#include <RTClib.h>
#include <Wire.h>
#include <DHT.h>

// DHT22 setup
#define DHTPIN 15  // Pin to which the data pin of DHT is connected
#define DHTTYPE DHT22 // DHT 22 (AM2302)
DHT dht(DHTPIN, DHTTYPE);

// Shift register pins
const int dataPin = 8;
const int clockPin = 9;
const int latchPin = 10;

RTC_DS1307 rtc;

const byte segmentMap[10] = {
  B11111100, // 0
  B01100000, // 1
  B11011010, // 2
  B11110010, // 3
  B01100110, // 4
  B10110110, // 5
  B10111110, // 6
  B11100000, // 7
  B11111110, // 8
  B11110110  // 9
};

// Global toggle for temp/humidity switch
bool showTemp = true;
unsigned long lastToggle = 0;
const unsigned long toggleInterval = 5000;

void setup() {
  pinMode(dataPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(latchPin, OUTPUT);

  Wire.begin();
  rtc.begin();
  dht.begin();

  if (!rtc.isrunning()) {
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }
}

void loop() {
  DateTime now = rtc.now();

  // Toggle temperature/humidity every 5 seconds
  if (millis() - lastToggle > toggleInterval) {
    showTemp = !showTemp;
    lastToggle = millis();
  }

  // Get time and date digits
  int digits[16] = {
    now.hour() / 10, now.hour() % 10,
    now.minute() / 10, now.minute() % 10,
    now.second() / 10, now.second() % 10,
    now.day() / 10, now.day() % 10,
    now.month() / 10, now.month() % 10,
    (now.year() / 1000) % 10, (now.year() / 100) % 10,
    (now.year() / 10) % 10, now.year() % 10
  };

  // Get the temperature and humidity
  float temp = dht.readTemperature();
  float hum = dht.readHumidity();
  int value = showTemp ? (int)temp : (int)hum;

  int th1 = value / 10;
  int th2 = value % 10;

  for (int i = 0; i < 6; i++) {
    updateDisplay(i, digits[i], 2); // Time: Common Cathode
    delay(1);
  }

  for (int i = 0; i < 8; i++) {
    updateDisplay(i, digits[i + 6], 3); // Date: Common Anode
    delay(1);
  }

  updateDisplay(0, th1, 4); // Temp/Humidity: Common Anode
  delay(1);
  updateDisplay(1, th2, 4);
  delay(1);

  updateLEDs(now.dayOfTheWeek(), showTemp);
}

void updateDisplay(int pos, int num, int ctrlRegister) {
  byte seg = segmentMap[num];

  // Reverse logic for common anode (date, temp/hum)
  if (ctrlRegister != 2) {
    seg = ~seg;
  }

  byte sr1 = seg; // Segment data
  byte sr2 = (ctrlRegister == 2) ? ~(1 << pos) : 0xFF; // Time digit enable
  byte sr3 = (ctrlRegister == 3) ? (1 << pos) : 0x00;  // Date digit enable
  byte sr4 = (ctrlRegister == 4) ? (1 << pos) : 0x00;  // Temp/Hum digit enable
  byte sr5 = 0; // LED unchanged

  digitalWrite(latchPin, LOW);
  shiftOut(dataPin, clockPin, MSBFIRST, sr5);
  shiftOut(dataPin, clockPin, MSBFIRST, sr4);
  shiftOut(dataPin, clockPin, MSBFIRST, sr3);
  shiftOut(dataPin, clockPin, MSBFIRST, sr2);
  shiftOut(dataPin, clockPin, LSBFIRST, sr1);
  digitalWrite(latchPin, HIGH);
}

void updateLEDs(int weekday, bool showTemp) {
  byte ledBits = 0;
  if (weekday >= 0 && weekday <= 6) {
    ledBits = (1 << weekday);
  }
  if (showTemp) {
    ledBits |= (1 << 7); // 8th LED for temp/hum toggle
  }

  // Just update LEDs (no digit selected)
  digitalWrite(latchPin, LOW);
  shiftOut(dataPin, clockPin, MSBFIRST, ledBits); // SR5
  shiftOut(dataPin, clockPin, MSBFIRST, 0);       // SR4
  shiftOut(dataPin, clockPin, MSBFIRST, 0);       // SR3
  shiftOut(dataPin, clockPin, MSBFIRST, 0);       // SR2
  shiftOut(dataPin, clockPin, LSBFIRST, 0);       // SR1
  digitalWrite(latchPin, HIGH);
}