* Copyright 2012 Comcast Corporation

*

* Licensed under the Apache License, Version 2.0 (the "License");

* you may not use this file except in compliance with the License.

* You may obtain a copy of the License at

*

*   http://www.apache.org/licenses/LICENSE-2.0

*

* Unless required by applicable law or agreed to in writing, software

* distributed under the License is distributed on an "AS IS" BASIS,

* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

* See the License for the specific language governing permissions and

* limitations under the License.

*/

* Publish action

* @author bwolf, jorge, aseem

*

*/

  private static Logger logger = Logger.getLogger(CNSPublishAction.class);

 

    private static volatile User cnsInternalUser = null;

    private static volatile BasicAWSCredentials awsCredentials = null;

    private static volatile AmazonSQSClient sqs = null;

   

    public static final String CNS_PUBLISH_QUEUE_NAME_PREFIX = CMBProperties.getInstance().getCNSPublishQueueNamePrefix();

    public static final String CNS_ENDPOINT_QUEUE_NAME_PREFIX = CMBProperties.getInstance().getCNSEndpointPublishQueueNamePrefix();

   

    public CNSPublishAction() {

    super("Publish");

  }

 

    /**

     * The method simply gets the information from the user and request to call publish the message passed in

     * the "Message" field in the request parameters, and publish them to all endpoints subscribed to the topic

     * designated by the "TopicArn" field in the request, then take the response and generate an XML response

     * and put it in the parameter response

     * @param user the user for whom we are listing the subscription

     * @param asyncContext

     */

  @Override

  public boolean doAction(User user, AsyncContext asyncContext) throws Exception {

   

        CQSHttpServletRequest request = (CQSHttpServletRequest)asyncContext.getRequest();

        HttpServletResponse response = (HttpServletResponse)asyncContext.getResponse();

   

    if (cnsInternalUser == null) {

      IUserPersistence userHandler = PersistenceFactory.getUserPersistence();

          cnsInternalUser = userHandler.getUserByName(CMBProperties.getInstance().getCNSUserName());

          if (cnsInternalUser == null) {           

            cnsInternalUser =  userHandler.createDefaultUser();

          }

    }

   

    if (awsCredentials == null) {

          awsCredentials = new BasicAWSCredentials(cnsInternalUser.getAccessKey(), cnsInternalUser.getAccessSecret());

    }

   

    if (sqs == null) {

            sqs = new AmazonSQSClient(awsCredentials);

            sqs.setEndpoint(CMBProperties.getInstance().getCQSServiceUrl());

    }

   

      String userId = user.getUserId();

      String message = request.getParameter("Message");

      String topicArn = request.getParameter("TopicArn");

      String messageStructure = null;

      String subject = null;

     

      CNSMessage cnsMessage = new CNSMessage();

      cnsMessage.generateMessageId();

      cnsMessage.setTimestamp(new Date());

      cnsMessage.setMessage(message);

     

      //TODO: optional shortcut

     

      if (request.getParameter("MessageStructure") != null) {

       

        messageStructure = request.getParameter("MessageStructure");    

       

        if (!messageStructure.equals("json")) {

          logger.error("event=cns_publish error_code=InvalidParameters message=" + message + " message_structure=" + messageStructure + " topic_arn=" + topicArn + " user_id=" + userId);

          throw new CMBException(CNSErrorCodes.CNS_InvalidParameter,"Invalid parameter: Invalid Message Structure parameter: " + messageStructure);

        }

       

        cnsMessage.setMessageStructure(CNSMessage.CNSMessageStructure.valueOf(messageStructure));

    }

     

      if (request.getParameter("Subject") != null) {

        subject = request.getParameter("Subject");

        cnsMessage.setSubject(subject);

    }

     

      if ((userId == null) || (message == null)) {

        logger.error("event=cns_publish error_code=InvalidParameters message=" + message + " topic_arn=" + topicArn + " user_id=" + userId);

      throw new CMBException(CNSErrorCodes.CNS_ValidationError,"1 validation error detected: Value null at 'message' failed to satisfy constraint: Member must not be null");

      }

     

    if ((topicArn == null) || !Util.isValidTopicArn(topicArn)) {

      logger.error("event=cns_publish error_code=InvalidParameters message=" + message + " topic_arn=" + topicArn + " user_id=" + userId);

      throw new CMBException(CNSErrorCodes.CNS_InvalidParameter,"TopicArn");

      }

   

    CNSTopic topic = CNSCache.getTopic(topicArn);

   

      if (topic == null) {

        logger.error("event=cns_publish error_code=NotFound message=" + message + " topic_arn=" + topicArn + " user_id=" + userId);

      throw new CMBException(CNSErrorCodes.CNS_NotFound,"Resource not found.");

      }

   

      cnsMessage.setUserId(topic.getUserId());

      cnsMessage.setTopicArn(topicArn);

      cnsMessage.setMessageType(CNSMessageType.Notification);

     

      cnsMessage.checkIsValid();

     

      CNSTopicAttributes topicAttributes = CNSCache.getTopicAttributes(topicArn);

      List<String> receiptHandles = new ArrayList<String>();

     

      boolean success = true;

     

      if (topicAttributes != null && topicAttributes.getSubscriptionsConfirmed() == 0) {

       

        // optimization: don't do anything if there are no confirmed subscribers

       

        logger.warn("event=no_confirmed_subscribers action=publish topic_arn=" + topicArn);

     

      } else if (CMBProperties.getInstance().isCNSBypassPublishJobQueueForSmallTopics() && topicAttributes != null && topicAttributes.getSubscriptionsConfirmed() <= CMBProperties.getInstance().getCNSMaxSubscriptionsPerEndpointPublishJob()) {

       

        // optimization: if there's only one chunk due to few subscribers, write directly into endpoint publish queue bypassing the publish job queue

       

        logger.debug("event=using_job_queue_overpass");

       

        List<CNSEndpointPublishJob.CNSEndpointSubscriptionInfo> subscriptions = CNSEndpointPublisherJobProducer.getSubscriptionsForTopic(topicArn);

       

            if (subscriptions != null && subscriptions.size() > 0) {

             

                List<CNSEndpointPublishJob> epPublishJobs = CNSEndpointPublisherJobProducer.createEndpointPublishJobs(cnsMessage, subscriptions);

               

                if (epPublishJobs.size() != 1) {

                  logger.warn("event=unexpected_number_of_endpoint_publish_jobs count=" + epPublishJobs.size());

                }

               

                for (CNSEndpointPublishJob epPublishJob: epPublishJobs) {

                String handle = sendMessageOnRandomShardAndCreateQueueIfAbsent(CNS_ENDPOINT_QUEUE_NAME_PREFIX, CMBProperties.getInstance().getCNSNumEndpointPublishJobQueues(), epPublishJob.serialize(), cnsInternalUser.getUserId());

                if (handle != null && !handle.equals("")) {

                  receiptHandles.add(handle);

                } else {

                  success = false;

                }

                }

            }

       

      } else {

     

        // otherwise pick publish job queue

        logger.debug("event=going_through_job_queue_town_center");

       

        String handle = sendMessageOnRandomShardAndCreateQueueIfAbsent(CNS_PUBLISH_QUEUE_NAME_PREFIX, CMBProperties.getInstance().getCNSNumPublishJobQueues(), cnsMessage.serialize(), cnsInternalUser.getUserId());

        if (handle != null && !handle.equals("")) {

          receiptHandles.add(handle);

        } else {

          success = false;

        }

      } 

     

      if (!success) {

        throw new CMBException(CMBErrorCodes.InternalError, "Failed to place message on internal cns queue");

      }

     

      request.setReceiptHandles(receiptHandles);

     

      String out = CNSSubscriptionPopulator.getPublishResponse(receiptHandles);

        writeResponse(out, response);

     

      return true;

  }

 

  private String sendMessageOnRandomShardAndCreateQueueIfAbsent(String prefix, int numShards, String message, String userId) {

   

    String receiptHandle = null;

   

      long ts1 = System.currentTimeMillis();

      String queueName =  prefix + (new Random()).nextInt(numShards);

      String relativeQueueUrl = com.comcast.cqs.util.Util.getRelativeQueueUrlForName(queueName, userId);

     

      try {

        receiptHandle = CQSHandler.sendMessage(relativeQueueUrl, message);

        } catch (Exception ex) {

        logger.error("event=publish_failure", ex);

        CQSHandler.ensureQueuesExist(prefix, numShards);

        }

     

      long ts2 = System.currentTimeMillis();

      CMBControllerServlet.valueAccumulator.addToCounter(AccumulatorName.CNSCQSTime, ts2 - ts1);

     

      return receiptHandle;

  }

}