/*

  * Copyright 2006-2011 The Kuali Foundation

  *

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  *

  * 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.

  */

 package org.kuali.rice.core.impl.style;

 import org.apache.commons.lang.StringUtils;

 import org.apache.log4j.Logger;

 import org.kuali.rice.core.api.config.property.ConfigContext;

 import org.kuali.rice.core.api.exception.RiceIllegalArgumentException;

 import org.kuali.rice.core.api.exception.RiceRuntimeException;

 import org.kuali.rice.core.api.style.Style;

 import org.kuali.rice.core.api.style.StyleRepositoryService;

 import org.kuali.rice.core.api.util.RiceUtilities;

 import org.kuali.rice.core.impl.services.CoreImplServiceLocator;

 import org.kuali.rice.ksb.api.cache.RiceCacheAdministrator;

 import javax.xml.transform.Templates;

 import java.io.IOException;

 import java.io.InputStream;

 import java.net.MalformedURLException;

 import java.util.List;

 /**

  * Implements generic StyleService via existing EDL style table

  *

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public class StyleRepositoryServiceImpl implements StyleRepositoryService {

     private static final Logger LOG = Logger.getLogger(StyleRepositoryServiceImpl.class);

     static final String TEMPLATES_CACHE_GROUP_NAME = "Templates";

     private static final String STYLE_CONFIG_PREFIX = "edl.style";

     private StyleDao styleDao;

     private RiceCacheAdministrator cache;

     public void setStyleDao(StyleDao styleDao) {

         this.styleDao = styleDao;

     }

     public void setCache(RiceCacheAdministrator cache) {

         this.cache = cache;

     }

     /**

      * Loads the named style from the database, or (if configured) imports it from a file

      * specified via a configuration parameter with a name of the format edl.style.<styleName>

      * {@inheritDoc}

      *

      * @see org.kuali.rice.edl.impl.service.StyleService#getStyle(java.lang.String)

      */

     @Override

     public Style getStyle(String styleName) {

         if (StringUtils.isBlank(styleName)) {

             throw new RiceIllegalArgumentException("styleName was null or blank");

         }

         // try to fetch the style from the database

         StyleBo style = styleDao.getStyle(styleName);

         // if it's null, look for a config param specifiying a file to load

         if (style == null) {

             String propertyName = STYLE_CONFIG_PREFIX + "." + styleName;

             String location = ConfigContext.getCurrentContextConfig().getProperty(propertyName);

             if (location != null) {

                 InputStream xml = null;

                 try {

                     xml = RiceUtilities.getResourceAsStream(location);

                 } catch (MalformedURLException e) {

                     throw new RiceRuntimeException(getUnableToLoadMessage(propertyName, location), e);

                 } catch (IOException e) {

                     throw new RiceRuntimeException(getUnableToLoadMessage(propertyName, location), e);

                 }

                 if (xml == null) {

                     throw new RiceRuntimeException(getUnableToLoadMessage(propertyName, location) + ", no such file");

                 }

                 LOG.info("Automatically loading style '" + styleName + "' from '" + location + "' as configured by " + propertyName);

                 List<Style> styles = CoreImplServiceLocator.getStyleXmlLoader().parseStyles(xml);

                 for (Style autoLoadedStyle : styles) {

                     if (autoLoadedStyle.getName().equals(styleName)) {

                         return autoLoadedStyle;

                     }

                 }

                 throw new RiceRuntimeException("Failed to locate auto-loaded style '" + styleName + "' after successful parsing of file from '" + location + "' as configured by " + propertyName);

             }

         }

         return StyleBo.to(style);

     }

     /**

      * This method ...

      *

      * @param propertyName

      * @param location

      * @return

      */

     private String getUnableToLoadMessage(String propertyName, String location) {

         return "unable to load resource at '" + location +

                 "' specified by configuration parameter '" + propertyName + "'";

     }

     /**

      * Does not currently take into account style sheet dependences robustly

      */

     private void removeStyleFromCache(String styleName) {

         LOG.info("Removing Style " + styleName + " from the style cache");

         // we don't know what styles may import other styles so we need to flush them all

         cache.flushGroup(TEMPLATES_CACHE_GROUP_NAME);

         //KEWServiceLocator.getCacheAdministrator().flushEntry(getTemplatesCacheKey(styleName));

     }

     @Override

     public void saveStyle(Style data) {

         if (data == null) {

             throw new RiceIllegalArgumentException("The given style was null.");

         }

         StyleBo styleToUpdate = StyleBo.from(data);

         saveStyleBo(styleToUpdate);

     }

     protected void saveStyleBo(StyleBo styleBo) {

         StyleBo existingData = styleDao.getStyle(styleBo.getName());

         if (existingData != null) {

             existingData.setActive(false);

             styleDao.saveStyle(existingData);

         }

         styleDao.saveStyle(styleBo);

         removeStyleFromCache(styleBo.getName());

     }

     @Override

     public List<String> getAllStyleNames() {

         return styleDao.getAllStyleNames();

     }

     // cache helper methods

     /**

      * Returns the key to be used for caching the Templates for the given style name.

      */

     protected String getTemplatesCacheKey(String styleName) {

         return TEMPLATES_CACHE_GROUP_NAME + ":" + styleName;

     }

     protected Templates fetchTemplatesFromCache(String styleName) {

         return (Templates) cache.getFromCache(getTemplatesCacheKey(styleName));

     }

     protected void putTemplatesInCache(String styleName, Templates templates) {

         cache.putInCache(getTemplatesCacheKey(styleName), templates, TEMPLATES_CACHE_GROUP_NAME);

     }

 }