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

#define alarm 7
#define set 8
#define up 9
#define down 10

int menitalarm = 0;
int jamalarm = 0;
int pagealarm = 0;
int realjam = true;
int pagejam = 0;
int jamReal;
int menitReal;
int jamm=0;
int menitt=0;
RTC_DS3231 rtc;

LiquidCrystal_I2C lcd(0x27, 16, 2);  // I2C LCD 16x2

void setup() {
  Serial.begin(9600);
  if (!rtc.begin()) {
    Serial.println("Couldn't find RTC");
    while (1);
  }
  if (rtc.lostPower()) {
    Serial.println("RTC lost power, let's set the time!");
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__))); // Ambil data jam
  }
  lcd.begin(16, 2);
  lcd.print("Digital Clock");
  delay(2000);
  lcd.setCursor(0, 1);
  delay(1000);  
  lcd.clear();
  pinMode(up, INPUT_PULLUP);
  pinMode(down, INPUT_PULLUP);
  pinMode(set, INPUT_PULLUP);
  pinMode(alarm, INPUT_PULLUP);
  
}

void loop() {
  DateTime now = rtc.now();
  jamReal = now.hour() + jamm;
  menitReal = now.minute() + menitt;
if(realjam == true){
  if(digitalRead(set)==LOW){
    pagejam +=1;
    if(pagejam == 3){ 
      pagejam = 0;
    }
    if(pagejam == -1){
      pagejam = 0;
    }
  }
  if(pagejam == 0){
  if(jamalarm == jamReal && menitalarm == menitReal){
  pinMode(3, OUTPUT);
  analogWrite(3, HIGH);
  }
    lcd.setCursor(0, 0);
    lcd.print("Time : ");
    lcd.print(jamReal, DEC);
    lcd.print(':');
    printDigits(menitReal);
    lcd.print(':');
    printDigits(now.second());
    lcd.setCursor(0, 1);
    lcd.print("Date : ");
    lcd.print(now.year(), DEC);
    lcd.print('/');
    lcd.print(now.month(), DEC);
    lcd.print('/');
    lcd.print(now.day(), DEC);
    delay(500);
  }
  if(pagejam == 1){
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Time : ");
  lcd.setCursor(9, 0);
  lcd.print(':');
  printDigits(menitReal);
  if(digitalRead(up) == LOW){
    menitt +=1;
    if(menitReal == 60){
      menitt = 0;
    }
    if(menitReal == -1){
      menitt = 0;
    }
  }
  if(digitalRead(down) == LOW){
    menitt -=1;
    if(menitReal == -1){
      menitt = 0;
    }
    if(menitReal == 60){
      menitt = 0;
    }
      if(menitt == -1){
      menitt = 0;
    }
  }
  }
if(pagejam == 2){
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Time : ");
  lcd.print(jamReal, DEC);
  if(digitalRead(up) == LOW){
    jamm +=1;
    if(jamReal == 25){
      jamm = 0;
    }
    if(jamReal == -1){
      jamm = 0;
    }
  }
  if(digitalRead(down) == LOW){
    jamm -=1;
    if(jamReal == -1){
      jamm = 0;
    }
    if(jamReal == 25){
      jamm = 0;
    }
    if(jamm == -1){
      jamm = 0;
    }
  }
}
}
if(digitalRead(alarm) == LOW){
  realjam = false;
  pagealarm +=1;
  if(pagealarm == 3){
    pagealarm = 0;
  }
  if(pagealarm == -1){
    pagealarm = 2;
  }
}
if(pagealarm == 0){
  realjam = true;
}
if(pagealarm == 1){
  realjam = false;
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Alarm : ");
  lcd.setCursor(9,0);
  lcd.print(':');
  printDigits(menitalarm);
  if(digitalRead(up) == LOW){
    menitalarm +=1;
    if(menitalarm == 60){
      menitalarm = 0;
    }
    if(menitalarm == -1){
      menitalarm = 59;
    }
  }
  if(digitalRead(down) == LOW){
    menitalarm -=1;
    if(menitalarm == -1){
      menitalarm = 59;
    }
    if(menitalarm == 60){
      menitalarm = 0;
    }
  }
}
if(pagealarm == 2){
  realjam = false;
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Alarm :");
  lcd.print(jamalarm, DEC);
  if(digitalRead(up) == LOW){
    jamalarm +=1;
    if(jamalarm == 25){
      jamalarm = 0;
    }
    if(jamalarm == -1){
      jamalarm = 24;
    }
  }
  if(digitalRead(down) == LOW){
    jamalarm -=1;
    if(jamalarm == -1){
      jamalarm = 24;
    }
    if(jamalarm == 25){
      jamalarm = 0;
    }
  }
}
  delay(500);
}

void printDigits(int digits) {
  // Utility function for printing two digits
  if (digits < 10)
    lcd.print('0');
  lcd.print(digits);
}