/* Blink Example with switch button

   This example code is in the Public Domain (or CC0 licensed, at your option.)

   Unless required by applicable law or agreed to in writing, this
   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
   CONDITIONS OF ANY KIND, either express or implied.
*/
#include <stdio.h>
#include <esp_timer.h>
#include <esp_log.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/gpio.h"
#include "sdkconfig.h"

// GPIO definitions
// See ../../esp-idf/components/driver/include/driver/gpio.h
#define RED_GPIO   GPIO_NUM_3
#define GREEN_GPIO GPIO_NUM_4
#define BLUE_GPIO  GPIO_NUM_5

#define EXTERN_BUT GPIO_NUM_1 // BUTTON on GPIO1
#define EXTERN_LED GPIO_NUM_2 // LED on GPIO2

#define EXTERN_BUT_MASK (1ULL<<EXTERN_BUT) // flag after pin number
#define ESP_INTR_FLAG_DEFAULT 0

#define ISR_MODE 1

// set initial state to blinking led on
static int state = 1;

// button manager with debounce timer definition
static esp_timer_handle_t debounce_timer;
static void test_button(void* arg);
const esp_timer_create_args_t debounce_timer_args = {
  .callback = &test_button,
  /* argument specified here will be passed to timer callback function */
  .arg = NULL,
  .name = "test_button"
};

static void test_button(void* arg) {
  if (gpio_get_level(EXTERN_BUT) == 1)
  {
    state = 1 - state;
    gpio_set_level(EXTERN_LED, 1 - state);
  }
}

static void isr_button_pressed(void* args) {
  if (gpio_get_level(EXTERN_BUT) == 0) 
    return; // we only want to manage pushed button
  if (!esp_timer_is_active(debounce_timer)) { // start only if the timer isn't active
    ESP_ERROR_CHECK(esp_timer_start_once(debounce_timer, 1000)); // 1ms = 1Kµs
  }
}

void app_main(void) {
    gpio_reset_pin(RED_GPIO);   // reset internal RGB LED GPIO
    gpio_reset_pin(GREEN_GPIO);
    gpio_reset_pin(BLUE_GPIO);
    gpio_reset_pin(EXTERN_LED); // reset external GPIO
    gpio_reset_pin(EXTERN_BUT);

    // create the timer
    esp_timer_create(&debounce_timer_args, &debounce_timer);

    if (ISR_MODE == 1) {  // Interrupt mode
      gpio_config_t btn_conf;
      btn_conf.intr_type = GPIO_INTR_POSEDGE;  // Interrupt at Posedge only
      btn_conf.mode = GPIO_MODE_INPUT;           // Use INPUT mode
      btn_conf.pin_bit_mask = EXTERN_BUT_MASK;   // MASK of the button pin
      btn_conf.pull_up_en = GPIO_PULLUP_DISABLE;    //Disable pullup
      btn_conf.pull_down_en = GPIO_PULLDOWN_ENABLE; //Enable pulldown
      gpio_config(&btn_conf); // send config
    } else {               // Naive mode
      gpio_set_direction(EXTERN_BUT, GPIO_MODE_INPUT);
    }
    printf("button configured\n");

    if (ISR_MODE == 1) {
      gpio_install_isr_service(ESP_INTR_FLAG_DEFAULT); // install GPIO interrupt
      gpio_isr_handler_add(EXTERN_BUT, isr_button_pressed, (void*) EXTERN_BUT); //Add handler of interrupt
      printf("Interrupt configured\n");
    } // end of ISR initialistaion

    /* Set the LED GPIO as a push/pull output */
    gpio_set_direction(RED_GPIO, GPIO_MODE_OUTPUT);
    gpio_set_direction(GREEN_GPIO, GPIO_MODE_OUTPUT);
    gpio_set_direction(BLUE_GPIO, GPIO_MODE_OUTPUT);
    gpio_set_direction(EXTERN_LED, GPIO_MODE_OUTPUT);
    printf("LED output configured\n");

    gpio_set_level(EXTERN_LED, 1 - state); // 1-1=0 1-0=1

    while(1) {
      printf("starting cycle by turning off the LEDs\n");
      gpio_set_level(RED_GPIO, 0);
      gpio_set_level(GREEN_GPIO, 0);
      gpio_set_level(BLUE_GPIO, 0);

      if ( ISR_MODE == 0 ) { // naive mode
        state = gpio_get_level(EXTERN_BUT);
      }
      printf("state=%d\n",state); // display current state on console
      vTaskDelay(1000 / portTICK_PERIOD_MS); // wait with lights off

      gpio_set_level(BLUE_GPIO, state); // light on blue if state up
      vTaskDelay(200 / portTICK_PERIOD_MS);
      gpio_set_level(BLUE_GPIO, 0);     // light off blue

      gpio_set_level(GREEN_GPIO, state);// light on green
      vTaskDelay(200 / portTICK_PERIOD_MS);
      gpio_set_level(GREEN_GPIO, 0);    // light off green

      gpio_set_level(RED_GPIO, state);  // light on red
      vTaskDelay(200 / portTICK_PERIOD_MS);
      gpio_set_level(RED_GPIO, 0);      // light off red

      gpio_set_level(RED_GPIO, state);  // light on red
      gpio_set_level(GREEN_GPIO, state);// and green => yellow!!
      vTaskDelay(200 / portTICK_PERIOD_MS); // end loop
    }
}