#include <unistd.h>
#include <sys/wait.h>
#include "stdio.h"
#include <stdlib.h>
#include <time.h>
#include "format.h"
#include <string.h>

/**
 * Utilities Unleashed
 * CS 241 - Fall 2019
 */

int main(int argc, char *argv[]) {
    pid_t child = fork();
    if (child == -1) {
        return -1;
    }
    struct timespec* timeSpec = malloc(sizeof(struct timespec));
    if (child != 0) { // Parent
        int firstRead = clock_gettime(CLOCK_MONOTONIC, timeSpec);
        double firstTimeSec = 0.00;
        double nextTimeSec = 0.00;
        double firstTimeNanoSec = 0.00;
        double nextTimeNanoSec = 0.00;
        if (firstRead != -1) {
            firstTimeSec = timeSpec->tv_sec;
            firstTimeNanoSec = (double) timeSpec->tv_nsec;
        }
        waitpid(child,NULL,0);
        int nextRead = clock_gettime(CLOCK_MONOTONIC, timeSpec);
        if (nextRead != -1) {
            nextTimeSec = timeSpec->tv_sec;
            nextTimeNanoSec = (double) timeSpec->tv_nsec;
        }
        double duration = (nextTimeSec - firstTimeSec) + ((nextTimeNanoSec-firstTimeNanoSec) / 1000000000.00);
        display_results(argv, duration);
        return (int) duration;
    }
    else {
        int execCode = execvp(argv[1], &argv[1]);
        if (execCode == -1) print_exec_failed();
    }
    return 0; // return seconds it took to complete
}