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

const int DG_LED = 2;
const int BESS_LED = 3;

LiquidCrystal_I2C lcd1(0x27, 16, 2); // DG/BESS status
LiquidCrystal_I2C lcd2(0x3F, 16, 2); // RTC display
RTC_DS3231 rtc;

void setup() {
  Serial.begin(9600);
  pinMode(DG_LED, OUTPUT);
  pinMode(BESS_LED, OUTPUT);

  lcd1.init(); lcd1.backlight();
  lcd2.init(); lcd2.backlight();

  lcd1.print("System Ready");
  lcd2.print("Clock Init...");

  if (!rtc.begin()) {
    lcd2.clear();
    lcd2.print("RTC Error");
    while (1);
  }
}

void loop() {
  // DG/BESS control on LCD1
  if (Serial.available()) {
    String input = Serial.readStringUntil('\n');
    input.trim();
    lcd1.clear();
    lcd1.setCursor(0, 0);

    if (input == "DG") {
      digitalWrite(DG_LED, HIGH);
      digitalWrite(BESS_LED, LOW);
      lcd1.print("DG ON, BESS OFF");
    } else if (input == "BESS") {
      digitalWrite(DG_LED, LOW);
      digitalWrite(BESS_LED, HIGH);
      lcd1.print("BESS ON, DG OFF");
    } else if (input == "DG+BESS" || input == "BESS+DG") {
      digitalWrite(DG_LED, HIGH);
      digitalWrite(BESS_LED, HIGH);
      lcd1.print("DG & BESS ON");
    } else if (input == "OFF") {
      digitalWrite(DG_LED, LOW);
      digitalWrite(BESS_LED, LOW);
      lcd1.print("DG & BESS OFF");
    } else {
      lcd1.print("Unknown command");
    }
  }

  // RTC display on LCD2
  DateTime now = rtc.now();
  lcd2.clear();
  lcd2.setCursor(0, 0);
  lcd2.print("Date:");
  lcd2.print(now.day());
  lcd2.print("-");
  lcd2.print(now.month());
  lcd2.print("-");
  lcd2.print(now.year());

  lcd2.setCursor(0, 1);
  lcd2.print("Time:");
  lcd2.print(now.hour());
  lcd2.print(":");
  lcd2.print(now.minute());
  lcd2.print(":");
  lcd2.print(now.second());

  delay(1000);
}