defmodule Bolty.BoltProtocol.Message.BeginMessage do
  @moduledoc false

  alias Bolty.BoltProtocol.MessageEncoder

  @signature 0x11

  def encode(bolt_version, extra_parameters)
      when is_float(bolt_version) and bolt_version >= 3.0 do
    message = [get_extra_parameters(extra_parameters)]
    MessageEncoder.encode(@signature, message)
  end

  def encode(_, _) do
    {:error,
     Bolty.Error.wrap(__MODULE__, %{
       code: :unsupported_message_version,
       message: "BEGIN message version not supported"
     })}
  end

  defp get_extra_parameters(extra_parameters) do
    keys_to_extract = [:bookmarks, :mode, :db, :tx_metadata]
    Map.take(extra_parameters, keys_to_extract)
  end
end