#include <util/delay.h>
  #include <avr/io.h>

  #include "PN532.h"

  #include <PN532_SPI/PN532_SPI.h>

  #define	MODEL_QUERY			0x80
  #define	SERIAL_ERROR		0x55
  #define	NFC_TAGQUERY		0x82
  #define	NFC_TAGQUERY_UID	0x84
  #define	NFC_ARDUINO			0x02
  #define	NFC_NOTAG			0x81

  #define	NFC_TYPE_PROFESSOR	0x04

  #define	NFC_TYPE_STUDENT	0x01

  #define	CPU_FREQ			16000000L

  
  boolean	tagDetected;
  boolean	tagType;
  

  PN532_SPI pn532spi(SPI, 10);
  PN532 nfc(pn532spi);
  

  void init_serial(int speed)
  {
  	UBRR0 = CPU_FREQ/(((unsigned long int)speed)<<4)-1;
  	UCSR0B = (1<<TXEN0 | 1<<RXEN0);
  	UCSR0C = (1<<UCSZ01 | 1<<UCSZ00);
  	UCSR0A &= ~(1 << U2X0);
  }
  
  void send_serial(unsigned char c)
  {
  	loop_until_bit_is_set(UCSR0A, UDRE0);
  	UDR0 = c;
  }
  
  unsigned char get_serial(void)
  {
  	loop_until_bit_is_set(UCSR0A, RXC0);
  	return UDR0;
  }
  
  

  void setup(void)
  {
  	int ser;
  

  	init_serial(9600);

  	send_serial('1');

  	nfc.begin();
  

  	send_serial('2');

  	uint32_t versiondata = nfc.getFirmwareVersion();

  	if(!versiondata)

  	{

  		send_serial(SERIAL_ERROR);

  		while (1);

  	}  
  

  	send_serial('3');

  	nfc.SAMConfig();
    

  	tagDetected = false;
  
  	do
  	{

  		ser = get_serial();

  		if(ser == MODEL_QUERY)

  			send_serial(NFC_ARDUINO);

  		else

  			send_serial(SERIAL_ERROR);

  	}while(ser != MODEL_QUERY);

  }
  
  
  void loop(void)
  {
  	uint8_t success;

  	uint8_t uid[] = { 0, 0, 0, 0, 0, 0, 0 };
  	uint8_t uidLength;
  	uint8_t data1[16];
  	uint8_t data2[16];

          char  professorTag[7];
          char  studentTag[9];

  	int ser;

  	success = nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, uid, &uidLength);

  
  	if(success && !tagDetected)

  	{

  		if(uidLength == 4)
  		{

  			uint8_t keya[6] = { 0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5 };

  			success = nfc.mifareclassic_AuthenticateBlock(uid, uidLength, 44, 0, keya);  

  			if(success)
  			{

  				success = nfc.mifareclassic_ReadDataBlock(44, data1);

  		
  				if(success)
  				{

  					//nfc.PrintHexChar(data1, 16);
  					success = nfc.mifareclassic_ReadDataBlock(45, data2);
  
  					if(success)
  					{
  						tagDetected = true;
  						if(data1[4] == data1[15] &&
  						data1[5] == data2[0] &&
  						data1[6] == data2[1] &&
  						data1[7] == data2[2] &&
  						data1[8] == data2[3] &&
  						data1[9] == data2[4])
  						{
  							tagType = NFC_TYPE_PROFESSOR;

  							professorTag[0] = (char) 48 + data1[4];
  							professorTag[1] = (char) 48 + data1[5];
  							professorTag[2] = (char) 48 + data1[6];
  							professorTag[3] = (char) 48 + data1[7];
  							professorTag[4] = (char) 48 + data1[8];
  							professorTag[5] = (char) 48 + data1[9];

  						}
  						else
  						{
  							tagType = NFC_TYPE_STUDENT;

  							studentTag[0] = (char) 48 + data1[15];
  							studentTag[1] = (char) 48 + data2[0];
  							studentTag[2] = (char) 48 + data2[1];
  							studentTag[3] = (char) 48 + data2[2];
  							studentTag[4] = (char) 48 + data2[3];
  							studentTag[5] = (char) 48 + data2[4];
  							studentTag[6] = (char) 48 + data2[5];
  							studentTag[7] = (char) 48 + data2[6];

  						}
  					}

  				}
  			}

  		}

  	}
  	else if(tagDetected)
  	{

  		ser = get_serial();

  		if(ser == NFC_TAGQUERY)

  			send_serial(tagType);

  		else if(ser == NFC_TAGQUERY_UID)

  		{

                      if(tagType == NFC_TYPE_STUDENT)
                      {/*
                          Serial.print((char) studentTag[0]);
  						Serial.print((char) studentTag[1]);
                          Serial.print((char) studentTag[2]);
  						Serial.print((char) studentTag[3]);
                          Serial.print((char) studentTag[4]);
  						Serial.print((char) studentTag[5]);
                          Serial.print((char) studentTag[6]);
  						Serial.print((char) studentTag[7]);*/
                          send_serial(0x10);
  						send_serial(0x20);
                          send_serial(0x30);
  						send_serial(0x40);
                          send_serial(0x50);
  						send_serial(0x60);
  	                    send_serial(0x70);
  						send_serial(0x80);
                      }
                      else
                      {
                          send_serial(professorTag[0]);
                      }
  		    tagDetected = false;

  		}

  		else

  			send_serial((char) SERIAL_ERROR);

  	}
  	else
  	{

  		if(get_serial() == NFC_TAGQUERY)
  			send_serial(NFC_NOTAG);

  	}
  }

  
  int main(void)
  {
  	setup();
  
  	while(1)
  		send_serial('Y');
  		//loop();
  
  	return 0;
  }