/**
    * This file Copyright (c) 2003-2010 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.module.workflow;
  
  import info.magnolia.module.ModuleLifecycle;
  import info.magnolia.module.ModuleLifecycleContext;
  import info.magnolia.module.workflow.flows.FlowDefinitionManager;
  import info.magnolia.module.workflow.jcr.JCRPersistedEngine;
  import info.magnolia.module.workflow.jcr.JCRWorkItemStore;
  import info.magnolia.objectfactory.Components;
  import openwfe.org.ServiceException;
  import openwfe.org.engine.impl.expool.SimpleExpressionPool;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  /**
   * Module "workflow" entry class.
   *
   * @author Sameer Charles
   * @author Fabrizio Giustina
   * @author Nicolas Modrzyk
   * @version 3.0
   */
  public class WorkflowModule implements ModuleLifecycle {
  
      private static final Logger log = LoggerFactory.getLogger(WorkflowModule.class);
  
      private static WorkflowModule instance;
  
      /**
       * The current used engine
       */
      private JCRPersistedEngine wfEngine;
  
      private JCRWorkItemStore workItemStore;
  
      /**
       * Do we backup the deleted workitems?
       */
      private boolean backupWorkItems = false;
  
      /**
       * Use life time jcr sessions or a session per operation
       */
      private boolean useLifeTimeJCRSession = true;
      
      
      public void start(ModuleLifecycleContext moduleLifecycleContext) {
          instance = this;
          startEngine();
          initializeWorkItemStore();
      }
      
      public void stop(ModuleLifecycleContext moduleLifecycleContext) {
          JCRPersistedEngine engine = getEngine();
          if (engine != null && engine.isRunning()) {
              log.info("Stopping workflow engine..");
              try {
                  // before try to stop purge and scheduling tasks
                  // TODO : this is already done by engine.stop() ... ?
                  ((SimpleExpressionPool) engine.getExpressionPool()).stop();
                  engine.stop();
              }
              catch (ServiceException se) {
                  log.error("Failed to stop Open WFE engine");
                  log.error(se.getMessage(), se);
             }
         }
     }
 
     /**
      * Cleanup empty parent nodes (for expressions, workitems)
      */
     private boolean cleanup = true;
 
     protected void startEngine() {
         try {
             log.info("Starting openwfe engine");
             wfEngine = new JCRPersistedEngine();
             wfEngine.registerParticipant(new MgnlParticipant(WorkflowConstants.PARTICIPANT_PREFIX_USER+".*"));
             wfEngine.registerParticipant(new MgnlParticipant(WorkflowConstants.PARTICIPANT_PREFIX_GROUP+".*"));
             wfEngine.registerParticipant(new MgnlParticipant(WorkflowConstants.PARTICIPANT_PREFIX_ROLE+".*"));
             wfEngine.registerParticipant(new MgnlParticipant(WorkflowConstants.PARTICIPANT_PREFIX_COMMAND+".*"));
         }
         catch (Exception e) {
             log.error("An exception arised when creating the workflow engine", e);
         }
     }
 
     protected void initializeWorkItemStore() {
         try {
             workItemStore = new JCRWorkItemStore(this.isUseLifeTimeJCRSession(), this.isCleanup(), this.isBackupWorkItems());
         }
         catch (Exception e) {
             log.error("can't initialize the workflow util", e);
         }
     }
 
     /**
      * return the global work flow engine
      */
     static public JCRPersistedEngine getEngine() {
         return instance.wfEngine;
     }
 
     /**
      * return the global work flow engine
      */
     static public JCRWorkItemStore getWorkItemStore() {
         return instance.workItemStore;
     }
 
     public static FlowDefinitionManager getFlowDefinitionManager() {
         return Components.getSingleton(FlowDefinitionManager.class);
     }
 
 
     public boolean isBackupWorkItems() {
         return this.backupWorkItems;
     }
 
 
     public void setBackupWorkItems(boolean backupWorkItems) {
         this.backupWorkItems = backupWorkItems;
     }
 
     public boolean isUseLifeTimeJCRSession() {
         return useLifeTimeJCRSession;
     }
 
     public void setUseLifeTimeJCRSession(boolean useLifeTimeJCRSession) {
         log.warn("Setting useLifeTimeJCRSession flag should not be used unless you really know what you do.");
 
         this.useLifeTimeJCRSession = useLifeTimeJCRSession;
     }
 
     public boolean isCleanup() {
         return cleanup;
     }
 
     public void setCleanup(boolean cleanup) {
         log.warn("Setting cleanup flag should not be used unless you really know what you do.");
         this.cleanup = cleanup;
     }
 
     public static WorkflowModule getInstance() {
         return instance;
     }
 
 }