from __future__ import print_function

import logging

PORT = '/dev/ttyUSB2'
BAUDRATE = 115200
PIN = None # SIM card PIN (if any)

from gsmmodem import GsmModem
# from gsmmodem.modem import GsmModem

def handleSms(sms):
    print(u'== SMS message received ==\nFrom: {0}\nTime: {1}\nMessage:\n{2}\n'.format(sms.number, sms.time, sms.text))
    print('Replying to SMS...')
    sms.reply(u'SMS received: "{0}{1}"'.format(sms.text[:20], '...' if len(sms.text) > 20 else ''))
    print('SMS sent.\n')

def main():
    print('Initializing modem...')
    # Uncomment the following line to see what the modem is doing:
    logging.basicConfig(format='%(levelname)s: %(message)s', level=logging.DEBUG)
    modem = GsmModem(PORT, BAUDRATE, smsReceivedCallbackFunc=handleSms)
    modem.smsTextMode = False
    modem.connect(PIN)
    print('Waiting for SMS message...')
    try:
        modem.rxThread.join(2**31) # Specify a (huge) timeout so that it essentially blocks indefinitely, but still receives CTRL+C interrupt signal
    finally:
        modem.close();

if __name__ == '__main__':
    main()