defmodule Gulib.String.IdPartition do

  @total_length 12
  @unit_length 3

  def parse(x, total_length \\ @total_length, unit_length \\ @unit_length) when is_binary(x) or is_integer(x) do
    cond do
      is_integer(x) -> 
        x |> Integer.to_string |> do_parse(total_length, unit_length)
      true ->
        do_parse x, total_length, unit_length
    end
  end

  defp do_parse x, total_length, unit_length do
    Regex.scan(~r/\w{#{unit_length}}/, String.pad_leading(x, total_length, "0")) |> Enum.join("/")
  end

end