nix-config-v2/modules/pwrMgmt/default.nix

{
  config,
  lib,
  pkgs,
  ...
}: let
  cfg = config.pwrMgmt;
in {
  options.pwrMgmt = {
    enable = lib.mkEnableOption "Custom power management configuration";
    cpuFreqGovernor = lib.mkOption {
      type = lib.types.enum [
        "performance"
        "powersave"
        "ondemand"
        "conservative"
      ];
      default = "performance";
      description = "CPU frequency scaling governor to use";
    };

    powertop = {
      enable = lib.mkEnableOption "PowerTop power management tool";

      autotuneOnBoot = lib.mkOption {
        type = lib.types.bool;
        default = false;
        description = "Automatically tune power settings on boot";
      };
    };

    battery = {
      enable = lib.mkEnableOption "Battery-specific power management";

      startChargeThreshold = lib.mkOption {
        type = lib.types.int;
        default = 20;
        description = "Percentage at which to start charging";
      };

      stopChargeThreshold = lib.mkOption {
        type = lib.types.int;
        default = 80;
        description = "Percentage at which to stop charging";
      };
    };
  };

  config = lib.mkIf cfg.enable {
    powerManagement = {
      enable = true;
      cpuFreqGovernor = cfg.cpuFreqGovernor;
    };

    environment.systemPackages = lib.mkIf cfg.powertop.enable [pkgs.powertop];
    systemd.services.battery-charge-threshold = lib.mkIf cfg.battery.enable {
      description = "Set battery charge thresholds";
      wantedBy = ["multi-user.target"];
      script = ''
        if [ -f /sys/class/power_supply/BAT0/charge_start_threshold ]; then
          echo ${toString cfg.battery.startChargeThreshold} > /sys/class/power_supply/BAT0/charge_start_threshold
        fi
        if [ -f /sys/class/power_supply/BAT0/charge_stop_threshold ]; then
          echo ${toString cfg.battery.stopChargeThreshold} > /sys/class/power_supply/BAT0/charge_stop_threshold
        fi
      '';
    };
  };
}