#include "pico/stdlib.h"
#include "hardware/i2c.h"
#include "hd44780.h"

#define I2C_PORT i2c0

bool button_pressed = false;
bool counting = false;
uint32_t seconds = 0;

void button_handler() {
    button_pressed = !button_pressed;
}

void setup() {
    gpio_init(26); // Button pin
    gpio_set_dir(26, GPIO_IN);
    gpio_pull_up(26);
    gpio_set_irq_enabled_with_callback(26, GPIO_IRQ_EDGE_RISE, true, &button_handler);

    gpio_init(7); // LED pin
    gpio_set_dir(7, GPIO_OUT);

    i2c_init(I2C_PORT, 100000);
    gpio_set_function(0, GPIO_FUNC_I2C); // SDA
    gpio_set_function(1, GPIO_FUNC_I2C); // SCL
    gpio_pull_up(0);
    gpio_pull_up(1);

    hd44780_init(I2C_PORT, 0x27, 16, 2);
}

void display_time(uint32_t time) {
    char buffer[17];
    snprintf(buffer, sizeof(buffer), "%02d:%02d:%02d", time / 3600, (time % 3600) / 60, time % 60);
    hd44780_clear();
    hd44780_gotoxy(0, 0);
    hd44780_puts(buffer);
}

void loop() {
    if (button_pressed) {
        counting = !counting;
        button_pressed = false;
    }

    if (counting) {
        seconds++;
        gpio_put(7, seconds % 2);
        display_time(seconds);
        sleep_ms(1000);
    }
}

int main() {
    setup();

    while (true) {
        loop();
    }

    return 0;
}