restructure and further configure sway

users/default/swww.nix

@@ -0,0 +1,42 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+{
+  options.services.swww-randomize = {
+    enable = lib.mkEnableOption "enable the randomization swww service";
+    backgroundDir = lib.mkOption {
+      default = config.home.homeDirectory + "/Pictures/Backgrounds";
+      description = "directory with images to use for the background";
+      type = with lib.types; uniq str;
+    };
+  };
+
+  config = {
+    services.swww.enable = true;
+    systemd.user = {
+      services.swww-randomize = {
+        Unit = {
+          Description = "randomly change the swww background image";
+          Requires = "swww.service";
+        };
+        Service = {
+          Type = "oneshot";
+          ExecStart = "${lib.getExe pkgs.bash} -c '${lib.getExe pkgs.findutils} ${config.services.swww-randomize.backgroundDir} -type f | ${lib.getExe' pkgs.coreutils "shuf"} -n 1 | ${lib.getExe' pkgs.findutils "xargs"} ${lib.getExe pkgs.swww} img --transition-step 16'";
+        };
+        Install.WantedBy = [ "default.target" ];
+      };
+      timers.swww-randomize = {
+        Unit.Description = "randomly changes the swww background image";
+        Timer = {
+          Unit = "swww-randomize";
+          OnCalendar = "*-*-* *:00,30:00";
+        };
+        Install.WantedBy = [ "timers.target" ];
+      };
+    };
+  };
+}