#include <Wire.h> 
#include <SPI.h>
#include <MFRC522.h>              // https://github.com/miguelbalboa/rfid
#include <LiquidCrystal_I2C.h>

const int RST_PIN   = 13;         // Configurable, see typical pin layout above
const int SS_1_PIN  = 32;         // Configurable, take a unused pin, only HIGH/LOW required, must be diffrent to SS 2 /3
const int SS_2_PIN  = 33;         // Configurable, take a unused pin, only HIGH/LOW required, must be diffrent to SS 1 / 3
const int Relay_1   = 25;
const int Relay_2   = 26;

#define NR_OF_READERS   2         // How many readers you have?

byte ssPins[] = {SS_1_PIN, SS_2_PIN};

MFRC522 mfrc522[NR_OF_READERS];   // Create MFRC522 instance.
LiquidCrystal_I2C lcd0(0x26, 16, 2);
LiquidCrystal_I2C lcd1(0x27, 16, 2);

String currentIDs[] = {"00000000", "00000000", "00000000"}; // Current ID's, changes as you play
String correctIDs[] = {"d745b819", "57d85d9",  "55fce42a"}; // Which ID's are correct? , stays constant as it checks this with the current ID's

void setup() {
  //Protocol Configuration
  Serial.begin(9600); // Initialize serial communications with the PC
  SPI.begin();        // MFRC522 Hardware uses SPI protocol
  lcd0.begin();
  lcd1.begin();
  
  Serial.println(F("Scan Your Card"));
  // Turn on the blacklight and print a message.
  lcd0.backlight(); lcd1.backlight();
  lcd0.print(F("Welcome")); lcd1.print(F("Welcome"));

  //Arduino Pin Configuration
  pinMode(Relay_1, OUTPUT);
  pinMode(Relay_2, OUTPUT);

  //Be careful how relay circuit behave on while resetting or power-cycling your Arduino
  digitalWrite(Relay_1, HIGH);  // Make sure door is locked
  digitalWrite(Relay_2, HIGH);
}

void loop() {
  for (uint8_t reader = 0; reader < NR_OF_READERS; reader++) {
    currentIDs[reader] = "00000000";
    digitalWrite(reader + 1, HIGH);
    delay(40);
    mfrc522[reader].PCD_Init(ssPins[reader], RST_PIN); // Init each MFRC522 card
    delay(40);
    
    if (mfrc522[reader].PICC_IsNewCardPresent() && mfrc522[reader].PICC_ReadCardSerial()) {
      currentIDs[reader] = getCode(mfrc522[reader].uid.uidByte, mfrc522[reader].uid.size);
      mfrc522[reader].PICC_HaltA();
      mfrc522[reader].PCD_StopCrypto1();
    }
    digitalWrite(reader + 2, LOW);
  }

  // Print out the current ID's
  Serial.print(currentIDs[0]);
  Serial.print(" , ");
  Serial.println(currentIDs[1]);
  
  if (currentIDs[0] == correctIDs[0]) { // If frst ID is correct
    lcd0.clear();
    lcd0.print(F("Access Locker 1"));
    digitalWrite(Relay_1,LOW);
    Serial.print(F("Acces 1 OK"));
    Serial.print(" , ");
  }
  else if (currentIDs[0] == correctIDs[2]) { // If frst ID is correct
    lcd0.clear();
    lcd0.print(F("Master Card"));
    digitalWrite(Relay_1,LOW);
    Serial.print(F("Acces 1 OK"));
    Serial.print(" , ");
  }
  else{
    lcd0.clear();
    lcd0.print(F("Scan Your Card!"));
    digitalWrite(Relay_1,HIGH);
  }

  if (currentIDs[1] == correctIDs[1]) { // If second ID is correct
    lcd1.clear();
    lcd1.print(F("Access Locker 2"));
    digitalWrite(Relay_2,LOW);
    Serial.print(F("Acces 2 OK"));
    Serial.print(" , ");
  }
  else if (currentIDs[1] == correctIDs[2]) { // If second ID is correct
    lcd1.clear();
    lcd1.print(F("Master Card"));
    digitalWrite(Relay_2,LOW);
    Serial.print(F("Acces 2 OK"));
    Serial.print(" , ");
  }
  else{
    lcd1.clear();
    lcd1.print(F("Scan Your Card!"));
    digitalWrite(Relay_2,HIGH);
  }
}

String getCode(byte *buffer, byte bufferSize) {
  String code = "";
  for (byte i = 0; i < bufferSize; i++) code = code + String(buffer[i], HEX);
  return (code);
}