/*
    * $Id$
    *
    * 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 java.io.IOException;
  import java.io.OutputStream;
  import java.io.PrintWriter;
  import java.io.Writer;
  import java.util.Locale;
  import java.util.Map;
  
  import javax.servlet.RequestDispatcher;
  import javax.servlet.ServletContext;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.tiles.TilesApplicationContext;
  import org.apache.tiles.context.TilesApplicationContextWrapper;
  import org.apache.tiles.context.TilesRequestContext;
  
  /**
   * Servlet-based implementation of the TilesApplicationContext interface.
   *
   * @version $Rev$ $Date$
   */
  public class ServletTilesRequestContext extends TilesApplicationContextWrapper
          implements TilesRequestContext {
  
      /**
       * The request object to use.
       */
      private HttpServletRequest request;
  
      /**
       * The response object to use.
       */
      private HttpServletResponse response;
  
      /**
       * The request objects, lazily initialized.
       */
      private Object[] requestObjects;
  
      /**
       * The response output stream, lazily initialized.
       */
      private OutputStream outputStream;
  
      /**
       * The response writer, lazily initialized.
       */
      private PrintWriter writer;
  
      /**
       * <p>The lazily instantiated <code>Map</code> of header name-value
       * combinations (immutable).</p>
       */
      private Map<String, String> header = null;
  
  
      /**
       * <p>The lazily instantitated <code>Map</code> of header name-values
       * combinations (immutable).</p>
       */
      private Map<String, String[]> headerValues = null;
  
  
      /**
       * <p>The lazily instantiated <code>Map</code> of request
       * parameter name-value.</p>
       */
      private Map<String, String> param = null;
  
  
      /**
       * <p>The lazily instantiated <code>Map</code> of request
       * parameter name-values.</p>
       */
      private Map<String, String[]> paramValues = null;
  
     /**
      * <p>The lazily instantiated <code>Map</code> of request scope
      * attributes.</p>
      */
     private Map<String, Object> requestScope = null;
 
     /**
      * <p>The lazily instantiated <code>Map</code> of session scope
      * attributes.</p>
      */
     private Map<String, Object> sessionScope = null;
 
 
     /**
      * Creates a new instance of ServletTilesRequestContext.
      *
      * @param applicationContext The application context.
      * @param request The request object.
      * @param response The response object.
      * @since 2.1.1
      */
     public ServletTilesRequestContext(
             TilesApplicationContext applicationContext,
             HttpServletRequest request, HttpServletResponse response) {
         super(applicationContext);
         initialize(request, response);
     }
 
     /**
      * Creates a new instance of ServletTilesRequestContext.
      *
      * @param servletContext The servlet context.
      * @param request The request object.
      * @param response The response object.
      * @deprecated Use
      * {@link #ServletTilesRequestContext(TilesApplicationContext, HttpServletRequest, HttpServletResponse)}
      * .
      */
     @Deprecated
     public ServletTilesRequestContext(ServletContext servletContext,
                                       HttpServletRequest request,
                                       HttpServletResponse response) {
         super(new ServletTilesApplicationContext(servletContext));
         initialize(request, response);
     }
 
 
     /** {@inheritDoc} */
     public Map<String, String> getHeader() {
 
         if ((header == null) && (request != null)) {
             header = new ServletHeaderMap(request, response);
         }
         return (header);
 
     }
 
 
     /** {@inheritDoc} */
     public Map<String, String[]> getHeaderValues() {
 
         if ((headerValues == null) && (request != null)) {
             headerValues = new ServletHeaderValuesMap(request);
         }
         return (headerValues);
 
     }
 
 
     /** {@inheritDoc} */
     public Map<String, String> getParam() {
 
         if ((param == null) && (request != null)) {
             param = new ServletParamMap(request);
         }
         return (param);
 
     }
 
 
     /** {@inheritDoc} */
     public Map<String, String[]> getParamValues() {
 
         if ((paramValues == null) && (request != null)) {
             paramValues = new ServletParamValuesMap(request);
         }
         return (paramValues);
 
     }
 
 
     /** {@inheritDoc} */
     public Map<String, Object> getRequestScope() {
 
         if ((requestScope == null) && (request != null)) {
             requestScope = new ServletRequestScopeMap(request);
         }
         return (requestScope);
 
     }
 
 
     /** {@inheritDoc} */
     public Map<String, Object> getSessionScope() {
 
         if ((sessionScope == null) && (request != null)) {
             sessionScope = new ServletSessionScopeMap(request);
         }
         return (sessionScope);
 
     }
 
     /** {@inheritDoc} */
     public TilesApplicationContext getApplicationContext() {
         return getWrappedApplicationContext();
     }
 
     /** {@inheritDoc} */
     public void dispatch(String path) throws IOException {
         if (response.isCommitted() || ServletUtil.isForceInclude(request)) {
             include(path);
         } else {
             forward(path);
         }
     }
 
     /**
      * Forwards to a path.
      *
      * @param path The path to forward to.
      * @throws IOException If something goes wrong during the operation.
      */
     protected void forward(String path) throws IOException {
         RequestDispatcher rd = request.getRequestDispatcher(path);
 
         if (rd == null) {
             throw new IOException("No request dispatcher returned for path '"
                     + path + "'");
         }
 
         try {
             rd.forward(request, response);
         } catch (ServletException ex) {
             throw ServletUtil.wrapServletException(ex, "ServletException including path '"
                     + path + "'.");
         }
     }
 
 
     /** {@inheritDoc} */
     public void include(String path) throws IOException {
         ServletUtil.setForceInclude(request, true);
         RequestDispatcher rd = request.getRequestDispatcher(path);
 
         if (rd == null) {
             throw new IOException("No request dispatcher returned for path '"
                     + path + "'");
         }
 
         try {
             rd.include(request, response);
         } catch (ServletException ex) {
             throw ServletUtil.wrapServletException(ex, "ServletException including path '"
                     + path + "'.");
         }
     }
 
     /** {@inheritDoc} */
     public OutputStream getOutputStream() throws IOException {
         if (outputStream == null) {
             outputStream = response.getOutputStream();
         }
         return outputStream;
     }
 
     /** {@inheritDoc} */
     public Writer getWriter() throws IOException {
         return getPrintWriter();
     }
 
     /** {@inheritDoc} */
     public PrintWriter getPrintWriter() throws IOException {
         if (writer == null) {
             writer = response.getWriter();
         }
         return writer;
     }
 
     /** {@inheritDoc} */
     public boolean isResponseCommitted() {
         return response.isCommitted();
     }
 
     /** {@inheritDoc} */
     public void setContentType(String contentType) {
         response.setContentType(contentType);
     }
 
     /** {@inheritDoc} */
     public Locale getRequestLocale() {
         return request.getLocale();
     }
 
     /** {@inheritDoc} */
     public Object[] getRequestObjects() {
         if (requestObjects == null) {
             requestObjects = new Object[2];
             requestObjects[0] = request;
             requestObjects[1] = response;
         }
         return requestObjects;
     }
 
     /** {@inheritDoc} */
     public HttpServletRequest getRequest() {
         return request;
     }
 
     /** {@inheritDoc} */
     public HttpServletResponse getResponse() {
         return response;
     }
 
     /**
      * <p>Initialize (or reinitialize) this {@link ServletTilesRequestContext} instance
      * for the specified Servlet API objects.</p>
      *
      * @param request  The <code>HttpServletRequest</code> for this request
      * @param response The <code>HttpServletResponse</code> for this request
      */
     public void initialize(HttpServletRequest request,
                            HttpServletResponse response) {
 
         // Save the specified Servlet API object references
         this.request = request;
         this.response = response;
         // 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
         header = null;
         headerValues = null;
         param = null;
         paramValues = null;
         requestScope = null;
         sessionScope = null;
 
         // Release references to Servlet API objects
         request = null;
         response = null;
     }
 
 
     /** {@inheritDoc} */
     public boolean isUserInRole(String role) {
         return request.isUserInRole(role);
     }
 
     /**
      * Wraps a ServletException to create an IOException with the root cause if
      * present.
      *
      * @param ex The exception to wrap.
      * @param message The message of the exception.
      * @return The wrapped exception.
      * @since 2.0.6
      * @deprecated Use
      * {@link ServletUtil#wrapServletException(ServletException,String)}
      * instead.
      */
     @Deprecated
     protected IOException wrapServletException(ServletException ex,
             String message) {
         return ServletUtil.wrapServletException(ex, message);
     }
 }