/**
    * This file Copyright (c) 2003-2014 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.files;
  
  import info.magnolia.cms.util.ClasspathResourcesUtil;
  import org.apache.commons.io.IOUtils;
  
  import java.io.File;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  
  /**
   * A simple FileExtractorOperation which just extracts a resource from the class path
   * to the filesystem.
   */
  public class BasicFileExtractorOperation implements FileExtractorOperation {
      protected final String resourcePath;
      protected final String absoluteTargetPath;
  
      BasicFileExtractorOperation(String resourcePath, String absoluteTargetPath) {
          this.resourcePath = resourcePath;
          this.absoluteTargetPath = absoluteTargetPath;
      }
  
      @Override
      public void extract() throws IOException {
          final InputStream resourceStream = checkInput();
          final File checkedTargetFile = checkOutput();
          if (checkedTargetFile != null) {
              final OutputStream out = openOutput(checkedTargetFile);
  
              copyAndClose(resourceStream, out);
          }
      }
  
      protected InputStream checkInput() throws IOException {
          final InputStream resourceStream = ClasspathResourcesUtil.getStream(resourcePath, false);
          if (resourceStream == null) {
              throw new IOException("Can't open " + resourcePath);
          }
          return resourceStream;
      }
  
      /**
       * @return a java.io.File corresponding to the absoluteTargetPath if the path is validated,
       *         or null if the file should not be extracted. TODO ugly.
       */
      protected File checkOutput() throws IOException {
          final File targetFile = new File(absoluteTargetPath);
          final File parent = targetFile.getParentFile();
          if (!parent.exists() && !parent.mkdirs()) {
              throw new IOException("Can't create directories for " + targetFile.getAbsolutePath());
          } else if (!parent.canWrite()) {
              throw new IOException("Can't write to " + targetFile.getAbsolutePath());
          }
          return targetFile;
      }
  
      protected OutputStream openOutput(File targetFile) throws IOException {
          return new FileOutputStream(targetFile);
      }
  
      protected void copyAndClose(InputStream in, OutputStream out) throws IOException {
          try {
              IOUtils.copy(in, out);
          } finally {
             IOUtils.closeQuietly(in);
             IOUtils.closeQuietly(out);
         }
     }
 }