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

// **Konfigurasi LCD**
LiquidCrystal_I2C lcd(0x27, 16, 2);

// **Konfigurasi Keypad**
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};
byte colPins[COLS] = {5, 4, 3, 2};
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

// **Konfigurasi Servo dan Buzzer**
Servo servos[5];
int servoPins[5] = {10, 11, 12, 13, 45};
const int buzzerPin = 44;

// **Harga Item**
int prices[5] = {25000, 28000, 30000, 33000, 35000};

// **Variabel Global**
int uangMasuk = 0;
int selectedItem = -1;

void setup() {
  lcd.init();
  lcd.backlight();

  for (int i = 0; i < 5; i++) {
    servos[i].attach(servoPins[i]);
    servos[i].write(0);
  }
  pinMode(buzzerPin, OUTPUT);

  Serial.begin(9600);
}

void loop() {
  uangMasuk = analogRead(A0);
  uangMasuk = map(uangMasuk, 0, 1023, 0, 50000);

  lcd.setCursor(0, 0);
  lcd.print("Uang: Rp ");
  lcd.print(uangMasuk);
  lcd.print("    ");

  char key = keypad.getKey();
  if (key) {
    if (key >= '1' && key <= '5') {
      selectedItem = key - '1';
      lcd.setCursor(0, 1);
      lcd.print("Item: ");
      lcd.print(selectedItem + 1);
      lcd.print(" Harga: ");
      lcd.print(prices[selectedItem]);

      if (uangMasuk >= prices[selectedItem] - 500 && uangMasuk <= prices[selectedItem] + 500) {
        int kembalian = uangMasuk - prices[selectedItem];
        delay(1000);
        keluarkanItem(selectedItem);
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Kembalian: Rp ");
        lcd.print(kembalian);
        delay(3000);
      } else {
        lcd.setCursor(0, 1);
        lcd.print("Uang Tidak Cukup");
        delay(2000);
      }
      resetTransaksi();
    }
  }
}

void keluarkanItem(int item) {
  servos[item].write(90);
  tone(buzzerPin, 1000, 200);
  delay(1000);
  servos[item].write(0);
}

void resetTransaksi() {
  uangMasuk = 0;
  selectedItem = -1;
}