import java.util.LinkedList;

public class FCFS {

    private int timeStep = 0;
    private int current = 0;
    private int disp;
    private int timeLastDisp = -1;

    LinkedList<Process> processList = new LinkedList<>();
    LinkedList<Process> waitingQueue = new LinkedList<>();
    LinkedList<Process> newProcesses = new LinkedList<>();
    //Constructors

    public FCFS(int dispInput, LinkedList<Process> processListInput)
    {
        disp = dispInput;
        processList = processListInput;
    }

    private void checkForArrivals()
    {
        for(int i = 0; i< processList.size(); i++)
        {
            if((processList.get(i).getArrive()<=timeStep) && (processList.get(i).getArrive() > timeLastDisp))
            {
            
                newProcesses.add(processList.get(i));
            }
            else
            {

            }
        }

        for(int i =0; i < newProcesses.size(); i++)
        {
            waitingQueue.add(newProcesses.get(i));
        }
        
        newProcesses.clear();
    }

    public void runDispatch()
    {
         System.out.println("FCFS:");
         do
         {
            timeStep+=disp;
            checkForArrivals();
            timeLastDisp = timeStep;
            runProcess(waitingQueue.removeFirst());
         }while(waitingQueue.size()!=0);

         //...
         printResults();         
    }

    private void runProcess(Process input)
    {   
        
        int startTime = timeStep;
        int endTime = -1;

        System.out.println("T"+startTime+": "+input.getId());

        for(int i = 0; i < input.getExecSize(); i++)
        {
            timeStep++;
        }

        endTime = timeStep;

        input.saveTurnTime(endTime-input.getArrive());
        input.saveWaitTime(startTime-input.getArrive());
    }

    public void printResults()
    {
        System.out.println("\nProcess \tTurnaround Time \tWaiting Time");
        for (int i = 0; i < processList.size(); i++)
        {
            System.out.print(processList.get(i).getId()+"\t\t");
            System.out.print(processList.get(i).getTurnTime()+"\t\t\t");
            System.out.print(processList.get(i).getWaitTime()+"\n");
        }
    }
}