wifi_switch.py

#!/usr/bin/env python3

import time
from pathlib import Path
from threading import Timer
from subprocess import call, check_output

import wlanpw

from netifaces import ifaddresses, AF_INET
from gpiozero import (
    Button,
    Buzzer,
    LED,
)

import setapname


setapname.main()

AP = "ap0"
CLIENT = "wlan0"
MODES = (AP, CLIENT)
WIFI_MODE = Path("/media/data/wifi_mode")


def set_mode(mode: str):
    """
    Write mode ap0 or wlan0 to file wifi_mode
    """
    if mode in MODES:
        WIFI_MODE.write_text(f"{mode}\n")


def get_mode():
    """
    Get the current mode from file wifi_mode and return it.
    If the file does not exist, AP mode is written to the file
    and returned.
    """
    mode = "ap0"
    if not WIFI_MODE.exists():
        set_mode(AP)
    else:
        mode = WIFI_MODE.read_text().strip()
        if mode not in MODES:
            set_mode(AP)
            mode = AP
    return mode


def start_hotspot():
    call(["ifdown", "wlan0"])
    call(["systemctl", "start", "wlan-ap"])
    call(["ifup", "ap0"])
    call(["systemctl", "start", "hostapd"])
    call(
        ["ip", "route", "add", "default", "via", "192.168.0.1", "dev", "ap0",]
    )


def start_client():
    call(
        ["ip", "route", "del", "default", "via", "192.168.0.1", "dev", "ap0",]
    )
    call(["systemctl", "stop", "hostapd"])
    call(["ifdown", "ap0"])
    # call(["systemctl", "start", "wlan-ap-del"])
    call(["ifup", "wlan0"])


class State:
    def __init__(self, initial: str):
        self._state = initial

    @property
    def state(self) -> str:
        return self._state

    @state.setter
    def state(self, value) -> None:
        value = value.strip()
        if value not in MODES:
            raise ValueError('Only "ap0" or "wlan0" is allowed')
        if value != self._state:
            if value == AP:
                led.off()
                start_hotspot()
                self._state = value
                buzzer.beep(1, 1, n=2)
            elif value == CLIENT:
                print("Connecting to hotspot")
                led.blink(0.1, 0.1)
                start_client()
                self._state = value
                buzzer.beep(0.5, 0.5, n=2)
                led.blink(0.1, 2)
                try:
                    ips = ifaddresses(CLIENT).get(AF_INET, [])
                    hosts = Path("/media/data/hosts.custom")
                    hostname = check_output(["hostname"], encoding="utf8")
                    with hosts.open("w") as fd:
                        for ip in ips:
                            fd.write(f'{ip.get("addr")}    {hostname}\n')
                except Exception as e:
                    print(repr(e))

    def switch(self):
        self.state = CLIENT if self.state == AP else AP


class SuperButton:
    def __init__(self, wifi_mode):
        self.button = Button(13, pull_up=True, bounce_time=0.1, hold_time=0.3)
        self.button.when_held = self.callback
        self.state = State(wifi_mode)
        self.count = 0
        self.timeout = None

    def callback(self):
        if self.timeout is None or time.time() > self.timeout:
            self.count = 1
            buzzer.beep(0.5, 0.5, n=1)
        else:
            self.count += 1
            buzzer.beep(0.1, 0.1, n=1)
        self.timeout = time.time() + 2.0
        print(self.count)
        Timer(interval=5, function=self.act, args=[self.count]).start()

    def act(self, n):
        print("ACT:", self.count, n)
        if self.count == n == 1:
            self.state.switch()
        elif self.count == n == 3:
            call(["shutdown", "-h", "0"])
        elif self.count == n == 5:
            wlanpw.reset()


if __name__ == "__main__":
    buzzer = Buzzer(5)
    led = LED(6)
    initial_mode = get_mode()
    if initial_mode == AP:
        start_hotspot()
        buzzer.beep(1, 1, n=2)
    elif initial_mode == CLIENT:
        start_client()
        buzzer.beep(0.5, 0.5, n=2)
        led.blink(0.1, 2)
    switch = SuperButton(initial_mode)
    while True:
        time.sleep(10)