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

// ---------------- LCD & RTC ----------------
LiquidCrystal_I2C lcd(0x27, 20, 4);
RTC_DS1307 myRTC;

// ---------------- ตัวแปรเวลา ----------------
DateTime RTC_Now;

byte H_Now, M_Now, S_Now;
byte D_Now, Mo_Now;
int  Y_Now;

byte Sec_Old = 99;

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

  Serial.println("==============================");
  Serial.println(" Hello Smart-ENEng. of RMUTI ");
  Serial.println("==============================");

  lcd.init();
  lcd.backlight();

  if (!myRTC.begin()) {
    Serial.println("RTC NOT FOUND");
    while (1);
  }

  // ตั้งเวลาเฉพาะครั้งแรก
  if (!myRTC.isrunning()) {
    Serial.println("RTC is NOT running, setting time");
    myRTC.adjust(DateTime(2026, 1, 21, 19, 27, 0));
  }

  // -------- Welcome Screen --------
  lcd.clear();

  lcd.setCursor(2,1);
  lcd.print("Hello Smart-ENEng");

  lcd.setCursor(7,2);
  lcd.print("RMUTI");

  delay(3000);
  lcd.clear();
}

// ---------------------- อ่านเวลา RTC ----------------------
void getDateTime(void)
{
  RTC_Now = myRTC.now();

  H_Now  = RTC_Now.hour();
  M_Now  = RTC_Now.minute();
  S_Now  = RTC_Now.second();
  D_Now  = RTC_Now.day();
  Mo_Now = RTC_Now.month();
  Y_Now  = RTC_Now.year();

  if (Sec_Old != S_Now)
  {
    Sec_Old = S_Now;

    // -------- LCD บรรทัดที่ 1 --------
    lcd.setCursor(0,0);
    lcd.print(" Smart ENEng System ");

    // -------- LCD บรรทัดที่ 2 --------
    lcd.setCursor(0,1);
    lcd.print("Date: ");

    if (D_Now < 10) lcd.print('0');
    lcd.print(D_Now);
    lcd.print('/');

    if (Mo_Now < 10) lcd.print('0');
    lcd.print(Mo_Now);
    lcd.print('/');

    lcd.print(Y_Now);

    // -------- LCD บรรทัดที่ 3 --------
    lcd.setCursor(0,2);
    lcd.print("Time: ");

    if (H_Now < 10) lcd.print('0');
    lcd.print(H_Now);
    lcd.print(':');

    if (M_Now < 10) lcd.print('0');
    lcd.print(M_Now);
    lcd.print(':');

    if (S_Now < 10) lcd.print('0');
    lcd.print(S_Now);

    // // -------- LCD บรรทัดที่ 4 --------
    // lcd.setCursor(0,3);
    // lcd.print(" RMUTI Engineering ");

    // -------- Serial Monitor --------
    Serial.print("Date: ");

    if (D_Now < 10) Serial.print('0');
    Serial.print(D_Now);
    Serial.print('/');

    if (Mo_Now < 10) Serial.print('0');
    Serial.print(Mo_Now);
    Serial.print('/');

    Serial.println(Y_Now);

    Serial.print("Time: ");

    if (H_Now < 10) Serial.print('0');
    Serial.print(H_Now);
    Serial.print(':');

    if (M_Now < 10) Serial.print('0');
    Serial.print(M_Now);
    Serial.print(':');

    if (S_Now < 10) Serial.print('0');
    Serial.println(S_Now);

    Serial.println("--------------------------");
  }
}

// ---------------------- LOOP ----------------------
void loop()
{
  getDateTime();
  static uint32_t nowtime;

  if(millis()>nowtime + 1000){
    nowtime = millis();
    lcd.setCursor(3,3);
    lcd.print("slide  :  ");
    lcd.print(String(analogRead(A0))+"   ");
    
  }
}