#include <LightChrono.h>
#include <Chrono.h>

const int digits[] = {9, 10, 11, 12};
const int segments[] = {2, 8, 4, 5, 6, 7, 3};

const bool one[7] = {false, true, true, false, false, false, false};
const bool two[7] = {true, true, false, true, true, false, true};
const bool three[7] = {true, true, true, true, false, false, true};
const bool four[7] = {false, true, true, false, false, true, true};
const bool five[7] = {true, false, true, true, false, true, true};
const bool six[7] = {true, false, true, true, true, true, true};
const bool seven[7] = {true, true, true, false, false, false, false};
const bool eight[7] = {true, true, true, true, true, true, true};
const bool nine[7] = {true, true, true, true, false, true, true};
const bool zero[7] = {true, true, true, true, true, true, false};

Chrono timer;

void writeDigit(char d, char val, bool dec) {
    const bool *segs;
    switch (val) {
        case 0:
            segs = zero;
            break;
        case 1:
            segs = one;
            break;
        case 2:
            segs = two;
            break;
        case 3:
            segs = three;
            break;
        case 4:
            segs = four;
            break;
        case 5:
            segs = five;
            break;
        case 6:
            segs = six;
            break;
        case 7:
            segs = seven;
            break;
        case 8:
            segs = eight;
            break;
        case 9:
            segs = nine;
            break;
    }
    for (int i = 0; i < 7; ++i) {
        if (segs[i]) {
            digitalWrite(segments[i], HIGH);
        } else {
            digitalWrite(segments[i], LOW);
        }
    }
    if (dec) {
      digitalWrite(segments[7], HIGH);
    }
    digitalWrite(digits[d], LOW);
    delay(1);
    digitalWrite(digits[d], HIGH);
    digitalWrite(segments[7], LOW);
}

void showNumber(float number) {
    int n = number;
    writeDigit(0, (n/1000U) % 10, false);
    writeDigit(1, (n/100U) % 10, false);
    writeDigit(2, (n/10U) % 10, false);
    writeDigit(3, n % 10, false);
}

void setup() {
    for (int i = 0; i < 4; ++i) {
        pinMode(digits[i], OUTPUT);
        digitalWrite(digits[i], HIGH);
    }
    for (int i = 0; i < 7; ++i) {
        pinMode(segments[i], OUTPUT);
        digitalWrite(segments[i], LOW);
    }
    timer.restart();
}

void loop() {
  showNumber(timer.elapsed()/1000);
}