/*
    * 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:
    *
    *   https://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.handler.codec.http.multipart;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.buffer.ByteBufAllocator;
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.handler.codec.DecoderResult;
  import io.netty.handler.codec.http.DefaultFullHttpRequest;
  import io.netty.handler.codec.http.DefaultHttpContent;
  import io.netty.handler.codec.http.EmptyHttpHeaders;
  import io.netty.handler.codec.http.FullHttpRequest;
  import io.netty.handler.codec.http.HttpConstants;
  import io.netty.handler.codec.http.HttpContent;
  import io.netty.handler.codec.http.HttpHeaderNames;
  import io.netty.handler.codec.http.HttpHeaderValues;
  import io.netty.handler.codec.http.HttpHeaders;
  import io.netty.handler.codec.http.HttpMethod;
  import io.netty.handler.codec.http.HttpRequest;
  import io.netty.handler.codec.http.HttpUtil;
  import io.netty.handler.codec.http.HttpVersion;
  import io.netty.handler.codec.http.LastHttpContent;
  import io.netty.handler.stream.ChunkedInput;
  import io.netty.util.internal.ObjectUtil;
  import io.netty.util.internal.StringUtil;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.UnsupportedEncodingException;
  import java.net.URLEncoder;
  import java.nio.charset.Charset;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.ListIterator;
  import java.util.Locale;
  import java.util.concurrent.ThreadLocalRandom;
  
  import static io.netty.buffer.Unpooled.wrappedBuffer;
  import static io.netty.util.internal.ObjectUtil.checkNotNull;
  
  /**
   * This encoder will help to encode Request for a FORM as POST.
   *
   * <P>According to RFC 7231, POST, PUT and OPTIONS allow to have a body.
   * This encoder will support widely all methods except TRACE since the RFC notes
   * for GET, DELETE, HEAD and CONNECT: (replaces XXX by one of these methods)</P>
   * <P>"A payload within a XXX request message has no defined semantics;
   * sending a payload body on a XXX request might cause some existing
   * implementations to reject the request."</P>
   * <P>On the contrary, for TRACE method, RFC says:</P>
   * <P>"A client MUST NOT send a message body in a TRACE request."</P>
   */
  public class HttpPostRequestEncoder implements ChunkedInput<HttpContent> {
  
      /**
       * Different modes to use to encode form data.
       */
      public enum EncoderMode {
          /**
           * Legacy mode which should work for most. It is known to not work with OAUTH. For OAUTH use
           * {@link EncoderMode#RFC3986}. The W3C form recommendations this for submitting post form data.
           */
          RFC1738,
  
          /**
           * Mode which is more new and is used for OAUTH
           */
          RFC3986,
  
          /**
           * The HTML5 spec disallows mixed mode in multipart/form-data
           * requests. More concretely this means that more files submitted
           * under the same name will not be encoded using mixed mode, but
           * will be treated as distinct fields.
           *
           * Reference:
           *   https://www.w3.org/TR/html5/forms.html#multipart-form-data
           */
          HTML5
      }
  
      private static final String ASTERISK = "*";
      private static final String PLUS = "+";
      private static final String TILDE = "~";
      private static final String ASTERISK_REPLACEMENT = "%2A";
      private static final String PLUS_REPLACEMENT = "%20";
     private static final String TILDE_REPLACEMENT = "%7E";
 
     /**
      * Factory used to create InterfaceHttpData
      */
     private final HttpDataFactory factory;
 
     /**
      * Request to encode
      */
     private final HttpRequest request;
 
     /**
      * Default charset to use
      */
     private final Charset charset;
 
     /**
      * Chunked false by default
      */
     private boolean isChunked;
 
     /**
      * InterfaceHttpData for Body (without encoding)
      */
     private final List<InterfaceHttpData> bodyListDatas;
     /**
      * The final Multipart List of InterfaceHttpData including encoding
      */
     final List<InterfaceHttpData> multipartHttpDatas;
 
     /**
      * Does this request is a Multipart request
      */
     private final boolean isMultipart;
 
     /**
      * If multipart, this is the boundary for the flobal multipart
      */
     String multipartDataBoundary;
 
     /**
      * If multipart, there could be internal multiparts (mixed) to the global multipart. Only one level is allowed.
      */
     String multipartMixedBoundary;
     /**
      * To check if the header has been finalized
      */
     private boolean headerFinalized;
 
     private final EncoderMode encoderMode;
 
     /**
      *
      * @param request
      *            the request to encode
      * @param multipart
      *            True if the FORM is a ENCTYPE="multipart/form-data"
      * @throws NullPointerException
      *             for request
      * @throws ErrorDataEncoderException
      *             if the request is a TRACE
      */
     public HttpPostRequestEncoder(HttpRequest request, boolean multipart) throws ErrorDataEncoderException {
         this(new DefaultHttpDataFactory(DefaultHttpDataFactory.MINSIZE), request, multipart,
                 HttpConstants.DEFAULT_CHARSET, EncoderMode.RFC1738);
     }
 
     /**
      *
      * @param factory
      *            the factory used to create InterfaceHttpData
      * @param request
      *            the request to encode
      * @param multipart
      *            True if the FORM is a ENCTYPE="multipart/form-data"
      * @throws NullPointerException
      *             for request and factory
      * @throws ErrorDataEncoderException
      *             if the request is a TRACE
      */
     public HttpPostRequestEncoder(HttpDataFactory factory, HttpRequest request, boolean multipart)
             throws ErrorDataEncoderException {
         this(factory, request, multipart, HttpConstants.DEFAULT_CHARSET, EncoderMode.RFC1738);
     }
 
     /**
      *
      * @param factory
      *            the factory used to create InterfaceHttpData
      * @param request
      *            the request to encode
      * @param multipart
      *            True if the FORM is a ENCTYPE="multipart/form-data"
      * @param charset
      *            the charset to use as default
      * @param encoderMode
      *            the mode for the encoder to use. See {@link EncoderMode} for the details.
      * @throws NullPointerException
      *             for request or charset or factory
      * @throws ErrorDataEncoderException
      *             if the request is a TRACE
      */
     public HttpPostRequestEncoder(
             HttpDataFactory factory, HttpRequest request, boolean multipart, Charset charset,
             EncoderMode encoderMode)
             throws ErrorDataEncoderException {
         this.request = checkNotNull(request, "request");
         this.charset = checkNotNull(charset, "charset");
         this.factory = checkNotNull(factory, "factory");
         if (HttpMethod.TRACE.equals(request.method())) {
             throw new ErrorDataEncoderException("Cannot create a Encoder if request is a TRACE");
         }
         // Fill default values
         bodyListDatas = new ArrayList<InterfaceHttpData>();
         // default mode
         isLastChunk = false;
         isLastChunkSent = false;
         isMultipart = multipart;
         multipartHttpDatas = new ArrayList<InterfaceHttpData>();
         this.encoderMode = encoderMode;
         if (isMultipart) {
             initDataMultipart();
         }
     }
 
     /**
      * Clean all HttpDatas (on Disk) for the current request.
      */
     public void cleanFiles() {
         factory.cleanRequestHttpData(request);
     }
 
     /**
      * Does the last non empty chunk already encoded so that next chunk will be empty (last chunk)
      */
     private boolean isLastChunk;
     /**
      * Last chunk already sent
      */
     private boolean isLastChunkSent;
     /**
      * The current FileUpload that is currently in encode process
      */
     private FileUpload currentFileUpload;
     /**
      * While adding a FileUpload, is the multipart currently in Mixed Mode
      */
     private boolean duringMixedMode;
     /**
      * Global Body size
      */
     private long globalBodySize;
     /**
      * Global Transfer progress
      */
     private long globalProgress;
 
     /**
      * True if this request is a Multipart request
      *
      * @return True if this request is a Multipart request
      */
     public boolean isMultipart() {
         return isMultipart;
     }
 
     /**
      * Init the delimiter for Global Part (Data).
      */
     private void initDataMultipart() {
         multipartDataBoundary = getNewMultipartDelimiter();
     }
 
     /**
      * Init the delimiter for Mixed Part (Mixed).
      */
     private void initMixedMultipart() {
         multipartMixedBoundary = getNewMultipartDelimiter();
     }
 
     /**
      *
      * @return a newly generated Delimiter (either for DATA or MIXED)
      */
     private static String getNewMultipartDelimiter() {
         // construct a generated delimiter
         return Long.toHexString(ThreadLocalRandom.current().nextLong());
     }
 
     /**
      * This getMethod returns a List of all InterfaceHttpData from body part.<br>
 
      * @return the list of InterfaceHttpData from Body part
      */
     public List<InterfaceHttpData> getBodyListAttributes() {
         return bodyListDatas;
     }
 
     /**
      * Set the Body HttpDatas list
      *
      * @throws NullPointerException
      *             for datas
      * @throws ErrorDataEncoderException
      *             if the encoding is in error or if the finalize were already done
      */
     public void setBodyHttpDatas(List<InterfaceHttpData> datas) throws ErrorDataEncoderException {
         ObjectUtil.checkNotNull(datas, "datas");
         globalBodySize = 0;
         bodyListDatas.clear();
         currentFileUpload = null;
         duringMixedMode = false;
         multipartHttpDatas.clear();
         for (InterfaceHttpData data : datas) {
             addBodyHttpData(data);
         }
     }
 
     /**
      * Add a simple attribute in the body as Name=Value
      *
      * @param name
      *            name of the parameter
      * @param value
      *            the value of the parameter
      * @throws NullPointerException
      *             for name
      * @throws ErrorDataEncoderException
      *             if the encoding is in error or if the finalize were already done
      */
     public void addBodyAttribute(String name, String value) throws ErrorDataEncoderException {
         String svalue = value != null? value : StringUtil.EMPTY_STRING;
         Attribute data = factory.createAttribute(request, checkNotNull(name, "name"), svalue);
         addBodyHttpData(data);
     }
 
     /**
      * Add a file as a FileUpload
      *
      * @param name
      *            the name of the parameter
      * @param file
      *            the file to be uploaded (if not Multipart mode, only the filename will be included)
      * @param contentType
      *            the associated contentType for the File
      * @param isText
      *            True if this file should be transmitted in Text format (else binary)
      * @throws NullPointerException
      *             for name and file
      * @throws ErrorDataEncoderException
      *             if the encoding is in error or if the finalize were already done
      */
     public void addBodyFileUpload(String name, File file, String contentType, boolean isText)
             throws ErrorDataEncoderException {
         addBodyFileUpload(name, file.getName(), file, contentType, isText);
     }
 
     /**
      * Add a file as a FileUpload
      *
      * @param name
      *            the name of the parameter
      * @param file
      *            the file to be uploaded (if not Multipart mode, only the filename will be included)
      * @param filename
      *            the filename to use for this File part, empty String will be ignored by
      *            the encoder
      * @param contentType
      *            the associated contentType for the File
      * @param isText
      *            True if this file should be transmitted in Text format (else binary)
      * @throws NullPointerException
      *             for name and file
      * @throws ErrorDataEncoderException
      *             if the encoding is in error or if the finalize were already done
      */
     public void addBodyFileUpload(String name, String filename, File file, String contentType, boolean isText)
             throws ErrorDataEncoderException {
         checkNotNull(name, "name");
         checkNotNull(file, "file");
         if (filename == null) {
             filename = StringUtil.EMPTY_STRING;
         }
         String scontentType = contentType;
         String contentTransferEncoding = null;
         if (contentType == null) {
             if (isText) {
                 scontentType = HttpPostBodyUtil.DEFAULT_TEXT_CONTENT_TYPE;
             } else {
                 scontentType = HttpPostBodyUtil.DEFAULT_BINARY_CONTENT_TYPE;
             }
         }
         if (!isText) {
             contentTransferEncoding = HttpPostBodyUtil.TransferEncodingMechanism.BINARY.value();
         }
         FileUpload fileUpload = factory.createFileUpload(request, name, filename, scontentType,
                 contentTransferEncoding, null, file.length());
         try {
             fileUpload.setContent(file);
         } catch (IOException e) {
             throw new ErrorDataEncoderException(e);
         }
         addBodyHttpData(fileUpload);
     }
 
     /**
      * Add a series of Files associated with one File parameter
      *
      * @param name
      *            the name of the parameter
      * @param file
      *            the array of files
      * @param contentType
      *            the array of content Types associated with each file
      * @param isText
      *            the array of isText attribute (False meaning binary mode) for each file
      * @throws IllegalArgumentException
      *             also throws if array have different sizes
      * @throws ErrorDataEncoderException
      *             if the encoding is in error or if the finalize were already done
      */
     public void addBodyFileUploads(String name, File[] file, String[] contentType, boolean[] isText)
             throws ErrorDataEncoderException {
         if (file.length != contentType.length && file.length != isText.length) {
             throw new IllegalArgumentException("Different array length");
         }
         for (int i = 0; i < file.length; i++) {
             addBodyFileUpload(name, file[i], contentType[i], isText[i]);
         }
     }
 
     /**
      * Add the InterfaceHttpData to the Body list
      *
      * @throws NullPointerException
      *             for data
      * @throws ErrorDataEncoderException
      *             if the encoding is in error or if the finalize were already done
      */
     public void addBodyHttpData(InterfaceHttpData data) throws ErrorDataEncoderException {
         if (headerFinalized) {
             throw new ErrorDataEncoderException("Cannot add value once finalized");
         }
         bodyListDatas.add(checkNotNull(data, "data"));
         if (!isMultipart) {
             if (data instanceof Attribute) {
                 Attribute attribute = (Attribute) data;
                 try {
                     // name=value& with encoded name and attribute
                     String key = encodeAttribute(attribute.getName(), charset);
                     String value = encodeAttribute(attribute.getValue(), charset);
                     Attribute newattribute = factory.createAttribute(request, key, value);
                     multipartHttpDatas.add(newattribute);
                     globalBodySize += newattribute.getName().length() + 1 + newattribute.length() + 1;
                 } catch (IOException e) {
                     throw new ErrorDataEncoderException(e);
                 }
             } else if (data instanceof FileUpload) {
                 // since not Multipart, only name=filename => Attribute
                 FileUpload fileUpload = (FileUpload) data;
                 // name=filename& with encoded name and filename
                 String key = encodeAttribute(fileUpload.getName(), charset);
                 String value = encodeAttribute(fileUpload.getFilename(), charset);
                 Attribute newattribute = factory.createAttribute(request, key, value);
                 multipartHttpDatas.add(newattribute);
                 globalBodySize += newattribute.getName().length() + 1 + newattribute.length() + 1;
             }
             return;
         }
         /*
          * Logic:
          * if not Attribute:
          *      add Data to body list
          *      if (duringMixedMode)
          *          add endmixedmultipart delimiter
          *          currentFileUpload = null
          *          duringMixedMode = false;
          *      add multipart delimiter, multipart body header and Data to multipart list
          *      reset currentFileUpload, duringMixedMode
          * if FileUpload: take care of multiple file for one field => mixed mode
          *      if (duringMixedMode)
          *          if (currentFileUpload.name == data.name)
          *              add mixedmultipart delimiter, mixedmultipart body header and Data to multipart list
          *          else
          *              add endmixedmultipart delimiter, multipart body header and Data to multipart list
          *              currentFileUpload = data
          *              duringMixedMode = false;
          *      else
          *          if (currentFileUpload.name == data.name)
          *              change multipart body header of previous file into multipart list to
          *                      mixedmultipart start, mixedmultipart body header
          *              add mixedmultipart delimiter, mixedmultipart body header and Data to multipart list
          *              duringMixedMode = true
          *          else
          *              add multipart delimiter, multipart body header and Data to multipart list
          *              currentFileUpload = data
          *              duringMixedMode = false;
          * Do not add last delimiter! Could be:
          * if duringmixedmode: endmixedmultipart + endmultipart
          * else only endmultipart
          */
         if (data instanceof Attribute) {
             if (duringMixedMode) {
                 InternalAttribute internal = new InternalAttribute(charset);
                 internal.addValue("\r\n--" + multipartMixedBoundary + "--");
                 multipartHttpDatas.add(internal);
                 multipartMixedBoundary = null;
                 currentFileUpload = null;
                 duringMixedMode = false;
             }
             InternalAttribute internal = new InternalAttribute(charset);
             if (!multipartHttpDatas.isEmpty()) {
                 // previously a data field so CRLF
                 internal.addValue("\r\n");
             }
             internal.addValue("--" + multipartDataBoundary + "\r\n");
             // content-disposition: form-data; name="field1"
             Attribute attribute = (Attribute) data;
             internal.addValue(HttpHeaderNames.CONTENT_DISPOSITION + ": " + HttpHeaderValues.FORM_DATA + "; "
                     + HttpHeaderValues.NAME + "=\"" + attribute.getName() + "\"\r\n");
             // Add Content-Length: xxx
             internal.addValue(HttpHeaderNames.CONTENT_LENGTH + ": " +
                     attribute.length() + "\r\n");
             Charset localcharset = attribute.getCharset();
             if (localcharset != null) {
                 // Content-Type: text/plain; charset=charset
                 internal.addValue(HttpHeaderNames.CONTENT_TYPE + ": " +
                         HttpPostBodyUtil.DEFAULT_TEXT_CONTENT_TYPE + "; " +
                         HttpHeaderValues.CHARSET + '='
                         + localcharset.name() + "\r\n");
             }
             // CRLF between body header and data
             internal.addValue("\r\n");
             multipartHttpDatas.add(internal);
             multipartHttpDatas.add(data);
             globalBodySize += attribute.length() + internal.size();
         } else if (data instanceof FileUpload) {
             FileUpload fileUpload = (FileUpload) data;
             InternalAttribute internal = new InternalAttribute(charset);
             if (!multipartHttpDatas.isEmpty()) {
                 // previously a data field so CRLF
                 internal.addValue("\r\n");
             }
             boolean localMixed;
             if (duringMixedMode) {
                 if (currentFileUpload != null && currentFileUpload.getName().equals(fileUpload.getName())) {
                     // continue a mixed mode
 
                     localMixed = true;
                 } else {
                     // end a mixed mode
 
                     // add endmixedmultipart delimiter, multipart body header
                     // and
                     // Data to multipart list
                     internal.addValue("--" + multipartMixedBoundary + "--");
                     multipartHttpDatas.add(internal);
                     multipartMixedBoundary = null;
                     // start a new one (could be replaced if mixed start again
                     // from here
                     internal = new InternalAttribute(charset);
                     internal.addValue("\r\n");
                     localMixed = false;
                     // new currentFileUpload and no more in Mixed mode
                     currentFileUpload = fileUpload;
                     duringMixedMode = false;
                 }
             } else {
                 if (encoderMode != EncoderMode.HTML5 && currentFileUpload != null
                         && currentFileUpload.getName().equals(fileUpload.getName())) {
                     // create a new mixed mode (from previous file)
 
                     // change multipart body header of previous file into
                     // multipart list to
                     // mixedmultipart start, mixedmultipart body header
 
                     // change Internal (size()-2 position in multipartHttpDatas)
                     // from (line starting with *)
                     // --AaB03x
                     // * Content-Disposition: form-data; name="files";
                     // filename="file1.txt"
                     // Content-Type: text/plain
                     // to (lines starting with *)
                     // --AaB03x
                     // * Content-Disposition: form-data; name="files"
                     // * Content-Type: multipart/mixed; boundary=BbC04y
                     // *
                     // * --BbC04y
                     // * Content-Disposition: attachment; filename="file1.txt"
                     // Content-Type: text/plain
                     initMixedMultipart();
                     InternalAttribute pastAttribute = (InternalAttribute) multipartHttpDatas.get(multipartHttpDatas
                             .size() - 2);
                     // remove past size
                     globalBodySize -= pastAttribute.size();
                     StringBuilder replacement = new StringBuilder(
                             139 + multipartDataBoundary.length() + multipartMixedBoundary.length() * 2 +
                                     fileUpload.getFilename().length() + fileUpload.getName().length())
 
                         .append("--")
                         .append(multipartDataBoundary)
                         .append("\r\n")
 
                         .append(HttpHeaderNames.CONTENT_DISPOSITION)
                         .append(": ")
                         .append(HttpHeaderValues.FORM_DATA)
                         .append("; ")
                         .append(HttpHeaderValues.NAME)
                         .append("=\"")
                         .append(fileUpload.getName())
                         .append("\"\r\n")
 
                         .append(HttpHeaderNames.CONTENT_TYPE)
                         .append(": ")
                         .append(HttpHeaderValues.MULTIPART_MIXED)
                         .append("; ")
                         .append(HttpHeaderValues.BOUNDARY)
                         .append('=')
                         .append(multipartMixedBoundary)
                         .append("\r\n\r\n")
 
                         .append("--")
                         .append(multipartMixedBoundary)
                         .append("\r\n")
 
                         .append(HttpHeaderNames.CONTENT_DISPOSITION)
                         .append(": ")
                         .append(HttpHeaderValues.ATTACHMENT);
 
                     if (!fileUpload.getFilename().isEmpty()) {
                         replacement.append("; ")
                                    .append(HttpHeaderValues.FILENAME)
                                    .append("=\"")
                                    .append(currentFileUpload.getFilename())
                                    .append('"');
                     }
 
                     replacement.append("\r\n");
 
                     pastAttribute.setValue(replacement.toString(), 1);
                     pastAttribute.setValue("", 2);
 
                     // update past size
                     globalBodySize += pastAttribute.size();
 
                     // now continue
                     // add mixedmultipart delimiter, mixedmultipart body header
                     // and
                     // Data to multipart list
                     localMixed = true;
                     duringMixedMode = true;
                 } else {
                     // a simple new multipart
                     // add multipart delimiter, multipart body header and Data
                     // to multipart list
                     localMixed = false;
                     currentFileUpload = fileUpload;
                     duringMixedMode = false;
                 }
             }
 
             if (localMixed) {
                 // add mixedmultipart delimiter, mixedmultipart body header and
                 // Data to multipart list
                 internal.addValue("--" + multipartMixedBoundary + "\r\n");
 
                 if (fileUpload.getFilename().isEmpty()) {
                     // Content-Disposition: attachment
                     internal.addValue(HttpHeaderNames.CONTENT_DISPOSITION + ": "
                             + HttpHeaderValues.ATTACHMENT + "\r\n");
                 } else {
                     // Content-Disposition: attachment; filename="file1.txt"
                     internal.addValue(HttpHeaderNames.CONTENT_DISPOSITION + ": "
                             + HttpHeaderValues.ATTACHMENT + "; "
                             + HttpHeaderValues.FILENAME + "=\"" + fileUpload.getFilename() + "\"\r\n");
                 }
             } else {
                 internal.addValue("--" + multipartDataBoundary + "\r\n");
 
                 if (fileUpload.getFilename().isEmpty()) {
                     // Content-Disposition: form-data; name="files";
                     internal.addValue(HttpHeaderNames.CONTENT_DISPOSITION + ": " + HttpHeaderValues.FORM_DATA + "; "
                             + HttpHeaderValues.NAME + "=\"" + fileUpload.getName() + "\"\r\n");
                 } else {
                     // Content-Disposition: form-data; name="files";
                     // filename="file1.txt"
                     internal.addValue(HttpHeaderNames.CONTENT_DISPOSITION + ": " + HttpHeaderValues.FORM_DATA + "; "
                             + HttpHeaderValues.NAME + "=\"" + fileUpload.getName() + "\"; "
                             + HttpHeaderValues.FILENAME + "=\"" + fileUpload.getFilename() + "\"\r\n");
                 }
             }
             // Add Content-Length: xxx
             internal.addValue(HttpHeaderNames.CONTENT_LENGTH + ": " +
                     fileUpload.length() + "\r\n");
             // Content-Type: image/gif
             // Content-Type: text/plain; charset=ISO-8859-1
             // Content-Transfer-Encoding: binary
             internal.addValue(HttpHeaderNames.CONTENT_TYPE + ": " + fileUpload.getContentType());
             String contentTransferEncoding = fileUpload.getContentTransferEncoding();
             if (contentTransferEncoding != null
                     && contentTransferEncoding.equals(HttpPostBodyUtil.TransferEncodingMechanism.BINARY.value())) {
                 internal.addValue("\r\n" + HttpHeaderNames.CONTENT_TRANSFER_ENCODING + ": "
                         + HttpPostBodyUtil.TransferEncodingMechanism.BINARY.value() + "\r\n\r\n");
             } else if (fileUpload.getCharset() != null) {
                 internal.addValue("; " + HttpHeaderValues.CHARSET + '=' + fileUpload.getCharset().name() + "\r\n\r\n");
             } else {
                 internal.addValue("\r\n\r\n");
             }
             multipartHttpDatas.add(internal);
             multipartHttpDatas.add(data);
             globalBodySize += fileUpload.length() + internal.size();
         }
     }
 
     /**
      * Iterator to be used when encoding will be called chunk after chunk
      */
     private ListIterator<InterfaceHttpData> iterator;
 
     /**
      * Finalize the request by preparing the Header in the request and returns the request ready to be sent.<br>
      * Once finalized, no data must be added.<br>
      * If the request does not need chunk (isChunked() == false), this request is the only object to send to the remote
      * server.
      *
      * @return the request object (chunked or not according to size of body)
      * @throws ErrorDataEncoderException
      *             if the encoding is in error or if the finalize were already done
      */
     public HttpRequest finalizeRequest() throws ErrorDataEncoderException {
         // Finalize the multipartHttpDatas
         if (!headerFinalized) {
             if (isMultipart) {
                 InternalAttribute internal = new InternalAttribute(charset);
                 if (duringMixedMode) {
                     internal.addValue("\r\n--" + multipartMixedBoundary + "--");
                 }
                 internal.addValue("\r\n--" + multipartDataBoundary + "--\r\n");
                 multipartHttpDatas.add(internal);
                 multipartMixedBoundary = null;
                 currentFileUpload = null;
                 duringMixedMode = false;
                 globalBodySize += internal.size();
             }
             headerFinalized = true;
         } else {
             throw new ErrorDataEncoderException("Header already encoded");
         }
 
         HttpHeaders headers = request.headers();
         List<String> contentTypes = headers.getAll(HttpHeaderNames.CONTENT_TYPE);
         List<String> transferEncoding = headers.getAll(HttpHeaderNames.TRANSFER_ENCODING);
         if (contentTypes != null) {
             headers.remove(HttpHeaderNames.CONTENT_TYPE);
             for (String contentType : contentTypes) {
                 // "multipart/form-data; boundary=--89421926422648"
                 // toLowerCase() without a Locale would corrupt the comparison under Turkish
                 // (tr_TR) locale, where 'I' -> 'ı' (U+0131): a request that sets
                 // Content-Type: MULTIPART/form-data would lowercase to "multıpart/form-data" and
                 // miss the prefix check, leaving the original header in place alongside the
                 // multipart one this encoder is about to add.
                 String lowercased = contentType.toLowerCase(Locale.US);
                 if (lowercased.startsWith(HttpHeaderValues.MULTIPART_FORM_DATA.toString()) ||
                         lowercased.startsWith(HttpHeaderValues.APPLICATION_X_WWW_FORM_URLENCODED.toString())) {
                     // ignore
                 } else {
                     headers.add(HttpHeaderNames.CONTENT_TYPE, contentType);
                 }
             }
         }
         if (isMultipart) {
             String value = HttpHeaderValues.MULTIPART_FORM_DATA + "; " + HttpHeaderValues.BOUNDARY + '='
                     + multipartDataBoundary;
             headers.add(HttpHeaderNames.CONTENT_TYPE, value);
         } else {
             // Not multipart
             headers.add(HttpHeaderNames.CONTENT_TYPE, HttpHeaderValues.APPLICATION_X_WWW_FORM_URLENCODED);
         }
         // Now consider size for chunk or not
         long realSize = globalBodySize;
         if (!isMultipart) {
             realSize -= 1; // last '&' removed
         }
         iterator = multipartHttpDatas.listIterator();
 
         headers.set(HttpHeaderNames.CONTENT_LENGTH, String.valueOf(realSize));
         if (realSize > HttpPostBodyUtil.chunkSize || isMultipart) {
             isChunked = true;
             if (transferEncoding != null) {
                 headers.remove(HttpHeaderNames.TRANSFER_ENCODING);
                 for (CharSequence v : transferEncoding) {
                     if (HttpHeaderValues.CHUNKED.contentEqualsIgnoreCase(v)) {
                         // ignore
                     } else {
                         headers.add(HttpHeaderNames.TRANSFER_ENCODING, v);
                     }
                 }
             }
             HttpUtil.setTransferEncodingChunked(request, true);
 
             // wrap to hide the possible content
             return new WrappedHttpRequest(request);
         } else {
             // get the only one body and set it to the request
             HttpContent chunk = nextChunk();
             if (request instanceof FullHttpRequest) {
                 FullHttpRequest fullRequest = (FullHttpRequest) request;
                 ByteBuf chunkContent = chunk.content();
                 if (fullRequest.content() != chunkContent) {
                     fullRequest.content().clear().writeBytes(chunkContent);
                     chunkContent.release();
                 }
                 return fullRequest;
             } else {
                 return new WrappedFullHttpRequest(request, chunk);
             }
         }
     }
 
     /**
      * @return True if the request is by Chunk
      */
     public boolean isChunked() {
         return isChunked;
     }
 
     /**
      * Encode one attribute
      *
      * @return the encoded attribute
      * @throws ErrorDataEncoderException
      *             if the encoding is in error
      */
     private String encodeAttribute(String s, Charset charset) throws ErrorDataEncoderException {
         if (s == null) {
             return "";
         }
         try {
             String encoded = URLEncoder.encode(s, charset.name());
             if (encoderMode == EncoderMode.RFC3986) {
                 encoded = encoded.replace(ASTERISK, ASTERISK_REPLACEMENT)
                                  .replace(PLUS, PLUS_REPLACEMENT)
                                  .replace(TILDE, TILDE_REPLACEMENT);
             }
             return encoded;
         } catch (UnsupportedEncodingException e) {
             throw new ErrorDataEncoderException(charset.name(), e);
         }
     }
 
     /**
      * The ByteBuf currently used by the encoder
      */
     private ByteBuf currentBuffer;
     /**
      * The current InterfaceHttpData to encode (used if more chunks are available)
      */
     private InterfaceHttpData currentData;
     /**
      * If not multipart, does the currentBuffer stands for the Key or for the Value
      */
     private boolean isKey = true;
 
     /**
      *
      * @return the next ByteBuf to send as an HttpChunk and modifying currentBuffer accordingly
      */
     private ByteBuf fillByteBuf() {
         int length = currentBuffer.readableBytes();
         if (length > HttpPostBodyUtil.chunkSize) {
             return currentBuffer.readRetainedSlice(HttpPostBodyUtil.chunkSize);
         } else {
             // to continue
             ByteBuf slice = currentBuffer;
             currentBuffer = null;
             return slice;
         }
     }
 
     /**
      * From the current context (currentBuffer and currentData), returns the next HttpChunk (if possible) trying to get
      * sizeleft bytes more into the currentBuffer. This is the Multipart version.
      *
      * @param sizeleft
      *            the number of bytes to try to get from currentData
      * @return the next HttpChunk or null if not enough bytes were found
      * @throws ErrorDataEncoderException
      *             if the encoding is in error
      */
     private HttpContent encodeNextChunkMultipart(int sizeleft) throws ErrorDataEncoderException {
         if (currentData == null) {
             return null;
         }
         ByteBuf buffer;
         if (currentData instanceof InternalAttribute) {
             buffer = ((InternalAttribute) currentData).toByteBuf();
             currentData = null;
         } else {
             try {
                 buffer = ((HttpData) currentData).getChunk(sizeleft);
             } catch (IOException e) {
                 throw new ErrorDataEncoderException(e);
             }
             if (buffer.capacity() == 0) {
                 // end for current InterfaceHttpData, need more data
                 currentData = null;
                 return null;
             }
         }
         if (currentBuffer == null) {
             currentBuffer = buffer;
         } else {
             currentBuffer = wrappedBuffer(currentBuffer, buffer);
         }
         if (currentBuffer.readableBytes() < HttpPostBodyUtil.chunkSize) {
             currentData = null;
             return null;
         }
         buffer = fillByteBuf();
         return new DefaultHttpContent(buffer);
     }
 
     /**
      * From the current context (currentBuffer and currentData), returns the next HttpChunk (if possible) trying to get
      * sizeleft bytes more into the currentBuffer. This is the UrlEncoded version.
      *
      * @param sizeleft
      *            the number of bytes to try to get from currentData
      * @return the next HttpChunk or null if not enough bytes were found
      * @throws ErrorDataEncoderException
      *             if the encoding is in error
      */
     private HttpContent encodeNextChunkUrlEncoded(int sizeleft) throws ErrorDataEncoderException {
         if (currentData == null) {
             return null;
         }
         int size = sizeleft;
         ByteBuf buffer;
 
         // Set name=
         if (isKey) {
             String key = currentData.getName();
             buffer = wrappedBuffer(key.getBytes(charset));
             isKey = false;
             if (currentBuffer == null) {
                 currentBuffer = wrappedBuffer(buffer, wrappedBuffer("=".getBytes(charset)));
             } else {
                 currentBuffer = wrappedBuffer(currentBuffer, buffer, wrappedBuffer("=".getBytes(charset)));
             }
             // continue
             size -= buffer.readableBytes() + 1;
             if (currentBuffer.readableBytes() >= HttpPostBodyUtil.chunkSize) {
                 buffer = fillByteBuf();
                 return new DefaultHttpContent(buffer);
             }
         }
 
         // Put value into buffer
         try {
             buffer = ((HttpData) currentData).getChunk(size);
         } catch (IOException e) {
             throw new ErrorDataEncoderException(e);
         }
 
         // Figure out delimiter
         ByteBuf delimiter = null;
         if (buffer.readableBytes() < size) {
             isKey = true;
             currentData = null;
             delimiter = iterator.hasNext() ? wrappedBuffer("&".getBytes(charset)) : null;
         }
 
         // End for current InterfaceHttpData, need potentially more data
         if (buffer.capacity() == 0) {
             isKey = true;
             currentData = null;
             if (currentBuffer == null) {
                 if (delimiter == null) {
                     return null;
                 } else {
                     currentBuffer = delimiter;
                 }
             } else {
                 if (delimiter != null) {
                     currentBuffer = wrappedBuffer(currentBuffer, delimiter);
                 }
             }
             if (currentBuffer.readableBytes() >= HttpPostBodyUtil.chunkSize) {
                 buffer = fillByteBuf();
                 return new DefaultHttpContent(buffer);
             }
             return null;
         }
 
         // Put it all together: name=value&
         if (currentBuffer == null) {
             if (delimiter != null) {
                 currentBuffer = wrappedBuffer(buffer, delimiter);
             } else {
                 currentBuffer = buffer;
             }
         } else {
             if (delimiter != null) {
                 currentBuffer = wrappedBuffer(currentBuffer, buffer, delimiter);
             } else {
                 currentBuffer = wrappedBuffer(currentBuffer, buffer);
             }
         }
 
         if (currentBuffer.readableBytes() >= HttpPostBodyUtil.chunkSize) {
             return new DefaultHttpContent(fillByteBuf());
         }
         return null;
     }
 
     @Override
     public void close() throws Exception {
         // NO since the user can want to reuse (broadcast for instance)
         // cleanFiles();
     }
 
     @Deprecated
     @Override
     public HttpContent readChunk(ChannelHandlerContext ctx) throws Exception {
         return readChunk(ctx.alloc());
     }
 
     /**
      * Returns the next available HttpChunk. The caller is responsible to test if this chunk is the last one (isLast()),
      * in order to stop calling this getMethod.
      *
      * @return the next available HttpChunk
      * @throws ErrorDataEncoderException
      *             if the encoding is in error
      */
     @Override
     public HttpContent readChunk(ByteBufAllocator allocator) throws Exception {
         if (isLastChunkSent) {
             return null;
         } else {
             HttpContent nextChunk = nextChunk();
             globalProgress += nextChunk.content().readableBytes();
             return nextChunk;
         }
     }
 
     /**
      * Returns the next available HttpChunk. The caller is responsible to test if this chunk is the last one (isLast()),
      * in order to stop calling this getMethod.
      *
      * @return the next available HttpChunk
      * @throws ErrorDataEncoderException
      *             if the encoding is in error
      */
     private HttpContent nextChunk() throws ErrorDataEncoderException {
         if (isLastChunk) {
             isLastChunkSent = true;
             return LastHttpContent.EMPTY_LAST_CONTENT;
         }
         // first test if previous buffer is not empty
         int size = calculateRemainingSize();
         if (size <= 0) {
             // NextChunk from buffer
             ByteBuf buffer = fillByteBuf();
             return new DefaultHttpContent(buffer);
         }
         // size > 0
         if (currentData != null) {
             // continue to read data
             HttpContent chunk;
             if (isMultipart) {
                 chunk = encodeNextChunkMultipart(size);
             } else {
                 chunk = encodeNextChunkUrlEncoded(size);
             }
             if (chunk != null) {
                 // NextChunk from data
                 return chunk;
             }
             size = calculateRemainingSize();
         }
         if (!iterator.hasNext()) {
             return lastChunk();
         }
         while (size > 0 && iterator.hasNext()) {
             currentData = iterator.next();
             HttpContent chunk;
             if (isMultipart) {
                 chunk = encodeNextChunkMultipart(size);
             } else {
                 chunk = encodeNextChunkUrlEncoded(size);
             }
             if (chunk == null) {
                 // not enough
                 size = calculateRemainingSize();
                 continue;
             }
             // NextChunk from data
             return chunk;
         }
         // end since no more data
         return lastChunk();
     }
 
     private int calculateRemainingSize() {
         int size = HttpPostBodyUtil.chunkSize;
         if (currentBuffer != null) {
             size -= currentBuffer.readableBytes();
         }
         return size;
     }
 
     private HttpContent lastChunk() {
         isLastChunk = true;
         if (currentBuffer == null) {
             isLastChunkSent = true;
             // LastChunk with no more data
             return LastHttpContent.EMPTY_LAST_CONTENT;
         }
         // NextChunk as last non empty from buffer
         ByteBuf buffer = currentBuffer;
         currentBuffer = null;
         return new DefaultHttpContent(buffer);
     }
 
     @Override
     public boolean isEndOfInput() throws Exception {
         return isLastChunkSent;
     }
 
     @Override
     public long length() {
         return isMultipart? globalBodySize : globalBodySize - 1;
     }
 
     @Override
     public long progress() {
         return globalProgress;
     }
 
     /**
      * Exception when an error occurs while encoding
      */
     public static class ErrorDataEncoderException extends Exception {
         private static final long serialVersionUID = 5020247425493164465L;
 
         public ErrorDataEncoderException() {
         }
 
         public ErrorDataEncoderException(String msg) {
             super(msg);
         }
 
         public ErrorDataEncoderException(Throwable cause) {
             super(cause);
         }
 
         public ErrorDataEncoderException(String msg, Throwable cause) {
             super(msg, cause);
         }
     }
 
     private static class WrappedHttpRequest implements HttpRequest {
         private final HttpRequest request;
         WrappedHttpRequest(HttpRequest request) {
             this.request = request;
         }
 
         @Override
         public HttpRequest setProtocolVersion(HttpVersion version) {
             request.setProtocolVersion(version);
             return this;
         }
 
         @Override
         public HttpRequest setMethod(HttpMethod method) {
             request.setMethod(method);
             return this;
         }
 
         @Override
         public HttpRequest setUri(String uri) {
             request.setUri(uri);
             return this;
         }
 
         @Override
         public HttpMethod getMethod() {
             return request.method();
         }
 
         @Override
         public HttpMethod method() {
             return request.method();
         }
 
         @Override
         public String getUri() {
             return request.uri();
         }
 
         @Override
         public String uri() {
             return request.uri();
         }
 
         @Override
         public HttpVersion getProtocolVersion() {
             return request.protocolVersion();
         }
 
         @Override
         public HttpVersion protocolVersion() {
             return request.protocolVersion();
         }
 
         @Override
         public HttpHeaders headers() {
             return request.headers();
         }
 
         @Override
         public DecoderResult decoderResult() {
             return request.decoderResult();
         }
 
         @Override
         @Deprecated
         public DecoderResult getDecoderResult() {
             return request.getDecoderResult();
         }
 
         @Override
         public void setDecoderResult(DecoderResult result) {
             request.setDecoderResult(result);
         }
     }
 
     private static final class WrappedFullHttpRequest extends WrappedHttpRequest implements FullHttpRequest {
         private final HttpContent content;
 
         private WrappedFullHttpRequest(HttpRequest request, HttpContent content) {
             super(request);
             this.content = content;
         }
 
         @Override
         public FullHttpRequest setProtocolVersion(HttpVersion version) {
             super.setProtocolVersion(version);
             return this;
         }
 
         @Override
         public FullHttpRequest setMethod(HttpMethod method) {
             super.setMethod(method);
             return this;
         }
 
         @Override
         public FullHttpRequest setUri(String uri) {
             super.setUri(uri);
             return this;
         }
 
         @Override
         public FullHttpRequest copy() {
             return replace(content().copy());
         }
 
         @Override
         public FullHttpRequest duplicate() {
             return replace(content().duplicate());
         }
 
         @Override
         public FullHttpRequest retainedDuplicate() {
             return replace(content().retainedDuplicate());
         }
 
         @Override
         public FullHttpRequest replace(ByteBuf content) {
             DefaultFullHttpRequest duplicate = new DefaultFullHttpRequest(protocolVersion(), method(), uri(), content);
             duplicate.headers().set(headers());
             duplicate.trailingHeaders().set(trailingHeaders());
             return duplicate;
         }
 
         @Override
         public FullHttpRequest retain(int increment) {
             content.retain(increment);
             return this;
         }
 
         @Override
         public FullHttpRequest retain() {
             content.retain();
             return this;
         }
 
         @Override
         public FullHttpRequest touch() {
             content.touch();
             return this;
         }
 
         @Override
         public FullHttpRequest touch(Object hint) {
             content.touch(hint);
             return this;
         }
 
         @Override
         public ByteBuf content() {
             return content.content();
         }
 
         @Override
         public HttpHeaders trailingHeaders() {
             if (content instanceof LastHttpContent) {
                 return ((LastHttpContent) content).trailingHeaders();
             } else {
                 return EmptyHttpHeaders.INSTANCE;
             }
         }
 
         @Override
         public int refCnt() {
             return content.refCnt();
         }
 
         @Override
         public boolean release() {
             return content.release();
         }
 
         @Override
         public boolean release(int decrement) {
             return content.release(decrement);
         }
     }
 }