/**
    *       Copyright 2010 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.client;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.io.PrintWriter;
  import java.net.HttpURLConnection;
  import java.net.URL;
  import java.net.URLConnection;
  import java.util.Map;
  
  import org.apache.amber.oauth2.client.request.OAuthClientRequest;
  import org.apache.amber.oauth2.client.response.OAuthClientResponse;
  import org.apache.amber.oauth2.client.response.OAuthClientResponseFactory;
  import org.apache.amber.oauth2.common.OAuth;
  import org.apache.amber.oauth2.common.exception.OAuthProblemException;
  import org.apache.amber.oauth2.common.exception.OAuthSystemException;
  import org.apache.amber.oauth2.common.utils.OAuthUtils;
  
  
  /**
   * Implementation of the OAuth HttpClient using URL Connection
   *
   *
   *
   *
   */
  public class URLConnectionClient implements HttpClient {
  
      public URLConnectionClient() {
      }
  
      public <T extends OAuthClientResponse> T execute(OAuthClientRequest request, Map<String, String> headers,
                                                       String requestMethod, Class<T> responseClass)
          throws OAuthSystemException, OAuthProblemException {
  
          String responseBody = null;
          URLConnection c = null;
          int responseCode = 0;
          try {
              URL url = new URL(request.getLocationUri());
  
              c = url.openConnection();
              responseCode = -1;
              if (c instanceof HttpURLConnection) {
                  HttpURLConnection httpURLConnection = (HttpURLConnection)c;
  
                  if (headers != null && !headers.isEmpty()) {
                      for (Map.Entry<String, String> header : headers.entrySet()) {
                          httpURLConnection.addRequestProperty(header.getKey(), header.getValue());
                      }
                  }
                  
                  if (request.getHeaders() != null) {
                      for (Map.Entry<String, String> header : request.getHeaders().entrySet()) {
                      	httpURLConnection.addRequestProperty(header.getKey(), header.getValue());
                      }
                  }
  
                  if (!OAuthUtils.isEmpty(requestMethod)) {
                      httpURLConnection.setRequestMethod(requestMethod);
                      if (requestMethod.equals(OAuth.HttpMethod.POST)) {
                          httpURLConnection.setDoOutput(true);
                          OutputStream ost = httpURLConnection.getOutputStream();
                          PrintWriter pw = new PrintWriter(ost);
                          pw.print(request.getBody());
                          pw.flush();
                          pw.close();
                      }
                  } else {
                      httpURLConnection.setRequestMethod(OAuth.HttpMethod.GET);
                  }
  
                  httpURLConnection.connect();
  
                  InputStream inputStream;
                  responseCode = httpURLConnection.getResponseCode();
                  if (responseCode == 400) {
                     inputStream = httpURLConnection.getErrorStream();
                 } else {
                     inputStream = httpURLConnection.getInputStream();
                 }
 
                 responseBody = OAuthUtils.saveStreamAsString(inputStream);
             }
         } catch (IOException e) {
             throw new OAuthSystemException(e);
         }
 
         return OAuthClientResponseFactory
             .createCustomResponse(responseBody, c.getContentType(), responseCode, responseClass);
     }
 
     @Override
     public void shutdown() {
         // Nothing to do here
     }
 
 }