OssError OssClientImpl::buildError()

in sdk/src/OssClientImpl.cc [230:274]
42 lines of code
14 McCabe index (conditional complexity)

OssError OssClientImpl::buildError(const Error &error) const
{
    OssError err;
    if (((error.Status() == 203) || (error.Status() > 299 && error.Status() < 600)) && 
        !error.Message().empty()) {
        XMLDocument doc;
        XMLError xml_err;
        if ((xml_err = doc.Parse(error.Message().c_str(), error.Message().size())) == XML_SUCCESS) {
            XMLElement* root =doc.RootElement();
            if (root && !std::strncmp("Error", root->Name(), 5)) {
                XMLElement *node;
                node = root->FirstChildElement("Code");
                err.setCode(node ? node->GetText(): "");
                node = root->FirstChildElement("Message");
                err.setMessage(node ? node->GetText(): "");
                node = root->FirstChildElement("RequestId");
                err.setRequestId(node ? node->GetText(): "");
                node = root->FirstChildElement("HostId");
                err.setHost(node ? node->GetText(): "");
            } else {
                err.setCode("ParseXMLError");
                err.setMessage("Xml format invalid, root node name is not Error. the content is:\n" + error.Message());
            }
        } else {
            std::stringstream ss;
            ss << "ParseXMLError:" << xml_err;
            err.setCode(ss.str());
            err.setMessage(XMLDocument::ErrorIDToName(xml_err));
        }
    } 
    else {
        err.setCode(error.Code());
        err.setMessage(error.Message());
    }

    //get from header if body has nothing
    if (err.RequestId().empty()) {
        auto it = error.Headers().find("x-oss-request-id");
        if (it != error.Headers().end()) {
            err.setRequestId(it->second);
        }
    }

    return err;
}