//  JobStream.h        Dave Reed        9/9/03
//
//  JobStream class implementation
////////////////////////////////////////////////////////////////

#include <iostream>
#include <fstream>
#include <string>
#include "Job.h"
#include "JobStream.h"
using namespace std;

JobStream::JobStream(string filename)
// Assumes: filename is the name of the job data file
// Results: constructs a queue of jobs from file
{
    ifstream infile(filename.c_str());

    if (!infile) {
        cout << "Input file not found.  Program aborted." << endl;
        exit(1);
    }

    int arr, id, len;
    while (infile >> arr >> id >> len) {
        Job j(id, arr, len);
        arrivingJobs.Enter(j);
    }
}

bool JobStream::JobsRemaining() const
// Returns: true if any jobs are left to be processed, else false
{
    return !arrivingJobs.IsEmpty();
}

bool JobStream::JobHasArrived(int time) const
// Returns: true if a job has arrived by given time, else false
{
    return (!arrivingJobs.IsEmpty() && arrivingJobs.Front().GetArrival() <= time);
}


Job JobStream::GetJob()
// Assumes: at least one job is waiting to be processed
// Returns: the next job (and removes it from the stream)
{
    Job nextJob = arrivingJobs.Front();
    arrivingJobs.Remove();
    return nextJob;
}