//#define PICO

#ifdef PICO
#include <pico/printf.h>
#include <pico/stdlib.h>
#include "FreeRTOS.h"
#include "task.h"
#else
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdint.h>
#include <stdbool.h>

#define PICO_DEFAULT_LED_PIN 0
#define GPIO_OUT 1
#define GPIO_IN 0
#endif

#include <math.h>

#include "log.h"
#include "jobs.h"
#include "gpio.h"

#define ALARM_BASE_FREQ 2000 // auditive frequency human range: [20; 20000] hertz
#define ALARM_PERIOD_MS 500
#define PI 3.14

/**
 * Oscillator for passive buzzer hardware.
 *
 * It generates desired `freq_hz` for `duration_ms`.
 *
 * NOTE: `sleep_us` method does not impact FreeRTOS engine
 * since, the scheduler started on two cores (RP2350). The behavior may differs
 * on one core. Update the FreeRTOS tick freq and implement `pdUS_TO_TICKS` if needed.
 */
void gen_freq(gpio* g, size_t freq_hz, size_t duration_ms) {
    if (!freq_hz) {
        gpio_set_state(g, 0);
        return;
    }

    float period = (1.0 / freq_hz) * 1000000; // signal period in micro seconds
    size_t duty_period = period / 2; // working period = period / 2
    size_t nb_period = duration_ms * 1000 / period; // number of period to play

    debug("freq_hz = (%ld), period_us = (%.2f), duty_period_us = (%ld), nb_period = (%ld)", freq_hz, period,
          duty_period, nb_period);

    for (size_t i = 0; i < nb_period; i++) {
        gpio_set_state(g, true);
        _sleep_us(duty_period);
        gpio_set_state(g, false);
        _sleep_us(duty_period);
    }
}

void run_alarm(void *const params) {
    for(;;) {
        debug("running alarm...");
        float sin_val;
        int tone_val;

        const size_t duration_ms = ALARM_PERIOD_MS / 36;

        for (size_t i = 0; i < 360; i+=10) {
            sin_val = sinf(i * (PI / 180));
            tone_val = ALARM_BASE_FREQ + sin_val * (ALARM_BASE_FREQ / 10);
            gen_freq(GPIOS[2], tone_val, duration_ms);
        }
    }
}

/* Initialize the main FreeRTOS task */
void init_rtos_main(TaskParam *params) {
#ifdef PICO
    BaseType_t res =
        xTaskCreate(check_btn_state, "main", configMINIMAL_STACK_SIZE,
                    (void *const)params, configMAX_PRIORITIES - 1U, NULL);

    if (res != pdPASS) {
        blink_failed(GPIOS[0]->pin, 500);
    }
#endif
}

/**
 * A program to run alarm on button pushed.
 *
 * To activate the alarm, push the button. Same for desactivation.
 * The alarm is launched in a separate task and controlled by
 * the main task (which holds the push button logic).
 *
 * Hardware:
 * - 1x Passive Buzzer
 * - 1x Push button
 * - 1 NPN transistor for signal amplification
 * - 1x 1k ohm resistor (NPN collector)
 * - 2x 10k ohm resistor
 * 
 * You can run the application in "DEBUG" mode using:
 * `make run-debug name=buzzer`
 * The FreeRTOS engine is replaced by threads.
 */
int main() {
    init_gpio();

    AppState as;
    init_app_state(&as);

    TaskParam params = (TaskParam) {
        .s = &as,
        .f = run_alarm,
    };

#ifdef PICO
    init_rtos_main(&params);
#else
    check_btn_state(&params);
#endif

#ifdef PICO
    vTaskStartScheduler();
#endif

    blink_failed(PICO_DEFAULT_LED_PIN, 200);
}