/*
    * Copyright 2007-2012 the original author or authors.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *      http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.springbyexample.jcr;
  
  import java.io.File;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.util.ArrayList;
  import java.util.List;
  
  import javax.jcr.Node;
  import javax.jcr.Property;
  import javax.jcr.RepositoryException;
  import javax.jcr.Session;
  
  import org.apache.commons.io.FileUtils;
  import org.apache.commons.io.IOUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springmodules.jcr.JcrConstants;
  
  /**
   * Processes JCR content repository and 
   * writes out all files into a root directory in the 
   * same hierarchical structure they were found in.
   * 
   * @author David Winterfeldt
   */
  public class JcrContentExporter {
  
      final Logger logger = LoggerFactory.getLogger(JcrContentExporter.class);
      
      protected JcrContentRecurser contentRecurser = null;
      protected String rootFolder = null;
  
      /**
       * Sets JCR content recurser.
       */
      public void setContentRecurser(JcrContentRecurser contentRecurser) {
          this.contentRecurser = contentRecurser;
      }
  
      /**
       * Sets root folder where repository content will be copied.
       */
      public void setRootFolder(String rootFolder) {
          this.rootFolder = rootFolder;
      }
      
      /**
       * Process content nodes.
       * 
       *  @return     List     List of content node paths processed.     
       */
      public List<String> process() {
          final List<String> lResults = new ArrayList<String>();
          
          contentRecurser.recurse(new JcrNodeCallback() {
              public void doInJcrNode(Session session, Node node)
                      throws IOException, RepositoryException {
                  JcrConstants jcrConstants = new JcrConstants(session);
                  // file name node is above content
                  String fileName = node.getParent().getName();
                  // file path is two above content
                  String path = node.getParent().getParent().getPath();
                  
                  logger.debug("In content recurser callback." + 
                               "  fileName='{}' path='{}'", fileName, path);
  
                  File fileDir = new File(rootFolder + path);
                  File file = new File(fileDir, fileName);
          
                  Property dataProperty = node.getProperty(jcrConstants.getJCR_DATA());
          
                  InputStream in = null;
                  OutputStream out = null;
                  
                  try {
                      FileUtils.forceMkdir(fileDir);
                      
                      in = dataProperty.getStream();
                      out = new FileOutputStream(file);
                      
                     IOUtils.copy(in, out);
                     
                     lResults.add(path + File.pathSeparator + fileName);
                 } finally {
                     IOUtils.closeQuietly(in);
                     IOUtils.closeQuietly(out);
                 }
             }
         });
         
         return lResults;
     }
 
 }