#!/usr/bin/env python3

import serial
import sys
import time
import os

MAX_TRY = 5
tries = 0
SERIAL_DEV = '/dev/ttyACM0'

while not os.path.exists(SERIAL_DEV):
    time.sleep(1)

ser = serial.Serial(SERIAL_DEV, 115200, timeout=0.5)

def execute_and_check(cmd):
    global tries
    ser.flushInput()
    ser.write(cmd)
    ser.write(b'\r')
    s = ser.read_until(b'OK')
    if b'OK' not in s:
        print("Failed cmd : " + str(cmd))
        print("Output: " + str(s))
        tries += 1
        if tries < MAX_TRY:
            time.sleep(1)
            execute_and_check(cmd)
        else:
            sys.exit(-1)
        tries = 0


print("Setting up bridge mode")
execute_and_check(b'AT+UBMCONF=2')


print("Setting up USB mode to ECM")
execute_and_check(b'AT+UUSBCONF=2,"ECM",0')


print("Resetting modem")
ser.write(b'AT+CFUN=16\r')

ser.close()

# Wait until modem rebooted
while True:
    dirs = os.listdir("/dev")
    for file in dirs:
        if file == 'ttyACM2':
            sys.exit(0);
    time.sleep(1)