import logging
try:
    import MFRC522
except:
    logging.critical("Need MFRC522 Library to read RFID tags, disable RFID if no reader is present!")
    exit()
#import signal
import thread
import time
#from multiprocessing import Process 

class RFID:

    def __init__(self, callbackf):
        logging.info("RFID Reader initialized!")
        self.reader = MFRC522.MFRC522(spd=500000)
        #signal.signal(signal.SIGINT, self.stop)
        self.callback = callbackf
        self.loop = True
        if 1:
            thread.start_new_thread(self.read, ())
	else:
            p = Process(target=self.read, args=())
	    p.start()
	    p.join()

    def read(self):
        while True:
            while self.loop:
                (status, tagtype) = self.reader.MFRC522_Request(self.reader.PICC_REQIDL)
                logging.debug("RFID Status: " + str(status))
                if status == self.reader.MI_OK:
                    (status, uid) = self.reader.MFRC522_Anticoll()
                    if status == self.reader.MI_OK:
                        uids = "0x" + "".join(format(x, '02x') for x in uid)
                        logging.info("RFID Detect: " + uids)
                        self.stop()
                        self.callback(uids)
            while not self.loop:
                time.sleep(0.1)

    def start(self):
        logging.info("RFID reader started")
        self.loop = True

    def stop(self):
        logging.info("RFID reader stopped")
        self.loop = False