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

#define SS_PIN 10
#define RST_PIN 9

#define GREEN_LED 4
#define RED_LED 5
#define SERVO_PIN 6

MFRC522 mfrc522(SS_PIN, RST_PIN);
Servo gateServo;

// CHANGE THIS TO YOUR CARD UID
byte authorizedUID[] = {0x11, 0x22, 0x33, 0x44};

void setup() {
  Serial.begin(9600);
  SPI.begin();
  mfrc522.PCD_Init();

  pinMode(GREEN_LED, OUTPUT);
  pinMode(RED_LED, OUTPUT);

  gateServo.attach(SERVO_PIN);
  gateServo.write(0); // Gate closed

  Serial.println("RFID Gate System Ready");
}

void loop() {
  if (!mfrc522.PICC_IsNewCardPresent()) return;
  if (!mfrc522.PICC_ReadCardSerial()) return;

  Serial.print("UID: ");
  for (byte i = 0; i < mfrc522.uid.size; i++) {
    Serial.print(mfrc522.uid.uidByte[i], HEX);
    Serial.print(" ");
  }
  Serial.println();

  if (isAuthorized()) {
    accessGranted();
  } else {
    accessDenied();
  }

  mfrc522.PICC_HaltA();
}

bool isAuthorized() {
  if (mfrc522.uid.size != 4) return false;

  for (byte i = 0; i < 4; i++) {
    if (mfrc522.uid.uidByte[i] != authorizedUID[i]) {
      return false;
    }
  }
  return true;
}

void accessGranted() {
  Serial.println("Access Granted");
  digitalWrite(GREEN_LED, HIGH);
  digitalWrite(RED_LED, LOW);

  gateServo.write(90); // Open gate
  delay(3000);

  gateServo.write(0); // Close gate
  delay(500);

  digitalWrite(GREEN_LED, LOW);
}

void accessDenied() {
  Serial.println("Access Denied");
  digitalWrite(RED_LED, HIGH);
  delay(2000);
  digitalWrite(RED_LED, LOW);
}