defmodule Ark do
  "# Ark\n" <> readme = File.read!("README.md")
  @moduledoc readme
  @all [:pipe_in, :ok]

  defmacro __using__(opts) do
    imports =
      case opts do
        mod when is_atom(mod) -> [mod]
        [] -> @all
        list -> list
      end

    imports
    |> Enum.map(&alias_module/1)
    |> Enum.map(&abuse_module/1)
  end

  defp alias_module(:ok), do: Ark.Ok
  defp alias_module(:pipe_in), do: Ark.PipeIn
  defp alias_module(mod), do: mod

  defp abuse_module(mod) do
    quote do
      use unquote(mod)
    end
  end
end