#include "Arduino.h"
#include "SL015M.h"

SL015M::SL015M()
{
    card = 0;
    rfcmdsent = false;
    rf_i = 0;
    pinset = false;
    readcmd = false;
}

void SL015M::setPins(int sensor, HardwareSerial* serialid)
{
    rfSENSOR = sensor;
    rfSerial = serialid;

    pinMode(rfSENSOR,INPUT);                            // Rfid sensor
    rfSerial->begin(RFID_BAUD);

    pinset=true;

}

void SL015M::update()
{
    if (!pinset)
        return;
    if (!readcmd)
        return;

    if (digitalRead(rfSENSOR)==LOW)            // card presence
    {

        if (!rfcmdsent)
        {

            rfSerial->write(0xBA);                  // pream
            rfSerial->write(0x02);                  // size
            rfSerial->write(0x31);                  // rfidcommand: get tag info
            rfSerial->write(0xBA ^ 0x02 ^ 0x31);    // checksum

            rf_i = 0;
            rfcmdsent= true;
            timesent = millis();
        }
        else // if command has been sent, let's read answer
        {

            if (rfSerial->available()>0)
            {

                rfidp[rf_i] = rfSerial->read();
                rf_i++;

                if (rfidp[0] != 0xBD)                // restart filling buffer from begining until received byte is 0xBD (preamb)
                    rf_i = 0;

                if (rf_i>2)                          // if we know paquet length
                {

                    byte length = rfidp[1];
                    if (rf_i >= length + 2)            // if paquet complete
                    {

                        // checksum check
                        byte chk = 0x00;
                        for (int i=0;i< length+1;i++)
                            chk ^= rfidp[i];

                        if (chk != rfidp[length+1])
                        {
                            rfcmdsent = false;             // checksum error, send cmd again
                        }
                        else
                        {
                            if (rfidp[3]!=0x00)            // Operation not succeeded
                            {
                                rfcmdsent = false;           // error, send again
                            }
                            else
                            {

                                //success, let's copy the uid
                                for (int i=0;i<8;i++)
                                {
                                    uid[i] = rfidp[11-i];
                                }

                                if (uid[0] == 0xE0 && uid[1] == 0x04) // if correct konami card
                                    card = 1;
                                else
                                    card = 0;

                                readcmd = false;//reading finished (card found)

                            }
                        }
                    }
                }
            }
            else
            {
                // command sent, but nothing to receive
                if (millis() - timesent >500)        // if last command was sent more than 500ms ago, send a new one
                    rfcmdsent = false;
            }
        }
    }
    else // if no tag in range
    {
        card = 0;
        rfcmdsent = false;
        readcmd = false;//reading finished (no card found)
    }
}

byte SL015M::isCardPresent()
{
    return card;
}

void SL015M::read()
{
    readcmd=true;
}

void SL015M::getUID(byte* uida)
{
    memcpy(uida,uid,8);
}