/*
 * Copyright 2018 Anton Tananaev (anton@traccar.org)
 *
 * Licensed 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.traccar.protocol;

import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.channel.Channel;
import org.traccar.BaseProtocolDecoder;
import org.traccar.DeviceSession;
import org.traccar.helper.UnitsConverter;
import org.traccar.model.Position;

import java.net.SocketAddress;
import java.util.Date;

public class ContinentalProtocolDecoder extends BaseProtocolDecoder {

    public ContinentalProtocolDecoder(ContinentalProtocol protocol) {
        super(protocol);
    }

    public static final int MSG_KEEPALIVE = 0x00;
    public static final int MSG_STATUS = 0x02;
    public static final int MSG_ACK = 0x06;
    public static final int MSG_NACK = 0x15;

    @Override
    protected Object decode(
            Channel channel, SocketAddress remoteAddress, Object msg) throws Exception {

        ChannelBuffer buf = (ChannelBuffer) msg;

        buf.skipBytes(2); // header
        buf.readUnsignedShort(); // length
        buf.readUnsignedByte(); // software version

        DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, String.valueOf(buf.readUnsignedInt()));
        if (deviceSession == null) {
            return null;
        }

        buf.readUnsignedByte(); // product

        int type = buf.readUnsignedByte();

        if (type == MSG_STATUS) {

            Position position = new Position(getProtocolName());
            position.setDeviceId(deviceSession.getDeviceId());

            position.setFixTime(new Date(buf.readUnsignedInt() * 1000L));

            buf.readUnsignedByte();
            position.setLatitude(buf.readMedium() / 3600.0);

            buf.readUnsignedByte();
            position.setLongitude(buf.readMedium() / 3600.0);

            position.setCourse(buf.readUnsignedShort());
            position.setSpeed(UnitsConverter.knotsFromKph(buf.readUnsignedShort()));

            position.setValid(buf.readUnsignedByte() > 0);

            position.setDeviceTime(new Date(buf.readUnsignedInt() * 1000L));

            position.set(Position.KEY_EVENT, buf.readUnsignedShort());
            position.set(Position.KEY_INPUT, buf.readUnsignedShort());
            position.set(Position.KEY_OUTPUT, buf.readUnsignedShort());
            position.set(Position.KEY_BATTERY, buf.readUnsignedByte());
            position.set(Position.KEY_DEVICE_TEMP, buf.readByte());

            buf.readUnsignedShort(); // reserved

            return position;

        }

        return null;
    }

}

@@ -683,24 +683,70 @@
 nnelBuffer;%0A
+import org.jboss.netty.buffer.ChannelBuffers;%0A
 import org.j
@@ -773,16 +773,16 @@
 hannel;%0A
-
 import o
@@ -1340,16 +1340,560 @@
  0x15;%0A%0A
+    private void sendResponse(Channel channel, long serialNumber) %7B%0A        if (channel != null) %7B%0A            ChannelBuffer response = ChannelBuffers.dynamicBuffer();%0A%0A            response.writeByte('S');%0A            response.writeByte('V');%0A            response.writeShort(2 + 2 + 1 + 4 + 2); // length%0A            response.writeByte(1); // version%0A            response.writeInt((int) serialNumber);%0A            response.writeByte(0); // product%0A            response.writeByte(MSG_ACK);%0A%0A            channel.write(response);%0A        %7D%0A    %7D%0A%0A
     @Ove
@@ -2199,16 +2199,67 @@
 ersion%0A%0A
+        long serialNumber = buf.readUnsignedInt();%0A
         
@@ -2344,37 +2344,28 @@
 valueOf(
-buf.readUnsignedInt()
+serialNumber
 ));%0A    
@@ -2418,24 +2418,24 @@
 eturn null;%0A
-
         %7D%0A%0A 
@@ -2425,32 +2425,78 @@
 ull;%0A        %7D%0A%0A
+        sendResponse(channel, serialNumber);%0A%0A
         buf.read

Implement Continental ACK response