#include "pico/stdlib.h"
#include "hardware/gpio.h"
#include "hardware/timer.h"


const uint SEGMENTS[8] = {0, 1, 2, 3, 4, 5, 6, 7}; // 
const uint DIGITS[4] = {8, 9, 10, 11};
const uint BUTTONS[4] = {12, 13, 14, 15}; // Start/Stop, Set, Increase, Reset

// Button states
volatile bool button_pressed[4] = {false, false, false, false};


volatile bool running = false;
volatile uint digits[4] = {0, 0, 0, 0};
volatile int selected_digit = -1; 
volatile bool blink = false;


const uint SEGMENT_MAP[10] = {
    0b00111111, // 0
    0b00000110, // 1
    0b01011011, // 2
    0b01001111, // 3
    0b01100110, // 4
    0b01101101, // 5
    0b01111101, // 6
    0b00000111, // 7
    0b01111111, // 8
    0b01101111  // 9
};


void update_display(volatile uint digits[4]);
bool timer_callback(struct repeating_timer *t);
void button_callback(uint gpio, uint32_t events);
void setup_gpio();
void process_buttons();

int main() {
    stdio_init_all();

    setup_gpio();

    struct repeating_timer timer;
    add_repeating_timer_ms(100, timer_callback, NULL, &timer);

    while (1) {
        process_buttons();
        update_display(digits);
    }
}

void setup_gpio() {
    for (int i = 0; i < 8; i++) {
        gpio_init(SEGMENTS[i]);
        gpio_set_dir(SEGMENTS[i], GPIO_OUT);
    }

    for (int i = 0; i < 4; i++) {
        gpio_init(DIGITS[i]);
        gpio_set_dir(DIGITS[i], GPIO_OUT);
        gpio_init(BUTTONS[i]);
        gpio_set_dir(BUTTONS[i], GPIO_IN);
        gpio_pull_up(BUTTONS[i]);
        gpio_set_irq_enabled_with_callback(BUTTONS[i], GPIO_IRQ_EDGE_FALL, true, button_callback);
    }
}

void button_callback(uint gpio, uint32_t events) {
    for (int i = 0; i < 4; i++) {
        if (gpio == BUTTONS[i]) {
            button_pressed[i] = true;
            break;
        }
    }
}

bool timer_callback(struct repeating_timer *t) {
    static uint blink_counter = 0;
    if (running) {
        digits[0]++;
        for (int i = 0; i < 3; i++) {
            if (digits[i] >= 10) {
                digits[i] = 0;
                digits[i + 1]++;
            }
        }
        if (digits[3] >= 10) {
            digits[3] = 0;
        }
    }
    blink_counter++;
    if (blink_counter >= 5) {
        blink = !blink;
        blink_counter = 0;
    }
    return true;
}

void process_buttons() {
    if (button_pressed[0]) {
        running = !running;
        button_pressed[0] = false;
    }
    if (button_pressed[1]) {
        selected_digit = (selected_digit + 1) % 4;
        button_pressed[1] = false;
    }
    if (button_pressed[2] && selected_digit != -1) {
        digits[selected_digit] = (digits[selected_digit] + 1) % 10;
        button_pressed[2] = false;
    }
    if (button_pressed[3]) {
        running = false;
        for (int i = 0; i < 4; i++) {
            digits[i] = 0;
        }
        selected_digit = -1;
        button_pressed[3] = false;
    }
}

void update_display(volatile uint digits[4]) {
    for (int i = 0; i < 4; i++) {
        if (i == selected_digit && blink) {
            for (int j = 0; j < 7; j++) {
                gpio_put(SEGMENTS[j], 0);
            }
        } else {
            uint digit = digits[i];
            for (int j = 0; j < 7; j++) {
                gpio_put(SEGMENTS[j], (SEGMENT_MAP[digit] >> j) & 1);
            }
        }

        if (i == 1) {
            gpio_put(SEGMENTS[7], 1);
        } else {
            gpio_put(SEGMENTS[7], 0);
        }

        gpio_put(DIGITS[3 - i], 0);
        sleep_ms(5);
        gpio_put(DIGITS[3 - i], 1);
    }
}