/*
    * Copyright 2009 The Kuali Foundation
    * 
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    * 
   * 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.kuali.ole.sys.batch;
  
  import java.io.File;
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  
  import org.apache.commons.io.DirectoryWalker;
  import org.apache.commons.io.filefilter.IOFileFilter;
  
  /**
   * A directory walker which finds files to purge; it's relatively simple, simply adding a file to
   * the given results if the IOFileMatcher has matched it
   */
  public class FilePurgeDirectoryWalker extends DirectoryWalker {
      private org.apache.log4j.Logger LOG = org.apache.log4j.Logger.getLogger(this.getClass());
      
      /**
       * Constructs a FilePurgeDirectoryWalker
       */
      public FilePurgeDirectoryWalker(IOFileFilter fileFilter) {
          super(fileFilter, fileFilter, -1);
      }
  
      /**
       * @see org.kuali.ole.sys.batch.service.FilePurgeDirectoryWalker#getFilesToPurge(java.lang.String, java.util.List)
       */
      public List<File> getFilesToPurge(String directory) {
          List<File> results = new ArrayList<File>();
          
          try {
              walk(new File(directory), results);
          }
          catch (IOException ioe) {
              throw new RuntimeException("Could not walk directory "+directory, ioe);
          }
          
          return results;
      }
  
      /**
       * @see org.apache.commons.io.DirectoryWalker#handleDirectory(java.io.File, int, java.util.Collection)
       */
      @Override
      protected boolean handleDirectory(File directory, int depth, Collection results) throws IOException {
          if (getLastSubDirectoryName(directory.getName()).startsWith(".")) return false; // don't follow hidden directories
          return true;
      }
      
      /**
       * Finds the last subdirectory name of the given directory name and returns it
       * @param directoryName a directory name with a sub directory
       * @return the last subdirectory name
       */
      protected String getLastSubDirectoryName(String directoryName) {
          final int lastIndex = directoryName.lastIndexOf(File.separator);
          if (lastIndex > -1) {
              return directoryName.substring(lastIndex+1);
          }
          return directoryName; // no directory separator...so just return the whole thing
      }
  
      /**
       * @see org.apache.commons.io.DirectoryWalker#handleDirectoryEnd(java.io.File, int, java.util.Collection)
       */
      @Override
      protected void handleDirectoryEnd(File directory, int depth, Collection results) throws IOException {
          LOG.debug("Leaving directory "+directory.getName());
          super.handleDirectoryEnd(directory, depth, results);
      }
  
      /**
       * @see org.apache.commons.io.DirectoryWalker#handleDirectoryStart(java.io.File, int, java.util.Collection)
       */
      @Override
      protected void handleDirectoryStart(File directory, int depth, Collection results) throws IOException {
          LOG.debug("Entering directory "+directory.getName());
          super.handleDirectoryStart(directory, depth, results);
      }
  
      /**
       * @see org.apache.commons.io.DirectoryWalker#handleEnd(java.util.Collection)
       */
     @Override
     protected void handleEnd(Collection results) throws IOException {
         LOG.debug("ending process");
         super.handleEnd(results);
     }
 
     /**
      * @see org.apache.commons.io.DirectoryWalker#handleFile(java.io.File, int, java.util.Collection)
      */
     @Override
     protected void handleFile(File file, int depth, Collection results) throws IOException {
         results.add(file);
     }
 
     /**
      * @see org.apache.commons.io.DirectoryWalker#handleStart(java.io.File, java.util.Collection)
      */
     @Override
     protected void handleStart(File startDirectory, Collection results) throws IOException {
         LOG.debug("starting process");
         super.handleStart(startDirectory, results);
     }
 }