nixos-config/subprojects/wrapper-manager-fds/modules/wrapper-manager/xdg-desktop-entries.nix

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

let
  # We're only setting up options for the most common keys typically used to
  # set up a desktop entry. Everything else is acceptable under a freeform
  # module anyways.
  xdgDesktopEntry = { name, lib, pkgs, ... }: {
    freeformType = with lib.types; attrsOf anything;

    options = {
      name = lib.mkOption {
        type = lib.types.nonEmptyStr;
        description = "The name of the desktop file.";
        default = name;
        example = "firefox";
      };

      desktopName = lib.mkOption {
        type = lib.types.nonEmptyStr;
        description = "Specific name of the application";
        default = name;
        example = "Firefox";
      };

      exec = lib.mkOption {
        type = with lib.types; nullOr nonEmptyStr;
        description = "Program with execute along with its arguments.";
        default = null;
        example = "firefox %U";
      };

      genericName = lib.mkOption {
        type = with lib.types; nullOr nonEmptyStr;
        description = "Generic name of the application";
        default = null;
        example = "Web browser";
      };

      terminal = lib.mkOption {
        type = lib.types.bool;
        description = "Whether the program runs in a terminal window.";
        default = false;
        example = true;
      };

      categories = lib.mkOption {
        type = with lib.types; listOf nonEmptyStr;
        description = "List of categories should the application be shown in a menu.";
        default = [ ];
        example = [ "Applications" "Network" ];
      };

      mimeTypes = lib.mkOption {
        type = with lib.types; listOf nonEmptyStr;
        description = "The MIME types supported by the application.";
        default = [ ];
        example = [ "text/html" "text/xml" ];
      };
    };
  };
in
{
  options.xdg.desktopEntries = lib.mkOption {
    type = with lib.types; attrsOf (submodule xdgDesktopEntry);
    description = ''
      A set of desktop entries to be exported along with the wrapped package.
    '';
    default = { };
    example = lib.literalExpression ''
      {
        firefox = {
          name = "Firefox";
          genericName = "Web browser";
          exec = "firefox %u";
          terminal = false;
          categories = [ "Application" "Network" "WebBrowser" ];
          mimeTypes = [ "text/html" "text/xml" ];
          extraConfig."X-GNOME-Autostart-Phase" = "WindowManager";
          keywords = [ "Web" "Browser" ];
          startupNotify = false;
          startupWMClass = "MyOwnClass";
        };
      }
    '';
  };

  options.wrappers = lib.mkOption {
    type =
      let
        xdgDesktopEntryWrapperSubmodule = { name, config, lib, ... }: {
          options.xdg.desktopEntry = {
            enable =
              lib.mkEnableOption "automatic creation of a desktop entry for the wrapper";
            settings = lib.mkOption {
              type = lib.types.submodule xdgDesktopEntry;
              description = ''
                Settings to be passed to the `makeDesktopItem` builder.
              '';
              example = lib.literalExpression ''
                {
                  mimeTypes = [ "text/html" "text/xml" ];
                  categories = [ "Applications" "Network" ];
                }
              '';
            };
          };

          config.xdg.desktopEntry.settings = lib.mkIf config.xdg.desktopEntry.enable {
            name = lib.mkDefault config.executableName;
            desktopName = lib.mkDefault name;
            type = lib.mkDefault "Application";

            # Welp, we could set it to the absolute location of the wrapper
            # executable in the final output but it's a big pain the ass to do
            # so but we're opting to the executable name instead. This current
            # way of doing it is simply the next (and the simplest) best thing.
            # We just have to make sure the build step for the wrapper script
            # is consistent throughout the entire module environment.
            #
            # Besides, if the user wants a desktop entry along with the wrapper
            # script, it will be included alongside in whatever environment
            # they are using it for anyways.
            exec = config.executableName;
          };
        };
      in
      with lib.types; attrsOf (submodule xdgDesktopEntryWrapperSubmodule);
  };

  config = {
    xdg.desktopEntries =
      let
        wrappersWithDesktopEntries = lib.filterAttrs (_: v: v.xdg.desktopEntry.enable) config.wrappers;
      in
        lib.mapAttrs (_: v: v.xdg.desktopEntry.settings) wrappersWithDesktopEntries;
  };
}