.files/nix/networks/wpa_supplicant-compat.nix

#
# This loads the list of networks as a NixOS wpa_supplicant compatible attrset
#
# View the example config
# less $(nix-build --no-out-link '<nixpkgs>' -A 'wpa_supplicant')/share/doc/wpa_supplicant/wpa_supplicant.conf.example
let
  sources = import ../../npins;
  lib = import (sources.nixpkgs + "/lib");

  # wpa_supplicant uses `strchr` to seek to the first `=`, so the only forbidden character is `=`.
  escapePwdKey = lib.replaceStrings [ "=" ] [ "_" ];

  go =
    networkArgs@{
      ssid,
      bssid ? null,
      # Custom fields wrapping nixpkgs module options
      hasPassword ? false,
      scanOnLowSignal ? false,
      randomizeMac ? false,
      ...
    }:
    {
      ${
        # We use a unique key here to make sure no "same ssid different bssid" networks collide in key.
        # This is ordered, we still show "null" so that it would come after hex characters [a-z0-9].
        # The serialization is based on string order.
        "${ssid},${if bssid != null then bssid else "null"}"
      } =
        lib.mkMerge [
          (builtins.removeAttrs networkArgs [
            "hasPassword"
            "scanOnLowSignal"
            "randomizeMac"
          ])
          (lib.optionalAttrs hasPassword {
            pskRaw = "ext:${
              # this implies changing the external password key if you set a bssid!
              escapePwdKey (if bssid == null then ssid else "${ssid},${bssid}")
            }";
          })
          {
            extraConfig = ''
              ${lib.optionalString scanOnLowSignal "bgscan=\"simple:30:-70:3600\""}
              ${lib.optionalString randomizeMac "mac_addr=1"}
            '';
          }
        ];
    };
in
ns: lib.mkMerge (map go ns)