feat(nixos): add support for where-is-my-sddm-theme

modules/nixos/all-modules.nix

@@ -7,5 +7,6 @@
   ./plymouth.nix
   ./sddm.nix
   ./tty.nix
+  ./where-is-my-sddm-theme.nix
   # keep-sorted end
 ]

modules/nixos/where-is-my-sddm-theme.nix

@@ -0,0 +1,74 @@
+{ catppuccinLib }:
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+let
+  inherit (catppuccinLib) importINI;
+  inherit (lib)
+    mkOption
+    recursiveUpdate
+    singleton
+    types
+    ;
+
+  cfg = config.catppuccin.where-is-my-sddm-theme;
+  enable = cfg.enable && config.services.displayManager.sddm.enable;
+in
+
+{
+  options.catppuccin.where-is-my-sddm-theme =
+    catppuccinLib.mkCatppuccinOption {
+      name = "where-is-my-sddm-theme";
+      default = config.catppuccin.enable && !config.catppuccin.sddm.enable;
+      defaultText = "config.catppuccin.enable && !config.catppuccin.sddm.enable";
+    }
+    // {
+      variant = mkOption {
+        type = types.enum [
+          "qt5"
+          "qt6"
+        ];
+        default =
+          if config.services.displayManager.sddm.package == pkgs.libsForQt5.sddm then "qt5" else "qt6";
+        defaultText = "Automatically determined based on your SDDM package - `qt6` for `kdePackages.sddm`, `qt5` for `libsForQt5.sddm`, and `qt6` as fallback";
+        example = "qt5";
+        description = "Which variant will be used for Where is my SDDM theme?";
+      };
+
+      settings = mkOption {
+        type = lib.types.submodule { freeformType = with types; attrsOf anything; };
+        default = { };
+        example = {
+          General.passwordCharacter = "*";
+        };
+        description = "Additional settings for Where is my SDDM theme?";
+      };
+    };
+
+  config = lib.mkIf enable {
+    assertions = [
+      {
+        assertion = config.catppuccin.sddm.enable -> cfg.enable;
+        message = "Only one of `catppuccin.sddm` and `catppuccin.where-is-my-sddm-theme` may be set at a time.";
+      }
+    ];
+
+    environment.systemPackages = [
+      (pkgs.where-is-my-sddm-theme.override {
+        variants = singleton cfg.variant;
+        themeConfig = recursiveUpdate (importINI "${config.catppuccin.sources.where-is-my-sddm-theme}/catppuccin-${cfg.flavor}.conf") cfg.settings;
+      })
+    ];
+
+    services.displayManager = {
+      sddm = {
+        theme =
+          if cfg.variant == "qt6" then "where_is_my_sddm_theme" else "where_is_my_sddm_theme_qt5";
+      };
+    };
+  };
+}

pkgs/sources.json

@@ -284,6 +284,11 @@
     "lastModified": "2023-04-12",
     "rev": "b1a81bae74d66eaae16457f2d8f151b5bd4fe5da"
   },
+  "where-is-my-sddm-theme": {
+    "hash": "sha256-f6d7bJoSbFzEhAIfilxNLQGtAMQWTtUTube/pTqP7AY=",
+    "lastModified": "2024-10-13",
+    "rev": "82a36df79ab596b9fbe85c86d3c2f3a1e39433af"
+  },
   "wlogout": {
     "hash": "sha256-0VCk+7t/cSEmcnfvKdxUDwwrtK0VLhZrVpw4enoBEbc=",
     "lastModified": "2025-08-07",