/**
 * TODO file description
 */

#include <stdio.h>
#include <FreeRTOS.h>
#include <task.h>
#include <math.h>
#include <driver/hw_timer.h>
#include "meteo_task.h"
#include "ds18b20.h"
#include "dht.h"
#include "driver/gpio.h"
#include "circbuf.h"

static volatile uint32_t timestamp = 0;

#define RPS_BUFFER_LEN (60*10)
static volatile uint16_t history[RPS_BUFFER_LEN] = {};
static CircBuf rps_cb;

static volatile float rpm_average = 0;
static volatile float rpm_gust = 0;

static volatile uint16_t cycle_count = 0;

void calculate_wind();

static void gpio_isr_handler(void *arg)
{
    if (cycle_count < 0xFFFF) {
        cycle_count++;
    }
}

void hw_timer_callback1s(void *arg)
{
    timestamp++;

    // FIXME use a freertos queue and pass this to a thread!
    if (cbuf_full(&rps_cb)) {
        cbuf_pop_back(&rps_cb, NULL);
    }
    cbuf_push(&rps_cb, (void*) &cycle_count);
    cycle_count = 0;

    calculate_wind();
}

void calculate_wind()
{
    // Wind speed is average from 10 minutes
    // Gust is max 3-second average anywhere within the 10 minutes

    float max_gust = 0;

    uint32_t tenmin_sum = 0;
    uint32_t numsecs = cbuf_count(&rps_cb);
    uint16_t threesec1 = 0, threesec2 = 0;
    for(size_t i = 0; i < numsecs; i++) {
        uint16_t *slot = cbuf_ptr_nth(&rps_cb, i);
        if (!slot) {
            continue;
        }

        uint16_t slotval = *slot;
        tenmin_sum += (uint32_t) slotval;

        // gust is max avg from 3 seconds within the 10 minutes
        uint32_t gust_sum = (uint32_t) threesec1 + (uint32_t) threesec2 + (uint32_t) slotval;
        threesec1 = threesec2;
        threesec2 = slotval;

        float gust_avg = (float)gust_sum * (float)20.0f;
        if (gust_avg > max_gust) {
            max_gust = gust_avg;
        }
    }
    rpm_gust = max_gust;
    rpm_average = ((float)tenmin_sum / (float)numsecs) * 60.0f;
}


void meteo_task(void* pvParameters)
{
    cbuf_init(&rps_cb, (void*)history, RPS_BUFFER_LEN, 2); // uint16 fields

    // Try to unfuck GPIOs
    PIN_FUNC_SELECT(PERIPHS_IO_MUX_MTDI_U, FUNC_GPIO12);
    PIN_FUNC_SELECT(PERIPHS_IO_MUX_MTCK_U, FUNC_GPIO13);
    PIN_FUNC_SELECT(PERIPHS_IO_MUX_MTMS_U, FUNC_GPIO14);
    PIN_FUNC_SELECT(PERIPHS_IO_MUX_MTDO_U, FUNC_GPIO15);

    // start timer used for timebase
    hw_timer_init(hw_timer_callback1s, NULL);
    hw_timer_alarm_us(1000000, true); // 1s timer

    gpio_config_t io_conf;
    io_conf.intr_type = GPIO_INTR_POSEDGE;
    io_conf.mode = GPIO_MODE_INPUT;
    io_conf.pin_bit_mask = 1 << 14;
    io_conf.pull_down_en = 1;
    io_conf.pull_up_en = 0;
    gpio_config(&io_conf);
    gpio_install_isr_service(0);
    gpio_isr_handler_add(14, gpio_isr_handler, NULL);

    float dht_hum, dht_temp, ds_temp;
    while (1) {
        // this works ...
        ds_temp = ds18b20_measure_and_read(0, DS18B20_ANY);

        if (!dht_read_float_data(DHT_TYPE_DHT22, 12, &dht_hum, &dht_temp)) {
            dht_hum = dht_temp = NAN;
        }

        printf("Dallas: %.2f °C, DHT %.2f °C, %.1f %%r.H, HALL avg %.1f RPM, gust %.1f RPM\n",
               ds_temp, dht_temp, dht_hum, rpm_average, rpm_gust);

        vTaskDelay(pdMS_TO_TICKS(500));
    }

    vTaskDelete(NULL);
}