Add basic theme config

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

users/configs/swww/default.nix

@@ -1,10 +1,33 @@
-{ user ? throw "user argument is required" }: { pkgs, ... }:
+{ user ? throw "user argument is required" }: { config, pkgs, ... }:
 
+let
+  hmConfig = config.home-manager.users."${user.name}";
+in
 {
   home-manager.users."${user.name}" = {
     home = {
       packages = with pkgs; [ swww ];
       persistence."/cache${user.home}".directories = [ ".cache/swww" ];
     };
+
+    theme.extraConfig = let name = "theme-swww"; in
+      "${pkgs.writeShellApplication {
+      inherit name;
+      runtimeInputs = with pkgs; [
+        coreutils-full
+        swww
+      ];
+      text = ''
+        if ! pgrep -x "swww-daemon" > /dev/null; then
+          swww-daemon &> /tmp/swww.log &
+        fi
+
+        while ! swww query &> /dev/null; do
+          sleep 0.1
+        done
+
+        swww img "${hmConfig.theme.configDir}/wallpaper"
+      '';
+    }}/bin/${name}";
   };
 }