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

#define TIME_YEAR_OFFSET 1900
#define PST_OFFSET -8
#define EST_OFFSET -5
#define AUS_OFFSET 9
#define FULL_DAYS_HOURS 24

int pstHour(int dubHour){
    if ( dubHour < -(PST_OFFSET) ){
        return dubHour + (FULL_DAYS_HOURS + PST_OFFSET);
    }
    return dubHour + PST_OFFSET;
}

int estHour(int dubHour){
    if ( dubHour < -(EST_OFFSET) ){
        return dubHour + (FULL_DAYS_HOURS + EST_OFFSET);
    }
    return dubHour + EST_OFFSET;
}

int ausHour(int dubHour){
    if ( dubHour + AUS_OFFSET > FULL_DAYS_HOURS) {
        return dubHour + (AUS_OFFSET - FULL_DAYS_HOURS);
    }
    return dubHour + AUS_OFFSET;
}

void apFromHour(int hour, int * outHour, char **outAP){
    *outHour = hour % 12;
    if(*outHour == 0){
        *outHour = 12;
    }
    if(hour > 11){
        *outAP = "PM";
    } else {
        *outAP = "AM";
    }
}

int main() {
    time_t doctor = time(NULL);
    struct tm * tardis = localtime(&doctor);

    int year = tardis->tm_year + TIME_YEAR_OFFSET;
    int month = tardis->tm_mon + 1;

    int rawHour = tardis->tm_hour;
    int dubHour;
    char * dubAP;
    apFromHour(rawHour, &dubHour, &dubAP);

    int sf24Hour = pstHour(rawHour);
    int sf12Hour;
    char * sfAP;
    apFromHour(sf24Hour, &sf12Hour, &sfAP);

    int ny24Hour = estHour(rawHour);
    int ny12Hour;
    char * nyAP;
    apFromHour(ny24Hour, &ny12Hour, &nyAP);

    int aus24Hour = ausHour(rawHour);
    int aus12Hour;
    char * ausAP;
    apFromHour(aus24Hour, &aus12Hour, &ausAP);

    char minuteString[3];
    minuteString[2] = '\0';
    int rawMin = tardis->tm_min;
    if(rawMin < 10){
        minuteString[0] = '0';
        minuteString[1] = '0' + rawMin;
    } else {
        minuteString[0] = '0' + (rawMin / 10);
        minuteString[1] = '0' + (rawMin % 10);
    }
    printf("================================\n");
    printf(" <<  %d-%d-%d\t%d:%s %s  >>\n", year, month, tardis->tm_mday, tardis->tm_hour, minuteString, tardis->tm_zone);
    printf("================================\n");
    printf("-> Melbourne: %d:%s %s\n", aus12Hour, minuteString, ausAP);
    printf("-> Dublin: %d:%s %s\n", dubHour, minuteString, dubAP);
    printf("-> New York: %d:%s %s\n", ny12Hour, minuteString, nyAP);
    printf("-> San Francisco: %d:%s %s\n", sf12Hour, minuteString, sfAP);
    return 0;
}