/*********************************************************************
 * LED MATRIX HODINY + SCROLL INFO
 * DS3231 + 4× FC-16 (MAX7219)
 *********************************************************************/

#include <MD_Parola.h>
#include <MD_MAX72xx.h>
#include <SPI.h>
#include <Wire.h>
#include "RTClib.h"

/* ---------- HARDVÉR ---------- */
#define HARDWARE_TYPE MD_MAX72XX::PAROLA_HW
#define MAX_DEVICES   4

#define CLK_PIN   13
#define DATA_PIN  11
#define CS_PIN    10

MD_Parola display(HARDWARE_TYPE, DATA_PIN, CLK_PIN, CS_PIN, MAX_DEVICES);
RTC_DS3231 rtc;

/* ---------- ČASY ---------- */
const unsigned long TIME_DURATION = 15000UL;

/* ---------- PREMENNÉ ---------- */
unsigned long lastClockStart = 0;
unsigned long lastBlink = 0;

bool showClock = true;
bool colonOn = true;

char timeBuf[6];      // HH:MM
char scrollBuf[64];   // dátum + deň + teplota

/* ---------- DNI ---------- */
const char *weekdayName[] = {
  "Nedela", "Pondelok", "Utorok",
  "Streda", "Stvrtok", "Piatok", "Sobota"
};

/* ---------- ZOBRAZENIE ---------- */
void showClockText()
{
  display.displayClear();
  display.setTextAlignment(PA_CENTER);
  display.displayText(timeBuf, PA_CENTER, 0, 0,
                      PA_PRINT, PA_NO_EFFECT);
  display.displayReset();
}

void showScrollText()
{
  display.displayClear();
  display.setTextAlignment(PA_LEFT);
  display.displayText(scrollBuf, PA_LEFT,
                      25, 1500,
                      PA_SCROLL_LEFT, PA_SCROLL_LEFT);
  display.displayReset();
}

/* ---------- SERIAL ---------- */
void checkSerial()
{
  if (!Serial.available()) return;

  String cmd = Serial.readStringUntil('\n');
  cmd.trim();

  int h, m, d, mo, y;

  if (sscanf(cmd.c_str(), "TIME %d:%d", &h, &m) == 2) {
    DateTime now = rtc.now();
    rtc.adjust(DateTime(now.year(), now.month(), now.day(), h, m, 0));
  }
  else if (sscanf(cmd.c_str(), "DATE %d.%d.%d", &d, &mo, &y) == 3) {
    if (y < 100) y += 2000;
    DateTime now = rtc.now();
    rtc.adjust(DateTime(y, mo, d, now.hour(), now.minute(), 0));
  }
}

/* ---------- SETUP ---------- */
void setup()
{
  Serial.begin(9600);
  Wire.begin();
  rtc.begin();

  display.begin();
  display.setIntensity(5);
  display.displayClear();

  DateTime now = rtc.now();
  sprintf(timeBuf, "%02d:%02d", now.hour(), now.minute());
  showClockText();

  lastClockStart = millis();
  lastBlink = millis();
}

/* ---------- LOOP ---------- */
void loop()
{
  bool animFinished = display.displayAnimate();
  checkSerial();

  DateTime now = rtc.now();

  /* ---------- BLIKANIE DVOJBODKY ---------- */
  if (showClock && millis() - lastBlink >= 1000UL) {
    lastBlink = millis();
    colonOn = !colonOn;
    timeBuf[2] = colonOn ? ':' : ' ';
    display.displayReset();
  }

  /* ---------- PRECHOD NA SCROLL ---------- */
  if (showClock && millis() - lastClockStart >= TIME_DURATION) {
    showClock = false;

    float temp = rtc.getTemperature();

    sprintf(scrollBuf, "%02d/%02d/%02d %s %.1fC",
            now.day(), now.month(), now.year() % 100,
            weekdayName[now.dayOfTheWeek()],
            temp);

    showScrollText();
  }

  /* ---------- NÁVRAT NA HODINY ---------- */
  if (!showClock && animFinished) {
    showClock = true;
    sprintf(timeBuf, "%02d:%02d", now.hour(), now.minute());
    colonOn = true;
    showClockText();
    lastClockStart = millis();
  }
}