#include <SPI.h>
#include <Wire.h>
#include <MFRC522.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define RST_PIN 13   
#define SS_PIN 5     
MFRC522 mfrc522(SS_PIN, RST_PIN);

Adafruit_SSD1306 display(
  SCREEN_WIDTH,
  SCREEN_HEIGHT,
  &Wire,
  -1
);

int buzzer = 25;
int led = 4;
int autorizado = 0;

byte tarjetaAutorizada[] = {0X11, 0X22, 0X33, 0X44};

void setup() {
  Serial.begin(115200);
  pinMode(buzzer, OUTPUT);
  pinMode(led, OUTPUT);

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    while (true);
  }

  SPI.begin();
  mfrc522.PCD_Init();

  display.clearDisplay();

  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);

  display.setCursor(0,0);

  display.print("Waiting for card...");

  display.display();
}

void loop() {
  digitalWrite(led, LOW);
  display.clearDisplay();
  display.setCursor(0, 0);
  display.print("Waiting for card...");
  display.display();

  if (mfrc522.PICC_IsNewCardPresent() && mfrc522.PICC_ReadCardSerial()){

    autorizado = 1;

    for (byte i = 0; i < mfrc522.uid.size; i++) {
      if (mfrc522.uid.uidByte[i] != tarjetaAutorizada[i]) {
        autorizado = 0;
        break;
      }
    
    Serial.print(mfrc522.uid.uidByte[i], HEX);
    Serial.print(" ");
    }

    Serial.println();

    mfrc522.PICC_HaltA();
    mfrc522.PCD_StopCrypto1();

    display.clearDisplay();
    display.setCursor(0, 0);

    if (autorizado){
      display.print("access    ");
      display.print("granted.");
      digitalWrite(led, HIGH);
      tone(buzzer,1000,10);
      display.display();
      delay(2000);
    }
    else {
      display.print("card is   ");
      display.print("too low   ");
      display.print("level.");
      digitalWrite(led, LOW);
      tone(buzzer,500,10);
      display.display();
      delay(2000);
    }
  }
  delay(10);
}