SPIGOT-4438: Add choice API to furnace recipes

By: md_5 <git@md-5.net>

paper-server/nms-patches/FurnaceRecipe.patch

@@ -1,17 +1,23 @@
 --- a/net/minecraft/server/FurnaceRecipe.java
 +++ b/net/minecraft/server/FurnaceRecipe.java
-@@ -2,6 +2,10 @@
+@@ -2,6 +2,16 @@
  
  import com.google.gson.JsonElement;
  import com.google.gson.JsonObject;
++// CraftBukkit start
++import java.util.ArrayList;
++import java.util.List;
 +import org.bukkit.craftbukkit.inventory.CraftFurnaceRecipe;
 +import org.bukkit.craftbukkit.inventory.CraftItemStack;
++import org.bukkit.craftbukkit.util.CraftMagicNumbers;
 +import org.bukkit.craftbukkit.util.CraftNamespacedKey;
 +import org.bukkit.inventory.Recipe;
++import org.bukkit.inventory.RecipeChoice;
++// CraftBukkit end
  
  public class FurnaceRecipe implements IRecipe {
  
-@@ -56,6 +60,19 @@
+@@ -56,6 +66,23 @@
          return this.key;
      }
  
@@ -20,9 +26,13 @@
 +        CraftItemStack result = CraftItemStack.asCraftMirror(this.result);
 +        RecipeItemStack list = this.ingredient;
 +        list.buildChoices();
-+        net.minecraft.server.ItemStack stack = list.choices[0];
 +
-+        CraftFurnaceRecipe recipe = new CraftFurnaceRecipe(CraftNamespacedKey.fromMinecraft(this.key), result, CraftItemStack.asCraftMirror(stack), this.experience, this.cookingTime);
++        List<org.bukkit.Material> choices = new ArrayList<>(list.choices.length);
++        for (ItemStack i : list.choices) {
++            choices.add(CraftMagicNumbers.getMaterial(i.getItem()));
++        }
++
++        CraftFurnaceRecipe recipe = new CraftFurnaceRecipe(CraftNamespacedKey.fromMinecraft(this.key), result, new RecipeChoice.MaterialChoice(choices), this.experience, this.cookingTime);
 +        recipe.setGroup(this.group);
 +
 +        return recipe;
@@ -31,7 +41,7 @@
      public static class a implements RecipeSerializer<FurnaceRecipe> {
  
          public a() {}
-@@ -106,11 +123,11 @@
+@@ -106,11 +133,11 @@
              return "smelting";
          }