/*
 * Copyright (C) 2020 Beuth Hochschule für Technik Berlin
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */

/**
 * @ingroup     tests
 * @{
 *
 * @file
 * @brief       Periodic timer test application
 *
 * @author      Benjamin Valentin <benpicco@beuth-hochschule.de>
 *
 * @}
 */

#include <stdint.h>
#include <stdio.h>
#include <string.h>

#include "board.h"
#include "macros/units.h"

#include "fmt.h"
#include "mutex.h"
#include "periph/timer.h"
#include "test_utils/expect.h"

/* recreate logic to obtain valid XTIMER_DEV used in xtimer.h, but don't include
 * xtimer.h, as this leads to issues on some boards when the xtimer module is
 * not used */
#ifndef XTIMER_DEV
#define XTIMER_DEV  TIMER_DEV(0)
#endif
#ifndef XTIMER_HZ
#define XTIMER_HZ   MHZ(1)
#endif

/* We use the timer used for xtimer with the frequency used by xtimer here
 * to make sure we have a known valid timer configuration.
 *
 * DO NOT USE any low-level timer functions demonstrated here when xtimer
 * is used with that timer!
 * Configure a separate timer, XTIMER_DEV is usually 'owned' by xtimer, but
 * as xtimer is not used in this test, we can use it and the fact that every board
 * provides a configuration for it.
 */
#define TIMER_CYCL      (XTIMER_DEV)
#define CYCLE_MS        (25UL)
#define CYCLES_MAX      (10)
#ifdef TIMER_CHANNEL_NUMOF
#define MAX_CHANNELS    (TIMER_CHANNEL_NUMOF)
#else
#define MAX_CHANNELS    (10)
#endif

#ifndef ITERATIONS
#define ITERATIONS 3
#endif

static unsigned count[MAX_CHANNELS];

static void cb(void *arg, int chan)
{
    unsigned c = count[chan]++;

    print_str("[");
    print_u32_dec(chan);
    print_str("] tick\n");

    if (c > CYCLES_MAX) {
        timer_stop(TIMER_CYCL);
        mutex_unlock(arg);
    }
}

static const char* _print_ok(int chan, bool *succeeded)
{
    if (chan == 0) {
        if (count[chan] > 0) {
            return "OK";
        }
    }
    else if (count[chan] == 0) {
        return "OK";
    }

    *succeeded = false;
    return "ERROR";
}

static void _cb_set_stopped(void *arg, int chan)
{
    (void)chan;

    bool *succeeded = arg;

    *succeeded = false;
    puts("TIM_FLAG_SET_STOPPED failed");

    timer_stop(TIMER_CYCL);
}

int main(void)
{
    mutex_t lock = MUTEX_INIT;
    const unsigned long timer_hz = XTIMER_HZ;
    const unsigned steps = (CYCLE_MS * timer_hz) / 1000;

    printf("\nRunning Timer %d at %lu Hz.\n", TIMER_CYCL, timer_hz);
    printf("One counter cycle is %u ticks or %lu ms\n", steps, CYCLE_MS);
    puts("Will print 'tick' every cycle.\n");

    expect(timer_init(TIMER_CYCL, timer_hz, cb, &lock) == 0);

    puts("TEST START");
    bool succeeded = true;
    unsigned channel_numof = 1;

    for (unsigned iter = 0; iter < ITERATIONS; iter++) {
        printf("Running iteration %u of %u\n", iter + 1, (unsigned)ITERATIONS);
        lock = (mutex_t)MUTEX_INIT_LOCKED;
        memset(count, 0x00, sizeof(count));

        /* Only the first channel should trigger and reset the counter */
        /* If subsequent channels trigger this is an error. */
        for (unsigned chan = 1; chan < MAX_CHANNELS; chan++) {
            if (!timer_set_periodic(TIMER_CYCL, chan, (1 + chan) * steps,
                                    TIM_FLAG_RESET_ON_SET))
                {
                channel_numof = chan;
                break;
            }
        }

        if (iter == 0) {
            /* configure timer on first iterations */
            timer_set_periodic(TIMER_CYCL, 0, steps, TIM_FLAG_RESET_ON_MATCH);
        }
        else {
            /* resume timer on subsequent iterations */
            timer_start(TIMER_CYCL);
        }

        mutex_lock(&lock);

        puts("\nCycles:");

        for (unsigned i = 0; i < channel_numof; ++i) {
            printf("channel %u = %02u\t[%s]\n",
                   i, count[i], _print_ok(i, &succeeded));
        }
    }

    expect(timer_init(TIMER_CYCL, timer_hz, _cb_set_stopped, &succeeded) == 0);
    timer_set_periodic(TIMER_CYCL, 0, 25, TIM_FLAG_RESET_ON_SET | TIM_FLAG_SET_STOPPED);

    /* busy wait */
    for (volatile uint32_t i = 0; i < CLOCK_CORECLOCK / 10; ++i) {}

    if (succeeded) {
        puts("TEST SUCCEEDED");
    } else {
        puts("TEST FAILED");
    }

    return 0;
}