#include <periph/rtt.h>
#include <ztimer.h>
#include <ztimer/stopwatch.h>

static void _cb(void* arg)
{
    (void)arg;
}

int main(void)
{
    unsigned max = 0;
    ztimer_stopwatch_t stopwatch;
    ztimer_t timer = { .callback = &_cb };

#ifndef MODULE_ZTIMER_MSEC

    // Normally ZTIMER_MSEC is backed by rtt, but if ZTIMER_MSEC isn't used,
    // we'll need to init rtt ourselves.
    rtt_init();

#endif

    ztimer_stopwatch_init(ZTIMER_USEC, &stopwatch);

    while (1)
    {
        ztimer_stopwatch_start(&stopwatch);

#ifdef MODULE_ZTIMER_MSEC

        // Demonstrate that setting a timer on ZTIMER_MSEC (when backed by rtt)
        // can take more time than we might expect. This is espesially bad when
        // timers are set from an ISR.
        ztimer_set(ZTIMER_MSEC, &timer, 100);

#else

        // silence unsused variable compiler warning
        (void)timer;

        // Demonstate that we spend an unexpectedly long amount of time  in this
        // call (with IRQs disabled).
        rtt_set_alarm(100, &_cb, NULL);

#endif

        ztimer_stopwatch_stop(&stopwatch);
        const unsigned time = ztimer_stopwatch_measure(&stopwatch);

        if (time > max)
        {
            max = time;
            printf("max: %u\n", max);
        }
    }

    return 0;
}