/*

  * $Id: ServletRequest.java 1375743 2012-08-21 20:05:58Z nlebas $

  *

  * 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.request.servlet;

 import java.io.IOException;

 import java.io.OutputStream;

 import java.io.PrintWriter;

 import java.io.Writer;

 import java.util.Arrays;

 import java.util.Collections;

 import java.util.List;

 import java.util.Locale;

 import java.util.Map;

 import javax.servlet.RequestDispatcher;

 import javax.servlet.ServletException;

 import javax.servlet.http.HttpServletRequest;

 import javax.servlet.http.HttpServletResponse;

 import org.apache.tiles.request.AbstractClientRequest;

 import org.apache.tiles.request.ApplicationContext;

 import org.apache.tiles.request.attribute.Addable;

 import org.apache.tiles.request.collection.HeaderValuesMap;

 import org.apache.tiles.request.collection.ReadOnlyEnumerationMap;

 import org.apache.tiles.request.collection.ScopeMap;

 import org.apache.tiles.request.servlet.extractor.ParameterExtractor;

 import org.apache.tiles.request.servlet.extractor.RequestScopeExtractor;

 import org.apache.tiles.request.servlet.extractor.HeaderExtractor;

 import org.apache.tiles.request.servlet.extractor.SessionScopeExtractor;

 /**

  * Servlet-based implementation of the TilesApplicationContext interface.

  *

  * @version $Rev: 1375743 $ $Date: 2012-08-22 06:05:58 +1000 (Wed, 22 Aug 2012) $

  */

 public class ServletRequest extends AbstractClientRequest {

     /**

      * The native available scopes: request, session and application.

      */

     private static final List<String> SCOPES

             = Collections.unmodifiableList(Arrays.asList(REQUEST_SCOPE, "session", APPLICATION_SCOPE));

     /**

      * The request object to use.

      */

     private HttpServletRequest request;

     /**

      * The response object to use.

      */

     private HttpServletResponse response;

     /**

      * 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 instantiated <code>Map</code> of header name-value

      * combinations (write-only).</p>

      */

     private Addable<String> responseHeaders = 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 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.

      */

     public ServletRequest(

             ApplicationContext applicationContext,

             HttpServletRequest request, HttpServletResponse response) {

         super(applicationContext);

         this.request = request;

         this.response = response;

     }

     /** {@inheritDoc} */

     public Map<String, String> getHeader() {

         if ((header == null) && (request != null)) {

             header = new ReadOnlyEnumerationMap<String>(new HeaderExtractor(request, null));

         }

         return (header);

     }

     /** {@inheritDoc} */

     public Addable<String> getResponseHeaders() {

         if ((responseHeaders == null) && (response != null)) {

             responseHeaders = new HeaderExtractor(null, response);

         }

         return (responseHeaders);

     }

     /** {@inheritDoc} */

     public Map<String, String[]> getHeaderValues() {

         if ((headerValues == null) && (request != null)) {

             headerValues = new HeaderValuesMap(new HeaderExtractor(request, response));

         }

         return (headerValues);

     }

     /** {@inheritDoc} */

     public Map<String, String> getParam() {

         if ((param == null) && (request != null)) {

             param = new ReadOnlyEnumerationMap<String>(new ParameterExtractor(request));

         }

         return (param);

     }

     /** {@inheritDoc} */

     @SuppressWarnings("unchecked")

     public Map<String, String[]> getParamValues() {

         return request.getParameterMap();

     }

     @Override

     public Map<String, Object> getContext(String scope) {

         if(REQUEST_SCOPE.equals(scope)){

             return getRequestScope();

         }else if("session".equals(scope)){

             return getSessionScope();

         }else if(APPLICATION_SCOPE.equals(scope)){

             return getApplicationScope();

         }

         throw new IllegalArgumentException(scope + " does not exist. Call getAvailableScopes() first to check.");

     }

     /** {@inheritDoc} */

     public Map<String, Object> getRequestScope() {

         if ((requestScope == null) && (request != null)) {

             requestScope = new ScopeMap(new RequestScopeExtractor(request));

         }

         return (requestScope);

     }

     /** {@inheritDoc} */

     public Map<String, Object> getSessionScope() {

         if ((sessionScope == null) && (request != null)) {

             sessionScope = new ScopeMap(new SessionScopeExtractor(request));

         }

         return (sessionScope);

     }

     @Override

     public List<String> getAvailableScopes() {

         return SCOPES;

     }

     /** {@inheritDoc} */

     public void doForward(String path) throws IOException {

         if (response.isCommitted()) {

             doInclude(path);

         } else {

             forward(path);

         }

     }

     /** {@inheritDoc} */

     public void doInclude(String path) throws IOException {

         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 + "'.");

         }

     }

     /**

      * Forwards to a path.

      *

      * @param path The path to forward to.

      * @throws IOException If something goes wrong during the operation.

      */

     private 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 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();

     }

     public HttpServletRequest getRequest() {

         return request;

     }

     public HttpServletResponse getResponse() {

         return response;

     }

     /** {@inheritDoc} */

     public boolean isUserInRole(String role) {

         return request.isUserInRole(role);

     }

 }