/*
 * 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 org.jboss.netty.example.http.upload;

import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelFutureListener;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
import org.jboss.netty.handler.codec.http.cookie.Cookie;
import org.jboss.netty.handler.codec.http.cookie.ServerCookieDecoder;
import org.jboss.netty.handler.codec.http.cookie.ServerCookieEncoder;
import org.jboss.netty.handler.codec.http.DefaultHttpResponse;
import org.jboss.netty.handler.codec.http.HttpChunk;
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;
import org.jboss.netty.handler.codec.http.QueryStringDecoder;
import org.jboss.netty.handler.codec.http.multipart.Attribute;
import org.jboss.netty.handler.codec.http.multipart.DefaultHttpDataFactory;
import org.jboss.netty.handler.codec.http.multipart.DiskAttribute;
import org.jboss.netty.handler.codec.http.multipart.DiskFileUpload;
import org.jboss.netty.handler.codec.http.multipart.FileUpload;
import org.jboss.netty.handler.codec.http.multipart.HttpDataFactory;
import org.jboss.netty.handler.codec.http.multipart.HttpPostRequestDecoder;
import org.jboss.netty.handler.codec.http.multipart.HttpPostRequestDecoder.EndOfDataDecoderException;
import org.jboss.netty.handler.codec.http.multipart.HttpPostRequestDecoder.ErrorDataDecoderException;
import org.jboss.netty.handler.codec.http.multipart.HttpPostRequestDecoder.IncompatibleDataDecoderException;
import org.jboss.netty.handler.codec.http.multipart.HttpPostRequestDecoder.NotEnoughDataDecoderException;
import org.jboss.netty.handler.codec.http.multipart.InterfaceHttpData;
import org.jboss.netty.handler.codec.http.multipart.InterfaceHttpData.HttpDataType;
import org.jboss.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;

public class HttpUploadServerHandler extends SimpleChannelUpstreamHandler {

    private static final HttpDataFactory factory =
            new DefaultHttpDataFactory(DefaultHttpDataFactory.MINSIZE); // Disk if size exceed MINSIZE

    static {
        //To limit to roughly 5MB each attribute, including fileupload
        //factory.setMaxLimit(5000000);
        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
    }

    private final StringBuilder responseContent = new StringBuilder();
    private HttpPostRequestDecoder decoder;
    private HttpRequest request;
    private boolean readingChunks;

    @Override
    public void channelClosed(ChannelHandlerContext ctx, ChannelStateEvent e) {
        if (decoder != null) {
            decoder.cleanFiles();
        }
    }

    @Override
    public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) throws Exception {
        if (!readingChunks) {
            // clean previous FileUpload if Any
            if (decoder != null) {
                decoder.cleanFiles();
                decoder = null;
            }

            HttpRequest request = this.request = (HttpRequest) e.getMessage();
            URI uri = new URI(request.getUri());
            if (!uri.getPath().startsWith("/form")) {
                // Write Menu
                writeMenu(e);
                return;
            }
            responseContent.setLength(0);
            responseContent.append("WELCOME TO THE WILD WILD WEB SERVER\r\n");
            responseContent.append("===================================\r\n");
            responseContent.append("VERSION: " + request.getProtocolVersion().getText() + "\r\n");
            responseContent.append("REQUEST_URI: " + request.getUri() + "\r\n\r\n");
            responseContent.append("\r\n\r\n");

            // new method
            for (Entry<String, String> entry: request.headers()) {
                responseContent.append("HEADER: " + entry.getKey() + '=' + entry.getValue() + "\r\n");
            }
            responseContent.append("\r\n\r\n");

            // new method
            Set<Cookie> cookies;
            String value = request.headers().get(HttpHeaders.Names.COOKIE);
            if (value == null) {
                cookies = Collections.emptySet();
            } else {
                cookies = ServerCookieDecoder.STRICT.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.getParameters();
            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 GET Method: should not try to create a HttpPostRequestDecoder
            try {
                decoder = new HttpPostRequestDecoder(factory, request);
            } catch (ErrorDataDecoderException e1) {
                e1.printStackTrace();
                responseContent.append(e1.getMessage());
                writeResponse(e.getChannel());
                Channels.close(e.getChannel());
                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(e.getChannel());
                return;
            }

            responseContent.append("Is Chunked: " + request.isChunked() + "\r\n");
            responseContent.append("IsMultipart: " + decoder.isMultipart() + "\r\n");
            if (request.isChunked()) {
                // Chunk version
                responseContent.append("Chunks: ");
                readingChunks = true;
            } else {
                // Not chunk version
                readHttpDataAllReceive(e.getChannel());
                responseContent.append("\r\n\r\nEND OF NOT CHUNKED CONTENT\r\n");
                writeResponse(e.getChannel());
            }
        } else {
            // New chunk is received
            HttpChunk chunk = (HttpChunk) e.getMessage();
            try {
                decoder.offer(chunk);
            } catch (ErrorDataDecoderException e1) {
                e1.printStackTrace();
                responseContent.append(e1.getMessage());
                writeResponse(e.getChannel());
                Channels.close(e.getChannel());
                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.isLast()) {
                readHttpDataAllReceive(e.getChannel());
                writeResponse(e.getChannel());
                readingChunks = false;
            }
        }
    }

    /**
     * Example of reading all InterfaceHttpData from finished transfer
     */
    private void readHttpDataAllReceive(Channel channel) {
        List<InterfaceHttpData> datas;
        try {
            datas = decoder.getBodyHttpDatas();
        } catch (NotEnoughDataDecoderException e1) {
            // Should not be!
            e1.printStackTrace();
            responseContent.append(e1.getMessage());
            writeResponse(channel);
            Channels.close(channel);
            return;
        }
        for (InterfaceHttpData data: datas) {
            writeHttpData(data);
        }
        responseContent.append("\r\n\r\nEND OF CONTENT AT FINAL END\r\n");
    }

    /**
     * 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) {
                    // new value
                    writeHttpData(data);
                }
            }
        } 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.
        ChannelBuffer buf = ChannelBuffers.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(HttpHeaders.Names.CONNECTION)) ||
                request.getProtocolVersion().equals(HttpVersion.HTTP_1_0) &&
                !HttpHeaders.Values.KEEP_ALIVE.equalsIgnoreCase(request.headers().get(HttpHeaders.Names.CONNECTION));

        // Build the response object.
        HttpResponse response = new DefaultHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
        response.setContent(buf);
        response.headers().set(HttpHeaders.Names.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(HttpHeaders.Names.CONTENT_LENGTH, String.valueOf(buf.readableBytes()));
        }

        Set<Cookie> cookies;
        String value = request.headers().get(HttpHeaders.Names.COOKIE);
        if (value == null) {
            cookies = Collections.emptySet();
        } else {
            cookies = ServerCookieDecoder.STRICT.decode(value);
        }
        if (!cookies.isEmpty()) {
            response.headers().add(HttpHeaders.Names.SET_COOKIE, ServerCookieEncoder.STRICT.encode(cookies));
        }
        // Write the response.
        ChannelFuture future = channel.write(response);
        // Close the connection after the write operation is done if necessary.
        if (close) {
            future.addListener(ChannelFutureListener.CLOSE);
        }
    }

    private void writeMenu(MessageEvent e) {
        // 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> ");
        responseContent.append("<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>");

        ChannelBuffer buf = ChannelBuffers.copiedBuffer(responseContent.toString(), CharsetUtil.UTF_8);
        // Build the response object.
        HttpResponse response = new DefaultHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
        response.setContent(buf);
        response.headers().set(HttpHeaders.Names.CONTENT_TYPE, "text/html; charset=UTF-8");
        response.headers().set(HttpHeaders.Names.CONTENT_LENGTH, String.valueOf(buf.readableBytes()));
        // Write the response.
        e.getChannel().write(response);
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
        e.getCause().printStackTrace();
        e.getChannel().close();
    }
}
