Add battery timer and btop

home/btop/default.nix

@@ -0,0 +1,12 @@
+{ ... }:
+
+{
+  programs.btop = {
+    enable = true;
+
+    settings = {
+      color_theme = "Default";
+      theme_background = false;
+    };
+  };
+}

home/default.nix

@@ -2,6 +2,7 @@
 
 {
   imports = [
+    ./btop
     ./dunst
     ./eza
     ./fastfetch

hosts/tardis/default.nix

@@ -4,6 +4,8 @@
   imports =
     [
       ./hardware-configuration.nix
+
+      ../../modules/battery
     ];
 
   boot.blacklistedKernelModules = [

modules/battery/default.nix

@@ -0,0 +1,40 @@
+{ config, pkgs, ... }:
+
+let
+  batteryNotify = pkgs.writeShellScript "battery-notify" ''
+    BAT="/sys/class/power_supply/BAT1"
+    LEVEL=$(cat "$BAT/capacity")
+    STATUS=$(cat "$BAT/status")
+    ID=9991
+
+    if [ "$STATUS" = "Discharging" ] && [ "$LEVEL" -lt 20 ]; then
+      ${pkgs.dunst}/bin/dunstify \
+        -r "$ID" -t 0 \
+        -u critical \
+        "Battery Low" \
+        "Battery is at ''${LEVEL}%"
+    else
+      ${pkgs.dunst}/bin/dunstify \
+        -C "$ID" 2>/dev/null || true
+    fi
+  '';
+in
+{
+  systemd.services.battery-notify = {
+    description = "Low battery notification";
+    serviceConfig = {
+      Type = "oneshot";
+      ExecStart = batteryNotify;
+    };
+  };
+
+  systemd.timers.battery-notify = {
+    description = "Check battery level every 20 seconds";
+    wantedBy = [ "timers.target" ];
+
+    timerConfig = {
+      OnBootSec = "20s";
+      OnUnitActiveSec = "20s";
+    };
+  };
+}