public class DelegatingResourcePack extends ResourcePack
{
    private final List<DelegatableResourcePack> delegates = new ArrayList<>();

    public DelegatingResourcePack(String name, File resourcePackFileIn)
    {
        super(new File(name));
    }

    public void addDelegate(DelegatableResourcePack pack)
    {
        synchronized(delegates)
        {
            this.delegates.add(pack);
        }
    }

    @Override
    public Collection<ResourceLocation> getAllResourceLocations(ResourcePackType type, String pathIn, int maxDepth, Predicate<String> filter)
    {
        synchronized(delegates)
        {
            return delegates.stream()
                    .flatMap(r -> r.getAllResourceLocations(type, pathIn, maxDepth, filter).stream())
                    .collect(Collectors.toList());
        }
    }

    @Override
    public Set<String> getResourceNamespaces(ResourcePackType type)
    {
        synchronized (delegates)
        {
            return delegates.stream()
                    .flatMap(r -> r.getResourceNamespaces(type).stream())
                    .collect(Collectors.toSet());
        }
    }

    @Override
    public void close() throws IOException
    {
        synchronized(delegates)
        {
            for (ResourcePack pack : delegates)
            {
                pack.close();
            }
        }
    }

    @Override
    protected InputStream getInputStream(String resourcePath) throws IOException
    {
        synchronized (delegates)
        {
            for (DelegatableResourcePack pack : delegates)
            {
                try
                {
                    return pack.getInputStream(resourcePath);
                }
                catch (ResourcePackFileNotFoundException e) {}
            }
        }
        throw new ResourcePackFileNotFoundException(this.file, resourcePath);
    }

    @Override
    protected boolean resourceExists(String resourcePath)
    {
        synchronized (delegates)
        {
            for (DelegatableResourcePack pack : delegates)
            {
                if (pack.resourceExists(resourcePath))
                {
                    return true;
                }
            }
        }
        return false;
    }
}