/**
    * This file Copyright (c) 2010-2013 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.rendering.renderer.registry;
  
  import info.magnolia.cms.util.ModuleConfigurationObservingManager;
  import info.magnolia.jcr.predicate.AbstractPredicate;
  import info.magnolia.jcr.predicate.NodeTypePredicate;
  import info.magnolia.jcr.util.NodeTypes;
  import info.magnolia.jcr.util.NodeUtil;
  import info.magnolia.jcr.util.NodeVisitor;
  import info.magnolia.module.ModuleRegistry;
  
  import java.util.ArrayList;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  import javax.inject.Inject;
  import javax.inject.Singleton;
  import javax.jcr.Node;
  import javax.jcr.RepositoryException;
  
  import org.apache.commons.lang.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * ObservedManager for {@link info.magnolia.rendering.renderer.Renderer} configured in repository.
   */
  @Singleton
  public class ConfiguredRendererManager extends ModuleConfigurationObservingManager {
  
      protected final Logger log = LoggerFactory.getLogger(getClass());
  
      private Set<String> registeredIds = new HashSet<String>();
      private final RendererRegistry registry;
  
      public static final String LISTENERS_NODE_NAME = "listeners";
      public static final String RENDER_EMPTY_AREAS_PROPERTY = "renderEmptyAreas";
  
      @Inject
      public ConfiguredRendererManager(ModuleRegistry moduleRegistry, RendererRegistry registry) {
          super("renderers", moduleRegistry);
          this.registry = registry;
      }
  
      @Override
      protected void reload(List<Node> nodes) throws RepositoryException {
  
          final List<RendererProvider> providers = new ArrayList<RendererProvider>();
  
          for (Node node : nodes) {
  
              NodeUtil.visit(node, new NodeVisitor() {
  
                  @Override
                  public void visit(Node parent) throws RepositoryException {
                      for (Node configNode : NodeUtil.getNodes(parent, LISTENERS_FILTER)) {
                          RendererProvider provider = readProvider(configNode);
                          if (provider != null) {
                              providers.add(provider);
                          }
                      }
                  }
              }, new NodeTypePredicate(NodeTypes.Content.NAME, false));
  
              readListeners(node); // register listeners
          }
 
         this.registeredIds = registry.unregisterAndRegister(registeredIds, providers);
     }
 
     protected RendererProvider readProvider(Node rendererNode) throws RepositoryException {
         final String id = createId(rendererNode);
 
         try {
             return new ConfiguredRendererProvider(id, rendererNode);
         } catch (Exception e) {
             log.error("Unable to create provider renderer [" + id + "]", e);
             return null;
         }
     }
 
     private String createId(Node rendererNode) throws RepositoryException {
         return rendererNode.getName();
     }
 
     private void readListeners(Node configNode) throws RepositoryException {
         if (!configNode.hasNode(LISTENERS_NODE_NAME)) {
             return; // no listeners
         }
         for (Node node : NodeUtil.getNodes(configNode.getNode("listeners"), NodeTypes.ContentNode.NAME)) {
             if (!node.hasProperty("class") || StringUtils.isEmpty(node.getProperty("class").getString())) { // editing might be not finished
                 continue;
             }
             final String className = node.getProperty("class").getString();
             registry.registerListener(className);
         }
     }
 
     private final AbstractPredicate<Node> LISTENERS_FILTER = new AbstractPredicate<Node>() {
 
         @Override
         public boolean evaluateTyped(Node node) {
 
             try {
                 String nodeTypeName = node.getPrimaryNodeType().getName();
                 return nodeTypeName.equals(NodeTypes.ContentNode.NAME) && !LISTENERS_NODE_NAME.equals(node.getName());
             } catch (RepositoryException e) {
                 log.error("Unable to read nodeType for node {}", node);
             }
             return false;
         }
     };
 }