added stuff

nyx/modules/extra/shared/home-manager/transience/default.nix

@@ -0,0 +1,76 @@
+{
+  config,
+  pkgs,
+  lib,
+  ...
+}: let
+  inherit (lib) mkOption mkEnableOption types;
+
+  cfg = config.services.transience;
+in {
+  meta.maintainers = [lib.maintainers.NotAShelf];
+  options.services.transience = {
+    enable = mkEnableOption "transience";
+
+    user = mkOption {
+      type = with types; nullOr string;
+      default = null;
+      description = "The user that the directories will be relative to";
+    };
+
+    days = mkOption {
+      type = types.int;
+      default = 30;
+      description = "Number of days after which files are deleted";
+    };
+
+    directories = mkOption {
+      type = with types; listOf path;
+      default = [];
+      description = ''
+        A list of directories that will be cleaned.
+
+        Must be relative to the user's home directory.
+      '';
+    };
+  };
+
+  config = {
+    assertions = [
+      {
+        assertion = cfg.enable -> cfg.user == null;
+        message = ''
+          You have enabled services.transience, but have not specified your user. You must specify a "main user"
+          for your system for Transience to work properly.
+        '';
+      }
+      {
+        assertion = cfg.directories == [];
+        message = ''
+          You have enabled services.transience, but have not specified any directories to clean up. Please specify
+          at least one folder. This option defaults to an empty list, but you must specify a list of directories for
+          Transience to work properly.
+        '';
+      }
+    ];
+
+    systemd.user.services.transience = let
+      dirs =
+        map (
+          x:
+            config.home-manager.users.${cfg.user}.home.homeDirectory + "/" + x
+        )
+        cfg.directories;
+    in {
+      Install.wantedBy = ["default.target"];
+      Service.ExecStart = ''
+        ${builtins.concatStringsSep "\n" (map (x: "find ${
+            lib.escapeShellArg x
+          } -mtime +${cfg.days} -exec rm -rv {} + -depth;")
+          dirs)}
+      '';
+
+      Unit.Description = "Clean up transient directories";
+    };
+  };
+}