#!/usr/bin/python
import requests
import sys,json,os
#find current ip address of preferred NIC
routes = json.loads(os.popen("ip -j -4 route").read())
for r in routes:
    if r.get("dev") == "wlan0" and r.get("prefsrc"):
        ip = r['prefsrc']
        continue
bcast=ip.split(".")
bcastAdd = bcast[0] + "." + bcast[1] + "." + bcast[2] + ".255" #broadcast address
bcastport = 4001 #whatever port is required
#############login and get a key
session = requests.session()
URL = 'http://localhost:3000/signalk/v1/auth/login' 
login_data = {
    'action': 'login',
    'username': 'admin',
    'password': 'secretPassword!'
}
r = session.post(URL,data=login_data)
jauthkey=session.cookies.get_dict()['JAUTHENTICATION']
######################

#update UDP NMEA0183 with what might be a new address.
headers = {"Cookie":"JAUTHENTICATION=" + jauthkey,"content-type":"application/json"}#credentials fetched from above.
destinations = {"configuration":{"destinations":[{"broadcastAddress": bcastAdd,"port": bcastport,"nmea0183": True,"nmea0183out": False,"lineDelimiter": "None"}]},"enabled": True}
s = session.post('http://127.0.0.1:3000/skServer/plugins/udp-nmea-sender/config',json = destinations,headers=headers)
print(s.text)