/*
    * Copyright (C) 2007 ETH Zurich
    *
    * This file is part of Fosstrak (www.fosstrak.org).
    *
    * Fosstrak is free software; you can redistribute it and/or
    * modify it under the terms of the GNU Lesser General Public
    * License version 2.1, as published by the Free Software Foundation.
    *
   * Fosstrak is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with Fosstrak; if not, write to the Free
   * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
   * Boston, MA  02110-1301  USA
   */
  
  package org.fosstrak.epcis.repository.query;
  
  import java.util.Calendar;
  
  import javax.management.Notification;
  import javax.management.timer.Timer;
  
  import org.fosstrak.epcis.model.ArrayOfString;
  import org.fosstrak.epcis.model.Poll;
  import org.fosstrak.epcis.model.QueryParam;
  import org.fosstrak.epcis.model.QueryParams;
  import org.fosstrak.epcis.model.QueryResults;
  import org.fosstrak.epcis.soap.ImplementationExceptionResponse;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  /**
   * Implementation of triggers. The Schedule checks every once in a while on the
   * trigger condition. If the trigger condition is met the query associated with
   * the subscription is executed. The checking frequency may be changed in the
   * properties.
   * 
   * @author Andrea Grössbauer
   */
  public class QuerySubscriptionTriggered extends QuerySubscriptionScheduled {
  
      private static final long serialVersionUID = 658402150914797471L;
  
      private static final Log LOG = LogFactory.getLog(QuerySubscriptionTriggered.class);
  
      private String trigger;
  
      public QuerySubscriptionTriggered(final String subscriptionID, final QueryParams queryParams, final String dest,
              final Boolean reportIfEmpty, final Calendar initialRecordTime,
              final Calendar lastTimeExecuted, final String queryName, final String trigger,
              final Schedule every10min) throws ImplementationExceptionResponse {
          super(subscriptionID, queryParams, dest, reportIfEmpty, initialRecordTime, lastTimeExecuted, every10min,
                queryName);
          this.trigger = trigger;
      }
  
      /**
       * {@inheritDoc} First checks on the trigger condition: if fulfilled then
       * execute Query.
       * 
       * @see org.fosstrak.epcis.repository.query.QuerySubscriptionScheduled#handleNotification(javax.management.Notification,
       *      java.lang.Object)
       */
      @Override
      public void handleNotification(final Notification pNotification, final Object pHandback) {
          if (pHandback == null) {
              LOG.error("The timer stating the next scheduled query execution time is null!");
              return;
          }
          Timer timer = (Timer) pHandback;
  
          if (!doItAgain.booleanValue()) {
              timer.stop();
          } else {
              try {
                  LOG.debug("Checking trigger condition ...");
                  String queryName = "SimpleEventQuery";
                  QueryParams params = new QueryParams();
  
                  // add MATCH_anyEPC query param
                  QueryParam param = new QueryParam();
                  param.setName("MATCH_anyEPC");
                  ArrayOfString strings = new ArrayOfString();
                  strings.getString().add(trigger);
                  param.setValue(strings);
                  params.getParam().add(param);
  
                  // add GE_recordTime query param
                  param = new QueryParam();
                  param.setName("GE_recordTime");
                  param.setValue(initialRecordTime);
                  params.getParam().add(param);
  
                  // send the query
                 Poll poll = new Poll();
                 poll.setParams(params);
                 poll.setQueryName(queryName);
                 QueryResults results = executePoll(poll);
                 if (results != null && results.getResultsBody() != null
                         && results.getResultsBody().getEventList() != null) {
                     LOG.debug("Trigger condition fulfilled!");
                     LOG.debug("Executing subscribed query associated with trigger event ...");
                     super.executeQuery();
                     LOG.debug("Triggered query successfully executed!");
                 }
             } catch (Exception e) {
                 String msg = "An error occurred while checking trigger condition for query with subscriptionID '"
                         + subscriptionID + "': " + e.getMessage();
                 LOG.error(msg, e);
             }
 
             // determine next scheduled execution time
             setNextScheduledExecutionTime(timer);
         }
     }
 }