{ pkgs, ... }:
{
  power.ups = {
    enable = true;
    ups."eaton" = {
      driver = "usbhid-ups";
      port = "auto";
    };
    upsmon.enable = false;
    users."eatonMon" = {
      passwordFile =
        (pkgs.writeTextFile {
          name = "pass";
          text = "YFEAee2%9PuPcEKf$7vW$3a&wdvNJME%UkP2Z~RVkk4ZaQHYW^";
        }).outPath;
      upsmon = "primary";
    };
    upsmon.monitor."eaton" = {
      user = "eatonMon";
    };
    schedulerRules =
      let
        cmdScript = pkgs.writeShellApplication {
          name = "upssched-cmd.sh";
          runtimeInputs = with pkgs; [ systemd ];
          text = ''
            case $1 in
              shutdown) shutdown now
              # TODO : warn
              # TODO : warn & log on unknown cmd
            esac
          '';
        };
        rules = ''
          CMDSCRIPT ${cmdScript}/bin/upssched-cmd.sh
          PIPEFN /var/state/ups/upssched/upssched.pipe
          LOCKFN /var/state/ups/upssched/upssched.lock
          AT LOWBATT * EXECUTE shutdown
          AT ONBATT * START-TIMER shutdown 900
          AT ONLINE * CANCEL-TIMER shutdown
          # TODO : warn admins at COMMBAD NOCOMM BYPASS (and maybe at ONBATT)
        '';
      in
      (pkgs.writeTextFile {
        name = "upssched.conf";
        text = rules;
      }).outPath;
  };

  systemd.tmpfiles.settings."10-upsmon" =
    let
      root = {
        user = "root";
        group = "root";
        mode = "0600";
      };
    in
    {
      "/var/state/ups/upssched".d = root // {
        mode = "0700";
      };
      "/var/state/ups/upssched/upssched.pipe".p = root;
    };

  services.prometheus.exporters.nut = {
    enable = true;
    listenAddress = "100.80.255.180";
    port = 9199;
  };
}