package net.minecraft.server.packs;

import com.google.common.collect.Lists;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import net.minecraft.resources.ResourceLocation;
import net.minecraft.server.packs.metadata.MetadataSectionType;
import net.minecraft.server.packs.resources.IoSupplier;
import org.jetbrains.annotations.Nullable;

public class CompositePackResources implements PackResources {
	private final PackResources primaryPackResources;
	private final List<PackResources> packResourcesStack;

	public CompositePackResources(PackResources primaryPackResources, List<PackResources> packResourcesStack) {
		this.primaryPackResources = primaryPackResources;
		List<PackResources> list = new ArrayList(packResourcesStack.size() + 1);
		list.addAll(Lists.reverse(packResourcesStack));
		list.add(primaryPackResources);
		this.packResourcesStack = List.copyOf(list);
	}

	@Nullable
	@Override
	public IoSupplier<InputStream> getRootResource(String... elements) {
		return this.primaryPackResources.getRootResource(elements);
	}

	@Nullable
	@Override
	public IoSupplier<InputStream> getResource(PackType packType, ResourceLocation location) {
		for (PackResources packResources : this.packResourcesStack) {
			IoSupplier<InputStream> ioSupplier = packResources.getResource(packType, location);
			if (ioSupplier != null) {
				return ioSupplier;
			}
		}

		return null;
	}

	@Override
	public void listResources(PackType packType, String namespace, String path, PackResources.ResourceOutput resourceOutput) {
		Map<ResourceLocation, IoSupplier<InputStream>> map = new HashMap();

		for (PackResources packResources : this.packResourcesStack) {
			packResources.listResources(packType, namespace, path, map::putIfAbsent);
		}

		map.forEach(resourceOutput);
	}

	@Override
	public Set<String> getNamespaces(PackType type) {
		Set<String> set = new HashSet();

		for (PackResources packResources : this.packResourcesStack) {
			set.addAll(packResources.getNamespaces(type));
		}

		return set;
	}

	@Nullable
	@Override
	public <T> T getMetadataSection(MetadataSectionType<T> type) throws IOException {
		return this.primaryPackResources.getMetadataSection(type);
	}

	@Override
	public PackLocationInfo location() {
		return this.primaryPackResources.location();
	}

	@Override
	public void close() {
		this.packResourcesStack.forEach(PackResources::close);
	}
}