package net.minecraft.util;

import com.google.common.collect.HashMultimap;
import com.google.common.collect.Multimap;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.function.BiConsumer;
import java.util.function.Consumer;

public class DependencySorter<K, V extends DependencySorter.Entry<K>> {
	private final Map<K, V> contents = new HashMap();

	public DependencySorter<K, V> addEntry(K key, V value) {
		this.contents.put(key, value);
		return this;
	}

	private void visitDependenciesAndElement(Multimap<K, K> dependencies, Set<K> visited, K element, BiConsumer<K, V> action) {
		if (visited.add(element)) {
			dependencies.get(element).forEach(object -> this.visitDependenciesAndElement(dependencies, visited, (K)object, action));
			V entry = (V)this.contents.get(element);
			if (entry != null) {
				action.accept(element, entry);
			}
		}
	}

	private static <K> boolean isCyclic(Multimap<K, K> dependencies, K source, K target) {
		Collection<K> collection = dependencies.get(target);
		return collection.contains(source) ? true : collection.stream().anyMatch(object2 -> isCyclic(dependencies, source, (K)object2));
	}

	private static <K> void addDependencyIfNotCyclic(Multimap<K, K> dependencies, K source, K target) {
		if (!isCyclic(dependencies, source, target)) {
			dependencies.put(source, target);
		}
	}

	public void orderByDependencies(BiConsumer<K, V> action) {
		Multimap<K, K> multimap = HashMultimap.create();
		this.contents.forEach((object, entry) -> entry.visitRequiredDependencies(object2 -> addDependencyIfNotCyclic(multimap, (K)object, (K)object2)));
		this.contents.forEach((object, entry) -> entry.visitOptionalDependencies(object2 -> addDependencyIfNotCyclic(multimap, (K)object, (K)object2)));
		Set<K> set = new HashSet();
		this.contents.keySet().forEach(object -> this.visitDependenciesAndElement(multimap, set, (K)object, action));
	}

	public interface Entry<K> {
		void visitRequiredDependencies(Consumer<K> visitor);

		void visitOptionalDependencies(Consumer<K> visitor);
	}
}