dotfiles/os/wireless/apply.py

"""
Add the networks saved in wireless_networks to wpa_supplicant,
without restarting it or touching its config file.
"""

import json
import os
import re
import subprocess

NETWORKS_FILE = "/etc/keys/wireless_networks.json"


def wpa_cli(command: list[str]) -> list[bytes]:
    command.insert(0, "wpa_cli")
    process = subprocess.run(command, stdout=subprocess.PIPE)
    process.check_returncode()
    lines = process.stdout.splitlines()
    while lines[0].startswith(b"Selected interface"):
        lines.pop(0)
    return lines


network_numbers: dict[str, int] = dict()
networks_tsv = wpa_cli(["list_networks"])
networks_tsv.pop(0)
for network_line in networks_tsv:
    split = network_line.split(b"\t")
    number = int(split[0])
    ssid_bytes = split[1]
    ssid = re.sub(
        rb"\\x([0-9a-f]{2})",
        lambda d: int(d[1], base=16).to_bytes(),
        ssid_bytes,
    ).decode()
    network_numbers[ssid] = number

if os.path.isfile(NETWORKS_FILE):
    with open(NETWORKS_FILE) as fd:
        networks = json.load(fd)

    for network in networks:
        ssid = network["ssid"]
        if ssid in network_numbers:
            number = network_numbers[ssid]
        else:
            number = int(wpa_cli(["add_network"])[0])
        number_str = str(number)
        for key, value in network.items():
            if isinstance(value, str):
                value_str = f'"{value}"'
            elif isinstance(value, list):
                value_str = " ".join(value)
            else:
                value_str = str(value)
            ret = wpa_cli(["set_network", number_str, key, value_str])
            if ret[0] != b"OK":
                raise RuntimeError(f"Couldn't set {key} for {ssid}, got {ret}")