(salvagedItem))) {
             return null;
         }
 
         for (Recipe recipe : server.getRecipesFor(new ItemStack(salvagedItem.getType(), salvagedItem.getAmount()))) {
+            BlacksmithPlugin.getInstance().getLogger().log(Level.INFO, "Considering recipe: " + recipe.getResult() + " -> " + getRawRecipeSalvage(recipe));
+
             // Only consider crafting table recipes
             if (!(recipe instanceof ShapedRecipe) && !(recipe instanceof ShapelessRecipe)) {
+                BlacksmithPlugin.getInstance().getLogger().log(Level.INFO, "Recipe had invalid type");
                 continue;
             }
 
             // Make sure the player has enough items
-            if (salvagedItem.getAmount() < getRequiredAmountForSalvage(Bukkit.getServer(), salvagedItem)) {
+            if (salvagedItem.getAmount() < recipe.getResult().getAmount()) {
+                BlacksmithPlugin.getInstance().getLogger().log(Level.INFO, "Too few items for recipe");
                 continue;
             }
 
             // Get actual salvage, as long as any can be produced
             List<ItemStack> salvage = getRecipeSalvage(recipe, salvagedItem, trashSalvage);
             if (salvage != null && !salvage.isEmpty()) {
-                return salvage;
+                BlacksmithPlugin.getInstance().getLogger().log(Level.INFO, "Valid recipe: " + recipe.getResult() + " -> " + getRawRecipeSalvage(recipe));
+                BlacksmithPlugin.getInstance().getLogger().log(Level.INFO, "Actual salvage: " + salvage);
+                return new RecipeResult(recipe, salvage);
             }
         }
 
@@ -207,7 +198,13 @@ public final class SalvageHelper {
         if (ingredients == null) {
             return null;
         }
-        return combineStacks(getSalvage(copyItems(ingredients), salvagedItem, trashSalvage));
+        List<ItemStack> copy = copyItems(ingredients);
+        BlacksmithPlugin.getInstance().getLogger().log(Level.INFO, "Copied salvage: " + copy);
+        List<ItemStack> salvage = getSalvage(copy, salvagedItem, trashSalvage);
+        BlacksmithPlugin.getInstance().getLogger().log(Level.INFO, "Combining salvage: " + salvage);
+        List<ItemStack> combined = combineStacks(salvage);
+        BlacksmithPlugin.getInstance().getLogger().log(Level.INFO, "Combined : " + combined);
+        return combined;
     }
 
     /**
@@ -247,7 +244,10 @@ public final class SalvageHelper {
             durability = 1;
         }
 
+        BlacksmithPlugin.getInstance().getLogger().log(Level.INFO, "Durability: " + durability + "/" + maxDurability);
+
         double percentageRemaining = (double) durability / maxDurability;
+        BlacksmithPlugin.getInstance().getLogger().log(Level.INFO, "Remaining: " + percentageRemaining);
         return pickRandomSalvage(recipeItems, trashSalvage, percentageRemaining);
     }
 
@@ -268,36 +268,47 @@ public final class SalvageHelper {
             percentageRemaining = 1;
         }
 
-        int totalItems = totalItemAmount(itemsToChooseFrom);
-        //Get the amount of recipe items to be returned
-        int itemsToReturn = (int) Math.floor(percentageRemaining * totalItems);
-        int bound = itemsToChooseFrom.size();
+        // If not damaged, just give everything
+        if (percentageRemaining == 1) {
+            BlacksmithPlugin.getInstance().getLogger().log(Level.INFO, "100% Remaining. Copying " + itemsToChooseFrom);
+            return copyItems(itemsToChooseFrom);
+        }
 
+        // Split into good items and trash items
         List<ItemStack> goodItems = copyItems(itemsToChooseFrom);
         goodItems.removeIf((item) -> trashSalvage.contains(item.getType()));
-        int goodSalvage = totalItemAmount(goodItems);
+        List<ItemStack> trashItems = copyItems(itemsToChooseFrom);
+        trashItems.removeIf((item) -> !trashSalvage.contains(item.getType()));
 
-        List<ItemStack> salvage = new ArrayList<>();
-        for (int i = 0; i < itemsToReturn; i++) {
-            // Pick random item
-            int itemIndex = SalvageHelper.random.nextInt(bound);
-            ItemStack itemStack = itemsToChooseFrom.get(itemIndex);
+        int itemsToReturn = (int) Math.floor(totalItemAmount(itemsToChooseFrom) * percentageRemaining);
+        int goodItemAmount = totalItemAmount(goodItems);
+        int pickedItems = 0;
+        List<ItemStack> salvage = new ArrayList<>(itemsToReturn);
 
-            // The selected item is trash, so skip it
-            if (trashSalvage.contains(itemStack.getType()) && i < goodSalvage) {
-                i--;
+        while (pickedItems < itemsToReturn && pickedItems < goodItemAmount) {
+            int index = SalvageHelper.random.nextInt(goodItems.size());
+            ItemStack itemStack = goodItems.get(index);
+            if (itemStack.getType().isAir() || itemStack.getAmount() == 0) {
                 continue;
             }
 
-            //Make sure to never give more of one item than the amount which exists in the recipe
-            if (itemStack.getAmount() <= 0) {
-                i--;
-                continue;
-            }
-
-            itemStack.setAmount(itemStack.getAmount() - 1);
             salvage.add(new ItemStack(itemStack.getType(), 1));
+            itemStack.setAmount(itemStack.getAmount() - 1);
+            pickedItems++;
         }
+
+        while (pickedItems < itemsToReturn) {
+            int index = SalvageHelper.random.nextInt(trashItems.size());
+            ItemStack itemStack = trashItems.get(index);
+            if (itemStack.getType().isAir() || itemStack.getAmount() == 0) {
+                continue;
+            }
+
+            salvage.add(new ItemStack(itemStack.getType(), 1));
+            itemStack.setAmount(itemStack.getAmount() - 1);
+            pickedItems++;
+        }
+
         return salvage;
     }
 
@@ -328,7 +339,7 @@ public final class SalvageHelper {
         Map<Material, Integer> itemAmounts = new HashMap<>();
         for (ItemStack item : items) {
             Material itemType = item.getType();
-            itemAmounts.put(itemType, itemAmounts.getOrDefault(itemType, 0) + 1);
+            itemAmounts.put(itemType, itemAmounts.getOrDefault(itemType, 0) + item.getAmount());
         }
 
         List<ItemStack> combined = new ArrayList<>();