package net.minecraft.core;

import java.util.Optional;
import net.minecraft.resources.ResourceKey;
import net.minecraft.tags.TagKey;
import net.minecraft.util.RandomSource;

public interface HolderGetter<T> {
	Optional<Holder.Reference<T>> get(final ResourceKey<T> id);

	default Holder.Reference<T> getOrThrow(final ResourceKey<T> id) {
		return (Holder.Reference<T>)this.get(id).orElseThrow(() -> new IllegalStateException("Missing element " + id));
	}

	Optional<HolderSet.Named<T>> get(final TagKey<T> id);

	default HolderSet.Named<T> getOrThrow(final TagKey<T> id) {
		return (HolderSet.Named<T>)this.get(id).orElseThrow(() -> new IllegalStateException("Missing tag " + id));
	}

	default Optional<Holder<T>> getRandomElementOf(final TagKey<T> tag, final RandomSource random) {
		return this.get(tag).flatMap(holderSet -> holderSet.getRandomElement(random));
	}

	public interface Provider {
		<T> Optional<? extends HolderGetter<T>> lookup(final ResourceKey<? extends Registry<? extends T>> key);

		default <T> HolderGetter<T> lookupOrThrow(final ResourceKey<? extends Registry<? extends T>> key) {
			return (HolderGetter<T>)this.lookup(key).orElseThrow(() -> new IllegalStateException("Registry " + key.identifier() + " not found"));
		}

		default <T> Optional<Holder.Reference<T>> get(final ResourceKey<T> id) {
			return this.lookup(id.registryKey()).flatMap(l -> l.get(id));
		}

		default <T> Holder.Reference<T> getOrThrow(final ResourceKey<T> id) {
			return (Holder.Reference<T>)this.lookup(id.registryKey()).flatMap(l -> l.get(id)).orElseThrow(() -> new IllegalStateException("Missing element " + id));
		}

		default <T> Optional<HolderSet.Named<T>> get(final TagKey<T> id) {
			return this.lookup(id.registry()).flatMap(l -> l.get(id));
		}

		default <T> HolderSet.Named<T> getOrThrow(final TagKey<T> id) {
			return (HolderSet.Named<T>)this.lookup(id.registry()).flatMap(l -> l.get(id)).orElseThrow(() -> new IllegalStateException("Missing tag " + id));
		}
	}
}