{ pkgs ? import <nixpkgs> {} }:

with pkgs;

let
  gems = bundlerEnv rec {
    name = "scrapers";

    inherit ruby;
    # expects Gemfile, Gemfile.lock and gemset.nix in the same directory
    # > nix-shell -p bundler --run 'bundle lock --update'
    # > nix-shell -p bundix --run bundix
    gemdir = ./.;
  };
  wrapScript = name: script:
    stdenv.mkDerivation {
      inherit name script;
      buildInputs = [ gems.wrappedRuby ];

      buildCommand = ''
        install -D -m755 $script $out/bin/${name}
        patchShebangs $out/bin/${name}
      '';
    };
in {
  xerox = wrapScript "xerox" ./xerox/scrape.rb;
}