/**
 * Copyright (c) 2014, the Railo Company Ltd.
 * Copyright (c) 2016, Lucee Assosication Switzerland
 *
 * This library 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 2.1 of the License, or (at your option) any later version.
 * 
 * This library 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 this library.  If not, see <http://www.gnu.org/licenses/>.
 * 
 */
package lucee.runtime.type.util;

import java.util.List;
import java.util.ListIterator;
import java.util.NoSuchElementException;



public class ListIteratorImpl<T> implements ListIterator<T> {
	
	private static final int UNDEFINED = Integer.MIN_VALUE;
	private List<T> list;
	private int index=-1;
	private int current=UNDEFINED;

	/**
	 * Constructor of the class
	 * @param arr
	 */
	public ListIteratorImpl(List<T> list){
		this(list,0);
	}
	
	/**
	 * Constructor of the class
	 * @param arr
	 * @param index 
	 */
	public ListIteratorImpl(List<T> list, int index){
		this.list=list;
		this.index=index-1;
	}

	@Override
	public void add(T o) {
		list.add(++index,o);
	}

	@Override
	public void remove() {
		if(current==UNDEFINED)throw new IllegalStateException();
		list.remove(current);
		current=UNDEFINED;
	}

	@Override
	public void set(T o) {
		if(current==UNDEFINED) throw new IllegalStateException();
		list.set(current, o);
	}
	
/////////////	
	

	@Override
	public boolean hasNext() {
		return list.size()>index+1;
	}

	@Override
	public boolean hasPrevious() {
		return index>-1;
	}

	@Override
	public int previousIndex() {
		return index;
	}

	@Override
	public int nextIndex() {
		return index+1;
	}

	@Override
	public T previous() {
		if(!hasPrevious())
			throw new NoSuchElementException();
		current=index;
		return list.get(index--);
	}

	@Override
	public T next() {
		if(!hasNext())
			throw new NoSuchElementException();
		return list.get(current=++index);
	}

}