nixos/davfs2: fix settings option

{ config, lib, pkgs, ... }:

let

  toStr = value:

    if true == value then "yes"

    else if false == value then "no"

    else toString value;

  inherit (lib.attrsets) mapAttrsToList optionalAttrs;

  inherit (lib.attrsets) optionalAttrs;

  inherit (lib.generators) toINIWithGlobalSection;

  inherit (lib.lists) optional;

  inherit (lib.modules) mkIf;

  inherit (lib.options) literalExpression mkEnableOption mkOption;

  inherit (lib.strings) concatLines;

  inherit (lib.types) lines str submodule;

  inherit (lib.strings) escape;

  inherit (lib.types) attrsOf bool int lines oneOf str submodule;

  cfg = config.services.davfs2;

  format = pkgs.formats.toml { };

  configFile = let

    settings = mapAttrsToList (n: v: "${n} = ${toStr v}") cfg.settings;

  in pkgs.writeText "davfs2.conf" ''

    ${concatLines settings}

  escapeString = escape ["\"" "\\"];

  formatValue = value:

    if true == value then "1"

    else if false == value then "0"

    else if builtins.isString value then "\"${escapeString value}\""

    else toString value;

  configFile = pkgs.writeText "davfs2.conf" ''

    ${toINIWithGlobalSection {

      mkSectionName = escapeString;

      mkKeyValue = k: v: "${k} ${formatValue v}";

    } cfg.settings}

    ${cfg.extraConfig}

  '';

in

    settings = mkOption {

      type = submodule {

        freeformType = format.type;

        freeformType = let

          valueTypes = [ bool int str ];

        in

        attrsOf (attrsOf (oneOf (valueTypes ++ [ (attrsOf (oneOf valueTypes)) ] )));

      };

      default = { };

      example = literalExpression ''

        {

          kernel_fs = "coda";

          globalSection = {

            proxy = "foo.bar:8080";

          use_locks = 0;

            use_locks = false;

          };

          sections = {

            "/media/dav" = {

              use_locks = true;

            };

            "/home/otto/mywebspace" = {

              gui_optimize = true;

            };

          };

        }

      '';

      description = ''

    environment.etc."davfs2/davfs2.conf".source = configFile;

    services.davfs2.settings = {

      globalSection = {

        dav_user = cfg.davUser;

        dav_group = cfg.davGroup;

      };

    };

    users.groups = optionalAttrs (cfg.davGroup == "davfs2") {

      davfs2.gid = config.ids.gids.davfs2;