wpaperd: add wpaperd configuration

Signed-off-by: Avimitin <dev@avimit.in>

modules/programs/wpaperd.nix

@@ -0,0 +1,49 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.programs.wpaperd;
+  tomlFormat = pkgs.formats.toml { };
+in {
+  meta.maintainers = [ hm.maintainers.Avimitin ];
+
+  options.programs.wpaperd = {
+    enable = mkEnableOption "wpaperd";
+
+    package = mkPackageOption pkgs "wpaperd" { };
+
+    settings = mkOption {
+      type = tomlFormat.type;
+      default = { };
+      example = literalExpression ''
+        {
+          eDP-1 = {
+            path = "/home/foo/Pictures/Wallpaper";
+            apply-shadow = true;
+          };
+          DP-2 = {
+            path = "/home/foo/Pictures/Anime";
+            sorting = "descending";
+          };
+        }
+      '';
+      description = ''
+        Configuration written to
+        {file}`$XDG_CONFIG_HOME/wpaperd/wallpaper.toml`.
+        See <https://github.com/danyspin97/wpaperd#wallpaper-configuration>
+        for the full list of options.
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
+    home.packages = [ cfg.package ];
+
+    xdg.configFile = {
+      "wpaperd/wallpaper.toml" = mkIf (cfg.settings != { }) {
+        source = tomlFormat.generate "wpaperd-wallpaper" cfg.settings;
+      };
+    };
+  };
+}