/*
    * $Id: KeyedDefinitionsFactoryTilesContainer.java 797754 2009-07-25 11:42:03Z 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.impl;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.tiles.Definition;
  import org.apache.tiles.context.TilesRequestContext;
  import org.apache.tiles.definition.DefinitionsFactory;
  
  /***
   * Container that can be used to store multiple {@link DefinitionsFactory}
   * instances mapped to different keys.
   *
   * @version $Rev: 797754 $ $Date: 2009-07-25 13:42:03 +0200 (sab, 25 lug 2009) $
   * @deprecated Register different containers using
   * {@link org.apache.tiles.access.TilesAccess#setContainer(
   * org.apache.tiles.TilesApplicationContext, org.apache.tiles.TilesContainer, String)}
   */
  public class KeyedDefinitionsFactoryTilesContainer extends BasicTilesContainer {
  
      /***
       * Constant representing the prefix of the configuration parameter used to
       * define the tiles definition resources for a specific key.
       */
      public static final String DEFINITIONS_CONFIG_PREFIX =
          "org.apache.tiles.impl.KeyedDefinitionsFactoryTilesContainer.DEFINITIONS_CONFIG@";
  
      /***
       * Maps definition factories to their keys.
       */
      protected Map<String, DefinitionsFactory> key2definitionsFactory;
  
      /***
       * The key extractor object.
       */
      protected KeyExtractor keyExtractor;
  
      /***
       * Constructor.
       */
      public KeyedDefinitionsFactoryTilesContainer() {
          key2definitionsFactory = new HashMap<String, DefinitionsFactory>();
      }
  
      /***
       * It represents an object able to return a key from a request. Each key
       * maps a different {@link DefinitionsFactory}.
       */
      public static interface KeyExtractor {
  
          /***
           * Returns the definitions factory key.
           *
           * @param request The request object.
           * @return The needed factory key.
           */
          String getDefinitionsFactoryKey(TilesRequestContext request);
      }
  
      /***
       * This is the default factory key. Takes the key from the request-scoped
       * attribute <code>DEFINITIONS_FACTORY_KEY_ATTRIBUTE_NAME</code>.
       */
      public static class DefaultKeyExtractor implements KeyExtractor {
  
          /***
           * Name of the attribute inside the request that will be used to get the
           * key of the definitions factory to be used.
           */
          public static final String DEFINITIONS_FACTORY_KEY_ATTRIBUTE_NAME =
              "org.apache.tiles.impl.KeyedDefinitionsFactoryTilesContainer.DefaultKeyExtractor.KEY";
  
          /***
           * Returns the definitions factory key.
           *
           * @param request The request object.
           * @return The needed factory key.
           */
         public String getDefinitionsFactoryKey(TilesRequestContext request) {
             String retValue = null;
             Map<String, Object> requestScope = request.getRequestScope();
             if (requestScope != null) { // Probably the request scope does not exist
                 retValue = (String) requestScope.get(
                         DEFINITIONS_FACTORY_KEY_ATTRIBUTE_NAME);
             }
 
             return retValue;
         }
     }
 
     /***
      * Returns a definition factory given its key.
      *
      * @return the definitions factory used by this container. If the key is not
      * valid, the default factory will be returned.
      * @param key The key of the needed definitions factory.
      */
     public DefinitionsFactory getDefinitionsFactory(String key) {
         DefinitionsFactory retValue = null;
 
         if (key != null) {
             retValue = key2definitionsFactory.get(key);
         }
         if (retValue == null) {
             retValue = getDefinitionsFactory();
         }
 
         return retValue;
     }
 
     /***
      * Returns the proper definition factory for the given key, i.e. if the key
      * is not present, <code>null</code> will be returned.
      *
      * @return the definitions factory used by this container. If the key is not
      * valid, <code>null</code> will be returned.
      * @param key The key of the needed definitions factory.
      */
     public DefinitionsFactory getProperDefinitionsFactory(String key) {
         DefinitionsFactory retValue = null;
 
         if (key != null) {
             retValue = key2definitionsFactory.get(key);
         }
 
         return retValue;
     }
 
     /***
      * Set the definitions factory. This method first ensures that the container
      * has not yet been initialized.
      *
      * @param key The key under which the definitions factory is catalogued.
      * @param definitionsFactory the definitions factory for this instance.
      * @param initParameters The init parameters to configure the definitions
      * factory.
      * @deprecated Use {@link #setDefinitionsFactory(String, DefinitionsFactory)}.
      */
     @Deprecated
     public void setDefinitionsFactory(String key,
             DefinitionsFactory definitionsFactory,
             Map<String, String> initParameters) {
         setDefinitionsFactory(key, definitionsFactory);
         if (key != null) {
             initializeDefinitionsFactory(definitionsFactory,
                     getResourceString(initParameters), initParameters);
         }
     }
 
     /***
      * Set the definitions factory. This method first ensures that the container
      * has not yet been initialized.
      *
      * @param key The key under which the definitions factory is catalogued.
      * @param definitionsFactory the definitions factory for this instance.
      * @since 2.1.0
      */
     public void setDefinitionsFactory(String key,
             DefinitionsFactory definitionsFactory) {
         if (key != null) {
             key2definitionsFactory.put(key, definitionsFactory);
         } else {
             setDefinitionsFactory(definitionsFactory);
         }
     }
 
     /***
      * Sets the key extractor to use.
      *
      * @param keyExtractor The key extractor.
      */
     public void setKeyExtractor(KeyExtractor keyExtractor) {
         this.keyExtractor = keyExtractor;
     }
 
     /*** {@inheritDoc} */
     @Override
     protected Definition getDefinition(String definitionName,
             TilesRequestContext request) {
         Definition retValue = null;
         String key = getDefinitionsFactoryKey(request);
         if (key != null) {
             DefinitionsFactory definitionsFactory =
                 key2definitionsFactory.get(key);
             if (definitionsFactory != null) {
                 retValue = definitionsFactory.getDefinition(definitionName,
                         request);
             }
         }
         if (retValue == null) {
             retValue = super.getDefinition(definitionName, request);
         }
         return retValue;
     }
 
     /***
      * Returns the definitions factory key.
      *
      * @param request The request object.
      * @return The needed factory key.
      */
     protected String getDefinitionsFactoryKey(TilesRequestContext request) {
         if (keyExtractor == null) {
             keyExtractor = new DefaultKeyExtractor();
         }
         return keyExtractor.getDefinitionsFactoryKey(request);
     }
 }