package org.bukkit.craftbukkit.util;

import java.util.Collection;
import java.util.Iterator;
import java.util.Set;


public abstract class LazyHashSet<E> implements Set<E>
{
	Set<E> reference = null;

	public int size()
	{
		return getReference().size();
	}

	public boolean isEmpty()
	{
		return getReference().isEmpty();
	}

	public boolean contains(Object o)
	{
		return getReference().contains(o);
	}

	public Iterator<E> iterator()
	{
		return getReference().iterator();
	}

	public Object[] toArray()
	{
		return getReference().toArray();
	}

	public <T> T[] toArray(T[] a)
	{
		return getReference().toArray(a);
	}

	public boolean add(E o)
	{
		return getReference().add(o);
	}

	public boolean remove(Object o)
	{
		return getReference().remove(o);
	}

	public boolean containsAll(Collection<?> c)
	{
		return getReference().containsAll(c);
	}

	public boolean addAll(Collection<? extends E> c)
	{
		return getReference().addAll(c);
	}

	public boolean retainAll(Collection<?> c)
	{
		return getReference().retainAll(c);
	}

	public boolean removeAll(Collection<?> c)
	{
		return getReference().removeAll(c);
	}

	public void clear()
	{
		getReference().clear();
	}

	public Set<E> getReference()
	{
		Set<E> reference = this.reference;
		if(reference != null)
		{
			return reference;
		}
		return this.reference = makeReference();
	}

	abstract Set<E> makeReference();

	public boolean isLazy()
	{
		return reference == null;
	}

	@Override
	public int hashCode()
	{
		return 157 * getReference().hashCode();
	}

	@Override
	public boolean equals(Object obj)
	{
		if(obj == this)
		{
			return true;
		}
		if(obj == null || this.getClass() != obj.getClass())
		{
			return false;
		}
		LazyHashSet<?> that = (LazyHashSet<?>) obj;
		return (this.isLazy() && that.isLazy()) || this.getReference().equals(that.getReference());
	}

	@Override
	public String toString()
	{
		return getReference().toString();
	}
}