// CPUScheduler.h     Dave Reed   
//
// CPUScheduler class
///////////////////////////////////////////////////////////////////////////////

#ifndef _CPU_SCHEDULER_
#define _CPU_SCHEDULER_

#include <iostream>
#include <queue>
#include "Job.h"
#include "RandGen.h"
using namespace std;

const int TIME_SLICE = 10;              // TIME SLICE DURATION FOR TIME SHARING
const int LOAD_DELAY = 2;               // SETUP TIME FOR A NEW JOB
const int IO_MIN_DELAY = 5;             // MINIMUM TIME TO SERVICE AN I/O REQUEST
const int IO_MAX_DELAY = 10;            // MAXIMUM TIME TO SERVICE AN I/O REQUEST

class CPUScheduler 
{
  public:
    CPUScheduler();
    bool JobsRemaining() const;             // RETURNS TRUE IF JOBS IN EITHER QUEUE 
    void AddNewJob(Job newJob, int time);   // ADDS NEW JOB TO READY QUEUE
    void Execute(int time);                 // EXECUTES CURRENT JOB, UPDATES QUEUES
  private:
      class PriorityJob : Job               // HIDDEN CLASS FOR PRIORITY QUEUE OF JOBS
      {
        public:
            PriorityJob(Job j, int pri) : Job(j) { priority = pri; }
            int GetPriority() const { return priority; }
            bool operator<(const PriorityJob & j) const { return priority > j.priority; }
        private:
          int priority;
      };
    queue<Job> ReadyQueue;                     // JOBS READY TO EXECUTE 
    priority_queue<PriorityJob> WaitQueue;     // JOBS WAITING ON I/O
    int sliceTimeRemaining, loadTimeRemaining; // TIME REMAINING IN JOB SLICE, LOADING
    RandGen randomizer;                        // RANDOM # GENERATOR (FOR I/O DELAYS)
};

#endif