#include <SPI.h> 
//#include <MFRC522.h> 
#include <Wire.h>
#include <LiquidCrystal_I2C.h> 
#include <Keypad.h>
#include<EEPROM.h>
 
int relPin;
int state=0; 
byte  COD[10]; 
byte  AUX[10]; 
int k=0; 
String accessCode="*123456#";
String codpairing="*654321#"; 
//NFC 
//#define RST_PIN   9 
//#define SS_PIN 10    
//MFRC522 mfrc522(SS_PIN, RST_PIN);   // Create MFRC522 instance 
//#define NEW_UID {0xDE, 0xAD, 0xBE, 0xEF} 
//MFRC522::MIFARE_Key key;
 
//lcd
LiquidCrystal_I2C lcd(0x27,16,2);
  
//KEYPAD
const byte numRows= 4; //number of rows on the keypad
const byte numCols= 4; //number of columns on the keypad
 
char keymap[numRows][numCols]=
{
{'1', '2', '3', 'A'},
{'4', '5', '6', 'B'},
{'7', '8', '9', 'C'},
{'*', '0', '#', 'D'}
};
 
//Code that shows the the keypad connections to the arduino terminals 
byte rowPins[numRows] = {2,3,4,5}; //Rows 0 to 3
byte colPins[numCols]= {A0,7,8,9}; //Columns 0 to 3
 
//initializes an instance of the Keypad class
Keypad myKeypad= Keypad(makeKeymap(keymap), rowPins, colPins, numRows, numCols);
  
void setup() {
  pinMode(A0,OUTPUT);
  digitalWrite(A0,HIGH);
  pinMode(A3,OUTPUT);
  digitalWrite(A3,HIGH);
  pinMode(A1,OUTPUT);
  digitalWrite(A1,HIGH);
  pinMode(A2,OUTPUT);
  digitalWrite(A2,LOW);
  //NFC
  //Serial.begin(9600);  // Initialize serial communications with the PC
  //while (!Serial);  // Do nothing if no serial port is opened
  //SPI.begin(); // Init SPI bus
 //mfrc522.PCD_Init();     // Init MFRC522 card
 
 //for (byte i = 0; i < 6; i++) {        
//key.keyByte[i] = 0xFF;
 //}
//lcd.init();
//lcd.backlight();
//lcd.setCursor(0,0);
//lcd.clear();
//lcd.print( "BLOCKED" );
//}
 
//void  readNFC(){   // This function will read the code stored on  
 //for (byte i =0; i<(mfrc522.uid.size); i++) {  // the  UID
   //COD[i]=mfrc522.uid.uidByte[i];
 //}
 //Serial.print("COD");
 //Serial.print(COD[0]);
 //Serial.print(COD[1]);
 //Serial.print(COD[2]);
 //Serial.print(COD[3]);
//}
 
//void pairNFC(){
 //Serial.println("COD in pair");
 //Serial.print(COD[0]);
 //Serial.print(COD[1]);
 //Serial.print(COD[2]);
 //Serial.print(COD[3]);
  //long  r=0;
  //int c=0;
  //for(int i=1;i<=EEPROM.read(0);i++){                       //The UID cannot be stored on
//switch(i%4){                                                     // one variable, it was needed to be
      //case 1 :{AUX[0]=EEPROM.read(i); break;}     // split
     // case 2 :{AUX[1]=EEPROM.read(i); break;}
      //case 3 :{AUX[2]=EEPROM.read(i); break;}
      //case 0 :{AUX[3]=EEPROM.read(i); break;}
}
//if((i)%4==0)
  // {Serial.println(r);
   // if( AUX[0]==COD[0] && AUX[1]==COD[1] && AUX[2]==COD[2] && AUX[3]==COD[3] ){                                      //Verify if the code is in EEPROM
    //     lcd.clear();
    //     lcd.setCursor(0,0);
    //     lcd.print("CODE ALREADY IN");
    //    lcd.setCursor(0,1);
//   lcd.print("SYSTEM");
     // delay(2000);
       //   c=1;
     // break;}
  //}
 // }
 
if(c==0){int aux2=EEPROM.read(0);
             Serial.println("CODE PAIRED");
Serial.print(COD[0]);
Serial.print(COD[1]);
Serial.print(COD[2]);
Serial.print(COD[3]);
 
         EEPROM.write(aux2+1,COD[0]);  //Writing code in EEPROM
         EEPROM.write(aux2+2,COD[1]);
         EEPROM.write(aux2+3,COD[2]);
         EEPROM.write(aux2+4,COD[3]);
 
         aux2=aux2+4; // Position for a new code
         Serial.println("aux2");
         Serial.println(aux2);
         EEPROM.write(0,0);
         EEPROM.write(0,aux2);    
         lcd.clear();
         lcd.setCursor(0,0);
         lcd.print("CODE PAIRED");
         delay(2000);}   
 }
 
boolean validationNFC(){
  boolean c=false;
  for(int i=1;i<=EEPROM.read(0);i++){   //Read the EEPROM
      switch(i%4){
      case 1 :{AUX[0]=EEPROM.read(i); break;}
      case 2 :{AUX[1]=EEPROM.read(i); break;}
      case 3 :{AUX[2]=EEPROM.read(i); break;}
      case 0 :{AUX[3]=EEPROM.read(i); break;}
    }
if((i)%4==0)
   {
    if( AUX[0]==COD[0] && AUX[1]==COD[1] && AUX[2]==COD[2] &&                AUX[3]==COD[3])
      c=true; //Verify if the code is in EEPROM and make flag=true;
     }
}       
  return c;  
}
 
int compareCODE(String a)    //We type a code on keypad and this will be compared
{ //with the accessCode;
 if(a.equals(accessCode))    
return 1;
 else if(a.equals(codpairing)) return 2;
 else return 0;  
}
 
String takeCode(char x) //Will display on the LCD the code typed
{ char vec[10];
 vec[0]=x;
 lcd.setCursor(0,0);
 lcd.clear();
 lcd.print('X');
 for(int i=1;i<8;i++)
    {vec[i]=myKeypad.waitForKey(); //Waits for 8 keys to be pressed and after that  
     lcd.print('X');} //is taking the decision
 vec[8]=0; //NULL
 String str(vec);
 return str;
}  
  void loop() {
  switch(state){
  case 0: {
    mfrc522.PCD_Init();
    if (  mfrc522.PICC_IsNewCardPresent() && mfrc522.PICC_ReadCardSerial() ){
    readNFC(); //It will read the card and it will search for UID in its
    if(validationNFC()) //memory
       { state=1;
        lcd.clear();
        lcd.setCursor(0,0);
lcd.print( "VALID NFC CODE" ); //The door will be opened
        delay(1000);
        return;
       }
    else{
         lcd.clear();
         lcd.setCursor(0,0);
         lcd.print( "INVALID NFC CODE" ); //If the code was wrongblocked
         delay(1000);
         lcd.setCursor(0,0);
         lcd.clear();
         lcd.print( "BLOCKED" );
         return;
        }
    }      
 
char c=myKeypad.getKey();
  if(c != NO_KEY){
 
String codcurent=takeCode(c);
int A=compareCODE(codcurent);
  if(A==0){                                //A is a variable that stores the current code
   lcd.clear();
   lcd.print("INVALID CODE");
   delay(2000);
    lcd.setCursor(0,0);
    lcd.clear();
    lcd.print("BLOCKED");
   return;
}
  if(A==1){
lcd.setCursor(0,0);
     lcd.clear();
   lcd.print( "VALID CODE " );
delay(2000);
   state = 1;
   return;
}
  if(A==2); {
state=2;
         lcd.clear();
         lcd.setCursor(0,0);
        lcd.print( " Pairing..." );
      delay(2000);
    return;}
  }
break;
  }
 case 1:{
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print( "UNLOCKED" );
    digitalWrite(A3,LOW);
    digitalWrite(A1,LOW); //The red LED will be off
    digitalWrite(A2,HIGH); //The green LED will be on
    tone(6,3000,5010); //The buzzer will make a sound
    delay(5000); //After 5 seconds the system will be blocked
    digitalWrite(A3,HIGH);
    digitalWrite(A1,HIGH);
    digitalWrite(A2,LOW);
    state=0;
    lcd.setCursor(0,0);
    lcd.clear();
    lcd.print( "BLOCKED" );
return;
    }
 
  case 2:{
   mfrc522.PCD_Init();
      if (  mfrc522.PICC_IsNewCardPresent() && mfrc522.PICC_ReadCardSerial() ){
      readNFC();
      pairNFC();
      state=0;
      delay(2000);
      lcd.clear();
      lcd.setCursor(0,0);
      lcd.print( "BLOCKED" );   }
break;
}
}
}