#include <stdio.h>
#include "pico/stdlib.h"
#include "hardware/gpio.h"
#include "hardware/irq.h"

#define LED_PIN 15
#define BUTTON_PIN 16
#define DEBOUNCE_DELAY_MS 20

volatile bool button_pressed = false;

void button_irq_handler(uint gpio, uint32_t events) {
  sleep_ms(DEBOUNCE_DELAY_MS);

  if (gpio_get(BUTTON_PIN) == 0) {
    button_pressed = true;
  }
}

int main() {
  stdio_init_all();

  gpio_init(LED_PIN);
  gpio_set_dir(LED_PIN, GPIO_OUT);

  gpio_init(BUTTON_PIN);
  gpio_set_dir(BUTTON_PIN, GPIO_IN);
  gpio_pull_up(BUTTON_PIN);

  // Set up IRQ handler for the button press
  gpio_set_irq_enabled_with_callback(BUTTON_PIN, GPIO_IRQ_EDGE_FALL, true, &button_irq_handler);

  // Enable IRQs
  irq_set_enabled(BUTTON_PIN, true);

  while (true) {
    // Toggle the LED when the button is pressed
    if (button_pressed) {
      gpio_put(LED_PIN, !gpio_get(LED_PIN));
      button_pressed = false; // Reset 
    }
    sleep_ms(100); // delay time
  }

  return 0;
}