/*
    * 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.hadoop.chukwa.hicc.proxy;
  
  import java.io.BufferedReader;
  import java.io.DataOutputStream;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.net.HttpURLConnection;
  import java.net.URL;
  import java.net.URLEncoder;
  import java.nio.charset.Charset;
  import java.util.Map;
  
  import javax.servlet.ServletException;
  import javax.servlet.ServletOutputStream;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.hadoop.chukwa.conf.ChukwaConfiguration;
  import org.apache.log4j.Logger;
  
  /**
   * HTTP Proxy Servlet for Solr
   *
   */
  public class HttpProxy extends HttpServlet {
    private static final long serialVersionUID = 7574L;
    private final String USER_AGENT = "Mozilla/5.0";
    private final static String SOLR_URL = "chukwa.solr.url";
    private final static Logger LOG = Logger.getLogger(HttpProxy.class);
    private String solrUrl = null;
  
    public HttpProxy() {
      super();
      ChukwaConfiguration conf = new ChukwaConfiguration();
      solrUrl = conf.get(SOLR_URL);
    }
  
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
      // Create Get request dynamically to remote server
      String url = solrUrl + request.getPathInfo()
          + "?" + request.getQueryString();
  
      URL obj = new URL(url);
      HttpURLConnection con = (HttpURLConnection) obj.openConnection();
  
      // optional default is GET
      con.setRequestMethod("GET");
  
      // add request header
      con.setRequestProperty("User-Agent", USER_AGENT);
  
      int responseCode = con.getResponseCode();
      LOG.info("Sending 'GET' request to URL : " + url);
      LOG.info("Response Code : " + responseCode);
  
      BufferedReader in = new BufferedReader(new InputStreamReader(
          con.getInputStream(), Charset.forName("UTF-8")));
      String inputLine;
      StringBuffer response1 = new StringBuffer();
  
      ServletOutputStream sout = response.getOutputStream();
  
      while ((inputLine = in.readLine()) != null) {
        response1.append(inputLine);
        sout.write(inputLine.getBytes(Charset.forName("UTF-8")));
      }
      in.close();
  
      sout.flush();
  
    }
  
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
      // Create Post request dynamically to remote server
      String url = solrUrl + request.getPathInfo();
  
      URL obj = new URL(url);
      HttpURLConnection con = (HttpURLConnection) obj.openConnection();
  
     // add reuqest header
     con.setRequestMethod("POST");
     con.setRequestProperty("User-Agent", USER_AGENT);
     con.setRequestProperty("Accept-Language", "en-US,en;q=0.5");
 
     StringBuilder sb = new StringBuilder();
     @SuppressWarnings("rawtypes")
     Map map = request.getParameterMap();
     for (Object key : request.getParameterMap().keySet()) {
       if (sb.length() > 0) {
         sb.append('&');
       }
       String keyStr = (String) key;
       String[] temp = (String[]) map.get(keyStr);
       for (String s : temp) {
         sb.append(URLEncoder.encode(keyStr, "UTF-8")).append('=')
             .append(URLEncoder.encode(s, "UTF-8"));
       }
     }
 
     String urlParameters = sb.toString();
 
     // Send post request
     con.setDoOutput(true);
     DataOutputStream wr = new DataOutputStream(con.getOutputStream());
     wr.writeBytes(urlParameters);
     wr.flush();
     wr.close();
 
     int responseCode = con.getResponseCode();
     LOG.debug("\nSending 'POST' request to URL : " + url);
     LOG.debug("Post parameters : " + urlParameters);
     LOG.debug("Response Code : " + responseCode);
 
     BufferedReader in = new BufferedReader(new InputStreamReader(
         con.getInputStream(), Charset.forName("UTF-8")));
     String inputLine;
     StringBuffer response1 = new StringBuffer();
 
     ServletOutputStream sout = response.getOutputStream();
 
     while ((inputLine = in.readLine()) != null) {
       response1.append(inputLine);
       sout.write(inputLine.getBytes(Charset.forName("UTF-8")));
     }
     in.close();
 
     sout.flush();
   }
 
 }