defmodule NOP.Element.Statistics do
  defmacro __using__([]) do
    quote do

      defp get_statistics_from_state(state) do
        Map.get(state, :statistics)
      end

      defp add_statistics_to_state(state, count) do
        old = get_statistics_from_state(state)
        Map.put(state, :statistics, old + count)
      end

      defp reset_statistics_to_state(state) do
        Map.put(state, :statistics, 0)
      end

      defp get_timestamp() do
        :erlang.now()
      end

      def diff_between_timestamp({_beg_g, beg_s, beg_m}, {_end_g, end_s, end_m}) do
        ((end_s * 1000) + end_m) - ((beg_s * 1000) + beg_m)
      end

      def handle_call(:get_statistics, _from, state) do
        {:reply, get_statistics_from_state(state), state}
      end

      def handle_cast(:reset_statistics, state) do
        {:noreply, reset_statistics_to_state(state)}
      end

    end
  end
end