/**
    * This file Copyright (c) 2003-2011 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.templating;
  
  import info.magnolia.cms.core.Content;
  import info.magnolia.cms.core.ItemType;
  import info.magnolia.cms.beans.config.ObservedManager;
  import info.magnolia.objectfactory.Classes;
  import info.magnolia.objectfactory.Components;
  
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.Map;
  
  import org.apache.commons.lang.StringUtils;
  
  
  /**
   * Manages the template renderers of the system.
   * @author fgiust
   * @version $Revision: 41137 $ ($Author: gjoseph $)
   */
  public class TemplateRendererManager extends ObservedManager {
  
      private static final String ND_RENDERER = "renderer";
  
      private static final String ND_TYPE = "type";
  
      private Map renderers = new HashMap();
  
      /**
       * @return Returns the instance.
       */
      public static TemplateRendererManager getInstance() {
          return Components.getSingleton(TemplateRendererManager.class);
      }
  
      /**
       * @see info.magnolia.cms.beans.config.ObservedManager#onRegister(info.magnolia.cms.core.Content)
       */
      protected void onRegister(Content node) {
          Collection list = node.getChildren(ItemType.CONTENTNODE);
          for (Iterator iter = list.iterator(); iter.hasNext();) {
              Content tr = (Content) iter.next();
              String type = tr.getNodeData(ND_TYPE).getString();
              String rendererClass = tr.getNodeData(ND_RENDERER).getString();
  
              if (StringUtils.isEmpty(type)) {
                  type = tr.getName();
              }
  
              if (StringUtils.isBlank(type) || StringUtils.isBlank(rendererClass)) {
                  log.warn("Can't register template render at {}, type=\"{}\" renderer=\"{}\"", new Object[]{tr.getHandle(), type, rendererClass});
                  continue;
              }
  
  
              try {
                  final TemplateRenderer renderer = (TemplateRenderer) Classes.newInstance(rendererClass);
                  log.debug("Registering template render [{}] for type {}", rendererClass, type);
                  registerTemplateRenderer(type, renderer);
              }
              catch (Exception e) {
                  log.warn("Can't register template renderer at {}, type=\"{}\" renderer=\"{}\" due to a {} exception: {}", new Object[]{tr.getHandle(), type, rendererClass, e.getClass().getName(), e.getMessage()}, e);
              }
  
          }
 
     }
 
     /**
      * @see info.magnolia.cms.beans.config.ObservedManager#onClear()
      */
     protected void onClear() {
         this.renderers.clear();
     }
 
     public void registerTemplateRenderer(String type, TemplateRenderer instance) {
         synchronized (renderers) {
             renderers.put(type, instance);
         }
     }
 
     public TemplateRenderer getRenderer(String type) {
         return (TemplateRenderer) renderers.get(type);
     }
 
 }