import nfc
from time import sleep
import sys
from datetime import datetime

def writeUID(UID):
	if len(sys.argv) >= 2:
		filename = str(sys.argv[1])
	else:
		filename = "nfclog.txt"
	f = open(filename, "a")
	todayandnow = datetime.now()
	f.write(todayandnow.strftime('%Y-%m-%d %H:%M:%S') + " " + UID + "\n")
	f.flush()

def connected(tag):
    #print(tag.type)
    if isinstance(tag, nfc.tag.tt1.Type1Tag):
        writeUID(str(tag.uid).encode("hex"))
    elif isinstance(tag, nfc.tag.tt2.Type2Tag):
        writeUID(str(tag.uid).encode("hex"))
    elif isinstance(tag, nfc.tag.tt3.Type3Tag):
        writeUID(str(tag.idm).encode("hex"))
    elif isinstance(tag, nfc.tag.tt4.Type4Tag):
        writeUID(str(tag.uid).encode("hex"))
    else:
        print("Error, unknown tag type or false read")

clf = nfc.ContactlessFrontend('usb')
clf.connect(rdwr={'on-connect': connected})