niveum/modules/networkmanager-declarative.nix

# https://github.com/jmackie/nixos-networkmanager-profiles/
{
  lib,
  config,
  ...
}:
with lib; let
  nm = config.networking.networkmanager;

  mkProfile = profileAttrs:
    if !(isAttrs profileAttrs)
    then throw "error 1"
    else {
      enable = true;
      mode = "0400"; # readonly (user)
      text =
        (foldlAttrs (accum: {
            name,
            value,
          }: ''
            ${accum}

            [${name}] ${mkProfileEntry value}'')
          "# Generated by nixos-networkmanager-profiles"
          profileAttrs)
        + "\n";
    };

  mkProfileEntry = entryAttrs:
    if !(isAttrs entryAttrs)
    then throw "error 2"
    else
      foldlAttrs (accum: {
        name,
        value,
      }: ''
        ${accum}
        ${name}=${toString value}'') ""
      entryAttrs;

  foldlAttrs = op: nul: attrs:
    foldl (accum: {
      fst,
      snd,
    }:
      op accum (nameValuePair fst snd))
    nul
    (lists.zipLists (attrNames attrs) (attrValues attrs));

  attrLength = attrs: length (attrValues attrs);
in {
  options.networking.networkmanager.profiles = mkOption {
    type = types.attrs;
    default = {};
  };

  config = mkIf (attrLength nm.profiles > 0) {
    environment.etc = foldlAttrs (accum: {
      name,
      value,
    }:
      accum
      // {
        "NetworkManager/system-connections/${name}.nmconnection" =
          mkProfile value;
      }) {}
    nm.profiles;
  };
}