defmodule EmailValidator do

    # ensure that the email looks valid
    def validate_email(email) when is_binary(email) do
      case Regex.run(~r/^[A-Za-z0-9._%+-+']+@[A-Za-z0-9.-]+\.[A-Za-z]+$/, email) do
        nil ->
          {:error, "Invalid email"}
        [email] ->
          try do
            Regex.run(~r/(\w+)@([\w.]+)/, email) |> validate_email
          rescue
            _ -> {:error, "Invalid email"}
          end
      end
    end

    # check the email against a list of accepted domains, then make check if it is unique
    def validate_email([email, username, host]) do
      case host in Config.accepted_domains do
        true ->
          case find_by_email(email) do
              nil -> :ok
              _account -> :account
          end
        _ ->
          {:error, "Not an accepted domain."}
      end
    end
  end