#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);

int upButtonPin = 8;
int downButtonPin = 9;
int selectButtonPin = 10;

int ledPin1 = 5;
int ledPin2 = 6;
int ledPin3 = 7;

int upButtonState = 0;
int downButtonState = 0;
int selectButtonState = 0;
int lastupButtonState = 0;
int lastdownButtonState = 0;
int lastselectButtonState = 0;

int menuitem = 1;
int page = 1;

volatile boolean upButtonPressed = false;
volatile boolean downButtonPressed = false;
volatile boolean selectButtonPressed = false;

void setup() {
  pinMode(upButtonPin, INPUT_PULLUP);
  pinMode(downButtonPin, INPUT_PULLUP);
  pinMode(selectButtonPin, INPUT_PULLUP);
  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
  pinMode(ledPin3, OUTPUT);
  lcd.begin();
  lcd.backlight();
  lcd.clear();
}

void drawMenu() {
  lcd.setCursor(0, 0);
  lcd.print("Menu : ");
  lcd.setCursor(0, 1);
  switch (menuitem) {
    case 1:
      lcd.print("Lampu 1");
      break;
    case 2:
      lcd.print("Lampu 2");
      break;
    case 3:
      lcd.print("Lampu 3");
      break;
  }
}

void loop() {
  drawMenu();

  upButtonState = digitalRead(upButtonPin);
  downButtonState = digitalRead(downButtonPin);
  selectButtonState = digitalRead(selectButtonPin);
  checkIfupButtonIsPressed();
  checkIfdownButtonIsPressed();
  checkIfselectButtonIsPressed();

  if (upButtonPressed && page == 1) {
    upButtonPressed = false;
    menuitem--;
    if (menuitem == 0) {
      menuitem = 3;
    }
  } else if (downButtonPressed && page == 1) {
    downButtonPressed = false;
    menuitem++;
    if (menuitem == 4) {
      menuitem = 1;
    }
  }
  if (selectButtonPressed && page == 1) {
    selectButtonPressed = false;
    switch (menuitem) {
      case 1:
        digitalWrite(ledPin1, !digitalRead(ledPin1));
        break;
      case 2:
        digitalWrite(ledPin2, !digitalRead(ledPin2));
        break;
      case 3:
        digitalWrite(ledPin3, !digitalRead(ledPin3));
        break;
    }
  }
}

void checkIfupButtonIsPressed() {
  if (upButtonState != lastupButtonState) {
    if (upButtonState == LOW) {
      upButtonPressed = true;
    }
    delay(50); // Debouncing
  }
  lastupButtonState = upButtonState;
}

void checkIfdownButtonIsPressed() {
  if (downButtonState != lastdownButtonState) {
    if (downButtonState == LOW) {
      downButtonPressed = true;
    }
    delay(50); // Debouncing
  }
  lastdownButtonState = downButtonState;
}

void checkIfselectButtonIsPressed() {
  if (selectButtonState != lastselectButtonState) {
    if (selectButtonState == LOW) {
      selectButtonPressed = true;
    }
    delay(50); // Debouncing
  }
  lastselectButtonState = selectButtonState;
}