/**
    * 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.admininterface;
  
  import info.magnolia.cms.beans.config.ObservedManager;
  import info.magnolia.cms.core.Content;
  import info.magnolia.cms.core.ItemType;
  import info.magnolia.cms.util.SystemContentWrapper;
  import info.magnolia.content2bean.Content2BeanUtil;
  import info.magnolia.objectfactory.Classes;
  import info.magnolia.objectfactory.Components;
  
  import java.lang.reflect.Constructor;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.Map;
  
  import javax.jcr.RepositoryException;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.commons.lang.StringUtils;
  
  public class TreeHandlerManager<H extends AdminTreeMVCHandler> extends ObservedManager {
  
      private static final String ND_CLASS = "class";
  
      private static final String ND_REPOSITORY = "repository";
  
      private static final String ND_NAME = "name";
  
      /**
       * Map with repository name/handler class for admin tree. When this servlet will receive a call with a parameter
       * <code>repository</code>, the corresponding handler will be used top display the admin tree.
       */
      private final Map<String, TreeHandlerConfig> treeHandlers = new HashMap<String, TreeHandlerConfig>();
  
      /**
       * Get the tree handler registered under a particular name.
       * @param name
       * @param request
       * @param response
       * @return
       */
      public AdminTreeMVCHandler getTreeHandler(String name, HttpServletRequest request, HttpServletResponse response) {
  
          TreeHandlerConfig th = treeHandlers.get(name);
  
          if (th == null) {
              throw new InvalidTreeHandlerException(name);
          }
  
          Class<H> treeHandlerClass = th.getHandler();
  
          try {
              Constructor<H> constructor = treeHandlerClass.getConstructor(String.class, HttpServletRequest.class, HttpServletResponse.class);
              AdminTreeMVCHandler newInstance = constructor.newInstance(name, request, response);
              Content2BeanUtil.setProperties(newInstance, th.getTreeDefinition(), true);
              return newInstance;
          }
          catch (Exception e) {
              throw new InvalidTreeHandlerException(name, e);
          }
      }
  
      protected void registerTreeHandler(String name, String repository, Class<H> treeHandler, Content treeDefinition) {
          log.info("Registering tree handler {}", name); //$NON-NLS-1$
          treeHandlers.put(name, new TreeHandlerConfig(treeHandler, repository, treeDefinition));
     }
 
     protected void onRegister(Content defNode) {
         Collection<Content> trees = defNode.getChildren(ItemType.CONTENTNODE.getSystemName());
         for (Object tree1 : trees) {
             Content tree = (Content) tree1;
             String name = tree.getNodeData(ND_NAME).getString();
 
             if (StringUtils.isEmpty(name)) {
                 name = tree.getName();
             }
 
             String repository = tree.getNodeData(ND_REPOSITORY).getString();
             String className = tree.getNodeData(ND_CLASS).getString();
 
             if (StringUtils.isEmpty(repository)) {
                 repository = name;
             }
 
             try {
                 final Class<H> treeHandler = Classes.getClassFactory().forName(className);
                 this.registerTreeHandler(name, repository, treeHandler, new SystemContentWrapper(tree));
             }
             catch (ClassNotFoundException e) {
                 log.error("Can't register tree handler [{}]: class [{}] not found", name, className);
             }
 
             // register commands if defined
             try {
                 // TODO - this should go - maybe still needs an update task
                 if (tree.hasContent("commands")) {
                     log.error("The definition of commands at the tree level is no longer supported. Move them to the modules commands node! [" + tree.getHandle() + "]");
                 }
             }
             catch (RepositoryException e) {
                 log.error("Can't check commands node of the tree node [" + tree.getHandle() + "]", e);
             }
         }
     }
 
     /**
      * @return Returns the instance.
      */
     public static <H extends AdminTreeMVCHandler> TreeHandlerManager<H> getInstance() {
         return Components.getSingleton(TreeHandlerManager.class);
     }
 
     /**
      * Clear the handlers
      */
     protected void onClear() {
         this.treeHandlers.clear();
     }
 
     class TreeHandlerConfig {
 
         private Class<H> handler;
 
         private String repository;
 
         private Content treeDefinition;
 
         TreeHandlerConfig(Class<H> handler, String repository, Content treeDefinition) {
             this.handler = handler;
             this.repository = repository;
             this.treeDefinition = treeDefinition;
         }
 
         public Class<H> getHandler() {
             return this.handler;
         }
 
         public String getRepository() {
             return this.repository;
         }
 
         public Content getTreeDefinition() {
             return treeDefinition;
         }
     }
 
 }