{ lib, pkgs, ... }:
let
  launchd-time = {
    Hour = 3;
    Minute = 15;
    Weekday = 7;
  };

  systemd-time = "weekly";

  isDarwin = pkgs.stdenv.hostPlatform.isDarwin;
in
{
  nixpkgs.config.allowUnfree = true;

  nix = {
    gc = {
      automatic = true;
      options = "--delete-older-than 30d";
    }
    // lib.optionalAttrs isDarwin {
      interval = launchd-time;
    }
    // lib.optionalAttrs (!isDarwin) {
      dates = systemd-time;
    };

    optimise = {
      automatic = true;
    }
    // lib.optionalAttrs isDarwin {
      interval = launchd-time;
    }
    // lib.optionalAttrs (!isDarwin) {
      dates = systemd-time;
    };

    settings = {
      use-xdg-base-directories = true;

      experimental-features = [
        "nix-command"
        "flakes"
      ];
    };
  };
}