/*
    * Copyright 2007-2014 the original author or authors.
    *
    * Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0
    *
   * 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.springbyexample.cometd.continuation;
  
  import java.io.IOException;
  import java.io.StringReader;
  import java.util.Map;
  
  import javax.annotation.PostConstruct;
  import javax.servlet.ServletContext;
  
  import org.cometd.DataFilter;
  import org.mortbay.cometd.continuation.ContinuationBayeux;
  import org.mortbay.cometd.continuation.ContinuationCometdServlet;
  import org.mortbay.cometd.filter.JSONDataFilter;
  import org.mortbay.util.ajax.JSON;
  import org.springframework.util.ClassUtils;
  import org.springframework.web.context.ServletContextAware;
  
  /**
   * A subclass of {@link ContinuationBayeux} that allows
   * full initialization of bayeux outside the {@link ContinuationCometdServlet}.
   *
   * @author David Winterfeldt
   */
  public class SpringContinuationBayeux extends ContinuationBayeux implements ServletContextAware {
  
      protected ServletContext servletContext = null;
  
      protected String filters = null;
      protected long maxInterval  = 10000;
  
      /**
       * Implementation of <code>ServletContextAware</code>.
       */
      @Override
      public void setServletContext(ServletContext servletContext) {
          this.servletContext = servletContext;
      }
  
      /**
       * Gets filters as JSON objects.
       */
      public String getFilters() {
          return filters;
      }
  
      /**
       * Sets filters as JSON objects.
       */
      public void setFilters(String filters) {
          this.filters = filters;
      }
  
      /**
       * <p>Sets max interval.</p>
       *
       * <p><strong>Note</strong>: Overriding parent because it sets value on
       * internal instance before initialization.</p>
       */
      @Override
      public void setMaxInterval(long maxInterval) {
          this.maxInterval = maxInterval;
      }
  
  
      /**
       * Initializes bayeux.
       */
      @PostConstruct
      public void init() {
          this.initialize(servletContext);
  
          super.setMaxInterval(maxInterval);
  
          // based on AbstractCometdServlet.init()
          if (filters != null) {
              try {
                  Object[] objects = (Object[]) JSON.parse(new StringReader(filters));
  
                  for (int i = 0; objects != null && i < objects.length; i++) {
                      Map<?, ?> filter_def = (Map<?, ?>) objects[i];
  
                      String className = (String) filter_def.get("filter");
                      DataFilter filter = (DataFilter) ClassUtils.forName(className, ClassUtils.getDefaultClassLoader()).newInstance();
  
                     if (filter instanceof JSONDataFilter)
                         ((JSONDataFilter) filter).init(filter_def.get("init"));
 
                     getChannel((String) filter_def.get("channels"), true).addDataFilter(filter);
                 }
             } catch (IOException e) {
                 throw new IllegalArgumentException("Unable to initialize bayuex filters.  " + e.getMessage());
             } catch (InstantiationException e) {
                 throw new IllegalArgumentException("Unable to initialize bayuex filters.  " + e.getMessage());
             } catch (IllegalAccessException e) {
                 throw new IllegalArgumentException("Unable to initialize bayuex filters.  " + e.getMessage());
             } catch (ClassNotFoundException e) {
                 throw new IllegalArgumentException("Unable to initialize bayuex filters.  " + e.getMessage());
             } catch (LinkageError e) {
                 throw new IllegalArgumentException("Unable to initialize bayuex filters.  " + e.getMessage());
             }
         }
     }
 
 }