//
//  FCFS.c
//  First Come First Serve Scheduling Algorithm
//
//  Created by Anthony Andrada on 9/27/16.
//
//

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int size = 50;
typedef int bool;
#define true 1
#define false 0

struct Process
{
    int arrival_time;
    int service_time;
    int priority;
};

int compare(const void * e1, const void * e2)
{
    struct Process *x = (struct Process *)e1;
    struct Process *y = (struct Process *)e2;
    if (x->arrival_time < y->arrival_time){
        return -1;
    }
    else if (x->arrival_time > y->arrival_time){
        return 1;
    }
    else return 0;
}

void sort (struct Process x[])
{
    qsort (x, size, sizeof(struct Process), compare);
}

void print (struct Process n[])
{
    for (int i = 0; i < size; i++)
    {
        int x = n[i].arrival_time;
        int y = n[i].service_time;
        int z = n[i].priority;
        printf("Job: %d, AT: %d, ST: %d, P: %d\r\n",i, x, y, z);
    }
}

void schedule(struct Process x[])
{
    struct Process* ptr = x;
    int job = 0;
    int start = 0;
    int finish = 0;
    bool isScheduled = false;
    float turnaround = 0;
    float wait = 0;
    float response = 0;
    for (int q = 0; q < 110; q++)
    {
        if (isScheduled == false && q > 99) break;
        printf("Quantum: %d. ", q);
        if (isScheduled == true && q == (start + ptr->service_time))
        {
            turnaround += (q - ptr->arrival_time);
            ptr++;
            printf("Finished Job %d. ", job);
            job++;
            isScheduled = false;
            if (q >= 99)
            {
                printf("\r\n");
                break;
            }
            finish = q;
        }
        else if (isScheduled == true)
        {
            printf("Working Job %d.", job);
        }
        if (isScheduled == false && q >= ptr->arrival_time)
        {
            response += (q - finish);
            wait += (q - ptr->arrival_time);
            printf("Starting Job %d. ", job);
            isScheduled = true;
            start = q;
        }
        printf("\r\n");
    }
    printf("\r\n");
    printf("Average turnaround time: %.2f", turnaround / job);
    printf("\r\n");
    printf("Average wait time: %.2f", wait / job);
    printf("\r\n");
    printf("Average response time: %.2f", response / job);
    printf("\r\n");
    printf("Thoroughput : %f", (float)job / 100);
    printf("\r\n");
}

int main()
{
    int seed = time(NULL);
    srand(seed);
    struct Process queue[size];
    int t;
    for (int i = 0; i < size; i++)
    {
        queue[i].arrival_time = rand() % 100;
        t = rand() % 11;
        if (t == 0) t +=1;
        queue[i].service_time = t;
        t = rand() % 5;
        if (t == 0) t += 1;
        queue[i].priority = t;
    }
    sort(queue);
    printf("\r\n");
    print(queue);
    printf("\r\n");
    schedule(queue);
    return 0;
}