/*
 * This file is part of Applied Energistics 2.
 * Copyright (c) 2013 - 2014, AlgorithmX2, All rights reserved.
 *
 * Applied Energistics 2 is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Applied Energistics 2 is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Applied Energistics 2.  If not, see <http://www.gnu.org/licenses/lgpl>.
 */

package appeng.me;


import java.util.Iterator;
import java.util.Map;

import appeng.api.networking.IGridHost;
import appeng.api.networking.IGridNode;


/**
 * Nested iterator for {@link appeng.me.MachineSet}
 *
 * Traverses first over the {@link appeng.me.MachineSet} and then over every containing
 * {@link appeng.api.networking.IGridNode}
 */
public class GridNodeIterator implements Iterator<IGridNode>
{
	private final Iterator<MachineSet> outerIterator;
	private Iterator<IGridNode> innerIterator;

	public GridNodeIterator( final Map<Class<? extends IGridHost>, MachineSet> machines )
	{
		this.outerIterator = machines.values().iterator();
		this.innerHasNext();
	}

	private boolean innerHasNext()
	{
		final boolean hasNext = this.outerIterator.hasNext();

		if( hasNext )
		{
			final MachineSet nextElem = this.outerIterator.next();
			this.innerIterator = nextElem.iterator();
		}

		return hasNext;
	}

	@Override
	public boolean hasNext()
	{
		while( true )
		{
			if( this.innerIterator.hasNext() )
			{
				return true;
			}
			else if( !this.innerHasNext() )
			{
				return false;
			}
		}
	}

	@Override
	public IGridNode next()
	{
		return this.innerIterator.next();
	}

	@Override
	public void remove()
	{
		this.innerIterator.remove();
	}
}