#include <stdio.h>
#include "driver/gpio.h"

#define CONFIG_LED_PIN GPIO_NUM_2
#define CONFIG_BUTTON_PIN GPIO_NUM_15

//initialize the boolean variable to false 
//done to ensure that variable starts with known state 
//indicating that the butto has not been pressed
volatile bool buttonPressed = false;

// When the button is pressed, the hardware generates an interrupt signal that triggers the execution of the ISR 
// setting buttonPressed to is to indicate that the button is pressed. 
// Allows the rest of the program to respond to this event by checking the value of buttonPressed
void IRAM_ATTR button_isr_handler(void* arg) 
{
    buttonPressed = true;
}

void setup() 
{
    gpio_pad_select_gpio(CONFIG_BUTTON_PIN);
    gpio_pad_select_gpio(CONFIG_LED_PIN);
    gpio_set_direction(CONFIG_BUTTON_PIN, GPIO_MODE_INPUT);
    gpio_set_direction(CONFIG_LED_PIN, GPIO_MODE_OUTPUT);
    gpio_set_intr_type(CONFIG_BUTTON_PIN, GPIO_INTR_NEGEDGE);
    gpio_install_isr_service(ESP_INTR_FLAG_EDGE);
    gpio_isr_handler_add(CONFIG_BUTTON_PIN, button_isr_handler, NULL);
}

void loop() 
{
    //checks if buttonPressed is true, which means the button ISR has been triggered.
    if (buttonPressed) 
    {
        //toggles the state of the LED
        //gpio_set_level(CONFIG_LED_PIN, ...) sets the state (high or low) of the LED pin.
        //!gpio_get_level(CONFIG_LED_PIN) gets the current level of the LED pin and then negates it 
        //This toggles the current state of the LED.
        gpio_set_level(CONFIG_LED_PIN, !gpio_get_level(CONFIG_LED_PIN));
        printf("Button pressed!!!\n");
        delay(1000); // Delay 
        buttonPressed = false;
    }
}

// Initially, when the button is pressed, the buttonPressed flag is set to true within the ISR (button_isr_handler). This indicates that the button has been pressed and the code inside the if block should execute to toggle the LED.

// Inside the if block, after the LED is toggled and the debounce delay has been applied using vTaskDelay(pdMS_TO_TICKS(1000));, the buttonPressed flag is reset to false. This is done to prevent rapid toggling of the LED due to multiple button presses during the debounce delay.

// By resetting buttonPressed to false, the code ensures that subsequent button presses are not immediately processed and that a new button press needs to occur before the LED is toggled again. This helps prevent unintentional toggling of the LED due to button bouncing or multiple presses.