class Aws::Binary::EncodeHandler

def call(context)
  if eventstream_member = eventstream_input?(context)
    input_es_handler = context[:input_event_stream_handler]
    input_es_handler.event_emitter.encoder = EventStreamEncoder.new(
      context.config.api.metadata['protocol'],
      eventstream_member,
      context.operation.input,
      signer_for(context)
    )
    context[:input_event_emitter] = input_es_handler.event_emitter
  end
  @handler.call(context)
end

def eventstream_input?(ctx)
  ctx.operation.input.shape.members.each do |_, ref|
    return ref if ref.eventstream
  end
end

def signer_for(context)
  # New endpoint/signing logic, use the auth scheme to make a signer
  if context[:auth_scheme]
    Aws::Plugins::Sign.signer_for(context[:auth_scheme], context.config)
  else
    # Previous implementation always assumed sigv4_signer from config.
    # Relies only on sigv4 signing (and plugin) for event stream services
    context.config.sigv4_signer
  end
end