import nfc, nfc.snep
import threading
import argparse

def send_uri(llc, uri):
    snep = nfc.snep.SnepClient(llc)
    snep.put(nfc.ndef.Message(nfc.ndef.UriRecord(uri)))

class Main(object):
    def __init__(self):
        parser = argparse.ArgumentParser()
        parser.add_argument("address", help="bitcoin receiver address")
        parser.add_argument("amount", type=float, help="amount to send")
        args = parser.parse_args()
        self.uri = "bitcoin:{address}?amount={amount}".format(
            address=args.address, amount=args.amount)

    def on_connect(self, llc):
        threading.Thread(target=send_uri, args=(llc, self.uri)).start()
        return llc

    def run(self):
        clf = nfc.ContactlessFrontend('usb')
        clf.connect(llcp={'on-connect': self.on_connect})
        
if __name__ == '__main__':
    Main().run()