/**
      This file is part of GoldenGate Project (named also GoldenGate or GG).
   
      Copyright 2009, Frederic Bregier, and individual contributors by the @author
      tags. See the COPYRIGHT.txt in the distribution for a full listing of
      individual contributors.
   
      All GoldenGate Project is free software: you can redistribute it and/or 
      modify it under the terms of the GNU General Public License as published 
     by the Free Software Foundation, either version 3 of the License, or
     (at your option) any later version.
  
     GoldenGate is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
  
     You should have received a copy of the GNU General Public License
     along with GoldenGate .  If not, see <http://www.gnu.org/licenses/>.
   */
  package openr66.protocol.http;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Set;
  
  import org.jboss.netty.buffer.ChannelBuffer;
  import org.jboss.netty.buffer.ChannelBuffers;
  import org.jboss.netty.channel.Channel;
  import org.jboss.netty.handler.codec.http.Cookie;
  import org.jboss.netty.handler.codec.http.CookieDecoder;
  import org.jboss.netty.handler.codec.http.CookieEncoder;
  import org.jboss.netty.handler.codec.http.DefaultHttpResponse;
  import org.jboss.netty.handler.codec.http.HttpHeaders;
  import org.jboss.netty.handler.codec.http.HttpRequest;
  import org.jboss.netty.handler.codec.http.HttpResponse;
  import org.jboss.netty.handler.codec.http.HttpResponseStatus;
  import org.jboss.netty.handler.codec.http.HttpVersion;
  
  /**
   * 
   * Utility class to write external file with cache enable properties
   * 
   * @author Frederic Bregier
   *
   */
  public class HttpWriteCacheEnable {
  
      /**
       * Write a file, taking into account cache enabled and removing session cookie
       * @param request
       * @param channel
       * @param filename
       * @param cookieNameToRemove
       */
      public static void writeFile(HttpRequest request, Channel channel, String filename, String cookieNameToRemove) {
          // Convert the response content to a ChannelBuffer.
          HttpResponse response;
          if (request.containsHeader(HttpHeaders.Names.IF_MODIFIED_SINCE)) {
              response = new DefaultHttpResponse(HttpVersion.HTTP_1_1,
                      HttpResponseStatus.NOT_MODIFIED);
              handleCookies(request, response, cookieNameToRemove);
              channel.write(response);
              return;
          }
          File file = new File(filename);
          byte [] bytes = new byte[(int) file.length()];
          FileInputStream fileInputStream;
          try {
              fileInputStream = new FileInputStream(file);
          } catch (FileNotFoundException e) {
              response = new DefaultHttpResponse(HttpVersion.HTTP_1_1,
                      HttpResponseStatus.NOT_FOUND);
              handleCookies(request, response, cookieNameToRemove);
              channel.write(response);
              return;
          }
          try {
              fileInputStream.read(bytes);
          } catch (IOException e) {
              response = new DefaultHttpResponse(HttpVersion.HTTP_1_1,
                      HttpResponseStatus.NOT_FOUND);
              handleCookies(request, response, cookieNameToRemove);
              channel.write(response);
              return;
          }
          ChannelBuffer buf = ChannelBuffers.copiedBuffer(bytes);
          // Build the response object.
          response = new DefaultHttpResponse(HttpVersion.HTTP_1_1,
                  HttpResponseStatus.OK);
          response.setContent(buf);
          response.setHeader(HttpHeaders.Names.CONTENT_LENGTH, String.valueOf(buf.readableBytes()));
          ArrayList<String> cache_control = new ArrayList<String>(2);
          cache_control.add(HttpHeaders.Values.PUBLIC);
          cache_control.add(HttpHeaders.Values.MAX_AGE+"="+31536000);//1 year
          response.setHeader(HttpHeaders.Names.CACHE_CONTROL, cache_control);
         response.setHeader(HttpHeaders.Names.LAST_MODIFIED, "Tue, 15 Nov 1994 12:45:26 GMT");
         handleCookies(request, response, cookieNameToRemove);
         // Write the response.
         channel.write(response);
     }
     /**
      * Remove the given named cookie
      * @param request
      * @param response
      * @param cookieNameToRemove
      */
     public static void handleCookies(HttpRequest request, HttpResponse response, String cookieNameToRemove) {
         String cookieString = request.getHeader(HttpHeaders.Names.COOKIE);
         if (cookieString != null) {
             CookieDecoder cookieDecoder = new CookieDecoder();
             Set<Cookie> cookies = cookieDecoder.decode(cookieString);
             if(!cookies.isEmpty()) {
                 // Reset the sessions if necessary.
                 CookieEncoder cookieEncoder = new CookieEncoder(true);
                 // Remove all Session for images
                 for (Cookie cookie : cookies) {
                     if (cookie.getName().equalsIgnoreCase(cookieNameToRemove)) {
                     } else {
                         cookieEncoder.addCookie(cookie);
                         response.addHeader(HttpHeaders.Names.SET_COOKIE, cookieEncoder.encode());
                         cookieEncoder = new CookieEncoder(true);
                     }
                 }
             }
         }
     }
 
 }