/*
    * $Id: ServletTilesApplicationContext.java 709140 2008-10-30 11:07:50Z 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.servlet.context;
  
  import org.apache.tiles.TilesApplicationContext;
  import org.apache.tiles.context.TilesRequestContext;
  
  import javax.servlet.ServletContext;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import java.io.IOException;
  import java.net.URL;
  import java.util.Map;
  import java.util.Set;
  import java.util.HashSet;
  
  /***
   * Servlet-based implementation of the TilesApplicationContext interface.
   *
   * @version $Rev: 709140 $ $Date: 2008-10-30 12:07:50 +0100 (gio, 30 ott 2008) $
   */
  public class ServletTilesApplicationContext implements TilesApplicationContext {
  
      /***
       * The servlet context to use.
       */
      private ServletContext servletContext;
  
  
      /***
       * <p>The lazily instantiated <code>Map</code> of application scope
       * attributes.</p>
       */
      private Map<String, Object> applicationScope = null;
  
  
      /***
       * <p>The lazily instantiated <code>Map</code> of context initialization
       * parameters.</p>
       */
      private Map<String, String> initParam = null;
  
  
      /***
       * Creates a new instance of ServletTilesApplicationContext.
       *
       * @param servletContext The servlet context to use.
       */
      public ServletTilesApplicationContext(ServletContext servletContext) {
          initialize(servletContext);
      }
  
      /*** {@inheritDoc} */
      public Object getContext() {
          return servletContext;
      }
  
      /*** {@inheritDoc} */
      public Map<String, Object> getApplicationScope() {
  
          if ((applicationScope == null) && (servletContext != null)) {
              applicationScope = new ServletApplicationScopeMap(servletContext);
          }
          return (applicationScope);
  
      }
  
  
      /*** {@inheritDoc} */
      public Map<String, String> getInitParams() {
  
          if ((initParam == null) && (servletContext != null)) {
              initParam = new ServletInitParamMap(servletContext);
          }
          return (initParam);
  
      }
  
      /*** {@inheritDoc} */
      public URL getResource(String path) throws IOException {
         return servletContext.getResource(path);
     }
 
     /*** {@inheritDoc} */
     public Set<URL> getResources(String path) throws IOException {
         HashSet<URL> urls = new HashSet<URL>();
         urls.add(getResource(path));
         return urls;
     }
 
     /***
      * Returns the servlet context.
      *
      * @return The servlet context.
      * @deprecated Use {@link #getContext()}.
      */
     public ServletContext getServletContext() {
         return servletContext;
     }
 
 
     /***
      * <p>Initialize (or reinitialize) this {@link TilesApplicationContext} instance
      * for the specified Servlet API objects.</p>
      *
      * @param context The <code>ServletContext</code> for this web application
      */
     public void initialize(ServletContext context) {
         // Save the specified Servlet API object references
         this.servletContext = context;
 
         // Perform other setup as needed
     }
 
 
     /***
      * <p>Release references to allocated resources acquired in
      * <code>initialize()</code> of via subsequent processing.  After this
      * method is called, subsequent calls to any other method than
      * <code>initialize()</code> will return undefined results.</p>
      */
     public void release() {
 
         // Release references to allocated collections
         applicationScope = null;
         initParam = null;
 
         // Release references to Servlet API objects
         servletContext = null;
 
     }
 
     /***
      * Creates a servlet context for a given request/response pair.
      *
      * @param request The request object.
      * @param response The response object.
      * @return The corresponding Tiles request context.
      * @deprecated Use
      * {@link org.apache.tiles.context.TilesContextFactory#createRequestContext(TilesApplicationContext, Object...)}
      * .
      */
     public TilesRequestContext createRequestContext(Object request, Object response) {
         if (request instanceof HttpServletRequest) {
             return new ServletTilesRequestContext(
                 servletContext,
                 (HttpServletRequest) request,
                 (HttpServletResponse) response
             );
         } else {
             throw new IllegalArgumentException("Invalid context specified. "
                 + servletContext.getClass().getName());
         }
     }
 }