#include <LiquidCrystal_I2C.h>

#define sw1 2
#define sw2 3
#define sw3 4
#define sw4 5
#define buzz 7

int next, back, menu, enter, home, mode, st ,sub_menu, sub_st, next_st, back_st;

LiquidCrystal_I2C lcd(0x27,16,2);

void setup() {

  Serial.begin(115200);
  lcd.init();
  lcd.clear();         
  lcd.backlight(); 

  pinMode(sw1, INPUT_PULLUP);
  pinMode(sw2, INPUT_PULLUP);
  pinMode(sw3, INPUT_PULLUP);
  pinMode(sw4, INPUT_PULLUP);
}

void loop() {

  next = digitalRead(sw1);
  back = digitalRead(sw2);
  enter = digitalRead(sw3);
  home = digitalRead(sw4);

  if (next == 0) {
     if (menu == 4 && sub_menu == 1) {
      //stopwatch
    } else if (menu == 4 && sub_menu == 2) {
      //CD 
    } else if (menu == 5 && sub_menu == 1) {
      // Proses setting LCD
    } else if (menu == 5 && sub_menu == 2) {
      // Proses setting buzzer
    } else {
      menu = menu + 1;
    }
  }

  if (back == 0) {
    if (menu == 3 && sub_menu > 0) {
      sub_menu = 0;
      lcd.clear();
    } else if (menu == 4 && sub_menu > 0) {
      sub_menu = 0;
      lcd.clear();
    } else if (menu == 5 && sub_menu > 0) {
      sub_menu = 0;
      lcd.clear();
    } else {
      menu = menu - 1;
    }
  }

  if (next == 0 && menu > 5) {
    menu = 1;
  }

  if (back == 0 && menu <= 1) {
    menu = 5;
  }

  switch (menu) {
    case 1:
      lcd.setCursor(0,0);
      lcd.print("Menu:");
      lcd.setCursor(6,0);
      lcd.print("1. Start  ");
      break;

    case 2:
      lcd.setCursor(0,0);
      lcd.print("Menu:");
      lcd.setCursor(6,0);
      lcd.print("2. Stop   ");
      break;

    case 3:
      lcd.setCursor(0,0);
      lcd.print("Menu:");
      lcd.setCursor(6,0);
      lcd.print("3. Reset  ");
      break;

    case 4:
      lcd.setCursor(0,0);
      lcd.print("Menu:");
      lcd.setCursor(6,0);
      lcd.print("4. Mode   ");
      if (enter == 0 && sub_menu == 0) {
        lcd.setCursor(0,1);
        lcd.print("1. Stopwatch ");
        sub_menu = 1;
      }
      else if (next == 0 && sub_menu == 1) {
        lcd.setCursor(0,1);
        lcd.print("2. Countdown ");
        sub_menu = 2;
        mode = 0;
      }
      else if (enter == 0 && mode == 0 && sub_menu == 2) {
        lcd.setCursor(0,1);
        lcd.print("2.1. 30 detik   ");
        mode = 1;
          /* if (enter == 0) {
                for(int i = 0; i <= 30; i++){
                lcd.setCursor(8,0);
                lcd.print(i);
                delay(1000);
                lcd.clear();
          }       
        } */
      }
      else if (next == 0 && mode == 1 && sub_menu == 2){
        lcd.setCursor(0,1);
        lcd.print("2.2. 1 menit    ");
        mode = 2;
      } 
  break;

    case 5:
  lcd.setCursor(0,0);
  lcd.print("Menu:");
  lcd.setCursor(6,0);
  lcd.print("5. Setting");
  st = 0;
  sub_st = 0;
  next_st = 0;
  back_st = 0;
  switch(st) {
    case 0:
      lcd.setCursor(0,1);
      lcd.print("1. LCD Backlight");
      if (enter == 0 && sub_st == 0) {
        lcd.setCursor(0,1);
        lcd.print("1.1. LED OFF    ");
        sub_st = 1;
      }
      else if (next == 0 && sub_st == 1) {
        lcd.setCursor(0,1);
        lcd.print("1.2. LED ON     ");
        sub_st = 2;
      }
      else if (back == 0 && sub_st > 0) {
        lcd.setCursor(0,1);
        lcd.print("1. LCD Backlight");
        sub_st = 0;
      }
      else if (enter == 0 && sub_st == 2) {
        lcd.backlight();
      }
      else if (next == 0 && sub_st == 2) {
        st = 1;
        sub_st = 0;
      }
      break;
    case 1:
      lcd.setCursor(0,1);
      lcd.print("2. Buzzer ON/OFF");
      if (enter == 0 && sub_st == 0) {
        lcd.setCursor(0,1);
        lcd.print("2.1. Buzzer OFF ");
        sub_st = 1;
      }
      else if (next == 0 && sub_st == 1) {
        lcd.setCursor(0,1);
        lcd.print("2.2. Buzzer ON  ");
        sub_st = 2;
      }
      else if (back == 0 && sub_st > 0) {
        lcd.setCursor(0,1);
        lcd.print("2. Buzzer ON/OFF");
        sub_st = 0;
      }
      else if (enter == 0 && sub_st == 2) {
        tone(buzz, 1000, 1000);
      }
      else if (next == 0 && sub_st == 2) {
        st = 2;
        sub_st = 0;
      }
      break;
  }

  // Tampilkan sub-menu ketika button enter ditekan
  if (enter == 0 && sub_st == 0) {
    sub_st = 1;
  }
  else if (enter == 0 && sub_st == 1 && st == 0) {
    lcd.setCursor(0,1);
    lcd.print("1.2. LED ON     ");
    sub_st = 2;
  }
  else if (enter == 0 && sub_st == 1 && st == 1) {
    lcd.setCursor(0,1);
    lcd.print("2.2. Buzzer ON  ");
    sub_st = 2;
  }

}

Serial.println(menu);
Serial.println(sub_menu);
Serial.println(mode);
delay(100);
}