nixos-conf/modules/programs/redshift.nix

{ config, lib, ... }:
let
  cfg = config.custom.programs.redshift;
in
{
  options.custom.programs.redshift.enable = lib.mkOption {
    type = lib.types.bool;
    default = false;
  };

  config = lib.mkIf cfg.enable {
    services.redshift = {
      executable = "/bin/redshift-gtk";
      enable = true;
      temperature = {
        night = 2800;
        day = 6500;
      };
      brightness = {
        night = "0.5";
        day = "1";
      };
    };

    location = {
      latitude = 60.17;
      longitude = 24.94;
    };
  };
}