feat(system): enable fingerprint reader only if lid is open

system/laptop.nix

@@ -0,0 +1,8 @@
+_:
+
+{
+  imports = [
+    ./desktop.nix
+    ./lid.nix
+  ];
+}

system/lid.nix

@@ -0,0 +1,27 @@
+{ config, lib, ... }:
+
+{
+  services.acpid = lib.mkIf config.services.fprintd.enable {
+    enable = true;
+    handlers.lidClosed = {
+      event = "button/lid \\w+ close";
+      action = ''
+        echo "Lid closed. Disabling fprintd."
+        systemctl stop fprintd
+        ln -s /dev/null /run/systemd/transient/fprintd.service
+        systemctl daemon-reload
+      '';
+    };
+    handlers.lidOpen = {
+      event = "button/lid \\w+ open";
+      action = ''
+        if ! $(systemctl is-active --quiet fprintd); then
+          echo "Lid open. Enabling fprintd."
+          rm -f /run/systemd/transient/fprintd.service
+          systemctl daemon-reload
+          systemctl start fprintd
+        fi
+      '';
+    };
+  };
+}