/*
    * $Id: TilesAccess.java 1044659 2010-12-11 14:16:04Z apetrelli $
    *
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.apache.tiles.access;
  
  import java.util.Map;
  
  import org.apache.tiles.NoSuchContainerException;
  import org.apache.tiles.TilesContainer;
  import org.apache.tiles.request.ApplicationContext;
  import org.apache.tiles.request.Request;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  /**
   * Provides static access to the tiles container.
   *
   * @version $Rev: 1044659 $ $Date: 2010-12-12 01:16:04 +1100 (Sun, 12 Dec 2010) $
   */
  public final class TilesAccess {
  
      /**
       * Name of the attribute used to store the current used container.
       */
      public static final String CURRENT_CONTAINER_ATTRIBUTE_NAME =
          "org.apache.tiles.servlet.context.ServletTilesRequestContext.CURRENT_CONTAINER_KEY";
  
      /**
       * Constructor, private to avoid instantiation.
       */
      private TilesAccess() {
      }
  
      /**
       * The name of the attribute to use when getting and setting the container
       * object in a context.
       */
      public static final String CONTAINER_ATTRIBUTE =
          "org.apache.tiles.CONTAINER";
  
      /**
       * Configures the default container to be used in the application.
       *
       * @param context The Tiles application context object to use.
       * @param container The container object to set.
       * @since 2.1.2
       */
      public static void setContainer(ApplicationContext context,
              TilesContainer container) {
          setContainer(context, container, CONTAINER_ATTRIBUTE);
      }
  
      /**
       * Configures the container to be used in the application.
       *
       * @param context The Tiles application context object to use.
       * @param container The container object to set.
       * @param key The key under which the container will be stored.
       * @since 2.1.2
       */
      public static void setContainer(ApplicationContext context,
              TilesContainer container, String key) {
          Logger log = LoggerFactory.getLogger(TilesAccess.class);
          if (key == null) {
              key = CONTAINER_ATTRIBUTE;
          }
  
          if (container == null) {
              if (log.isInfoEnabled()) {
                  log.info("Removing TilesContext for context: " + context.getClass().getName());
              }
              context.getApplicationScope().remove(key);
          } else {
              if (log.isInfoEnabled()) {
                  log.info("Publishing TilesContext for context: " + context.getClass().getName());
              }
              context.getApplicationScope().put(key, container);
          }
      }
  
      /**
      * Returns default the container to be used in the application.
      *
      * @param context The Tiles application context object to use.
      * @return The default container object.
      * @since 3.0.0
      */
     public static TilesContainer getContainer(ApplicationContext context) {
         return getContainer(context, CONTAINER_ATTRIBUTE);
     }
 
     /**
      * Returns the container to be used in the application registered under a specific key.
      *
      * @param context The Tiles application context object to use.
      * @param key The key under which the container will be stored.
      * @return The container object.
      * @since 3.0.0
      */
     public static TilesContainer getContainer(ApplicationContext context,
             String key) {
         if (key == null) {
             key = CONTAINER_ATTRIBUTE;
         }
 
         return (TilesContainer) context.getApplicationScope().get(key);
     }
 
     /**
      * Sets the current container to use in web pages.
      *
      * @param request The request to use.
      * @param key The key under which the container is stored.
      * @since 2.1.0
      */
     public static void setCurrentContainer(Request request,
             String key) {
         ApplicationContext applicationContext = request.getApplicationContext();
         TilesContainer container = getContainer(applicationContext, key);
         if (container != null) {
             request.getContext("request").put(CURRENT_CONTAINER_ATTRIBUTE_NAME, container);
         } else {
             throw new NoSuchContainerException("The container with the key '"
                     + key + "' cannot be found");
         }
     }
 
     /**
      * Sets the current container to use in web pages.
      *
      * @param request The request to use.
      * @param container The container to use as the current container.
      * @since 2.1.0
      */
     public static void setCurrentContainer(Request request,
             TilesContainer container) {
         if (container != null) {
             request.getContext("request").put(CURRENT_CONTAINER_ATTRIBUTE_NAME, container);
         } else {
             throw new NullPointerException("The container cannot be null");
         }
     }
 
     /**
      * Returns the current container that has been set, or the default one.
      *
      * @param request The request to use.
      * @return The current Tiles container to use in web pages.
      * @since 2.1.0
      */
     public static TilesContainer getCurrentContainer(Request request) {
         ApplicationContext context = request.getApplicationContext();
         Map<String, Object> requestScope = request.getContext("request");
         TilesContainer container = (TilesContainer) requestScope.get(CURRENT_CONTAINER_ATTRIBUTE_NAME);
         if (container == null) {
             container = getContainer(context);
             requestScope.put(CURRENT_CONTAINER_ATTRIBUTE_NAME, container);
         }
 
         return container;
     }
 }