/*

  * 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.dao.file;

 import net.sourceforge.pebble.dao.PersistenceException;

 import net.sourceforge.pebble.dao.RefererFilterDAO;

 import net.sourceforge.pebble.domain.Blog;

 import net.sourceforge.pebble.domain.RefererFilter;

 import net.sourceforge.pebble.domain.RefererFilterManager;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import java.io.*;

 import java.util.ArrayList;

 import java.util.Collection;

 import java.util.Iterator;

 /**

  * A mock implementation of the CategoryDAO interface that does nothing. This

  * is used when performing unit tests.

  *

  * @author    Simon Brown

  */

 public class FileRefererFilterDAO implements RefererFilterDAO {

   /** the name of the file containing the filter */

   private static final String FILTERS_FILE = "refererFilters.txt";

   /** the log used by this class */

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

   /**

    * Loads the referer filters.

    *

    * @param rootBlog    the owning Blog instance

    * @return  a Collection of RefererFilter instances

    * @throws  PersistenceException    if filters cannot be loaded

    */

   public Collection getRefererFilters(Blog rootBlog) throws PersistenceException {

     ArrayList filters = new ArrayList();

     String root = rootBlog.getRoot();

     try {

       File filtersFile = new File(root, FILTERS_FILE);

       if (!filtersFile.exists()) {

         return filters;

       }

       BufferedReader reader = new BufferedReader(new FileReader(filtersFile));

       String expression = reader.readLine();

       while (expression != null) {

         filters.add(new RefererFilter(expression));

         expression = reader.readLine();

       }

       reader.close();

     } catch (IOException ioe) {

       log.error("A " + FILTERS_FILE + " file at " + root + " cannot be loaded", ioe);

     }

     return filters;

   }

   /**

    * Adds the specified referer filter.

    *

    * @param filter    the RefererFilter instance to be added

    * @param rootBlog    the owning Blog instance

    * @throws PersistenceException   if something goes wrong storing the filters

    */

   public void addRefererFilter(RefererFilter filter, Blog rootBlog) throws PersistenceException {

     Collection filters = getRefererFilters(rootBlog);

     filters.add(filter);

     store(filters, rootBlog);

   }

   /**

    * Removes the specified referer filter.

    *

    * @param filter    the RefererFilter instance to be removed

    * @param rootBlog    the owning Blog instance

    * @throws PersistenceException   if something goes wrong removing the filter

    */

   public void deleteRefererFilter(RefererFilter filter, Blog rootBlog) throws PersistenceException {

     Collection filters = getRefererFilters(rootBlog);

     filters.remove(filter);

     store(filters, rootBlog);

   }

   /**

    * Helper method to store all filters for a given blog.

    *

    * @param filters   the Collection of RefererFilter instances to store

    * @param rootBlog      the blog to which the filters belong

    */

   private void store(Collection filters, Blog rootBlog) throws PersistenceException {

     try {

       String root = rootBlog.getRoot();

       BufferedWriter writer = new BufferedWriter(new FileWriter(new File(root, FILTERS_FILE)));

       Iterator it = filters.iterator();

       RefererFilter filter;

       while (it.hasNext()) {

         filter = (RefererFilter)it.next();

         writer.write(filter.getExpression());

         writer.newLine();

       }

       writer.flush();

       writer.close();

     } catch (IOException ioe) {

       log.error(ioe);

       throw new PersistenceException("Filters could not be saved : " + ioe.getMessage());

     }

   }

 }