import java.util.*;


public class SingleQueue {
	
	final static int arrivalTimeLimit = 3600; // set the arrival time limit in seconds
	final static double arrivalProbability = 1.0/10; // Probability a request will arrive at any given second
	final static int numberOfServers = 5; // set the number of servers available to process the queue
	

	public static void main(String[] args) {
		Queue<Request> queue = new Queue<Request>();
		Random checkArrival = new Random();
		int totalWaitTime = 0;
		int totalServed = 0;
		int [] serverArray = new int[numberOfServers];

		//
		// In the simulation, we simulate each second of time.  We continue the simulation until we reach
		// the time limit and the queue is empty.
		//
		for (int currentSecond = 1; currentSecond <= arrivalTimeLimit || queue.size() > 0; currentSecond++) {
			// System.out.println(currentSecond);
			//
			// If the number of seconds has not exceeded the time after which no one is allowed to queue up,
			// check whether someone has arrived.  If so, put their arrival time on the queue.
			//
			if (currentSecond <= arrivalTimeLimit) {
				boolean arrivalHappened = (checkArrival.nextDouble() <= arrivalProbability);
				if (arrivalHappened) {
					Random setTimeToServe = new Random(); // creates a random object to generate a random timeToServe for each request
					int timeToServe = setTimeToServe.nextInt(49) + 10;
					Request newRequest = new Request(currentSecond, timeToServe);
					queue.enqueue(newRequest);					
				}
			}
			
			for (int server = 0; server < numberOfServers; server++){
				//
				// If someone is currently being served, decrement the time remaining to serve by 1.
				// Do this if server is serving
				if (serverArray[server] > 0) {
					serverArray[server]--;
				}
				//
				// Otherwise no one is being served.  Check whether anyone is waiting on the queue and,
				// if so, begin serving them.  Add their wait to time to the total wait time and increment
				// the number served.
				//
				else if (queue.size() > 0) {
					Request processRequest = queue.dequeue();
					serverArray[server] = processRequest.serviceTime;
					int arrivalTime = processRequest.arrivalTime;
					int waitTime = currentSecond - arrivalTime;
					totalWaitTime += waitTime;
					totalServed++;
				
				}
			}
		}
		System.out.println("Number served: " + totalServed);
		System.out.println("Total wait time: " + totalWaitTime);
		System.out.println("Average wait time: " + (double)totalWaitTime/totalServed);
		
	}
}