/**
    * This file Copyright (c) 2010-2015 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.module.blossom.support;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.List;
  
  import javax.servlet.RequestDispatcher;
  import javax.servlet.ServletException;
  import javax.servlet.ServletRequest;
  import javax.servlet.ServletResponse;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletRequestWrapper;
  
  import org.springframework.web.util.WebUtils;
  
  /**
   * Request wrapper that makes the request appear like an include operation. Exposes the special request attributes that
   * needs to be present during an include.
   *
   * @since 1.2
   */
  public class IncludeRequestWrapper extends SpecialAttributeRequestWrapper {
  
      private static final String INCLUDE_ATTRIBUTES_COMMON_PREFIX = "javax.servlet.include.";
      private static final String[] INCLUDE_ATTRIBUTE_NAMES = new String[]{
              WebUtils.INCLUDE_REQUEST_URI_ATTRIBUTE,
              WebUtils.INCLUDE_CONTEXT_PATH_ATTRIBUTE,
              WebUtils.INCLUDE_SERVLET_PATH_ATTRIBUTE,
              WebUtils.INCLUDE_PATH_INFO_ATTRIBUTE,
              WebUtils.INCLUDE_QUERY_STRING_ATTRIBUTE};
  
      private final List<Object> previousChainState = new ArrayList<Object>(48);
  
      public IncludeRequestWrapper(HttpServletRequest request, String requestUri, String contextPath, String servletPath, Object pathInfo, String queryString) {
          super(request);
          setOverriddenAttributes(
                  INCLUDE_ATTRIBUTES_COMMON_PREFIX,
                  INCLUDE_ATTRIBUTE_NAMES,
                  new Object[]{
                          requestUri,
                          contextPath,
                          servletPath,
                          pathInfo,
                          queryString}
          );
  
          // Disable all IncludeRequestWrappers already in chain to increase performance, they won't have any effect anyway
          ServletRequest wrapper = request;
          while (wrapper instanceof HttpServletRequestWrapper) {
              if (wrapper instanceof IncludeRequestWrapper) {
                  IncludeRequestWrapper includeRequestWrapper = (IncludeRequestWrapper) wrapper;
                  previousChainState.add(includeRequestWrapper);
                  previousChainState.add(includeRequestWrapper.isEnabled());
                  includeRequestWrapper.setEnabled(false);
              }
              wrapper = ((HttpServletRequestWrapper) wrapper).getRequest();
          }
      }
  
      public void restore() {
          for (int i = 0; i < previousChainState.size(); ) {
              IncludeRequestWrapper includeRequestWrapper = (IncludeRequestWrapper) previousChainState.get(i++);
              includeRequestWrapper.setEnabled((Boolean) previousChainState.get(i++));
          }
      }
  
     @Override
     public RequestDispatcher getRequestDispatcher(final String path) {
 
         if (!isEnabled()) {
             return super.getRequestDispatcher(path);
         }
 
         final RequestDispatcher dispatcher = super.getRequestDispatcher(path);
 
         return new RequestDispatcher() {
 
             @Override
             public void forward(ServletRequest servletRequest, ServletResponse servletResponse) throws ServletException, IOException {
                 boolean previousValue = isEnabled();
                 setEnabled(false);
                 try {
                     dispatcher.forward(servletRequest, servletResponse);
                 } finally {
                     setEnabled(previousValue);
                 }
             }
 
             @Override
             public void include(ServletRequest servletRequest, ServletResponse servletResponse) throws ServletException, IOException {
                 boolean previousValue = isEnabled();
                 setEnabled(false);
                 try {
                     dispatcher.include(servletRequest, servletResponse);
                 } finally {
                     setEnabled(previousValue);
                 }
             }
         };
     }
 }