#include <patty/timer.h>

int patty_timer_expired(struct timeval *timer) {
    return (timer->tv_sec <= 0 && timer->tv_usec == 0)? 1: 0;
}

void patty_timer_cancel(struct timeval *timer) {
    timer->tv_sec  = 0;
    timer->tv_usec = 0;
}

void patty_timer_start(struct timeval *timer,
                       struct timeval *target,
                       time_t ms) {
    timer->tv_sec  =  ms / 1000;
    timer->tv_usec = (ms % 1000) * 1000;

    if (timercmp(timer, target, >)) {
        struct timeval res;

        timeradd(timer, target, &res);

        timer->tv_sec  = res.tv_sec;
        timer->tv_usec = res.tv_usec;
    }
}

void patty_timer_tick(struct timeval *timer,
                      struct timeval *elapsed) {
    struct timeval res;

    timersub(timer, elapsed, &res);

    timer->tv_sec  = res.tv_sec;
    timer->tv_usec = res.tv_usec;
}