/**
    * Copyright 2005-2013 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.kcb.quartz;
  
  import org.apache.log4j.Logger;
  import org.kuali.rice.core.framework.persistence.dao.GenericDao;
  import org.kuali.rice.kcb.bo.Message;
  import org.kuali.rice.kcb.bo.MessageDelivery;
  import org.kuali.rice.kcb.bo.MessageDeliveryStatus;
  import org.kuali.rice.kcb.deliverer.BulkMessageDeliverer;
  import org.kuali.rice.kcb.deliverer.MessageDeliverer;
  import org.kuali.rice.kcb.api.exception.MessageDeliveryProcessingException;
  import org.kuali.rice.kcb.quartz.ProcessingResult.Failure;
  import org.kuali.rice.kcb.service.GlobalKCBServiceLocator;
  import org.kuali.rice.kcb.service.MessageDelivererRegistryService;
  import org.kuali.rice.kcb.service.MessageDeliveryService;
  import org.kuali.rice.kcb.service.MessageService;
  import org.quartz.JobExecutionContext;
  import org.quartz.JobExecutionException;
  import org.quartz.StatefulJob;
  import org.springframework.beans.factory.annotation.Required;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  /**
   * Job that delivers messages to endpoints.  This job is not really stateful,
   * but should not be executed concurrently.
   * 
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class MessageProcessingJob extends ConcurrentJob<MessageDelivery> implements StatefulJob {
      public static final String NAME = "MessageProcessingJobDetail";
      public static final String GROUP = "KCB-Delivery";
  
      public static enum Mode {
          DELIVER, REMOVE
      }
  
      private static final Logger LOG = Logger.getLogger(MessageProcessingJob.class);
      
      private GenericDao dao;
      private MessageDelivererRegistryService registry;
      private MessageDeliveryService messageDeliveryService;
      private Long messageId;
      private Mode mode = null;
      private String user;
      private String cause;
  
      public MessageProcessingJob(Long messageId, Mode mode, String user, String cause) {
          this();
          this.messageId = messageId;
          this.mode = mode;
          this.user = user;
          this.cause = cause;
      }
  
  
      public MessageProcessingJob() {
          dao = GlobalKCBServiceLocator.getInstance().getKcbGenericDao();
          registry = GlobalKCBServiceLocator.getInstance().getMessageDelivererRegistryService();
          messageDeliveryService = GlobalKCBServiceLocator.getInstance().getMessageDeliveryService();
          txManager = GlobalKCBServiceLocator.getInstance().getTransactionManager();
      }
  
      /**
       * Sets the {@link GenericDao}
       * @param dao the {@link GenericDao}
       */
      @Required
      public void setGenericDao(GenericDao dao) {
          this.dao = dao;
      }
  
      /**
       * Sets the {@link MessageDelivererRegistryService}
       * @param registry the {@link MessageDelivererRegistryService}
       */
      @Required
      public void setMessageDelivererRegistry(MessageDelivererRegistryService registry) {
         this.registry = registry;
     }
     
     /**
      * Sets the {@link MessageDeliveryService}
      * @param messageDeliveryService the {@link MessageDeliveryService}
      */
     @Required
     public void setMessageDeliveryService(MessageDeliveryService messageDeliveryService) {
         this.messageDeliveryService = messageDeliveryService;
     }
 
     @Override
     protected Collection<MessageDelivery> takeAvailableWorkItems() {
         MessageDeliveryStatus[] statuses;
         switch (mode) {
             case DELIVER: {
                 statuses = new MessageDeliveryStatus[] { MessageDeliveryStatus.UNDELIVERED };
                 break;
             }
             case REMOVE: {
                 if (messageId == null) {
                     throw new IllegalStateException("Message id must be specified for message removal mode");
                 }
                 statuses = new MessageDeliveryStatus[] { MessageDeliveryStatus.DELIVERED, MessageDeliveryStatus.UNDELIVERED };
                 break;
             }
             default:
                 throw new RuntimeException("Invalid mode: " + mode);
         }
         for (MessageDeliveryStatus status: statuses) {
             LOG.debug("Taking message deliveries with status: " + status);
         }
         Collection<MessageDelivery> ds = messageDeliveryService.lockAndTakeMessageDeliveries(messageId, statuses);
         LOG.debug("Took " + ds.size() + " deliveries");
         for (MessageDelivery md: ds) {
             LOG.debug(md);
             md.setProcessCount(md.getProcessCount().intValue() + 1);
         }
         return ds;
     }
 
     @Override
     protected void unlockWorkItem(MessageDelivery item) {
         item.setLockedDate(null);
         dao.save(item);
     }
 
     /**
      * Group work items by deliverer and notification, so that deliveries to bulk deliverers are grouped
      * by notification
      * @see org.kuali.rice.ken.service.impl.ConcurrentJob#groupWorkItems(java.util.Collection)
      */
     @Override
     protected Collection<Collection<MessageDelivery>> groupWorkItems(Collection<MessageDelivery> workItems, ProcessingResult<MessageDelivery> result) {
         Collection<Collection<MessageDelivery>> groupedWorkItems = new ArrayList<Collection<MessageDelivery>>(workItems.size());
 
         Map<String, Collection<MessageDelivery>> bulkWorkUnits = new HashMap<String, Collection<MessageDelivery>>();
         for (MessageDelivery messageDelivery: workItems) {
             
             MessageDeliverer deliverer = registry.getDeliverer(messageDelivery);
             if (deliverer == null) {
                 LOG.error("Error obtaining message deliverer for message delivery: " + messageDelivery);
                 result.addFailure(new Failure<MessageDelivery>(messageDelivery, "Error obtaining message deliverer for message delivery"));
                 unlockWorkItemAtomically(messageDelivery);
                 continue;
             }
 
             if (deliverer instanceof BulkMessageDeliverer) {
                 // group by bulk-deliverer+message combo
                 String key = messageDelivery.getDelivererTypeName() + ":" + messageDelivery.getMessage().getId();
                 Collection<MessageDelivery> workUnit = bulkWorkUnits.get(key);
                 if (workUnit == null) {
                     workUnit = new LinkedList<MessageDelivery>();
                     bulkWorkUnits.put(key, workUnit);
                 }
                 workUnit.add(messageDelivery);
             } else {
                 ArrayList<MessageDelivery> l = new ArrayList<MessageDelivery>(1);
                 l.add(messageDelivery);
                 groupedWorkItems.add(l);
             }
         }
 
         return groupedWorkItems;
     }
     
     
     @Override
     protected Collection<MessageDelivery> processWorkItems(Collection<MessageDelivery> messageDeliveries) {
         MessageDelivery firstMessageDelivery = messageDeliveries.iterator().next();
         // get our hands on the appropriate MessageDeliverer instance
         MessageDeliverer messageDeliverer = registry.getDeliverer(firstMessageDelivery);
         if (messageDeliverer == null) {
             throw new RuntimeException("Message deliverer could not be obtained");
         }
     
         if (messageDeliveries.size() > 1) {
             // this is a bulk deliverer, so we need to batch the MessageDeliveries
             if (!(messageDeliverer instanceof BulkMessageDeliverer)) {
                 throw new RuntimeException("Discrepency in dispatch service: deliverer for list of message deliveries is not a BulkMessageDeliverer");
             }
             return bulkProcess((BulkMessageDeliverer) messageDeliverer, messageDeliveries, mode);
         } else {
             return process(messageDeliverer, firstMessageDelivery, mode);
         }
     }
 
     /**
      * Implements delivery of a single MessageDelivery
      * @param deliverer the deliverer
      * @param messageDelivery the delivery
      * @return collection of strings indicating successful deliveries
      */
     protected Collection<MessageDelivery> process(MessageDeliverer messageDeliverer, MessageDelivery messageDelivery, Mode mode) {
         // we have our message deliverer, so tell it to deliver the message
         try {
             if (mode == Mode.DELIVER) {
                 messageDeliverer.deliver(messageDelivery);
                 // if processing was successful, set the count back to zero
                 messageDelivery.setProcessCount(Integer.valueOf(0));
                 // by definition we have succeeded at this point if no exception was thrown by the messageDeliverer
                 // so update the status of the delivery message instance to DELIVERED (and unmark as taken)
                 // and persist
                 updateStatusAndUnlock(messageDelivery, mode == Mode.DELIVER ? MessageDeliveryStatus.DELIVERED : MessageDeliveryStatus.REMOVED);
             } else {
                 messageDeliverer.dismiss(messageDelivery, user, cause);
                 // don't need to set the processing count down to zero because we are just deleting the record entirely
                 messageDeliveryService.deleteMessageDelivery(messageDelivery);
             }
         } catch (MessageDeliveryProcessingException nmde) {
             LOG.error("Error processing message delivery " + messageDelivery, nmde);
             throw new RuntimeException(nmde);
         }
 
         LOG.debug("Message delivery '" + messageDelivery.getId() + "' for message '" + messageDelivery.getMessage().getId() + "' was successfully processed.");
         //PerformanceLog.logDuration("Time to dispatch notification delivery for notification " + messageDelivery.getMessage().getId(), System.currentTimeMillis() - messageDelivery.getNotification().getSendDateTime().getTime());
 
         List<MessageDelivery> success = new ArrayList<MessageDelivery>(1);
         success.add(messageDelivery);
         return success;
     }
 
     /**
      * Implements bulk delivery of a collection of {@link MessageDelivery}s
      * @param deliverer the deliverer
      * @param messageDeliveries the deliveries
      * @return collection of strings indicating successful deliveries
      */
     protected Collection<MessageDelivery> bulkProcess(BulkMessageDeliverer messageDeliverer, Collection<MessageDelivery> messageDeliveries,  Mode mode) {
         MessageDeliveryStatus targetStatus = (mode == Mode.DELIVER ? MessageDeliveryStatus.DELIVERED : MessageDeliveryStatus.REMOVED);
         // we have our message deliverer, so tell it to deliver the message
         try {
             if (mode == Mode.DELIVER) {
                 messageDeliverer.bulkDeliver(messageDeliveries);
             } else {
                 messageDeliverer.bulkDismiss(messageDeliveries);
             }
         } catch (MessageDeliveryProcessingException nmde) {
             LOG.error("Error bulk-delivering messages " + messageDeliveries, nmde);
             throw new RuntimeException(nmde);
         }
 
         // by definition we have succeeded at this point if no exception was thrown by the messageDeliverer
         // so update the status of the delivery message instance to DELIVERED (and unmark as taken)
         // and persist
         List<MessageDelivery> successes = new ArrayList<MessageDelivery>(messageDeliveries.size());
         for (MessageDelivery nmd: messageDeliveries) {
             successes.add(nmd);
             LOG.debug("Message delivery '" + nmd.getId() + "' for notification '" + nmd.getMessage().getId() + "' was successfully delivered.");
             //PerformanceLog.logDuration("Time to dispatch notification delivery for notification " + nmd.getMessage().getId(), System.currentTimeMillis() - nmd.getNotification().getSendDateTime().getTime());
             if (mode == Mode.REMOVE) {
                 messageDeliveryService.deleteMessageDelivery(nmd);
             } else {
                 nmd.setProcessCount(0);
                 updateStatusAndUnlock(nmd, targetStatus);                
             }
         }
         
         return successes;
     }
 
     @Override
     protected void finishProcessing(ProcessingResult<MessageDelivery> result) {
         LOG.debug("Message processing job: " + result.getSuccesses().size() + " processed, " + result.getFailures().size() + " failures");
         Set<Long> messageIds = new HashSet<Long>(result.getSuccesses().size());
         for (MessageDelivery md: result.getSuccesses()) {
             messageIds.add(md.getMessage().getId());
         }
         MessageService ms = GlobalKCBServiceLocator.getInstance().getMessageService();
         for (Long id: messageIds) {
             LOG.debug("Finishing processing message " + id);
             //if (Mode.REMOVE == mode) {
             
             Message m = ms.getMessage(id);
             
             Collection<MessageDelivery> c = messageDeliveryService.getMessageDeliveries(m);
             if (c.size() == 0) {
                 LOG.debug("Deleting message " + m);
                 ms.deleteMessage(m);
             } else {
                 LOG.debug("Message " + m.getId() + " has " + c.size() + " deliveries");
                 for (MessageDelivery md: c) {
                     LOG.debug(md);
                 }
             }
         }
     }
 
     /**
      * Marks a MessageDelivery as having been delivered, and unlocks it
      * @param messageDelivery the messageDelivery instance to mark
      */
     protected void updateStatusAndUnlock(MessageDelivery messageDelivery, MessageDeliveryStatus status) {
         messageDelivery.setDeliveryStatus(status);
         // mark as unlocked
         messageDelivery.setLockedDate(null);
         dao.save(messageDelivery);
     }
 
     @Override
     public ProcessingResult<MessageDelivery> run() {
         LOG.debug("MessageProcessingJob running in Thread " + Thread.currentThread() + ": " + mode + " " + user + " " + cause);
         return super.run();
     }
 
     public void execute(JobExecutionContext context) throws JobExecutionException {
         String mode = context.getMergedJobDataMap().getString("mode");
         if (mode != null) {
             this.mode = Mode.valueOf(mode);
         } else {
             this.mode = Mode.DELIVER;
         }
         this.user = context.getMergedJobDataMap().getString("user");
         this.cause = context.getMergedJobDataMap().getString("cause");
         if (context.getMergedJobDataMap().containsKey("messageId")) {
             this.messageId = context.getMergedJobDataMap().getLong("messageId");
         }
         LOG.debug("==== message processing job: " + this.mode + " message id: " + this.messageId + "====");
         super.run();
     }
 }