/*
 * Copyright 2015 - 2019 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 io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufUtil;
import io.netty.buffer.Unpooled;
import io.netty.channel.Channel;
import org.traccar.BaseProtocolDecoder;
import org.traccar.DeviceSession;
import org.traccar.NetworkMessage;
import org.traccar.Protocol;
import org.traccar.helper.BcdUtil;
import org.traccar.helper.BitUtil;
import org.traccar.helper.DateBuilder;
import org.traccar.helper.UnitsConverter;
import org.traccar.model.CellTower;
import org.traccar.model.Network;
import org.traccar.model.Position;

import java.net.SocketAddress;

public class T800xProtocolDecoder extends BaseProtocolDecoder {

    public T800xProtocolDecoder(Protocol protocol) {
        super(protocol);
    }

    public static final int MSG_LOGIN = 0x01;
    public static final int MSG_GPS = 0x02;
    public static final int MSG_HEARTBEAT = 0x03;
    public static final int MSG_ALARM = 0x04;
    public static final int MSG_COMMAND = 0x81;

    private void sendResponse(Channel channel, short header, int type, ByteBuf imei) {
        if (channel != null) {
            ByteBuf response = Unpooled.buffer(15);
            response.writeShort(header);
            response.writeByte(type);
            response.writeShort(response.capacity()); // length
            response.writeShort(0x0001); // index
            response.writeBytes(imei);
            channel.writeAndFlush(new NetworkMessage(response, channel.remoteAddress()));
        }
    }

    private String decodeAlarm(short value) {
        switch (value) {
            case 3:
                return Position.ALARM_SOS;
            case 4:
                return Position.ALARM_OVERSPEED;
            case 5:
                return Position.ALARM_GEOFENCE_ENTER;
            case 6:
                return Position.ALARM_GEOFENCE_EXIT;
            case 8:
            case 10:
                return Position.ALARM_VIBRATION;
            default:
                break;
        }
        return null;
    }

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

        ByteBuf buf = (ByteBuf) msg;

        short header = buf.readShort();
        int type = buf.readUnsignedByte();
        buf.readUnsignedShort(); // length
        int index = buf.readUnsignedShort();
        ByteBuf imei = buf.readSlice(8);

        DeviceSession deviceSession = getDeviceSession(
                channel, remoteAddress, ByteBufUtil.hexDump(imei).substring(1));
        if (deviceSession == null) {
            return null;
        }

        if (type == MSG_LOGIN || type == MSG_ALARM || type == MSG_HEARTBEAT) {
            sendResponse(channel, header, type, imei);
        }

        if (type == MSG_GPS || type == MSG_ALARM) {

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

            position.set(Position.KEY_INDEX, index);

            buf.readUnsignedShort(); // acc on interval
            buf.readUnsignedShort(); // acc off interval
            buf.readUnsignedByte(); // angle compensation
            buf.readUnsignedShort(); // distance compensation
            buf.readUnsignedShort(); // speed alarm

            int status = buf.readUnsignedByte();
            position.set(Position.KEY_SATELLITES, BitUtil.to(status, 5));

            buf.readUnsignedByte(); // gsensor manager status
            buf.readUnsignedByte(); // other flags
            buf.readUnsignedByte(); // heartbeat
            buf.readUnsignedByte(); // relay status
            buf.readUnsignedShort(); // drag alarm setting

            int io = buf.readUnsignedShort();
            position.set(Position.KEY_IGNITION, BitUtil.check(io, 14));
            position.set("ac", BitUtil.check(io, 13));

            position.set(Position.PREFIX_ADC + 1, buf.readUnsignedShort());
            position.set(Position.PREFIX_ADC + 2, buf.readUnsignedShort());

            position.set(Position.KEY_ALARM, decodeAlarm(buf.readUnsignedByte()));

            buf.readUnsignedByte(); // reserved

            position.set(Position.KEY_ODOMETER, buf.readUnsignedInt());

            int battery = BcdUtil.readInteger(buf, 2);
            if (battery == 0) {
                battery = 100;
            }
            position.set(Position.KEY_BATTERY, battery);

            DateBuilder dateBuilder = new DateBuilder()
                    .setYear(BcdUtil.readInteger(buf, 2))
                    .setMonth(BcdUtil.readInteger(buf, 2))
                    .setDay(BcdUtil.readInteger(buf, 2))
                    .setHour(BcdUtil.readInteger(buf, 2))
                    .setMinute(BcdUtil.readInteger(buf, 2))
                    .setSecond(BcdUtil.readInteger(buf, 2));

            if (BitUtil.check(status, 6)) {

                position.setValid(!BitUtil.check(status, 7));
                position.setTime(dateBuilder.getDate());
                position.setAltitude(buf.readFloatLE());
                position.setLongitude(buf.readFloatLE());
                position.setLatitude(buf.readFloatLE());
                position.setSpeed(UnitsConverter.knotsFromKph(BcdUtil.readInteger(buf, 4) * 0.1));
                position.setCourse(buf.readUnsignedShort());

            } else {

                getLastLocation(position, dateBuilder.getDate());

                int mcc = buf.readUnsignedShortLE();
                int mnc = buf.readUnsignedShortLE();

                if (mcc != 0xffff && mnc != 0xffff) {
                    Network network = new Network();
                    for (int i = 0; i < 3; i++) {
                        network.addCellTower(CellTower.from(
                                mcc, mnc, buf.readUnsignedShortLE(), buf.readUnsignedShortLE()));
                    }
                    position.setNetwork(network);
                }

            }

            if (buf.readableBytes() >= 2) {
                position.set(Position.KEY_POWER, BcdUtil.readInteger(buf, 4) * 0.01);
            }

            return position;

        }

        return null;
    }

}

@@ -1665,16 +1665,27 @@
 nt type,
+ int index,
  ByteBuf
@@ -1955,25 +1955,15 @@
 ort(
-0x0001); // 
 index
+);
 %0A   
@@ -3225,91 +3225,8 @@
  %7D%0A%0A
-        if (type == MSG_LOGIN %7C%7C type == MSG_ALARM %7C%7C type == MSG_HEARTBEAT) %7B%0A    
     
@@ -3270,23 +3270,20 @@
 e, i
-mei);%0A        %7D
+ndex, imei);
 %0A%0A  

Fix message response