/**
    *       Copyright 2011 Newcastle University
    *
    *          http://research.ncl.ac.uk/smart/
    *
    * 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.amber.oauth2.ext.dynamicreg.server.request;
  
  import java.util.Collections;
  import java.util.Enumeration;
  import java.util.HashMap;
  import java.util.Map;
  import javax.servlet.ServletInputStream;
  import javax.servlet.ServletRequest;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletRequestWrapper;
  
  import org.apache.amber.oauth2.common.OAuth;
  import org.apache.amber.oauth2.common.exception.OAuthProblemException;
  import org.apache.amber.oauth2.common.exception.OAuthRuntimeException;
  import org.apache.amber.oauth2.common.utils.OAuthUtils;
  import org.codehaus.jettison.json.JSONArray;
  import org.codehaus.jettison.json.JSONException;
  import org.codehaus.jettison.json.JSONObject;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   *
   */
  public class JSONHttpServletRequestWrapper extends HttpServletRequestWrapper {
      private Logger log = LoggerFactory.getLogger(JSONHttpServletRequestWrapper.class);
      private JSONObject body;
      private boolean bodyRead = false;
  
      public JSONHttpServletRequestWrapper(HttpServletRequest request) {
          super(request);
      }
  
      public String getParameter(String name) {
          final String[] values = getParameterMap().get(name);
          if (values == null || values.length == 0) {
              return null;
          }
          return values[0];
      }
  
      public Map<String, String[]> getParameterMap() {
          try {
              readJsonBody();
              Map<String, String[]> parameters = new HashMap<String, String[]>();
  
              if (body != null) {
                  final JSONArray attributeNames = body.names();
                  for (int i = 0; i < attributeNames.length(); i++) {
                      final String attributeName = attributeNames.getString(i);
                      final String attributeValue = body.getString(attributeName);
  
                      parameters.put(attributeName, new String[] {attributeValue});
                  }
              }
  
              return Collections.unmodifiableMap(parameters);
          } catch (JSONException e) {
              log.error("Dynamic client registration error: ", e);
              throw new OAuthRuntimeException("OAuth server error");
          }
      }
  
      public Enumeration getParameterNames() {
          return Collections.enumeration(getParameterMap().keySet());
      }
  
      public String[] getParameterValues(String name) {
          return getParameterMap().get(name);
      }
  
      /**
       * Lazily read JSON from request
       *
       * @throws OAuthProblemException
       */
      private void readJsonBody() {
          if (!bodyRead) {
              bodyRead = true;
             try {
                 final ServletRequest request = getRequest();
                 String contentType = request.getContentType();
                 final String expectedContentType = OAuth.ContentType.JSON;
                 if (!OAuthUtils.hasContentType(contentType, expectedContentType)) {
                     return;
                 }
 
                 final ServletInputStream inputStream = request.getInputStream();
                 if (inputStream == null) {
                     return;
                 }
                 final String jsonString = OAuthUtils.saveStreamAsString(inputStream);
                 body = new JSONObject(jsonString);
             } catch (JSONException e) {
                 log.error("Cannot decode request body as a JSON: ", e);
             } catch (Exception e) {
                 log.error("Dynamic client registration error: ", e);
                 throw new OAuthRuntimeException("OAuth server error");
             }
         }
     }
 }