defmodule OMTT.Util.Random do

  @spec string(String.t) :: String.t
  def string( length ) do
      get_string( length )
  end

  @spec string() :: String.t
  def string() do
      get_string( 8 )
  end

  defp get_string( length ) do
      alphabet
          =  "abcdefghijklmnopqrstuvwxyz"
          <> "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
          <> "0123456789"
      alphabet_length = alphabet |> String.length
      1..length
      |> Enum.map_join(fn(_) ->
          alphabet |> String.at(:rand.uniform( alphabet_length ) - 1)
      end)
  end

  @spec number() :: Integer.t
  def number() do
    number(8)
  end

  @spec number(Integer.t) :: Integer.t
  def number( length ) do
    round(:rand.uniform(round(:math.pow(10, length) - :math.pow(10, length-1))) + :math.pow(10, length-1)) - 1
  end

end