#include "pico/stdlib.h"
#include "hardware/gpio.h"
#include "hardware/irq.h"
#include "pico/time.h"

const uint BUTTON_PIN = 16;
const uint LED_PINS[] = {2, 6, 10, 15}; 

volatile bool buttonPressed = false;
volatile bool counterRunning = false;
volatile uint32_t counterValue = 0;

void button_isr() {
    if (gpio_get(BUTTON_PIN)) {
        return;
    }

     sleep_ms(50);

    if (!gpio_get(BUTTON_PIN)) {
        buttonPressed = true;
    }
}

int main() {
    stdio_init_all();

    for (int i = 0; i < sizeof(LED_PINS) / sizeof(LED_PINS[0]); ++i) {
        gpio_init(LED_PINS[i]);
        gpio_set_dir(LED_PINS[i], GPIO_OUT);
    }

    gpio_init(BUTTON_PIN);
    gpio_set_dir(BUTTON_PIN, GPIO_IN);
    gpio_set_pulls(BUTTON_PIN, true, false);

   gpio_set_irq_enabled_with_callback(BUTTON_PIN, GPIO_IRQ_EDGE_FALL, true, &button_isr);

    irq_set_enabled(PIO0_IRQ_0, true);

    while (true) {
        if (buttonPressed) {
            counterRunning = !counterRunning; 
            buttonPressed = false;
        }

        if (counterRunning) {
             for (int i = 0; i < sizeof(LED_PINS) / sizeof(LED_PINS[0]); ++i) {
                gpio_put(LED_PINS[i], (counterValue >> i) & 1);
            }

            counterValue++;
            sleep_ms(500); 
           } else {
              for (int i = 0; i < sizeof(LED_PINS) / sizeof(LED_PINS[0]); ++i) {
                gpio_put(LED_PINS[i], 0);
            }
        }
    }

    return 0;
}