package queue;

import exceptions.EmptyQueueException;
import stack.utility.Node;

import java.awt.image.AreaAveragingScaleFilter;

/**
 * Created with xgiovio.macbookair.
 * User: xgiovio
 * Date: 17/03/14
 * Time: 14:08
 */
public class NodeQueue<E> implements Queue<E> {


    @Override
    public void enqueue(E element) {

            Node<E> temp = new Node<E>(element,null);
            if (rear == null){
                rear = temp;
            }else {
                rear.setNext(temp);
                rear = temp;
            }
            number_of_elements++;
            if (number_of_elements == 1){
                front = rear;
            }

    }

    @Override
    public E dequeue() throws EmptyQueueException {
            if (isEmpty()){
                throw new EmptyQueueException();
            }else{
               Node<E> temp = front;
               front = front.getNext();
               number_of_elements--;
               if (number_of_elements == 0){
                   rear = front;
               }
               return temp.getElement();
            }
    }

    @Override
    public E front() throws EmptyQueueException {
        if (isEmpty()){
            throw new EmptyQueueException();
        } else{
            return front.getElement();
        }
    }

    @Override
    public boolean isEmpty() {
        if (number_of_elements == 0){
            return true;
        }else{
            return false;
        }
    }



    @Override
    public int size() {
        return number_of_elements;
    }


    @Override
    public String toString() {
        Node<E> temp;
        String to_return = "[";
            for (temp = front;temp != null;temp = temp.getNext()){
                to_return+=temp.getElement();
                if (temp.getNext() != null){
                    to_return+=",";
                }

            }
       to_return += "]";

        return to_return;

    }






    private Node<E> front = null;
    private Node<E> rear = null;
    private int number_of_elements = 0;


}