#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <RTClib.h>

// LCD setup (I2C address: 0x27, size: 16x2)
LiquidCrystal_I2C lcd(0x27, 16, 2);

// RTC setup
RTC_DS3231 rtc;

void setup() {
  Serial.begin(9600);

  // Initialize LCD
  lcd.init();
  delay(100);
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("ESP32 Digital");
  lcd.setCursor(0, 1);
  lcd.print("Clock Starting");
  delay(2000);
  lcd.clear();

  // Initialize RTC
  if (!rtc.begin()) {
    Serial.println("RTC module is NOT found!");
    lcd.setCursor(0, 0);
    lcd.print("RTC ERROR!");
    while (1); // Stop here if RTC not found
  }

  // If RTC lost power → set time from computer compile time
  if (rtc.lostPower()) {
    Serial.println("RTC lost power, setting time...");
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));  
  }
}

void loop() {
  // Get current time from RTC
  DateTime now = rtc.now();

  // Clear LCD
  lcd.clear();

  // Print Date on first line
  lcd.setCursor(0, 0);
  lcd.print("Date: ");
  lcd.print(now.year());
  lcd.print("/");
  lcd.print(now.month());
  lcd.print("/");
  lcd.print(now.day());

  // Print Time on second line
  lcd.setCursor(0, 1);
  lcd.print("Time: ");
  if (now.hour() < 10) lcd.print("0"); 
  lcd.print(now.hour());
  lcd.print(":");
  if (now.minute() < 10) lcd.print("0");
  lcd.print(now.minute());
  lcd.print(":");
  if (now.second() < 10) lcd.print("0");
  lcd.print(now.second());

  // Debug print to Serial Monitor
  Serial.print("Date: ");
  Serial.print(now.year());
  Serial.print("/");
  Serial.print(now.month());
  Serial.print("/");
  Serial.print(now.day());
  Serial.print("  Time: ");
  Serial.print(now.hour());
  Serial.print(":");
  Serial.print(now.minute());
  Serial.print(":");
  Serial.println(now.second());

  delay(1000); // Update every second
}