package cz.cuni.amis.utils.iterators;
   
   import java.util.Iterator;
   
   /**
    * Implements a circular iterator that iterates over any reasonable iterable instance.
    * Not fully tested!
    * @author Radek 'Black_Hand' Pibil
    *
   * @param <E> contents of the iterable
   */
  public class CircularIterator<E> implements Iterator<E> {
  	
  	protected boolean passedEnd = false;
  	private Iterable<E> toIterateOver;
  	private Iterator<E> iterator;
  	
  	public CircularIterator(Iterable<E> toIterateOver) {
  		this.toIterateOver = toIterateOver;
  		iterator = toIterateOver.iterator();
  	}
  
  	@Override
  	public boolean hasNext() {
  		return toIterateOver.iterator().hasNext();
  	}
  
  	@Override
  	public E next() {
  		E value = iterator.next();
  		if (!iterator.hasNext()) {
  			restartIterator();
  			passedEnd = true;
  		}
  		return value;
  	}
  
  	@Override
  	public void remove() {
  		iterator.remove();
  	}
  	
  	public boolean hasPassedEnd() {
  		if (passedEnd) {
  			passedEnd = false;
  			return passedEnd;
  		}
  		return false;
  	}
  	
  	protected Iterable<E> getIterable() {
  		return toIterateOver;
  	}
  	
  	protected Iterator<E> getIterator() {
  		return iterator;
  	}
  	
  	protected void restartIterator() {
  		iterator = toIterateOver.iterator();	
  	}
  }