/*

  * 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.index;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import net.sourceforge.pebble.domain.Blog;

 import net.sourceforge.pebble.domain.Tag;

 import net.sourceforge.pebble.domain.BlogEntry;

 import java.util.*;

 import java.io.*;

 /**

  * Represents the tag index for a blog.

  *

  * @author    Simon Brown

  */

 public class EmailSubscriptionList {

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

   private Blog blog;

   /** the list of e-mail addresses */

   private List<String> emailAddresses = new LinkedList<String>();

   public EmailSubscriptionList(Blog blog) {

     this.blog = blog;

     readIndex();

   }

   /**

    * Clears the index.

    */

   public void clear() {

     emailAddresses = new LinkedList<String>();

     writeIndex();

   }

   /**

    * Adds an e-mail address.

    *

    * @param emailAddress    an e-mail address

    */

   public synchronized void addEmailAddress(String emailAddress) {

     if (!emailAddresses.contains(emailAddress)) {

       emailAddresses.add(emailAddress);

       writeIndex();

     }

   }

   /**

    * Removes an e-mail address.

    *

    * @param emailAddress    an e-mail address

    */

   public synchronized void removeEmailAddress(String emailAddress) {

     emailAddresses.remove(emailAddress);

     writeIndex();

   }

   /**

    * Helper method to load the index.

    */

   private void readIndex() {

     File indexFile = new File(blog.getIndexesDirectory(), "email-subscriptions.index");

     if (indexFile.exists()) {

       try {

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

         String emailAddress = reader.readLine();

         while (emailAddress != null) {

           emailAddresses.add(emailAddress);

           emailAddress = reader.readLine();

         }

         reader.close();

       } catch (Exception e) {

         log.error("Error while reading index", e);

       }

     }

   }

   /**

    * Helper method to write out the index to disk.

    */

   private void writeIndex() {

     try {

       File indexFile = new File(blog.getIndexesDirectory(), "email-subscriptions.index");

       BufferedWriter writer = new BufferedWriter(new FileWriter(indexFile));

       for (String emailAddress : emailAddresses) {

         writer.write(emailAddress);

         writer.newLine();

       }

       writer.flush();

       writer.close();

     } catch (Exception e) {

       log.error("Error while writing index", e);

     }

   }

   /**

    * Gets the list of e-mail addresses.

    */

   public List<String> getEmailAddresses() {

     List list = new ArrayList<String>(emailAddresses);

     Collections.sort(list);

     return list;

   }

 }