nixdots/system/roles/laptop/power/default.nix

{ pkgs, lib, config, ...}: let
  inherit (lib) mkIf mkDefault;
  deviceType = config.myOptions.device.roles.type;
  acceptedTypes = ["laptop"];
in {
  config = mkIf (builtins.elem deviceType acceptedTypes) {
    hardware.acpilight.enable = true;

    environment.systemPackages = with pkgs; [
      acpi
      powertop
    ];

    services = {
      # handle ACPI events
      acpid.enable = true;

      # allows changing system behavior based upon user-selected power profiles
      power-profiles-daemon.enable = true;

      # temperature target on battery
      undervolt = {
        tempBat = 65; # deg C
        package = pkgs.undervolt;
      };

      # superior power management
      auto-cpufreq = {
        enable = true;

        # define the profiles
        # (you can manually switch between profiles using `powerprofilesctl` cmd)
        settings = let
          MHz = x: x * 1000;
        in {
          battery = {
            governor = "powersave";
            scaling_min_freq = mkDefault (MHz 1200);
            scaling_max_freq = mkDefault (MHz 1800);
            turbo = "never";
          };

          charger = {
            governor = "performance";
            scaling_min_freq = mkDefault (MHz 1800);
            scaling_max_freq = mkDefault (MHz 3800);
            turbo = "auto";
          };
        };
      };

      # DBus service that provides power management support to applications
      upower = {
        enable = true;
        percentageLow = 15;
        percentageCritical = 5;
        percentageAction = 3;
        criticalPowerAction = "Hibernate";
      };
    };

    boot = {
      kernelModules = ["acpi_call"];
      extraModulePackages = with config.boot.kernelPackages; [
        acpi_call
        cpupower
      ];
    };
  };
}