/**
 * TicketCounter demonstrates the use of a queue for simulating a waiting line.
 *
 * @author Dr. Lewis
 * @author Dr. Chase
 * @version 1.0, 08/12/08
 */

public class TicketCounter    
{
   final static int PROCESS = 120;
   final static int MAX_CASHIERS = 10;
   final static int NUM_CUSTOMERS = 100;

   public static void main ( String[] args) 
   {
      Customer customer;
      LinkedQueue<Customer> customerQueue = new LinkedQueue<Customer>();
      int[] cashierTime = new int[MAX_CASHIERS];	
      int totalTime, averageTime, departs;

      /** process the simulation for various number of cashiers */
      for (int cashiers=0; cashiers < MAX_CASHIERS; cashiers++)
      { 
         /** set each cashiers time to zero initially*/
         for (int count=0; count < cashiers; count++)
            cashierTime[count] = 0;

         /** load customer queue */
         for (int count=1; count <= NUM_CUSTOMERS; count++)
            customerQueue.enqueue(new Customer(count*15));

         totalTime = 0;

         /** process all customers in the queue */
         while (!(customerQueue.isEmpty())) 
         {
            for (int count=0; count <= cashiers; count++)
            {
               if (!(customerQueue.isEmpty()))
               {
                  customer = customerQueue.dequeue();
                  if (customer.getArrivalTime() > cashierTime[count])
                     departs = customer.getArrivalTime() + PROCESS;
                  else
                     departs = cashierTime[count] + PROCESS; 
                  customer.setDepartureTime (departs);
                  cashierTime[count] = departs;
                  totalTime += customer.totalTime();
               }
            }
         }

         /** output results for this simulation */
         averageTime = totalTime / NUM_CUSTOMERS;
         System.out.println ("Number of cashiers: " + (cashiers+1));
         System.out.println ("Average time: " + averageTime + "\n");
      }
   }
}