/**
   * If the user wants to access a service URL we must check if he is logged into the service.
   *
   * @return the given HTTP request, a request wrapper which must be used to perform the service
   *     login or null if the caller should continue with the filter chain
   * @throws IOException
   * @throws ServletException
   * @throws DatatypeConfigurationException
   * @throws SAML2AuthnRequestException
   * @throws Exception
   */
  private HttpServletRequest processServiceUrl(
      HttpServletRequest request,
      HttpServletResponse response,
      FilterChain chain,
      String subKey,
      String contextPath,
      AuthorizationRequestData rdo)
      throws ServletException, IOException {

    HttpSession session = request.getSession();
    ServiceAccess serviceAccess = ServiceAccess.getServiceAcccessFor(session);

    if ("/".equals(contextPath) && !BesServletRequestReader.onlyServiceLogin(session)) {
      // if the user accesses a subscription from the my subscription list
      // we check the subscription key map in the session (this causes
      // some overhead - EJB call - and should NOT be done for every
      // service request)

      // preserve mId
      String mId = (String) session.getAttribute(Constants.REQ_PARAM_MARKETPLACE_ID);

      SessionListener.cleanup(session);

      session = request.getSession();
      session.setAttribute(Constants.REQ_PARAM_MARKETPLACE_ID, mId);
    }

    Map<String, VOSubscription> map = getSubMapFromSession(session);
    VOSubscription sub = map.get(subKey);
    VOUserDetails userDetails = (VOUserDetails) session.getAttribute(Constants.SESS_ATTR_USER);
    if (BesServletRequestReader.onlyServiceLogin(session)) {
      session.removeAttribute(Constants.SESS_ATTR_ONLY_SERVICE_LOGIN);

      // at least remove the user details from the session
      session.removeAttribute(Constants.SESS_ATTR_USER);
      if (userDetails != null) {
        session.setAttribute(Constants.REQ_PARAM_LOCALE, userDetails.getLocale());
      }
    }

    if (userDetails != null
        && userDetails.getStatus() != UserAccountStatus.PASSWORD_MUST_BE_CHANGED) {
      // the user is already logged in

      if (sub == null) {
        // the user is not logged in the service, we must call the
        // SSO bridge

        sub = getSubscription(serviceAccess, subKey);

        if (sub == null) {
          UserNotAssignedException e =
              new UserNotAssignedException(subKey, userDetails.getUserId());
          logger.logError(
              Log4jLogger.SYSTEM_LOG | Log4jLogger.AUDIT_LOG,
              e,
              LogMessageIdentifier.ERROR_ACTIVE_SUBSCRIPTION_FOR_CURRENT_USER_FAILED,
              subKey);
          setErrorAttributesAndForward(
              getDefaultUrl(serviceAccess, rdo, request), request, response, e);
          return null;

        } else if (sub.getStatus() != SubscriptionStatus.ACTIVE
            && sub.getStatus() != SubscriptionStatus.PENDING_UPD) {
          SubscriptionStateException e =
              new SubscriptionStateException(
                  "Subscription '" + subKey + "' not active or pending update.",
                  Reason.ONLY_ACTIVE);
          logger.logError(
              Log4jLogger.SYSTEM_LOG | Log4jLogger.AUDIT_LOG,
              e,
              LogMessageIdentifier.ERROR_SUBSCRIPTION_NOT_ACTIVE,
              subKey);
          setErrorAttributesAndForward(
              getDefaultUrl(serviceAccess, rdo, request), request, response, e);
          return null;

        } else if (!sub.getServiceBaseURL()
            .toLowerCase()
            .startsWith(request.getScheme().toLowerCase() + "://")) {
          setErrorAttributesAndForward(errorPage, request, response, new ServiceSchemeException());
          return null;
        }

        String userToken = ADMStringUtils.getRandomString(40);

        // create a service session database record (which is used by
        // the service to resolve the user token)
        try {
          synchronized (map) {
            createServiceSession(serviceAccess, subKey, session.getId(), userToken);
            // the map must be filled after the service session was
            // created otherwise the session listener cleanup method
            // might clear the list
            map.put(subKey, sub);
          }
        } catch (ObjectNotFoundException e) {
          handleSubscriptionNotFound(chain, request, response, rdo);
          return null;
        } catch (ServiceParameterException e) {
          setErrorAttributesAndForward(Constants.SERVICE_USAGE_ERROR_URI, request, response, e);
          return null;
        } catch (SaaSApplicationException e) {
          setErrorAttributesAndForward(errorPage, request, response, e);
          return null;
        }

        if (sub.getServiceAccessType() == ServiceAccessType.LOGIN) {
          // perform a redirect to the SSO bridge with the user token
          String url = removeEndingSlash(sub.getServiceBaseURL());
          if (sub.getServiceLoginPath() != null) {
            url += sub.getServiceLoginPath();
          }
          if (url.contains("?")) {
            url += "&";
          } else {
            url += "?";
          }
          SsoParameters ssoParameters = new SsoParameters();
          ssoParameters.setContextPath(contextPath);
          ssoParameters.setInstanceId(sub.getServiceInstanceId());
          ssoParameters.setLanguage(userDetails.getLocale());
          ssoParameters.setSubscriptionKey(subKey);
          ssoParameters.setBssId(request.getSession().getId());
          ssoParameters.setUsertoken(userToken);
          url += ssoParameters.getQueryString();
          JSFUtils.sendRedirect(response, url);
          return null;
        }

      } else {
        if (sub.getServiceAccessType() == ServiceAccessType.LOGIN) {
          // send a redirect to the service base URL, the service
          // session should be still active
          JSFUtils.sendRedirect(response, sub.getServiceBaseURL());
          return null;
        }

        // nothing to do (the user is logged in the platform and the
        // service) the rewriting is done by the subsequent filters in
        // the filter chain which is activated by the caller
      }
    } else {
      // the user is not logged in

      if (sub == null) {
        // the user is neither logged in platform nor in the
        // service,
        //
        // The later processing will forward to the service login
        // page processing. After the login there will be a redirect to
        // the primarily requested URL which will perform the service
        // login
        session.setAttribute(Constants.SESS_ATTR_ONLY_SERVICE_LOGIN, Boolean.TRUE);

      } else {
        // the user is logged in the service

        if (sub.getServiceAccessType() == ServiceAccessType.LOGIN) {
          // send a redirect to the service base URL, the service
          // session should be still active
          JSFUtils.sendRedirect(response, sub.getServiceBaseURL());
        } else {
          // don't perform any other checks continue with the
          // filter chain which will perform the rewriting
          chain.doFilter(request, response);
        }
        return null;
      }
    }
    return request;
  }