/*

  * Copyright 2007 The Kuali Foundation

  *

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  *

  * 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.

  */

 package org.kuali.rice.ken.service.impl;

 import java.sql.Timestamp;

 import java.util.ArrayList;

 import java.util.Collection;

 import java.util.HashSet;

 import java.util.Iterator;

 import java.util.List;

 import java.util.concurrent.ExecutorService;

 import org.kuali.rice.core.dao.GenericDao;

 import org.kuali.rice.ken.bo.Notification;

 import org.kuali.rice.ken.bo.NotificationMessageDelivery;

 import org.kuali.rice.ken.bo.NotificationRecipient;

 import org.kuali.rice.ken.bo.NotificationRecipientList;

 import org.kuali.rice.ken.bo.UserChannelSubscription;

 import org.kuali.rice.ken.deliverer.impl.KEWActionListMessageDeliverer;

 import org.kuali.rice.ken.exception.NotificationMessageDeliveryException;

 import org.kuali.rice.ken.service.NotificationMessageDeliveryResolverService;

 import org.kuali.rice.ken.service.NotificationRecipientService;

 import org.kuali.rice.ken.service.NotificationService;

 import org.kuali.rice.ken.service.ProcessingResult;

 import org.kuali.rice.ken.service.UserPreferenceService;

 import org.kuali.rice.ken.util.NotificationConstants;

 import org.kuali.rice.kim.util.KimConstants.KimGroupMemberTypes;

 import org.springframework.transaction.PlatformTransactionManager;

 /**

  * This is the default out-of-the-box implementation that leverages the status flag on a notification (RESOLVED versus UNRESOLVED) to determine whether

  * the notification's message deliveries need to be resolved or not.  This also looks at the start and auto remove

  * dates and times.

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public class NotificationMessageDeliveryResolverServiceImpl extends ConcurrentJob<Notification> implements NotificationMessageDeliveryResolverService {

     private static org.apache.log4j.Logger LOG = org.apache.log4j.Logger

         .getLogger(NotificationMessageDeliveryResolverServiceImpl.class);

     private NotificationRecipientService notificationRecipientService;

     private GenericDao businessObjectDao;

     private UserPreferenceService userPreferenceService;

     private NotificationService notificationService;

     /**

      * Constructs a NotificationMessageDeliveryDispatchServiceImpl instance.

      * @param notificationRecipientService

      * @param businessObjectDao

      * @param txManager

      * @param executor

      * @param userPreferenceService

      */

     public NotificationMessageDeliveryResolverServiceImpl(NotificationService notificationService, NotificationRecipientService notificationRecipientService,

             GenericDao businessObjectDao, PlatformTransactionManager txManager, ExecutorService executor,

             UserPreferenceService userPreferenceService) {

         super(txManager, executor);

         this.notificationService = notificationService;

         this.notificationRecipientService = notificationRecipientService;

         this.businessObjectDao = businessObjectDao;

         this.userPreferenceService = userPreferenceService;

     }

     /**

      * Obtains and marks as taken all unresolved (and untaken) notifications

      * @return a collection of available Notifications to process

      */

     @Override

     protected Collection<Notification> takeAvailableWorkItems() {

         Collection<Notification> nots = notificationService.takeNotificationsForResolution();

         LOG.debug("Took " + nots.size() + " notifications");

         for (Notification not: nots) {

             LOG.debug("Took notification: " + not.getId() + " " + not.getTitle());

         }

         return nots;

     }

     /**

      * This method is responsible for building out the complete recipient list, which will resolve all members for groups, and add

      * them to the official list only if they are not already in the list.

      * @param notification

      * @return HashSet<String>

      */

     private HashSet<String> buildCompleteRecipientList(Notification notification) {

         HashSet<String> completeRecipientList = new HashSet<String>(notification.getRecipients().size());

         // process the list that came in with the notification request

            for (int i = 0; i < notification.getRecipients().size(); i++) {

                NotificationRecipient recipient = notification.getRecipient(i);

                if (KimGroupMemberTypes.GROUP_MEMBER_TYPE.equals(recipient.getRecipientType())) {

                    // resolve group's users

                    String[] groupMembers = notificationRecipientService.getGroupMembers(recipient.getRecipientId());

                    for(int j = 0; j < groupMembers.length; j++) {

                        completeRecipientList.add(groupMembers[j]);

                    }

                } else {  // just a user, so add to the list

                    completeRecipientList.add(recipient.getRecipientId());

                }

            }

            // now process the default recipient lists that are associated with the channel

            Iterator<NotificationRecipientList> i = notification.getChannel().getRecipientLists().iterator();

            while (i.hasNext()) {

                NotificationRecipientList listRecipient  = i.next();

                if (KimGroupMemberTypes.GROUP_MEMBER_TYPE.equals(listRecipient.getRecipientType())) {

                    // resolve group's users

                    String[] groupMembers = notificationRecipientService.getGroupMembers(listRecipient.getRecipientId());

                    for (int j = 0; j < groupMembers.length; j++) {

                        completeRecipientList.add(groupMembers[j]);

                    }

                } else {  // just a user, so add to the list

                    completeRecipientList.add(listRecipient.getRecipientId());

                }

            }

            // now process the subscribers that are associated with the channel

            List<UserChannelSubscription> subscriptions = notification.getChannel().getSubscriptions();

            for (UserChannelSubscription subscription: subscriptions) {

                // NOTE: at this time channel subscriptions are USER-only - GROUP is not supported

                // this could be implemented by adding a recipientType/userType column as we do in

                // other recipient/user-related tables/BOs

                completeRecipientList.add(subscription.getUserId());

            }

            return completeRecipientList;

     }

     /**

      * Generates all message deliveries for a given notification and save thems to the database.

      * Updates each Notification record to indicate it has been resolved.

      * Should be performed within a separate transaction

      * @param notification the Notification for which to generate message deliveries

      * @return a count of the number of message deliveries generated

      */

     /* Perform within transaction */

     @Override

     protected Collection<Object> processWorkItems(Collection<Notification> notifications) {

         List<Object> successes = new ArrayList<Object>();

         // because this concurrent job does not performed grouping of work items, there should only

         // ever be one notification object per work unit anyway...

         for (Notification notification: notifications) {

             // now figure out each unique recipient for this notification

             HashSet<String> uniqueRecipients = buildCompleteRecipientList(notification);

             // now for each unique recipient, figure out each delivery end point and create a NotificationMessageDelivery record

             Iterator<String> j = uniqueRecipients.iterator();

             while(j.hasNext()) {

                 String userRecipientId = j.next();

                 NotificationMessageDelivery defaultMessageDelivery = new NotificationMessageDelivery();

                 defaultMessageDelivery.setMessageDeliveryStatus(NotificationConstants.MESSAGE_DELIVERY_STATUS.UNDELIVERED);

                 defaultMessageDelivery.setNotification(notification);

                 defaultMessageDelivery.setUserRecipientId(userRecipientId);

                 //now save that delivery end point; this record will be later processed by the dispatch service which will actually deliver it

                 businessObjectDao.save(defaultMessageDelivery);

                 try {

                     new KEWActionListMessageDeliverer().deliverMessage(defaultMessageDelivery);

                 } catch (NotificationMessageDeliveryException e) {

                     throw new RuntimeException(e);

                 }

                 // we have no delivery stage any more, anything we send to KCB needs to be considered "delivered" from

                 // the perspective of KEN

                 defaultMessageDelivery.setMessageDeliveryStatus(NotificationConstants.MESSAGE_DELIVERY_STATUS.DELIVERED);

                 businessObjectDao.save(defaultMessageDelivery);

                 successes.add(defaultMessageDelivery);

                 // also, update the status of the notification so that it's message deliveries are not resolved again

                 notification.setProcessingFlag(NotificationConstants.PROCESSING_FLAGS.RESOLVED);

                 // unlock the record now

                 notification.setLockedDate(null);

                 businessObjectDao.save(notification);

             }

         }

         return successes;

     }

     /**

      * @see org.kuali.rice.ken.service.impl.ConcurrentJob#unlockWorkItem(java.lang.Object)

      */

     @Override

     protected void unlockWorkItem(Notification notification) {

         LOG.debug("Unlocking notification: " + notification.getId() + " " + notification.getTitle());

         notificationService.unlockNotification(notification);

     }

     /**

      * This method is responsible for resolving the list of NotificationMessageDelivery records for a given notification.  This service will look

      * at all notifications that are ready to be delivered and will "explode" out specific message delivery records for given delivery end points.

      * @see org.kuali.rice.ken.service.NotificationMessageDeliveryResolverService#resolveNotificationMessageDeliveries()

      */

     public ProcessingResult resolveNotificationMessageDeliveries() {

         LOG.debug("[" + new Timestamp(System.currentTimeMillis()).toString() + "] STARTING RESOLUTION OF NOTIFICATION MESSAGE DELIVERIES");

         ProcessingResult result = run();

         LOG.debug("[" + new Timestamp(System.currentTimeMillis()).toString() + "] FINISHED RESOLUTION OF NOTIFICATION MESSAGE DELIVERIES - " +

                   "Message Delivery End Points Resolved = " + result.getSuccesses().size());

         return result;

     }

 }