{ lib, pkgs, ... }: {
  imports = [
    ./audio.nix
    ./tailscale.nix
  ];

  # use nix version 2.22
  nix = {
    package = pkgs.nixVersions.nix_2_22;

    settings = {
      auto-optimise-store = lib.mkDefault true;
      experimental-features = [
        "nix-command"
        "flakes"
        "ca-derivations"
      ];
    };

    gc = {
      automatic = true;
      dates = "weekly";
      options = "--delete-older-than +3";
    };
  };

  users.users.lu.extraGroups = ["audio"];

  # auto mount external drives
  services.devmon.enable = true;
  services.gvfs.enable = true;
  services.udisks2.enable = true;
}