swappy: add module

modules/programs/swappy.nix

@@ -0,0 +1,61 @@
+{
+  lib,
+  pkgs,
+  config,
+  ...
+}:
+let
+  inherit (lib)
+    mkIf
+    mkEnableOption
+    mkPackageOption
+    mkOption
+    ;
+
+  cfg = config.programs.swappy;
+  iniFormat = pkgs.formats.ini { };
+in
+{
+  meta.maintainers = with lib.hm.maintainers; [ aguirre-matteo ];
+
+  options.programs.swappy = {
+    enable = mkEnableOption "swappy";
+    package = mkPackageOption pkgs "swappy" { nullable = true; };
+    settings = mkOption {
+      inherit (iniFormat) type;
+      default = { };
+      example = {
+        Default = {
+          save_dir = "$HOME/Desktop";
+          save_filename_format = "swappy-%Y%m%d-%H%M%S.png";
+          show_panel = false;
+          line_size = 5;
+          text_size = 20;
+          text_font = "sans-serif";
+          paint_mode = "brush";
+          early_exit = false;
+          fill_shape = false;
+          auto_save = false;
+          custom_color = "rgba(193,125,17,1)";
+          transparent = false;
+          transparency = 50;
+        };
+      };
+      description = ''
+        Configuration settings for swappy. All the available options can be found
+        here: <https://github.com/jtheoof/swappy?tab=readme-ov-file#config>
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
+    assertions = [
+      (lib.hm.assertions.assertPlatform "programs.swappy" pkgs lib.platforms.linux)
+    ];
+
+    home.packages = mkIf (cfg.package != null) [ cfg.package ];
+    xdg.configFile."swappy/config" = mkIf (cfg.settings != { }) {
+      source = iniFormat.generate "swappy-config" cfg.settings;
+    };
+  };
+}