/*

  * 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.CategoryDAO;

 import net.sourceforge.pebble.dao.PersistenceException;

 import net.sourceforge.pebble.domain.Blog;

 import net.sourceforge.pebble.domain.Category;

 import net.sourceforge.pebble.domain.CategoryBuilder;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import javax.xml.bind.JAXBContext;

 import javax.xml.bind.JAXBElement;

 import javax.xml.bind.Marshaller;

 import javax.xml.bind.Unmarshaller;

 import java.io.File;

 import java.io.FileWriter;

 import java.util.List;

 /**

  * DAO responsible for managing the storage of category definitions.

  *

  * @author    Simon Brown

  */

 public class FileCategoryDAO implements CategoryDAO {

   /** the name of the file containing the category information */

   private static final String CATEGORIES_FILE_NAME = "categories.xml";

   /** the log used by this class */

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

   private JAXBContext jaxbContext;

   /**

    * Default, no args constructor.

    */

   public FileCategoryDAO() {

     try {

       jaxbContext = JAXBContext.newInstance(getClass().getPackage().getName());

     } catch (Exception e) {

       e.printStackTrace();

     }

   }

   /**

    * Gets the categories for a particular blog.

    *

    * @param blog    the owning Blog instance

    * @return  a Collection of Category instances

    * @throws  PersistenceException    if categories cannot be loaded

    */

   public Category getCategories(Blog blog) throws PersistenceException {

     CategoryBuilder categoryBuilder = new CategoryBuilder(blog);

     File source = new File(blog.getRoot(), CATEGORIES_FILE_NAME);

     if (source.exists()) {

       try {

         Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();

         JAXBElement<CategoriesType> controller = (JAXBElement)unmarshaller.unmarshal(source);

         CategoriesType categoriesType = controller.getValue();

         for (CategoryType categoryType : categoriesType.getCategory()) {

           Category category = new Category(categoryType.getId(), categoryType.getName());

           category.setBlog(blog);

           category.setTags(categoryType.getTags());

           categoryBuilder.addCategory(category);

         }

       } catch (Exception e) {

         log.error(e.getMessage(), e);

         e.printStackTrace();

         throw new PersistenceException(e.getMessage());

       }

     }                                                           

     return categoryBuilder.getRootCategory();

   }

   /**

    * Adds the specified category.

    *

    * @param category    the Category instance to be added

    * @param blog    the owning blog

    * @throws PersistenceException   if something goes wrong storing the category

    */

   public void addCategory(Category category, Blog blog) throws PersistenceException {

     store(blog);

   }

   /**

    * Updates the specified category.

    *

    * @param updatedCategory   the Category instance to be updated

    * @param blog    the owning blog

    * @throws PersistenceException   if something goes wrong storing the category

    */

   public void updateCategory(Category updatedCategory, Blog blog) throws PersistenceException {

     store(blog);

   }

   /**

    * Removes the specified category.

    *

    * @param category    the Category instance to be removed

    * @param blog    the owning blog

    * @throws PersistenceException   if something goes wrong removing the category

    */

   public void deleteCategory(Category category, Blog blog) throws PersistenceException {

     store(blog);

   }

   /**

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

    *

    * @param blog      the blog to which the categories belong

    * @throws  PersistenceException    if the categories cannnot be stored

    */

   private void store(Blog blog) throws PersistenceException {

     List<Category> categories = blog.getCategories();

     File destination = new File(blog.getRoot(), CATEGORIES_FILE_NAME);

     try {

       Marshaller marshaller = jaxbContext.createMarshaller();

       CategoriesType categoriesType = new CategoriesType();

       for (Category category : categories) {

         CategoryType categoryType = new CategoryType();

         categoryType.setId(category.getId());

         categoryType.setName(category.getName());

         categoryType.setTags(category.getTags());

         categoriesType.getCategory().add(categoryType);

       }

       log.debug("Saving to " + destination.getAbsolutePath());

       ObjectFactory objectFactory = new ObjectFactory();

       JAXBElement jaxbElement = objectFactory.createCategories(categoriesType);

       marshaller.setProperty("jaxb.formatted.output", true);

       marshaller.setProperty("jaxb.encoding", blog.getCharacterEncoding());

       FileWriter writer = new FileWriter(destination);

       marshaller.marshal(jaxbElement, writer);

       writer.flush();

       writer.close();

     } catch (Exception e) {

       log.error(e.getMessage(), e);

       e.printStackTrace();

       throw new PersistenceException(e.getMessage());

     }

   }

 }