defmodule NDCConfig do
  def check_mandatory_provider_config(config) do
    if is_nil(config[:label]) || is_nil(config[:server][:url]) || is_nil(config[:rest][:generic_headers]) || is_nil(config[:ndc]) do
      raise ConfigError
    else
      config
    end
  end
  def load_provider(path), do:  path |> test_file_exists |> read_file |> expose_provider_config |> check_mandatory_provider_config
  def load_consumer(path), do:  path |> test_file_exists |> read_file |> expose_consumer_config
  defp test_file_exists(path) do
      {status, _} = File.read("#{path}/config.exs")
      if status === :error do
        raise ConfigNotExistError
      else
        path
      end
  end
  defp read_file(path), do: Mix.Config.read!("#{path}/config.exs")
  defp expose_provider_config(provider_config), do: provider_config[:PROVIDER]
  defp expose_consumer_config(consumer_config), do: consumer_config[:CONSUMER]
end

defmodule ConfigError do
  defexception message: "The configuration file is missing some mandatory data."
end

defmodule ConfigNotExistError do
  defexception message: "The configuration file is missed."
end