content: /*
   * This library is part of OpenCms -
   * the Open Source Content Management System
   *
   * Copyright (c) Alkacon Software GmbH & Co. KG (https://www.alkacon.com)
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * For further information about Alkacon Software GmbH & Co. KG, please see the
   * company website: https://www.alkacon.com
   *
   * For further information about OpenCms, please see the
   * project website: https://www.opencms.org
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  package org.opencms.main;
  
  import org.opencms.file.CmsObject;
  import org.opencms.file.CmsResource;
  import org.opencms.file.CmsResourceFilter;
  import org.opencms.i18n.CmsMessageContainer;
  import org.opencms.security.CmsPermissionViolationException;
  import org.opencms.util.CmsUUID;
  
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.commons.logging.Log;
  
  /**
   * Resource init handler that loads a resource given its permalink.<p>
   *
   * The permalink must have following format:<br>
   * <code>/${CONTEXT}/${SERVLET}/permalink/${UUID}.${EXT}</code><p>
   *
   * for example:<br>
   * <code>/opencms/opencms/permalink/a7b5d298-b3ab-11d8-b3e3-514d35713fed.html</code><p>
   *
   * @since 6.3
   */
  public class CmsPermalinkResourceHandler implements I_CmsResourceInit {
  
      /** Regex for capturing a UUID. */
      public static final String CAPTURE_UUID_REGEX = "(" + CmsUUID.UUID_REGEX + ")";
  
      /** The permalink handler path. */
      public static final String PERMALINK_HANDLER = "/permalink/";
  
      /** Regex for the optional file extension. */
      public static final String SUFFIX_REGEX = "(?:\\.[a-zA-Z0-9]*)?$";
  
      /** The log object for this class. */
      private static final Log LOG = CmsLog.getLog(CmsPermalinkResourceHandler.class);
  
      /** The compiled pattern for detail page permalinks. */
      private Pattern m_detailPattern;
  
      /** The pattern used to match permalink uris and extract the structure id. */
      private Pattern m_simplePermalinkPattern;
  
      /**
       * Default constructor.<p>
       */
      public CmsPermalinkResourceHandler() {
  
          String uriRegex = PERMALINK_HANDLER + CAPTURE_UUID_REGEX + SUFFIX_REGEX;
          String detailUriRegex = PERMALINK_HANDLER + CAPTURE_UUID_REGEX + ":" + CAPTURE_UUID_REGEX + SUFFIX_REGEX;
          m_simplePermalinkPattern = Pattern.compile(uriRegex);
          m_detailPattern = Pattern.compile(detailUriRegex);
      }
  
      /**
       * @see org.opencms.main.I_CmsResourceInit#initResource(org.opencms.file.CmsResource, org.opencms.file.CmsObject, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
       */
      public CmsResource initResource(
          CmsResource resource,
          CmsObject cms,
          HttpServletRequest req,
          HttpServletResponse res)
      throws CmsResourceInitException, CmsPermissionViolationException {
  
          // only do something if the resource was not found
          if (resource == null) {
              String uri = cms.getRequestContext().getUri();
              // check if the resource starts with the PERMALINK_HANDLER
              Matcher matcher = m_simplePermalinkPattern.matcher(uri);
              if (matcher.find()) {
                  CmsResource resource1 = resource;
                  // get the id of the real resource
                  String id = matcher.group(1);
                  String storedSiteRoot = cms.getRequestContext().getSiteRoot();
                  try {
                      // we now must switch to the root site to read the resource
                      cms.getRequestContext().setSiteRoot("/");
                      // read the resource
                      boolean online = cms.getRequestContext().getCurrentProject().isOnlineProject();
                      CmsResourceFilter filter = online ? CmsResourceFilter.DEFAULT : CmsResourceFilter.IGNORE_EXPIRATION;
                      resource1 = cms.readDefaultFile(id, filter);
                  } catch (CmsPermissionViolationException e) {
                      throw e;
                  } catch (Throwable e) {
                      CmsMessageContainer msg = Messages.get().container(Messages.ERR_PERMALINK_1, id);
                      if (LOG.isErrorEnabled()) {
                          LOG.error(msg.key(), e);
                      }
                      throw new CmsResourceInitException(msg, e);
                  } finally {
                      // restore the siteroot
                      cms.getRequestContext().setSiteRoot(storedSiteRoot);
                      // resource may be null in case of an error
                      if (resource1 != null) {
                          // modify the uri to the one of the real resource
                          cms.getRequestContext().setUri(cms.getSitePath(resource1));
                      }
                  }
                  resource = resource1;
              } else {
                  matcher = m_detailPattern.matcher(uri);
                  // detail page permalink. Handle the cases 'getI18NInfo' and 'showResource' differently:
                  // In the 'showResource' case, we do a redirect to the real detail page URL
                  // In the 'getI18NInfo' case, we return the container page so the locale in the CmsRequestContext is set correctly for the 'showResource' case
                  if (matcher.find()) {
                      try {
                          CmsUUID pageId = new CmsUUID(matcher.group(1));
                          CmsUUID detailId = new CmsUUID(matcher.group(2));
                          CmsResource pageResource = cms.readResource(pageId);
                          if (res != null) {
                              CmsResource detailResource = cms.readResource(detailId);
                              String detailName = cms.getDetailName(
                                  detailResource,
                                  cms.getRequestContext().getLocale(), // the locale in the request context should be the locale of the container page
                                  OpenCms.getLocaleManager().getDefaultLocales());
                              CmsResource parentFolder;
                              if (pageResource.isFile()) {
                                  parentFolder = cms.readParentFolder(pageResource.getStructureId());
                              } else {
                                  parentFolder = pageResource;
                              }
                              String baseLink = OpenCms.getLinkManager().substituteLink(cms, parentFolder);
                              String redirectLink = baseLink + (baseLink.endsWith("/") ? "" : "/") + detailName;
                              CmsResourceInitException resInitException = new CmsResourceInitException(getClass());
  
                              resInitException.setClearErrors(true);
                              res.sendRedirect(redirectLink);
                              throw resInitException;
                          } else {
                              // we're being called from getI18NInfo; assume that the locale for the container page is the locale we want
                              return pageResource;
                          }
                      } catch (CmsResourceInitException e) {
                          throw e;
                      } catch (Exception e) {
                          LOG.error(e.getLocalizedMessage(), e);
                          throw new CmsResourceInitException(getClass());
                      }
                  }
                  return null;
              }
          }
          if ((resource != null) && resource.isInternalOrInInternalFolder()) {
              return null;
          }
          return resource;
      }
  
  }