/*

  * This file is part of dependency-check-core.

  *

  * 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.

  *

  * Copyright (c) 2013 Jeremy Long. All Rights Reserved.

  */

 package org.owasp.dependencycheck.utils;

 import java.io.BufferedInputStream;

 import java.io.BufferedOutputStream;

 import java.io.File;

 import java.io.FileInputStream;

 import java.io.FileNotFoundException;

 import java.io.FileOutputStream;

 import java.io.IOException;

 import java.util.logging.Level;

 import java.util.logging.Logger;

 import java.util.zip.ZipEntry;

 import java.util.zip.ZipInputStream;

 import org.owasp.dependencycheck.Engine;

 import static org.owasp.dependencycheck.utils.FileUtils.getFileExtension;

 /**

  *

  * @author Jeremy Long <jeremy.long@owasp.org>

  */

 public final class ExtractionUtil {

     /**

      * The logger.

      */

     private static final Logger LOGGER = Logger.getLogger(ExtractionUtil.class.getName());

     /**

      * The buffer size to use when extracting files from the archive.

      */

     private static final int BUFFER_SIZE = 4096;

     /**

      * Private constructor for a utility class.

      */

     private ExtractionUtil() {

     }

     /**

      * Extracts the contents of an archive into the specified directory.

      *

      * @param archive an archive file such as a WAR or EAR

      * @param extractTo a directory to extract the contents to

      * @throws ExtractionException thrown if an exception occurs while extracting the files

      */

     public static void extractFiles(File archive, File extractTo) throws ExtractionException {

         extractFiles(archive, extractTo, null);

     }

     /**

      * Extracts the contents of an archive into the specified directory. The files are only extracted if they are

      * supported by the analyzers loaded into the specified engine. If the engine is specified as null then all files

      * are extracted.

      *

      * @param archive an archive file such as a WAR or EAR

      * @param extractTo a directory to extract the contents to

      * @param engine the scanning engine

      * @throws ExtractionException thrown if there is an error extracting the files

      */

     public static void extractFiles(File archive, File extractTo, Engine engine) throws ExtractionException {

         if (archive == null || extractTo == null) {

             return;

         }

         FileInputStream fis = null;

         ZipInputStream zis = null;

         try {

             fis = new FileInputStream(archive);

         } catch (FileNotFoundException ex) {

             LOGGER.log(Level.FINE, null, ex);

             throw new ExtractionException("Archive file was not found.", ex);

         }

         zis = new ZipInputStream(new BufferedInputStream(fis));

         ZipEntry entry;

         try {

             while ((entry = zis.getNextEntry()) != null) {

                 if (entry.isDirectory()) {

                     final File d = new File(extractTo, entry.getName());

                     if (!d.exists() && !d.mkdirs()) {

                         final String msg = String.format("Unable to create '%s'.", d.getAbsolutePath());

                         throw new ExtractionException(msg);

                     }

                 } else {

                     final File file = new File(extractTo, entry.getName());

                     final String ext = getFileExtension(file.getName());

                     if (engine == null || engine.supportsExtension(ext)) {

                         BufferedOutputStream bos = null;

                         FileOutputStream fos;

                         try {

                             fos = new FileOutputStream(file);

                             bos = new BufferedOutputStream(fos, BUFFER_SIZE);

                             int count;

                             final byte data[] = new byte[BUFFER_SIZE];

                             while ((count = zis.read(data, 0, BUFFER_SIZE)) != -1) {

                                 bos.write(data, 0, count);

                             }

                             bos.flush();

                         } catch (FileNotFoundException ex) {

                             LOGGER.log(Level.FINE, null, ex);

                             final String msg = String.format("Unable to find file '%s'.", file.getName());

                             throw new ExtractionException(msg, ex);

                         } catch (IOException ex) {

                             LOGGER.log(Level.FINE, null, ex);

                             final String msg = String.format("IO Exception while parsing file '%s'.", file.getName());

                             throw new ExtractionException(msg, ex);

                         } finally {

                             if (bos != null) {

                                 try {

                                     bos.close();

                                 } catch (IOException ex) {

                                     LOGGER.log(Level.FINEST, null, ex);

                                 }

                             }

                         }

                     }

                 }

             }

         } catch (IOException ex) {

             final String msg = String.format("Exception reading archive '%s'.", archive.getName());

             LOGGER.log(Level.FINE, msg, ex);

             throw new ExtractionException(msg, ex);

         } finally {

             try {

                 zis.close();

             } catch (IOException ex) {

                 LOGGER.log(Level.FINEST, null, ex);

             }

         }

     }

 }