/*

  * Copyright (c) 2003-2011, Simon Brown

  * All rights reserved.

  *

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions are met:

  *

  *   - Redistributions of source code must retain the above copyright

  *     notice, this list of conditions and the following disclaimer.

  *

  *   - Redistributions in binary form must reproduce the above copyright

  *     notice, this list of conditions and the following disclaimer in

  *     the documentation and/or other materials provided with the

  *     distribution.

  *

  *   - Neither the name of Pebble nor the names of its contributors may

  *     be used to endorse or promote products derived from this software

  *     without specific prior written permission.

  *

  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

  * POSSIBILITY OF SUCH DAMAGE.

  */

 package net.sourceforge.pebble.domain;

 import net.sourceforge.pebble.util.FileUtils;

 import org.apache.commons.io.IOUtils;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import java.io.File;

 import java.io.FileInputStream;

 import java.io.FileOutputStream;

 import java.io.IOException;

 import java.nio.channels.FileChannel;

 /**

  * Represents the user's editable theme.

  *

  * @author Simon Brown

  */

 public class Theme {

   /**

    * the log used by this class

    */

   private static Log log = LogFactory.getLog(Theme.class);

   /**

    * the name of the theme that should be used as a default

    */

   public static final String DEFAULT_THEME_NAME = "default";

   /**

    * the blog to which this theme belongs

    */

   private Blog blog;

   /**

    * the name of the theme

    */

   private String name;

   /**

    * the path of the live theme (under the webapp root)

    */

   private String pathToLiveThemes;

   /**

    * Creates a new Theme instance with the specified details.

    *

    * @param blog             the owning Blog instance

    * @param name             the name of the theme

    * @param pathToLiveThemes the path to the live themes

    */

   public Theme(Blog blog, String name, String pathToLiveThemes) {

     this.blog = blog;

     this.name = name;

     this.pathToLiveThemes = pathToLiveThemes;

   }

   /**

    * Gets the location where the backup version of the blog theme is stored -

    * under the blog.dir directory, in a sub-directory called "theme".

    *

    * @return an absolute, local path on the filing system

    */

   String getBackupThemeDirectory() {

     return blog.getRoot() + File.separator + "theme";

   }

   public File getPathToLiveTheme() {

     return new File(pathToLiveThemes, name);

   }

   /**

    * Restores the theme from the blog.dir to the webapp.

    */

   public void restore() {

     restore(DEFAULT_THEME_NAME);

   }

   /**

    * Restores the theme from the blog.dir to the webapp.

    */

   public void restore(String themeName) {

     File blogTheme = new File(getBackupThemeDirectory());

     if (!blogTheme.exists() || blogTheme.listFiles().length == 0) {

       copy(themeName);

     }

     log.debug("Restoring " + name + " theme from " + getBackupThemeDirectory());

     copy(blogTheme, getPathToLiveTheme());

   }

   /**

    * Restores the theme from the blog.dir to the webapp.

    */

   public void restoreToSpecifiedTheme(String themeName) {

     File blogTheme = new File(getBackupThemeDirectory());

     FileUtils.deleteFile(blogTheme);

     FileUtils.deleteFile(getPathToLiveTheme());

     restore(themeName);

   }

   /**

    * Backs up the theme from the webapp to the blog.dir.

    */

   public void backup() {

     backup(name);

   }

   /**

    * Backs up the named theme from the webapp to the blog.dir.

    *

    * @param themeName the name of the theme to backup

    */

   private void backup(String themeName) {

     log.debug("Backing up " + themeName + " theme to " + getBackupThemeDirectory());

     File liveTheme = new File(pathToLiveThemes, themeName);

     File blogTheme = new File(getBackupThemeDirectory());

     File blogThemeBackup = getUniqueBackupBackupDirectory();

     if (blogTheme.exists()) {

       blogTheme.renameTo(blogThemeBackup);

     }

     copy(liveTheme, blogTheme);

     FileUtils.deleteFile(blogThemeBackup);

   }

   /**

    * Copies the named theme from the webapp to blog.dir/theme.

    *

    * @param themeName the name of the theme to backup

    */

   private void copy(String themeName) {

     log.info("Copying " + themeName + " theme to " + getBackupThemeDirectory());

     File liveTheme = new File(pathToLiveThemes, themeName);

     File blogTheme = new File(getBackupThemeDirectory());

     File blogThemeBackup = getUniqueBackupBackupDirectory();

     if (blogTheme.exists()) {

       blogTheme.renameTo(blogThemeBackup);

     }

     copy(liveTheme, blogTheme);

     FileUtils.deleteFile(blogThemeBackup);

   }

   /**

    * Copies one file to another.

    *

    * @param source      the source

    * @param destination the destination

    */

   private void copy(File source, File destination) {

     if (!destination.exists()) {

       destination.mkdir();

     }

     File files[] = source.listFiles();

     if (files != null) {

       for (int i = 0; i < files.length; i++) {

         if (files[i].isDirectory()) {

           copy(files[i], new File(destination, files[i].getName()));

         } else {

           FileInputStream is = null;

           FileOutputStream os = null;

           try {

             is = new FileInputStream(files[i]);

             FileChannel srcChannel = is.getChannel();

             long size = srcChannel.size();

             os = new FileOutputStream(new File(destination, files[i].getName()));

             FileChannel dstChannel = os.getChannel();

             dstChannel.transferFrom(srcChannel, 0, size);

           } catch (IOException ioe) {

             // We MUST throw an exception here, otherwise very bad things will happen.  For example, if some error

             // prevented us from copying a theme file from the blog directory to the live directory, if we don't

             // complain now, Pebble will happily start up, and that file will end up blank.  Then, when pebble shuts

             // down, backup will be called, and the blank file will be copied over the file in the blog directory, and

             // so that file will be lost.  It's simple to reproduce this, just shutdown pebble while its coming up,

             // Tomcat will interrupt the thread that is bringing it up and consequently all NIO the operations above will

             // throw exceptions.  Pebble never checks if the threads been interrupted, so if you ignore the exceptions,

             // pebble keeps on coming up, each time writing a blank file to the webapp directory.  Then Tomcat shuts

             // down the context listener, and that causes backup to be called, the thread is now not interrupted, and

             // so backup successfully writes all our blank files back to the blog directory, and all your themes are

             // lost.  I speak from experience.  Thankfully I had backups.

             throw new RuntimeException("Error copying files", ioe);

           } finally {

             IOUtils.closeQuietly(is);

             IOUtils.closeQuietly(os);

           }

         }

       }

     }

   }

   /**

    * If there is still a backup directory lying around, it means that something went wrong in a previous shutdown.  We

    * don't want to use it in case a user is starting/restarting pebble multiple times and hasn't realised they've

    * corrupted their theme yet.

    *

    * @return A unique directory name

    */

   private File getUniqueBackupBackupDirectory() {

     File dir = new File(getBackupThemeDirectory() + ".bak");

     if (dir.exists()) {

       dir = new File(getBackupThemeDirectory() + "-" + System.currentTimeMillis() + ".bak");

     }

     return dir;

   }

   /**

    * Gets the name of this theme.

    *

    * @return the name

    */

   public String getName() {

     return name;

   }

 }