package LinkedLists;

class CustomerQueue
{
	// queue size

	static final int MAXSIZE = 10; // number of elements in default queue

	// pointers to front and rear

	private CustomerNode front;
	private CustomerNode  rear;

	// size of queue and variable for max elements
	
	private int size;
	private int max; 
/**
 * default constructor
 */
public CustomerQueue()
{
	front = null;
	rear = null;
	size = 0;
	max = MAXSIZE;
}
/**
 *  Constructor for queue of size s
 */
public CustomerQueue(int s)
{
	front = null;
	rear = null;
	size = 0;
	max = s;
}
/**
 * This method removes a customer from the front of the queue
 */
public CustomerNode dequeue() throws QueueEmptyException
{
	CustomerNode temp;
	
	if (!isEmpty())
	{
		temp = front;
		front = front.getNext();
		size--;
		return temp;
	}
	else
	{
		throw new QueueEmptyException("nobody is in the queue");
	}
}
/**
 * This method adds a customer to the rear of the queue
 */
public void enqueue(CustomerNode cn) throws QueueFullException
{
	if (!isFull())
	{
		if (isEmpty())
		{
			newQueue(cn);
		}
		else
		{
			rear.setNext(cn);
			rear = cn;
			size++;
		}
	}
	else
	{
		throw new QueueFullException("Out of space in queue");
	}
}
/**
 * This method was created in VisualAge.
 */
public CustomerNode getFront()
{
	return front;
}
/**
 * This method was created in VisualAge.
 */
public CustomerNode getNext(CustomerNode n)
{
	if (n != null)
	{
	    return n.getNext();
	}
	return null;
}
/**
 * This method was created in VisualAge.
 */
public CustomerNode getRear()
{
	return rear;
}
/**
 * This method was created in VisualAge.
 * @return int
 */
public int getSize()
{
	return size;
}
/**
 * This method was created in VisualAge.
 * @return boolean
 */
public boolean isEmpty()
{
	if (size == 0)
	{
		return true;
	}
	return false;
}
/**
 * This method was created in VisualAge.
 * @return boolean
 */
public boolean isFull()
{
	if (size == max)
	{
		return true;
	}
	return false;
}
/**
 * This method initialises a queue
 * @param cn LinkedLists.CustomerNode
 */
public void newQueue(CustomerNode cn)
{
	front = cn;
	rear = cn;
	size = 1;
}
}