/**
    * This file Copyright (c) 2014-2015 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.ui.framework.task;
  
  import info.magnolia.cms.security.SecuritySupport;
  import info.magnolia.event.EventBus;
  import info.magnolia.event.SystemEventBus;
  import info.magnolia.task.Task;
  import info.magnolia.task.event.TaskEvent;
  import info.magnolia.task.event.TaskEventHandler;
  
  import java.util.Collection;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  import javax.inject.Inject;
  import javax.inject.Named;
  import javax.inject.Provider;
  import javax.inject.Singleton;
  
  import org.apache.commons.lang3.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.google.common.collect.ArrayListMultimap;
  import com.google.common.collect.ListMultimap;
  import com.google.common.collect.Multimaps;
  
  /**
   * LocalTaskDispatcherManager.
   */
  @Singleton
  public class LocalTaskDispatcherManager implements TaskEventHandler {
  
      private static final Logger log = LoggerFactory.getLogger(LocalTaskDispatcherManager.class);
  
      private final ListMultimap<String, TaskEventDispatcher> listeners = Multimaps.synchronizedListMultimap(ArrayListMultimap.<String, TaskEventDispatcher>create());
  
      private Provider<SecuritySupport> securitySupport;
  
      @Inject
      public LocalTaskDispatcherManager(@Named(SystemEventBus.NAME) final EventBus systemEventBus, Provider<SecuritySupport> securitySupport) {
          this.securitySupport = securitySupport;
          systemEventBus.addHandler(TaskEvent.class, this);
      }
  
      @Override
      public void taskClaimed(TaskEvent taskEvent) {
          Set<String> users = getAllRecipients(taskEvent.getTask());
          sendTaskEvent(taskEvent, users);
      }
  
      @Override
      public void taskAdded(TaskEvent taskEvent) {
          Set<String> users = getAllRecipients(taskEvent.getTask());
          sendTaskEvent(taskEvent, users);
      }
  
      @Override
      public void taskResolved(TaskEvent taskEvent) {
          Set<String> users = getAllRecipients(taskEvent.getTask());
          sendTaskEvent(taskEvent, users);
      }
  
      @Override
      public void taskFailed(TaskEvent taskEvent) {
          Set<String> users = getAllRecipients(taskEvent.getTask());
         sendTaskEvent(taskEvent, users);
     }
 
     @Override
     public void taskArchived(TaskEvent taskEvent) {
         Set<String> users = getAllRecipients(taskEvent.getTask());
         sendTaskEvent(taskEvent, users);
     }
 
     @Override
     public void taskRemoved(TaskEvent taskEvent) {
         Set<String> users = getAllRecipients(taskEvent.getTask());
         sendTaskEvent(taskEvent, users);
     }
 
     @Override
     public void taskScheduled(TaskEvent taskEvent) {
         Set<String> users = getAllRecipients(taskEvent.getTask());
         sendTaskEvent(taskEvent, users);
     }
 
     private Set<String> getAllRecipients(final Task task) {
 
         HashSet<String> users = new HashSet<String>();
 
         log.debug("Found actorId [{}]", task.getActorId());
         if (StringUtils.isNotBlank(task.getActorId())) {
             users.add(task.getActorId());
         }
 
         if (task.getActorIds() != null) {
             log.debug("Found actorIds {}", task.getActorIds());
             users.addAll(task.getActorIds());
         }
 
 
         log.debug("Found groups {}", task.getGroupIds());
         if (task.getGroupIds() != null) {
             for (String group : task.getGroupIds()) {
                 Collection<String> usersOfGroupTransitive = securitySupport.get().getUserManager().getUsersWithGroup(group, true);
                 users.addAll(usersOfGroupTransitive);
             }
         }
 
         return users;
     }
 
     private void sendTaskEvent(TaskEvent taskEvent, Set<String> users) {
 
         log.debug("Sending a task event to the following users {}", users);
         for (String userId : users) {
             final List<TaskEventDispatcher> listenerList = listeners.get(userId);
             if (listenerList != null) {
                 for (final TaskEventDispatcher listener : listenerList) {
                     listener.onTaskEvent(taskEvent);
                 }
             }
         }
     }
 
     public void registerLocalTasksListener(String userName, TaskEventDispatcher listener) {
         listeners.put(userName, listener);
     }
 
     public void unregisterLocalTasksListener(String userName, TaskEventDispatcher listener) {
         listeners.remove(userName, listener);
     }
 
 }