#!/usr/bin/env python
import io
import serial
import re
import sys

class VzwModem:
  def __init__(self, sport):
    self.current_message = ''
    self.ser = serial.Serial(sport, 115200)

  def wait_for(self, message, timeout = None):
    self.ser.timeout = timeout
    self.current_message = ''
    while not self.current_message.endswith(message):
      c = self.ser.read()
      if c != '':
        self.current_message += c
      else:
        print "Timeout waiting for " + message
        return False
    self.ser.flushInput()
    return True

  def send(self, message):
    self.ser.write(message + "\r")

  def connect(self):
    self.send("AT$NWQMICONNECT=,,,,,,vzwinternet")
    self.wait_for("OK", 5)

  def disconnect(self):
    self.send("AT$NWQMIDISCONNECT")
    self.wait_for("OK", 2)

  def connected(self):
    self.send("AT$NWQMISTATUS")
    self.ser.timeout = 2
    stat = self.ser.readlines()[2]
    return re.search(r": ([A-Z]+)\r\n", stat).group(1) == "CONNECTED"

if __name__ == "__main__":
  v = VzwModem('/dev/modem')
  if sys.argv[1] == "up":
    if not v.connected():
      v.connect()
  elif sys.argv[1] == "down":
    if v.connected():
      v.disconnect()
  elif sys.argv[1] == "status":
    print ("Connected" if v.connected() else "Disconnected")
  else:
    print "Usage:  " + __file__ + " [ up | down | status ]"
    sys.exit(1)