frugality

defmodule Frugality.Generator.Default do
  @moduledoc false

  alias Frugality.Core.Utils

  @behaviour Frugality.Generator

  @impl true
  def etag(%{etag: etag}) when is_binary(etag),
    do: Utils.parse_entity_tag(etag)

  def etag(%{etag: {validation, tag} = etag})
      when validation in [:weak, :strong] and is_binary(tag),
      do: etag

  def etag(_), do: nil

  @impl true
  def last_modified(%{last_modified: dt}) when is_binary(dt),
    do: Utils.parse_httpdate(dt)

  def last_modified(%{last_modified: %s{} = dt})
      when s in [DateTime, NaiveDateTime],
      do: dt

  def last_modified(_), do: nil
end