#include <CoreFoundation/CoreFoundation.h>

#include <unistd.h>

enum
{
    SECONDS = 1,
    MINUTES = 60,
    HOURS = 60 * 60
};

void print_usage(void)
{
    printf("Usage: Alarm <duration> [units] [message]\n\n");    
}

int main(int argc, const char *argv[])
{
    long        duration;
    long        units = SECONDS;
    char const *message = NULL;
    CFStringRef alert_message = NULL;

    if (argc < 2)
    {
        printf("Too few arguments\n");
        print_usage();
        return EXIT_FAILURE;
    }
    
    duration = strtol(argv[1], NULL, 0);
    if (errno != 0)
    {
        printf("Duration must be a number\n");
        print_usage();
        return EXIT_FAILURE;
    }
    
    if (argc > 2)
    {
        if (strncasecmp("seconds", argv[2], 8) == 0)
        {
            units = SECONDS;
        }
        else if (strncasecmp("minutes", argv[2], 8) == 0)
        {
            units = MINUTES;
        }
        else if (strncasecmp("hours", argv[2], 6) == 0)
        {
            units = HOURS;
        }
        else
        {
            message = argv[2];
        }
        
        if (argc == 4)
        {
            if (message != NULL)
            {
                printf("%s is not a valid unit", message);
                print_usage();
                return EXIT_FAILURE;
            }
            
            message = argv[3];
        }
        else
        {
            printf("Too many arguments\n");
            print_usage();
            return EXIT_FAILURE;
        }
    }

    sleep(duration * units);
    
    if (message == NULL)
    {
        alert_message = CFSTR("Time's Up");
    }
    else
    {
        alert_message = CFStringCreateWithCString(kCFAllocatorDefault,
                                                  message,
                                                  kCFStringEncodingUTF8);
    }
    
    CFUserNotificationDisplayNotice(0.0,
                                    kCFUserNotificationPlainAlertLevel,
                                    NULL,
                                    NULL,
                                    NULL,
                                    CFSTR("Alarm"),
                                    alert_message,
                                    NULL);
    
    return EXIT_SUCCESS;
}