src/game/java/net/minecraft/data/recipes/TransmuteRecipeBuilder.java

package net.minecraft.data.recipes;

import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Objects;
import javax.annotation.Nullable;
import net.minecraft.advancements.Advancement;
import net.minecraft.advancements.AdvancementRequirements;
import net.minecraft.advancements.AdvancementRewards;
import net.minecraft.advancements.Criterion;
import net.minecraft.advancements.critereon.RecipeUnlockedTrigger;
import net.minecraft.core.Holder;
import net.minecraft.resources.ResourceKey;
import net.minecraft.world.item.Item;
import net.minecraft.world.item.crafting.Ingredient;
import net.minecraft.world.item.crafting.Recipe;
import net.minecraft.world.item.crafting.TransmuteRecipe;

public class TransmuteRecipeBuilder implements RecipeBuilder {
    private final RecipeCategory category;
    private final Holder<Item> result;
    private final Ingredient input;
    private final Ingredient material;
    private final Map<String, Criterion<?>> criteria = new LinkedHashMap<>();
    @Nullable
    private String group;

    private TransmuteRecipeBuilder(RecipeCategory p_365540_, Holder<Item> p_368366_, Ingredient p_365902_, Ingredient p_366998_) {
        this.category = p_365540_;
        this.result = p_368366_;
        this.input = p_365902_;
        this.material = p_366998_;
    }

    public static TransmuteRecipeBuilder transmute(RecipeCategory p_367390_, Ingredient p_365855_, Ingredient p_361211_, Item p_366896_) {
        return new TransmuteRecipeBuilder(p_367390_, p_366896_.builtInRegistryHolder(), p_365855_, p_361211_);
    }

    public TransmuteRecipeBuilder unlockedBy(String p_361429_, Criterion<?> p_362231_) {
        this.criteria.put(p_361429_, p_362231_);
        return this;
    }

    public TransmuteRecipeBuilder group(@Nullable String p_364491_) {
        this.group = p_364491_;
        return this;
    }

    @Override
    public Item getResult() {
        return this.result.value();
    }

    @Override
    public void save(RecipeOutput p_369743_, ResourceKey<Recipe<?>> p_369659_) {
        this.ensureValid(p_369659_);
        Advancement.Builder advancement$builder = p_369743_.advancement()
            .addCriterion("has_the_recipe", RecipeUnlockedTrigger.unlocked(p_369659_))
            .rewards(AdvancementRewards.Builder.recipe(p_369659_))
            .requirements(AdvancementRequirements.Strategy.OR);
        this.criteria.forEach(advancement$builder::addCriterion);
        TransmuteRecipe transmuterecipe = new TransmuteRecipe(
            Objects.requireNonNullElse(this.group, ""), RecipeBuilder.determineBookCategory(this.category), this.input, this.material, this.result
        );
        p_369743_.accept(
            p_369659_, transmuterecipe, advancement$builder.build(p_369659_.location().withPrefix("recipes/" + this.category.getFolderName() + "/"))
        );
    }

    private void ensureValid(ResourceKey<Recipe<?>> p_368853_) {
        if (this.criteria.isEmpty()) {
            throw new IllegalStateException("No way of obtaining recipe " + p_368853_.location());
        }
    }
}