/*
    * Copyright 2012 The Netty Project
    *
    * The Netty Project 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 io.netty.example.http.upload;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.channel.Channel;
  import io.netty.channel.ChannelFuture;
  import io.netty.channel.ChannelFutureListener;
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.channel.SimpleChannelInboundHandler;
  import io.netty.handler.codec.http.Cookie;
  import io.netty.handler.codec.http.CookieDecoder;
  import io.netty.handler.codec.http.DefaultFullHttpResponse;
  import io.netty.handler.codec.http.FullHttpResponse;
  import io.netty.handler.codec.http.HttpContent;
  import io.netty.handler.codec.http.HttpHeaders;
  import io.netty.handler.codec.http.HttpMethod;
  import io.netty.handler.codec.http.HttpObject;
  import io.netty.handler.codec.http.HttpRequest;
  import io.netty.handler.codec.http.HttpResponseStatus;
  import io.netty.handler.codec.http.HttpVersion;
  import io.netty.handler.codec.http.LastHttpContent;
  import io.netty.handler.codec.http.QueryStringDecoder;
  import io.netty.handler.codec.http.ServerCookieEncoder;
  import io.netty.handler.codec.http.multipart.Attribute;
  import io.netty.handler.codec.http.multipart.DefaultHttpDataFactory;
  import io.netty.handler.codec.http.multipart.DiskAttribute;
  import io.netty.handler.codec.http.multipart.DiskFileUpload;
  import io.netty.handler.codec.http.multipart.FileUpload;
  import io.netty.handler.codec.http.multipart.HttpDataFactory;
  import io.netty.handler.codec.http.multipart.HttpPostRequestDecoder;
  import io.netty.handler.codec.http.multipart.HttpPostRequestDecoder.EndOfDataDecoderException;
  import io.netty.handler.codec.http.multipart.HttpPostRequestDecoder.ErrorDataDecoderException;
  import io.netty.handler.codec.http.multipart.HttpPostRequestDecoder.IncompatibleDataDecoderException;
  import io.netty.handler.codec.http.multipart.InterfaceHttpData;
  import io.netty.handler.codec.http.multipart.InterfaceHttpData.HttpDataType;
  import io.netty.util.CharsetUtil;
  
  import java.io.IOException;
  import java.net.URI;
  import java.util.Collections;
  import java.util.List;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.Set;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  
  import static io.netty.buffer.Unpooled.*;
  import static io.netty.handler.codec.http.HttpHeaders.Names.*;
  
  public class HttpUploadServerHandler extends SimpleChannelInboundHandler<HttpObject> {
  
      private static final Logger logger = Logger.getLogger(HttpUploadServerHandler.class.getName());
  
      private HttpRequest request;
  
      private boolean readingChunks;
  
      private final StringBuilder responseContent = new StringBuilder();
  
      private static final HttpDataFactory factory =
              new DefaultHttpDataFactory(DefaultHttpDataFactory.MINSIZE); // Disk if size exceed
  
      private HttpPostRequestDecoder decoder;
  
      static {
          DiskFileUpload.deleteOnExitTemporaryFile = true; // should delete file
                                                           // on exit (in normal
                                                           // exit)
          DiskFileUpload.baseDirectory = null; // system temp directory
          DiskAttribute.deleteOnExitTemporaryFile = true; // should delete file on
                                                          // exit (in normal exit)
          DiskAttribute.baseDirectory = null; // system temp directory
      }
  
      @Override
      public void channelUnregistered(ChannelHandlerContext ctx) throws Exception {
          if (decoder != null) {
              decoder.cleanFiles();
          }
      }
  
      @Override
      public void channelRead0(ChannelHandlerContext ctx, HttpObject msg) throws Exception {
          if (msg instanceof HttpRequest) {
             HttpRequest request = this.request = (HttpRequest) msg;
             URI uri = new URI(request.getUri());
             if (!uri.getPath().startsWith("/form")) {
                 // Write Menu
                 writeMenu(ctx);
                 return;
             }
             responseContent.setLength(0);
             responseContent.append("WELCOME TO THE WILD WILD WEB SERVER\r\n");
             responseContent.append("===================================\r\n");
 
             responseContent.append("VERSION: " + request.getProtocolVersion().text() + "\r\n");
 
             responseContent.append("REQUEST_URI: " + request.getUri() + "\r\n\r\n");
             responseContent.append("\r\n\r\n");
 
             // new getMethod
             for (Entry<String, String> entry : request.headers()) {
                 responseContent.append("HEADER: " + entry.getKey() + '=' + entry.getValue() + "\r\n");
             }
             responseContent.append("\r\n\r\n");
 
             // new getMethod
             Set<Cookie> cookies;
             String value = request.headers().get(COOKIE);
             if (value == null) {
                 cookies = Collections.emptySet();
             } else {
                 cookies = CookieDecoder.decode(value);
             }
             for (Cookie cookie : cookies) {
                 responseContent.append("COOKIE: " + cookie + "\r\n");
             }
             responseContent.append("\r\n\r\n");
 
             QueryStringDecoder decoderQuery = new QueryStringDecoder(request.getUri());
             Map<String, List<String>> uriAttributes = decoderQuery.parameters();
             for (Entry<String, List<String>> attr: uriAttributes.entrySet()) {
                 for (String attrVal: attr.getValue()) {
                     responseContent.append("URI: " + attr.getKey() + '=' + attrVal + "\r\n");
                 }
             }
             responseContent.append("\r\n\r\n");
 
             if (request.getMethod().equals(HttpMethod.GET)) {
                 // GET Method: should not try to create a HttpPostRequestDecoder
                 // So stop here
                 responseContent.append("\r\n\r\nEND OF GET CONTENT\r\n");
                 // Not now: LastHttpContent will be sent writeResponse(ctx.channel());
                 return;
             }
 
             try {
                 decoder = new HttpPostRequestDecoder(factory, request);
             } catch (ErrorDataDecoderException e1) {
                 e1.printStackTrace();
                 responseContent.append(e1.getMessage());
                 writeResponse(ctx.channel());
                 ctx.channel().close();
                 return;
             } catch (IncompatibleDataDecoderException e1) {
                 // GET Method: should not try to create a HttpPostRequestDecoder
                 // So OK but stop here
                 responseContent.append(e1.getMessage());
                 responseContent.append("\r\n\r\nEND OF GET CONTENT\r\n");
                 writeResponse(ctx.channel());
                 return;
             }
 
             readingChunks = HttpHeaders.isTransferEncodingChunked(request);
             responseContent.append("Is Chunked: " + readingChunks + "\r\n");
             responseContent.append("IsMultipart: " + decoder.isMultipart() + "\r\n");
             if (readingChunks) {
                 // Chunk version
                 responseContent.append("Chunks: ");
                 readingChunks = true;
             }
         }
 
         // check if the decoder was constructed before
         // if not it handles the form get
         if (decoder != null) {
             if (msg instanceof HttpContent) {
                 // New chunk is received
                 HttpContent chunk = (HttpContent) msg;
                 try {
                     decoder.offer(chunk);
                 } catch (ErrorDataDecoderException e1) {
                     e1.printStackTrace();
                     responseContent.append(e1.getMessage());
                     writeResponse(ctx.channel());
                     ctx.channel().close();
                     return;
                 }
                 responseContent.append('o');
                 // example of reading chunk by chunk (minimize memory usage due to
                 // Factory)
                 readHttpDataChunkByChunk();
                 // example of reading only if at the end
                 if (chunk instanceof LastHttpContent) {
                     writeResponse(ctx.channel());
                     readingChunks = false;
 
                     reset();
                 }
             }
         } else {
             writeResponse(ctx.channel());
         }
     }
 
     private void reset() {
         request = null;
 
         // destroy the decoder to release all resources
         decoder.destroy();
         decoder = null;
     }
 
     /**
      * Example of reading request by chunk and getting values from chunk to chunk
      */
     private void readHttpDataChunkByChunk() {
         try {
             while (decoder.hasNext()) {
                 InterfaceHttpData data = decoder.next();
                 if (data != null) {
                     try {
                         // new value
                         writeHttpData(data);
                     } finally {
                         data.release();
                     }
                 }
             }
         } catch (EndOfDataDecoderException e1) {
             // end
             responseContent.append("\r\n\r\nEND OF CONTENT CHUNK BY CHUNK\r\n\r\n");
         }
     }
 
     private void writeHttpData(InterfaceHttpData data) {
         if (data.getHttpDataType() == HttpDataType.Attribute) {
             Attribute attribute = (Attribute) data;
             String value;
             try {
                 value = attribute.getValue();
             } catch (IOException e1) {
                 // Error while reading data from File, only print name and error
                 e1.printStackTrace();
                 responseContent.append("\r\nBODY Attribute: " + attribute.getHttpDataType().name() + ": "
                         + attribute.getName() + " Error while reading value: " + e1.getMessage() + "\r\n");
                 return;
             }
             if (value.length() > 100) {
                 responseContent.append("\r\nBODY Attribute: " + attribute.getHttpDataType().name() + ": "
                         + attribute.getName() + " data too long\r\n");
             } else {
                 responseContent.append("\r\nBODY Attribute: " + attribute.getHttpDataType().name() + ": "
                         + attribute + "\r\n");
             }
         } else {
             responseContent.append("\r\nBODY FileUpload: " + data.getHttpDataType().name() + ": " + data
                     + "\r\n");
             if (data.getHttpDataType() == HttpDataType.FileUpload) {
                 FileUpload fileUpload = (FileUpload) data;
                 if (fileUpload.isCompleted()) {
                     if (fileUpload.length() < 10000) {
                         responseContent.append("\tContent of file\r\n");
                         try {
                             responseContent.append(fileUpload.getString(fileUpload.getCharset()));
                         } catch (IOException e1) {
                             // do nothing for the example
                             e1.printStackTrace();
                         }
                         responseContent.append("\r\n");
                     } else {
                         responseContent.append("\tFile too long to be printed out:" + fileUpload.length() + "\r\n");
                     }
                     // fileUpload.isInMemory();// tells if the file is in Memory
                     // or on File
                     // fileUpload.renameTo(dest); // enable to move into another
                     // File dest
                     // decoder.removeFileUploadFromClean(fileUpload); //remove
                     // the File of to delete file
                 } else {
                     responseContent.append("\tFile to be continued but should not!\r\n");
                 }
             }
         }
     }
 
     private void writeResponse(Channel channel) {
         // Convert the response content to a ChannelBuffer.
         ByteBuf buf = copiedBuffer(responseContent.toString(), CharsetUtil.UTF_8);
         responseContent.setLength(0);
 
         // Decide whether to close the connection or not.
         boolean close = HttpHeaders.Values.CLOSE.equalsIgnoreCase(request.headers().get(CONNECTION))
                 || request.getProtocolVersion().equals(HttpVersion.HTTP_1_0)
                 && !HttpHeaders.Values.KEEP_ALIVE.equalsIgnoreCase(request.headers().get(CONNECTION));
 
         // Build the response object.
         FullHttpResponse response = new DefaultFullHttpResponse(
                 HttpVersion.HTTP_1_1, HttpResponseStatus.OK, buf);
         response.headers().set(CONTENT_TYPE, "text/plain; charset=UTF-8");
 
         if (!close) {
             // There's no need to add 'Content-Length' header
             // if this is the last response.
             response.headers().set(CONTENT_LENGTH, buf.readableBytes());
         }
 
         Set<Cookie> cookies;
         String value = request.headers().get(COOKIE);
         if (value == null) {
             cookies = Collections.emptySet();
         } else {
             cookies = CookieDecoder.decode(value);
         }
         if (!cookies.isEmpty()) {
             // Reset the cookies if necessary.
             for (Cookie cookie : cookies) {
                 response.headers().add(SET_COOKIE, ServerCookieEncoder.encode(cookie));
             }
         }
         // Write the response.
         ChannelFuture future = channel.writeAndFlush(response);
         // Close the connection after the write operation is done if necessary.
         if (close) {
             future.addListener(ChannelFutureListener.CLOSE);
         }
     }
 
     private void writeMenu(ChannelHandlerContext ctx) {
         // print several HTML forms
         // Convert the response content to a ChannelBuffer.
         responseContent.setLength(0);
 
         // create Pseudo Menu
         responseContent.append("<html>");
         responseContent.append("<head>");
         responseContent.append("<title>Netty Test Form</title>\r\n");
         responseContent.append("</head>\r\n");
         responseContent.append("<body bgcolor=white><style>td{font-size: 12pt;}</style>");
 
         responseContent.append("<table border=\"0\">");
         responseContent.append("<tr>");
         responseContent.append("<td>");
         responseContent.append("<h1>Netty Test Form</h1>");
         responseContent.append("Choose one FORM");
         responseContent.append("</td>");
         responseContent.append("</tr>");
         responseContent.append("</table>\r\n");
 
         // GET
         responseContent.append("<CENTER>GET FORM<HR WIDTH=\"75%\" NOSHADE color=\"blue\"></CENTER>");
         responseContent.append("<FORM ACTION=\"/formget\" METHOD=\"GET\">");
         responseContent.append("<input type=hidden name=getform value=\"GET\">");
         responseContent.append("<table border=\"0\">");
         responseContent.append("<tr><td>Fill with value: <br> <input type=text name=\"info\" size=10></td></tr>");
         responseContent.append("<tr><td>Fill with value: <br> <input type=text name=\"secondinfo\" size=20>");
         responseContent
                 .append("<tr><td>Fill with value: <br> <textarea name=\"thirdinfo\" cols=40 rows=10></textarea>");
         responseContent.append("</td></tr>");
         responseContent.append("<tr><td><INPUT TYPE=\"submit\" NAME=\"Send\" VALUE=\"Send\"></INPUT></td>");
         responseContent.append("<td><INPUT TYPE=\"reset\" NAME=\"Clear\" VALUE=\"Clear\" ></INPUT></td></tr>");
         responseContent.append("</table></FORM>\r\n");
         responseContent.append("<CENTER><HR WIDTH=\"75%\" NOSHADE color=\"blue\"></CENTER>");
 
         // POST
         responseContent.append("<CENTER>POST FORM<HR WIDTH=\"75%\" NOSHADE color=\"blue\"></CENTER>");
         responseContent.append("<FORM ACTION=\"/formpost\" METHOD=\"POST\">");
         responseContent.append("<input type=hidden name=getform value=\"POST\">");
         responseContent.append("<table border=\"0\">");
         responseContent.append("<tr><td>Fill with value: <br> <input type=text name=\"info\" size=10></td></tr>");
         responseContent.append("<tr><td>Fill with value: <br> <input type=text name=\"secondinfo\" size=20>");
         responseContent
                 .append("<tr><td>Fill with value: <br> <textarea name=\"thirdinfo\" cols=40 rows=10></textarea>");
         responseContent.append("<tr><td>Fill with file (only file name will be transmitted): <br> "
                 + "<input type=file name=\"myfile\">");
         responseContent.append("</td></tr>");
         responseContent.append("<tr><td><INPUT TYPE=\"submit\" NAME=\"Send\" VALUE=\"Send\"></INPUT></td>");
         responseContent.append("<td><INPUT TYPE=\"reset\" NAME=\"Clear\" VALUE=\"Clear\" ></INPUT></td></tr>");
         responseContent.append("</table></FORM>\r\n");
         responseContent.append("<CENTER><HR WIDTH=\"75%\" NOSHADE color=\"blue\"></CENTER>");
 
         // POST with enctype="multipart/form-data"
         responseContent.append("<CENTER>POST MULTIPART FORM<HR WIDTH=\"75%\" NOSHADE color=\"blue\"></CENTER>");
         responseContent.append("<FORM ACTION=\"/formpostmultipart\" ENCTYPE=\"multipart/form-data\" METHOD=\"POST\">");
         responseContent.append("<input type=hidden name=getform value=\"POST\">");
         responseContent.append("<table border=\"0\">");
         responseContent.append("<tr><td>Fill with value: <br> <input type=text name=\"info\" size=10></td></tr>");
         responseContent.append("<tr><td>Fill with value: <br> <input type=text name=\"secondinfo\" size=20>");
         responseContent
                 .append("<tr><td>Fill with value: <br> <textarea name=\"thirdinfo\" cols=40 rows=10></textarea>");
         responseContent.append("<tr><td>Fill with file: <br> <input type=file name=\"myfile\">");
         responseContent.append("</td></tr>");
         responseContent.append("<tr><td><INPUT TYPE=\"submit\" NAME=\"Send\" VALUE=\"Send\"></INPUT></td>");
         responseContent.append("<td><INPUT TYPE=\"reset\" NAME=\"Clear\" VALUE=\"Clear\" ></INPUT></td></tr>");
         responseContent.append("</table></FORM>\r\n");
         responseContent.append("<CENTER><HR WIDTH=\"75%\" NOSHADE color=\"blue\"></CENTER>");
 
         responseContent.append("</body>");
         responseContent.append("</html>");
 
         ByteBuf buf = copiedBuffer(responseContent.toString(), CharsetUtil.UTF_8);
         // Build the response object.
         FullHttpResponse response = new DefaultFullHttpResponse(
                 HttpVersion.HTTP_1_1, HttpResponseStatus.OK, buf);
 
         response.headers().set(CONTENT_TYPE, "text/html; charset=UTF-8");
         response.headers().set(CONTENT_LENGTH, buf.readableBytes());
 
         // Write the response.
         ctx.channel().writeAndFlush(response);
     }
 
     @Override
     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
         logger.log(Level.WARNING, responseContent.toString(), cause);
         ctx.channel().close();
     }
 }