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, 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.staticexport;
  
  import org.opencms.cache.CmsVfsMemoryObjectCache;
  import org.opencms.file.CmsFile;
  import org.opencms.file.CmsObject;
  import org.opencms.file.CmsResource;
  import org.opencms.main.CmsException;
  import org.opencms.main.CmsLog;
  import org.opencms.main.OpenCms;
  import org.opencms.xml.content.CmsXmlContent;
  import org.opencms.xml.content.CmsXmlContentFactory;
  
  import java.net.URI;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Locale;
  
  import org.apache.commons.logging.Log;
  
  /**
   * Advanced link substitution behavior.<p>
   * You can define additional paths that are always used as external links, even if
   * they point to the same configured site than the OpenCms itself.
   *
   * @since 7.5.0
   *
   * @see CmsLinkManager#substituteLink(org.opencms.file.CmsObject, String, String, boolean)
   *      for the method where this handler is used.
   */
  public class CmsAdvancedLinkSubstitutionHandler extends CmsDefaultLinkSubstitutionHandler {
  
      /** Filename of the link exclude definition file. */
      private static final String LINK_EXCLUDE_DEFINIFITON_FILE = "linkexcludes";
  
      /** The log object for this class. */
      private static final Log LOG = CmsLog.getLog(CmsAdvancedLinkSubstitutionHandler.class);
  
      /** XPath for link exclude in definition file. */
      private static final String XPATH_LINK = "link";
  
      /**
       * @see org.opencms.staticexport.CmsDefaultLinkSubstitutionHandler#getLink(org.opencms.file.CmsObject, java.lang.String, java.lang.String, boolean)
       */
      @Override
      public String getLink(CmsObject cms, String link, String siteRoot, boolean forceSecure) {
  
          if (isExcluded(cms, link)) {
              return link;
          }
          return super.getLink(cms, link, siteRoot, forceSecure);
      }
  
      /**
       * @see org.opencms.staticexport.I_CmsLinkSubstitutionHandler#getRootPath(org.opencms.file.CmsObject, java.lang.String, java.lang.String)
       */
      @Override
      public String getRootPath(CmsObject cms, String targetUri, String basePath) {
  
          if (cms == null) {
              // required by unit test cases
              return targetUri;
          }
  
          URI uri;
          String path;
  
          // check for malformed URI
          try {
              uri = new URI(targetUri);
              path = uri.getPath();
          } catch (Exception e) {
              if (LOG.isWarnEnabled()) {
                  LOG.warn(Messages.get().getBundle().key(Messages.LOG_MALFORMED_URI_1, targetUri), e);
              }
              return null;
          }
          // opaque URI
          if (uri.isOpaque()) {
              return null;
          }
  
          // in case the target is the workplace UI
          if (CmsLinkManager.isWorkplaceUri(uri)) {
              return null;
          }
          if (isExcluded(cms, path)) {
              return null;
          }
  
          return super.getRootPath(cms, targetUri, basePath);
      }
  
      /**
       * Returns if the given path starts with an exclude prefix.<p>
       *
       * @param cms the cms context
       * @param path the path to check
       *
       * @return <code>true</code> if the given path starts with an exclude prefix
       */
      protected boolean isExcluded(CmsObject cms, String path) {
  
          List<String> excludes = getExcludes(cms);
          // now check if the current link start with one of the exclude links
          for (int i = 0; i < excludes.size(); i++) {
              if (path.startsWith(excludes.get(i))) {
                  return true;
              }
          }
          return false;
      }
  
      /**
       * Returns the exclude prefix list.<p>
       *
       * @param cms the cms context
       *
       * @return the exclude prefix list
       */
      private List<String> getExcludes(CmsObject cms) {
  
          // get the list of link excludes form the cache if possible
          CmsVfsMemoryObjectCache cache = CmsVfsMemoryObjectCache.getVfsMemoryObjectCache();
          String filePath = OpenCms.getSystemInfo().getConfigFilePath(cms, LINK_EXCLUDE_DEFINIFITON_FILE);
          @SuppressWarnings("unchecked")
          List<String> excludes = (List<String>)cache.getCachedObject(cms, filePath);
          if (excludes == null) {
              // nothing found in cache, so read definition file and store the result in cache
              excludes = readLinkExcludes(cms);
              cache.putCachedObject(cms, filePath, excludes);
          }
          return excludes;
      }
  
      /**
       * Reads the link exclude definition file and extracts all excluded links stored in it.<p>
       *
       * @param cms the current CmsObject
       * @return list of Strings, containing link exclude paths
       */
      private List<String> readLinkExcludes(CmsObject cms) {
  
          List<String> linkExcludes = new ArrayList<String>();
  
          try {
              // get the link exclude file
              String filePath = OpenCms.getSystemInfo().getConfigFilePath(cms, LINK_EXCLUDE_DEFINIFITON_FILE);
              CmsResource res = cms.readResource(filePath);
              CmsFile file = cms.readFile(res);
              CmsXmlContent linkExcludeDefinitions = CmsXmlContentFactory.unmarshal(cms, file);
  
              // get number of excludes
              int count = linkExcludeDefinitions.getIndexCount(XPATH_LINK, Locale.ENGLISH);
  
              for (int i = 1; i <= count; i++) {
  
                  String exclude = linkExcludeDefinitions.getStringValue(cms, XPATH_LINK + "[" + i + "]", Locale.ENGLISH);
                  linkExcludes.add(exclude);
  
              }
  
          } catch (CmsException e) {
              LOG.error(e.getLocalizedMessage(), e);
          }
  
          return linkExcludes;
      }
  }