package iterator;

import exceptions.BoundaryViolationException;
import position.Position;
import position.PositionList;

import java.util.Iterator;
import java.util.NoSuchElementException;

/**
 * Created with MONSTER.
 * User: xgiovio
 * Date: 06/04/2014
 * Time: 21:06
 */

//iterable of positions implementation with cursor for PositionList data structures.

public class IterablePosition<E> implements Iterable<Position<E>> {

    PositionList<E>  new_structure = null;

    public IterablePosition(PositionList<E> structure){

        new_structure = structure;

    }


    @Override
    public Iterator<Position<E>> iterator() {
        return new getpositionsiterator(new_structure);
    }


    class getpositionsiterator implements Iterator<Position<E>> {

        PositionList<E>  new_structure = null;
        Position<E> pos = null;

        public getpositionsiterator (PositionList<E> in){
              new_structure = in;
        }

        @Override
        public boolean hasNext() {
            if (pos == null){
                if (new_structure. size() <= 0){
                    return false;
                } else {
                    return true;
                }

            } else {

                try {
                    new_structure.next(pos);
                    return true;
                }
                catch (BoundaryViolationException err){
                    return false;

                }


            }
        }

        @Override
        public Position<E> next() throws NoSuchElementException {
            if (hasNext()){
                if (pos == null){
                    pos = new_structure.first();
                }else {
                    pos = new_structure.next(pos);
                }
                return pos;
            } else{
                throw new NoSuchElementException();
            }
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException ();
        }



    }


}