{ den, modules, ... }:
{
  modules.battery-ac-targets = {
    nixos =
      { ... }:
      {
        services.udev.extraRules = ''
          SUBSYSTEM=="power_supply",ENV{POWER_SUPPLY_ONLINE}=="0", RUN+="/run/current-system/systemd/bin/systemctl start battery.target"
          SUBSYSTEM=="power_supply", ENV{POWER_SUPPLY_ONLINE}=="1", RUN+="/run/current-system/systemd/bin/systemctl start ac.target"
        '';
        systemd.targets = {
          "ac" = {
            description = "On AC power";
            unitConfig = {
              StopWhenUnneeded = "yes";
            };
          };
          "battery" = {
            description = "On battery power";
            unitConfig = {
              StopWhenUnneeded = "yes";
            };
          };
        };
      };
  };
}