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

LiquidCrystal_I2C lcd(0x27, 16, 2);

// Pin tombol
const int buttonAdd = 2;     // Tombol tambah
const int buttonSub = 3;     // Tombol kurang

// Variabel tombol
int lastAddState = HIGH;
int lastSubState = HIGH;

int count = 0;

void setup() {
  pinMode(buttonAdd, INPUT_PULLUP);
  pinMode(buttonSub, INPUT_PULLUP);

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

  lcd.setCursor(0, 0);
  lcd.print("Smart Counter");
  delay(1000);
  lcd.clear();
}

void loop() {

  int addState = digitalRead(buttonAdd);
  int subState = digitalRead(buttonSub);

  // ============================
  //       TOMBOL TAMBAH
  // ============================
  if (lastAddState == HIGH && addState == LOW) {
    count++;
    updateLCD();
    delay(200); // debouncing
  }

  // ============================
  //      TOMBOL KOMURANG
  // ============================
  if (lastSubState == HIGH && subState == LOW) {
    if (count > 0) {        // agar tidak minus
      count--;
    }
    updateLCD();
    delay(200);
  }

  lastAddState = addState;
  lastSubState = subState;
}

// =====================================
//      FUNGSI UNTUK UPDATE TAMPILAN
// =====================================
void updateLCD() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Jumlah: ");
  lcd.print(count);

  lcd.setCursor(0, 1);

  if (count >= 10) {
    lcd.print("Ruangan Penuh!");
  } else {
    lcd.print("Ruangan Tersedia");
  }
}