{ lib, config, ... }:

let
  cfg = config.this.unfree;
  inherit (builtins) elem;
  inherit (lib) getName;
in
{
  options = {
    this.unfree.allowed = lib.mkOption {
      type = with lib.types; listOf str;
      default = [];
    };
  };

  config = {
    nixpkgs.config.allowUnfreePredicate =
      pkg: elem (getName pkg) cfg.allowed;
  };
}