defmodule Localizator.Translator.Direction do
  alias Localizator.Commons

  defstruct [:from, :to]

  @typedoc """
  Locale
  """
  @type locale :: String.t() | Atom.t()
  @type from :: locale
  @type from_may_be_nil :: from | nil
  @type to :: locale
  @type direction :: {from, to} | to | %{from: from, to: to} | %{to: to}
  @type direction_struct :: %{to: to, from: from_may_be_nil}

  @spec get(direction) :: direction_struct
  def get(direction) do
    direction_map =
      case direction do
        [from: from, to: to] -> %{to: "#{to}", from: "#{from}"}
        [from, to] -> %{to: "#{to}", from: "#{from}"}
        {from, to} -> %{to: "#{to}", from: "#{from}"}
        %{from: from, to: to} -> %{to: "#{to}", from: "#{from}"}
        %{to: to} -> %{to: "#{to}", from: nil}
        [to: to] -> %{to: "#{to}", from: nil}
        to -> %{to: "#{to}", from: nil}
      end

    Commons.struct_from_map(direction_map, as: %__MODULE__{})
  end
end