class Aws::Rest::Response::Parser

def apply(response)
  # TODO : remove this unless check once response stubbing is fixed
  if rules = response.context.operation.output
    response.data = rules.shape.struct_class.new
    extract_status_code(rules, response)
    extract_headers(rules, response)
    extract_body(rules, response)
  else
    response.data = EmptyStructure.new
  end
end

def extract_body(rules, response)
  Body.new(parser_class(response), rules).
    apply(
      response.context.http_response.body,
      response.data
    )
end

def extract_headers(rules, response)
  headers = Headers.new(rules)
  headers.apply(response.context.http_response, response.data)
end

def extract_status_code(rules, response)
  status_code = StatusCode.new(rules)
  status_code.apply(response.context.http_response, response.data)
end

def parser_class(response)
  protocol = response.context.config.api.metadata['protocol']
  case protocol
  when 'rest-xml' then Xml::Parser
  when 'rest-json' then Json::Parser
  when 'api-gateway' then Json::Parser
  else raise "unsupported protocol #{protocol}"
  end
end