/**
    * This file Copyright (c) 2003-2014 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.cms.filters;
  
  import info.magnolia.cms.beans.runtime.File;
  import info.magnolia.cms.beans.runtime.FileProperties;
  import info.magnolia.cms.core.AggregationState;
  import info.magnolia.cms.core.Content;
  import info.magnolia.cms.core.HierarchyManager;
  import info.magnolia.cms.core.NodeData;
  import info.magnolia.cms.security.AccessDeniedException;
  import info.magnolia.context.MgnlContext;
  
  import java.io.IOException;
  
  import javax.jcr.PathNotFoundException;
  import javax.jcr.PropertyType;
  import javax.jcr.RepositoryException;
  import javax.servlet.FilterChain;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.commons.lang.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  /**
   * Reads the accessed content from the repository and puts it into the {@link AggregationState}.
   * @author philipp
   * @version $Id$
   *
   */
  public class AggregatorFilter extends AbstractMgnlFilter{
      private static final Logger log = LoggerFactory.getLogger(AggregatorFilter.class);
      private final String VERSION_NUMBER = "mgnlVersion";
  
      @Override
      public void doFilter(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws IOException, ServletException{
  
          boolean success;
          try {
              success = collect();
          }
          catch (AccessDeniedException e) {
              // don't throw further, simply return error and break filter chain
              log.debug(e.getMessage(), e);
              if (!response.isCommitted()) {
                  response.setStatus(HttpServletResponse.SC_FORBIDDEN);
              }
              // stop the chain
              return;
          }
          catch (RepositoryException e) {
              log.error(e.getMessage(), e);
              throw new ServletException(e.getMessage(), e);
          }
  
          if (!success) {
              log.debug("Resource not found, redirecting request for [{}] to 404 URI", request.getRequestURI());
  
              if (!response.isCommitted()) {
                  response.sendError(HttpServletResponse.SC_NOT_FOUND);
              }
              else {
                  log.info("Unable to redirect to 404 page, response is already committed. URI was {}", request.getRequestURI());
              }
             // stop the chain
             return;
         }
         chain.doFilter(request, response);
     }
 
     /**
      * Collect content from the pre configured repository and attach it to the HttpServletRequest.
      * @throws PathNotFoundException
      * @throws RepositoryException
      */
     protected boolean collect() throws RepositoryException {
         final AggregationState aggregationState = MgnlContext.getAggregationState();
         final String repository = aggregationState.getRepository();
         final String handle = aggregationState.getHandle();
 
         final HierarchyManager hierarchyManager = MgnlContext.getHierarchyManager(repository);
 
         Content requestedPage = null;
         NodeData requestedData = null;
         final String templateName;
 
         if (!isJcrPathValid(handle)) {
             // avoid calling isExist if the path can't be valid
             return false;
         }
 
         if (hierarchyManager.isExist(handle) && !hierarchyManager.isNodeData(handle)) {
             requestedPage = hierarchyManager.getContent(handle);
 
             // check if its a request for a versioned page
             if (MgnlContext.getAttribute(VERSION_NUMBER) != null) {
                 // get versioned state
                 try {
                     requestedPage = requestedPage.getVersionedContent((String)MgnlContext.getAttribute(VERSION_NUMBER));
                 }
                 catch (RepositoryException re) {
                     log.debug(re.getMessage(), re);
                     log.error("Unable to get versioned state, rendering current state of {}", handle);
                 }
             }
 
             templateName = requestedPage.getMetaData().getTemplate();
 
             if (StringUtils.isBlank(templateName)) {
                 log.error("No template configured for page [{}].", requestedPage.getHandle());
             }
         }
         else {
             if (hierarchyManager.isNodeData(handle)) {
                 requestedData = hierarchyManager.getNodeData(handle);
             }
             else {
                 // check again, resource might have different name
                 int lastIndexOfSlash = handle.lastIndexOf("/");
 
                 if (lastIndexOfSlash > 0) {
 
                     final String handleToUse = StringUtils.substringBeforeLast(handle, "/");
 
                     try {
                         requestedData = hierarchyManager.getNodeData(handleToUse);
                         aggregationState.setHandle(handleToUse);
                         // this is needed for binary nodedata, e.g. images are found using the path:
                         // /features/integration/headerImage instead of /features/integration/headerImage/header30_2
                     }
                     catch (PathNotFoundException e) {
                         // no page available
                         return false;
                     }
                     catch (RepositoryException e) {
                         log.debug(e.getMessage(), e);
                         return false;
                     }
                 }
             }
 
             if (requestedData != null) {
                 templateName = requestedData.getAttribute(FileProperties.PROPERTY_TEMPLATE);
             }
             else {
                 return false;
             }
         }
 
         // Attach all collected information to the HttpServletRequest.
         if (requestedPage != null) {
             aggregationState.setMainContent(requestedPage);
             aggregationState.setCurrentContent(requestedPage);
         }
         if ((requestedData != null) && (requestedData.getType() == PropertyType.BINARY)) {
             File file = new File(requestedData);
             aggregationState.setFile(file);
         }
 
         aggregationState.setTemplateName(templateName);
 
         return true;
     }
 
     /**
      * Check if the path *may be* a valid path before calling getItem, in order to avoid annoying logs.
      * @param handle node handle
      * @return true if the path is invalid
      */
     private boolean isJcrPathValid(String handle) {
         if (StringUtils.isBlank(handle) || StringUtils.equals(handle, "/")) {
             // empty path not allowed
             return false;
         }
         if (StringUtils.containsAny(handle, new char[]{':', '*', '\n'})) {
             // not allowed chars
             return false;
         }
         if (StringUtils.contains(handle, " /")) {
             // trailing slash not allowed
             return false;
         }
         return true;
     }
 
 }