defimpl Timex.Comparable, for: Timex.AmbiguousDateTime do
  alias Timex.{Comparable, AmbiguousDateTime}

  @doc """
  See docs for `Timex.compare/3`
  """
  def compare(_, :distant_future, _granularity), do: -1
  def compare(_, :distant_past, _granularity), do: 1

  def compare(%AmbiguousDateTime{:after => a}, %AmbiguousDateTime{:after => b}, granularity) do
    Comparable.compare(a, b, granularity)
  end

  def compare(a, _b, _granularity) do
    {:error, {:ambiguous_comparison, a}}
  end

  def diff(%AmbiguousDateTime{:after => a}, %AmbiguousDateTime{:after => b}, granularity) do
    Comparable.diff(a, b, granularity)
  end

  def diff(a, _b, _granularity) do
    {:error, {:ambiguous_comparison, a}}
  end
end