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

// Inisialisasi LCD I2C
LiquidCrystal_I2C lcd(0x27, 16, 2); // Alamat I2C bisa berbeda, sesuaikan dengan modul Anda

// Inisialisasi Keypad 4x4
const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
byte rowPins[ROWS] = {9, 8, 7, 6}; // Pin baris keypad
byte colPins[COLS] = {5, 4, 3, 2}; // Pin kolom keypad
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

// Variabel global
int menuIndex = 0; // Indeks menu saat ini
String inputBuffer = ""; // Buffer untuk input data
String menu[] = {"Menu 1", "Menu 2", "Input", "About"};
int totalMenus = sizeof(menu) / sizeof(menu[0]);

void setup() {
  lcd.begin(16,2);
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Welcome!");
  delay(2000);
  showMenu();
}

void loop() {
  char key = keypad.getKey();

  if (key) {
    switch (key) {
      case 'A':
        // Back
        if (menuIndex > 0) {
          menuIndex--;
        }
        showMenu();
        break;

      case 'B':
        // Enter
        if (menu[menuIndex] == "Input") {
          handleInput();
        } else {
          lcd.clear();
          lcd.print("Selected: ");
          lcd.setCursor(0, 1);
          lcd.print(menu[menuIndex]);
          delay(2000);
          showMenu();
        }
        break;

      case 'C':
        // Up
        menuIndex = (menuIndex > 0) ? menuIndex - 1 : totalMenus - 1;
        showMenu();
        break;

      case 'D':
        // Down
        menuIndex = (menuIndex < totalMenus - 1) ? menuIndex + 1 : 0;
        showMenu();
        break;

      case '#':
        // Titik
        if (menu[menuIndex] == "Input") {
          inputBuffer += ".";
          lcd.setCursor(0, 1);
          lcd.print(inputBuffer);
        }
        break;

      case '*':
        // Reset / Clear input
        if (menu[menuIndex] == "Input") {
          inputBuffer = "";
          lcd.setCursor(0, 1);
          lcd.print("                "); // Clear line
          lcd.setCursor(0, 1);
          lcd.print(inputBuffer);
        }
        break;

      default:
        // Handle angka atau karakter lain
        if (menu[menuIndex] == "Input" && isDigit(key)) {
          inputBuffer += key;
          lcd.setCursor(0, 1);
          lcd.print(inputBuffer);
        }
        break;
    }
  }
}

void showMenu() {
  lcd.clear();
  for (int i = 0; i < totalMenus; i++) {
    lcd.setCursor(0, i == menuIndex ? 1 : 0);
    if (i == menuIndex) {
      lcd.print(">"); // Indikator pilihan
      lcd.setCursor(1, 1);
      lcd.print(menu[i]);
    } else {
      lcd.setCursor(1, 0);
      lcd.print(" ");
      lcd.print(menu[i]);
    }
  }
}

void handleInput() {
  lcd.clear();
  lcd.print("Enter value:");
  inputBuffer = "";
  lcd.setCursor(0, 1);
}