import java.util.*;				// for JCFs and Random

public class Bank				// our Bank will have some number of tellers and process Customers based on a duration passed in to the constructor
{
	private Queue<Customer> queue;		// we will have a LinkedList or PriorityQueue (could also use another type such as Stack)
	private int numCustomers, numTellers, duration, currentTime, totalWait;	// numCustomers = total number of Customers at end of simulation, currentTime = loop index, totalWait = sum of all Customer wait times
	private Teller[] tellers;			// our tellers are stored in an array
	public Bank(String q_type, int numT, int d)		// q_type is used if we want a priority queue
	{	
		if(q_type.equals("priority")) queue=new PriorityQueue<>();		// establish actual line type
		else queue=new LinkedList<>();				// note: if you add another type like ArrayList or Stack, you will have to alter the enqueue command below as it ishard-coded as offer
		numTellers=numT;							// initialize other variables appropriately
		duration=d;
		currentTime=0;
		numCustomers=0;
		tellers=new Teller[numTellers];
		for(int i=0;i<numTellers;i++)
			tellers[i]=new Teller();
	}
	
	public void run()				// run the simulation - which iterates duration number of cycles plus the number of cycles needed to empty out the queue
	{
		Random g=new Random();		// needed to determine randomly number of Customers entering/minute and each Customer's wait time
		int random, newCustomers=0, timeNeeded, waitTime;	// random used to store random number, newCustomers is how many Customers come in during this minute, timeNeeded is time of a new customer
		Customer c;					// local variable to store a temporary Customer to enqueue or dequeue
		while(currentTime<duration||queue.size()>0)		// run simulation until we reach time limit AND queue becomes empty
		{
			if(currentTime<duration)		// true if bank is still open, so doors are open and we may get new Customers
			{
				random=g.nextInt(100);		
				if(random<30) newCustomers=1;		// 30% chance of 1 new Customer			 change these percentages to vary the simulation
				else if(random<42) newCustomers=2;	// 12% chance of 2 new Customers
				else if(random<48) newCustomers=3;	// 6% chance of 3 new Customers
				else if(random<50) newCustomers=4;	// 2% chance of 4 new Customers (50% chance of 0 new Customers)
				for(int i=0;i<newCustomers;i++)		// for each new Customer (if any)
				{
					numCustomers++;					// another Customer is getting in line
					random=g.nextInt(100);			// determine wait time
					if(random<40) timeNeeded=1;				// 40% chance of 1 minute service time			change these percentages to vary the simulation
					else if(random<80) timeNeeded=2;		// 40% chance of 2 minutes service time
					else if(random<90) timeNeeded=3;		// 10% chance of 3 minutes service time
					else if(random<98) timeNeeded=4;		// 8% chance of 4 minutes service time
					else timeNeeded=5;						// 2% chance of 5 minutes service time
					c=new Customer(currentTime,timeNeeded);			// create the new Customer
					queue.offer(c);							// and add to queue
				}
			}
			for(int i=0;i<numTellers;i++)			// now we let each Teller operate
			{
				if(tellers[i].isBusy()) 			// if Teller is with a Customer, process Customer for 1 more minute
				{
					tellers[i].serviceCustomer();		// this decrement's Customer's serviceTime until 0 and if 0, then the Customer leaves this Teller making Teller available again
				}
				else {								// otherwise Teller is not busy, if there are any Customers in line, dequeue the next one for this Teller
					if(queue.size()>0)
					{
						c=queue.remove();			// dequeue
						totalWait+=currentTime-c.getInTime();	// add the time this Customer waited in line to totalWait
						tellers[i].newCustomer(c);				// add this Customer to tellers[i]
					}
				}
			}
			currentTime++;						// end of this minute, start next minute
		}
	}
	
	// accessors
	public int getTotalWaitTime()			// total amount of wait time of all Customers
	{
		return totalWait;
	}
	
	public int getTotalCustomers()			// how many Customers were served during the simulation
	{
		return numCustomers;
	}
}