nixos/servarr: add options and env-var functions

{ lib, pkgs }:

{

  mkServarrSettingsOptions =

    name: port:

    lib.mkOption {

      type = lib.types.submodule {

        freeformType = (pkgs.formats.ini { }).type;

        options = {

          update = {

            mechanism = lib.mkOption {

              type =

                with lib.types;

                nullOr (enum [

                  "external"

                  "builtIn"

                  "script"

                ]);

              description = "which update mechanism to use";

              default = "external";

            };

            automatically = lib.mkOption {

              type = lib.types.bool;

              description = "Automatically download and install updates.";

              default = false;

            };

          };

          server = {

            port = lib.mkOption {

              type = lib.types.int;

              description = "Port Number";

              default = port;

            };

          };

          log = {

            analyticsEnabled = lib.mkOption {

              type = lib.types.bool;

              description = "Send Anonymous Usage Data";

              default = false;

            };

          };

        };

      };

      example = lib.options.literalExpression ''

        {

          update.mechanism = "internal";

          server = {

            urlbase = "localhost";

            port = ${toString port};

            bindaddress = "*";

          };

        }

      '';

      default = { };

      description = ''

        Attribute set of arbitrary config options.

        Please consult the documentation at the [wiki](https://wiki.servarr.com/useful-tools#using-environment-variables-for-config).

        WARNING: this configuration is stored in the world-readable Nix store!

        For secrets use [](#opt-services.${name}.environmentFiles).

      '';

    };

  mkServarrEnvironmentFiles =

    name:

    lib.mkOption {

      type = lib.types.listOf lib.types.path;

      default = [ ];

      description = ''

        Environment file to pass secret configuration values.

        Each line must follow the `${lib.toUpper name}__SECTION__KEY=value` pattern.

        Please consult the documentation at the [wiki](https://wiki.servarr.com/useful-tools#using-environment-variables-for-config).

      '';

    };

  mkServarrSettingsEnvVars =

    name: settings:

    lib.pipe settings [

      (lib.mapAttrsRecursive (

        path: value:

        lib.optionalAttrs (value != null) {

          name = lib.toUpper "${name}__${lib.concatStringsSep "__" path}";

          value = toString (if lib.isBool value then lib.boolToString value else value);

        }

      ))

      (lib.collect (x: lib.isString x.name or false && lib.isString x.value or false))

      lib.listToAttrs

    ];

}