Add timer script for desktop machines

Based on https://github.com/sdaschner/dotfiles/blob/master/bin/timer and
https://github.com/sdaschner/dotfiles/blob/master/bin/_timer.

Seen in https://youtu.be/8CZIv3MJvic?si=PiVPM_vwuUKI7ak3&t=1460.

lib/nixos/home-manager/default.nix

@@ -24,7 +24,9 @@ let
       username
       ;
   };
-  shared-packages = import "${self}/lib/shared/home-manager-packages.nix" { inherit inputs pkgs; };
+  shared-packages = import "${self}/lib/shared/home-manager-packages.nix" {
+    inherit desktop inputs pkgs;
+  };
 in
 {
   imports =

lib/shared/home-manager-packages.nix

@@ -1,22 +1,23 @@
-{ inputs, pkgs, ... }:
+{
+  desktop,
+  inputs,
+  pkgs,
+  ...
+}:
 let
   php = pkgs.php82;
   phpPackages = pkgs.php82Packages;
 
   inherit (pkgs) writeShellApplication;
 
-  scripts = {
-    notetaker = writeShellApplication (import ./scripts/notetaker.nix);
-    run = writeShellApplication (import ./scripts/run.nix { inherit pkgs; });
-    t = writeShellApplication (import ./scripts/t.nix { inherit pkgs; });
-  };
+  _timer = writeShellApplication (import ./scripts/_timer.nix);
+  notetaker = writeShellApplication (import ./scripts/notetaker.nix);
+  run = writeShellApplication (import ./scripts/run.nix { inherit pkgs; });
+  t = writeShellApplication (import ./scripts/t.nix { inherit pkgs; });
+  timer = writeShellApplication (import ./scripts/timer.nix);
 in
 with pkgs;
 [
-  scripts.notetaker
-  scripts.run
-  scripts.t
-
   age
   awscli2
   bitwarden-cli
@@ -58,4 +59,14 @@ with pkgs;
   xdg-utils
   xh
   yarn
+
+  # Scripts.
+  notetaker
+  run
+  t
+]
+++ pkgs.lib.optionals desktop [
+  # Scripts.
+  _timer
+  timer
 ]

lib/shared/scripts/_timer.nix

@@ -0,0 +1,13 @@
+{
+  name = "_timer";
+
+  runtimeInputs = [ ];
+
+  text = ''
+    mins=$1
+    message=''${2:-Time out!}
+
+    sleep -- "$mins" * 60
+    notify-send -t 0 "''${message}" "Your timer of $mins min is over" -u normal
+  '';
+}

lib/shared/scripts/timer.nix

@@ -0,0 +1,20 @@
+{
+  name = "timer";
+
+  runtimeInputs = [ ];
+
+  text = ''
+    if [[ "$1" == "" ]]; then
+      echo "Usage: ''${0##*/} <mins> [message]"
+      exit 1
+    fi
+
+    mins=$1
+    message=$2
+
+    nohup _timer "$mins" "$message" &> /dev/null &
+
+    echo "timer started for $mins min"
+    echo "timer started for $mins min, message: '$message'" | systemd-cat -t timer
+  '';
+}

lib/wsl2/default.nix

@@ -16,7 +16,11 @@ let
       username
       ;
   };
-  shared-packages = import "${self}/lib/shared/home-manager-packages.nix" { inherit inputs pkgs; };
+
+  shared-packages = import "${self}/lib/shared/home-manager-packages.nix" {
+    inherit inputs pkgs;
+    desktop = false;
+  };
 in
 inputs.home-manager.lib.homeManagerConfiguration {
   inherit pkgs;