#include <SPI.h>
#include <MFRC522.h>

// RFID
#define SS_PIN 5
#define RST_PIN 22
MFRC522 rfid(SS_PIN, RST_PIN);

// Buzzer
#define BUZZER 26

// Isi ini dengan UID dari kartu yang kamu scan
String MASTER_UID = "01020304";

void setup() {
  Serial.begin(115200);
  delay(500);

  SPI.begin();          // default SPI Wokwi
  rfid.PCD_Init();

  pinMode(BUZZER, OUTPUT);
  digitalWrite(BUZZER, LOW);

  Serial.println("System Ready - Tempel kartu");
}

void loop() {
  if (!rfid.PICC_IsNewCardPresent()) return;
  if (!rfid.PICC_ReadCardSerial()) return;

  String uid = "";
  for (byte i = 0; i < rfid.uid.size; i++) {
    if (rfid.uid.uidByte[i] < 0x10) uid += "0";
    uid += String(rfid.uid.uidByte[i], HEX);
  }
  uid.toUpperCase();

  Serial.print("UID: ");
  Serial.println(uid);

  if (uid == MASTER_UID) {
    Serial.println("ACCESS GRANTED");
    tone(BUZZER, 2000, 300);
    delay(500);
  } else {
    Serial.println("ACCESS DENIED");
    tone(BUZZER, 500, 800);
    delay(800);
  }

  rfid.PICC_HaltA();
  rfid.PCD_StopCrypto1();
}