wifi-switch

#!/usr/bin/env python3

import subprocess
import shlex
import time
from RPi import GPIO

CLIENT_MODE = 19
AP_MODE = 26

def run(program):
    proc = subprocess.Popen(shlex.split(program), stderr=subprocess.PIPE, stdout=subprocess.PIPE)
    return proc.communicate()[0].decode()

def is_connected(dev):
    data = run('/bin/ip link show').splitlines()
    for line in data:
        if '{}:'.format(dev) in line:
            return True
    else:
        return False

def remove_ip(dev):
    run('/bin/ip addr flush dev {}'.format(dev))

def set_ip(dev, ip):
    run('/bin/ip add add dev {dev} {ip}/24'.format(dev=dev, ip=ip))

def kill_wpa():
    run('/usr/bin/pkill -9 wpa_supplicant')

def start_dhclient(dev):
    run('/sbin/dhclient -nw {}'.format(dev))

def kill_dhclient():
    run('pkill -9 dhclient')

def kill_hostapd():
    run('/bin/systemctl stop hostapd')

def dnsmasq(action):
    run('/bin/systemctl {} dnsmasq'.format(action))

def kill(dev):
    dnsmasq('stop')
    kill_dhclient()
    kill_wpa()
    kill_hostapd()
    remove_ip(dev)


def client(dev, conf):
    if is_connected(dev):
        kill(dev)
        time.sleep(1)
        cmd = '/sbin/wpa_supplicant -Dnl80211 -i{dev} -c {conf} -B'.format(dev=dev, conf=conf)
        run(cmd)
        start_dhclient(dev)

def ap(dev):
    if is_connected(dev):
        kill(dev)
        #cmd = '/usr/sbin/hostapd /etc/hostapd/hostapd.conf -B'
        cmd = '/bin/systemctl start hostapd'
        run(cmd)
        set_ip(dev, '192.168.0.254')
        dnsmasq('start')

def status(ap_mode, client_mode):
    if ap_mode:
        print("Activating Access Point Mode")
        ap('wlan0')
    elif client_mode:
        print("Activating Client Mode")
        client('wlan0', '/home/server/China2.conf')
    else:
        print('Switch is not connected')
        print('Starting Access Point Mode')
        ap('wlan0')

class Switch:
    def __init__(self, callback):
        GPIO.setmode(GPIO.BCM)
        GPIO.setup(AP_MODE, GPIO.IN, GPIO.PUD_UP)
        GPIO.setup(CLIENT_MODE, GPIO.IN, GPIO.PUD_UP)
        self.ap_mode = GPIO.input(AP_MODE)
        self.client_mode = GPIO.input(CLIENT_MODE)
        self.callback = callback
        self.callback(self.ap_mode, self.client_mode)

    def update(self):
        ap_mode = GPIO.input(AP_MODE)
        client_mode = GPIO.input(CLIENT_MODE)
        #print('AP: {}\tCLIENT: {}'.format(ap_mode, client_mode))
        if ap_mode != client_mode:
            if ap_mode != self.ap_mode or client_mode != self.client_mode:
                self.ap_mode = ap_mode
                self.client_mode = client_mode
                self.callback(ap_mode, client_mode)


    def run(self):
        while True:
            self.update()
            time.sleep(2)


if __name__ == '__main__':
    switch = Switch(status)
    switch.run()