/* BankLine.java is a simple class that implements a bank queue.
 *
 * Started by: Charles Hoot, for Hands On Java.
 * Date: July, 2000      
 * Finished by:
 *
 * It is responsible for knowing the average amount of time
 * customers spent waiting in the line.
 *****************************************************************/

import java.util.*;

import Customer;

class BankLine extends Object
{

	private long myTotalWaitTime;
	private int myCustomersServed;
	private Vector theLine;
	private boolean tellAll;
	private String myName;


	/*****************************************************************
	 * BankLine constructor
	 *
	 * 
	 * PostCondition: created a Vector to hold the customers
	 *				  total wait time is zero
	 *				  no customers have been served
	 *****************************************************************/
	public BankLine(String name, boolean verbose){
		myName = name;
		tellAll = verbose;
		theLine = new Vector();
		myTotalWaitTime = 0;
		myCustomersServed = 0;
	}
	
	
	/*****************************************************************
	 * accessors
	 *
	 *****************************************************************/
	public double totalWaitTime(){
		return myTotalWaitTime;
	}
	
	public int myCustomersServed(){
		return myCustomersServed;
	}
	
	public double averageWaitTime(){
		return (double) myTotalWaitTime/myCustomersServed;
	}



	/*****************************************************************
	 * addCustomer - adds a customer to the line
	 *
	 * Input: a customer to be added
	 * PostCondition: customer was added at the end of the line
	 *				  customer was informed that they are in line
	 *****************************************************************/
	synchronized public void addCustomer( Customer newCustomer){
		theLine.addElement(newCustomer);
		newCustomer.inLine();
		if(tellAll)
			System.out.println("Customer " + newCustomer.name() 
						+ " was added to line " + myName);
	}
	
	
	/*****************************************************************
	 * provideCustomer - gets the first customer in line
	 *
	 * Output: the first customer in line or null if none
	 * PostCondition: customer was removed from the line
	 *				  customer was asked for their time in line
	 *				  total wait time and number served are updated
	 *****************************************************************/
	synchronized public Customer provideCustomer(){
	
		if (theLine.size() == 0) return null;
		
		//get the first customer in line
		Customer firstInLine = (Customer) theLine.elementAt(0);
		theLine.removeElementAt(0);
		
		myTotalWaitTime += firstInLine.outOfLine();
		myCustomersServed++;

		if(tellAll)
			System.out.println("Customer " + firstInLine.name() 
						+ " was removed from the line " + myName);
		
		return firstInLine;
	}
	
	
	/*****************************************************************
	 * toString - provide a report on the line
	 *
	 * Output: a report string
	 *****************************************************************/
	public String toString(){
		return "Bank Line - waiting currently: " + theLine.size() 
		   + "\n             customers served: " + myCustomersServed 
		   + "\n            average wait time: " + averageWaitTime();
		
	}	


} // end of class