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

struct time {
  unsigned int hours, minutes, seconds;
};

unsigned int timeToSeconds(struct time);
struct time secondsToTime(unsigned int);
void displayTime(unsigned int);

int main(int argc, char *argv[]) {

  struct time t;
  t.seconds = 0;
  t.minutes = 0;
  t.hours = 0;
  char c;

  if (argc == 1) {
    printf("No time passed--using default: 1 min\n");
    t.minutes = 1;
  } else {
    while ((c = getopt(argc, argv, "h:m:s:")) != -1) {
      switch (c) {
      case 'h':
        t.hours = atoi(optarg);
        break;
      case 'm':
        t.minutes = atoi(optarg);
        break;
      case 's':
        t.seconds = atoi(optarg);
        break;
      }
    }
  }

  unsigned int seconds = timeToSeconds(t);
  while (seconds > 0) {

    displayTime(seconds);
    sleep(1);
    seconds -= 1;
  }

  return 0;
}

unsigned int timeToSeconds(struct time t) {
  unsigned int seconds = 0;

  seconds = t.seconds;
  seconds += t.minutes * 60;
  seconds += t.hours * 60 * 60;
  return seconds;
}
struct time secondsToTime(unsigned int seconds) {
  struct time t;

  t.hours = seconds / 3600;
  t.minutes = (seconds - (3600 * t.hours)) / 60;
  t.seconds = (seconds - (3600 * t.hours)) - (t.minutes * 60);

  return t;
}

void displayTime(unsigned int seconds) {
  system("clear");
  struct time t = secondsToTime(seconds);
  printf("%02d:%02d:%02d\n", t.hours, t.minutes, t.seconds);
}