wrapper-manager-fds/modules: add configuring XDG-related directories per-wrapper

modules/wrapper-manager/default.nix

@@ -2,6 +2,7 @@
   imports = [
     ./base.nix
     ./xdg-desktop-entries.nix
+    ./xdg-dirs.nix
     ./build.nix
     ./extra-args.nix
   ];

modules/wrapper-manager/xdg-dirs.nix

@@ -0,0 +1,59 @@
+{ config, lib, ... }:
+
+let
+  cfg = config.xdg;
+
+  xdgDirsOption = {
+    configDirs = lib.mkOption {
+      type = with lib.types; listOf str;
+      description = ''
+        A list of paths to be appended as part of the `XDG_CONFIG_DIRS`
+        environment to be applied per-wrapper.
+      '';
+      default = [ ];
+      example = lib.literalExpression ''
+        wrapperManagerLib.getXdgConfigDirs (with pkgs; [
+          yt-dlp
+          neofetch
+        ])
+      '';
+    };
+
+    dataDirs = lib.mkOption {
+      type = with lib.types; listOf str;
+      description = ''
+        A list of paths to be appended as part of the `XDG_DATA_DIRS`
+        environment to be applied per-wrapper.
+      '';
+      default = [ ];
+      example = lib.literalExpression ''
+        wrapperManagerLib.getXdgDataDirs (with pkgs; [
+          yt-dlp
+          neofetch
+        ])
+      '';
+    };
+  };
+in
+{
+  options.xdg = xdgDirsOption;
+
+  options.wrappers = lib.mkOption {
+    type =
+      let
+        xdgDirsType = { name, lib, config, ... }: {
+          options.xdg = xdgDirsOption;
+
+          config.makeWrapperArgs =
+            let
+              # Just take note wrapper-specific values should be the one taking over.
+              configDirs = cfg.configDirs ++ config.xdg.configDirs;
+              dataDirs = cfg.dataDirs ++ config.xdg.dataDirs;
+            in
+            builtins.map (v: "--prefix 'XDG_CONFIG_DIRS' ':' ${v}") configDirs
+            ++ (builtins.map (v: "--prefix 'XDG_DATA_DIRS' ':' ${v}") dataDirs);
+        };
+      in
+      with lib.types; attrsOf (submodule xdgDirsType);
+  };
+}