package cz.cuni.amis.utils.iterators;
   
   /**
    * Circular iterator that can start from any given position in given iterable.
    * Even less tested then {@link CircularIterator} or {@link CircularListIterator}.
    * @author Radek 'Black_Hand' Pibil
    *
    * @param <E>
    */
  public class ShiftedCircularIterator<E> extends CircularIterator<E> {
  	
  	private int steps;
  	private int passedSteps = 0;
  
  	public ShiftedCircularIterator(Iterable<E> toIterateOver, int steps) {
  		super(toIterateOver);
  		
  		for (int i = 0; i < steps; ++i)
  			next();
  		
  		this.steps = steps;
  		passedSteps = 0;
  	}
  	
  	@Override
  	public boolean hasNext() {
  		return getIterable().iterator().hasNext();
  	}
  
  	@Override
  	public E next() {
  		
  		E value = getIterator().next();
  		++passedSteps;
  		
  		if (!getIterator().hasNext()) {
  			restartIterator();
  			passedSteps = 0;
  		}
  		
  		if (passedSteps == steps)
  			passedEnd = true;
  		
  		return value;
  	}
  
  	@Override
  	public void remove() {
  		getIterator().remove();
  	}
  	
  	public boolean hasPassedEnd() {
  		if (passedEnd) {
  			passedEnd = false;
  			return passedEnd;
  		}
  		return false;
  	}
  }