/*
 * Copyright 2013 - 2015 Anton Tananaev (anton.tananaev@gmail.com)
 *
 * 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 java.net.SocketAddress;
import java.util.ArrayList;
import java.util.Date;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.Channel;
import org.traccar.BaseProtocolDecoder;
import org.traccar.Context;
import org.traccar.helper.ChannelBufferTools;
import org.traccar.helper.Checksum;
import org.traccar.helper.UnitsConverter;
import org.traccar.model.Event;
import org.traccar.model.Position;

public class AplicomProtocolDecoder extends BaseProtocolDecoder {

    public AplicomProtocolDecoder(AplicomProtocol protocol) {
        super(protocol);
    }

    private static final long IMEI_BASE_TC65_V20 = 0x1437207000000L;
    private static final long IMEI_BASE_TC65_V28 = 358244010000000L;
    private static final long IMEI_BASE_TC65I_V11 = 0x14143B4000000L;

    private static boolean validateImei(long imei) {
        return Checksum.luhn(imei / 10) == imei % 10;
    }

    private static long imeiFromUnitId(long unitId) {

        if (unitId == 0) {

            return 0;

        } else {

            // Try TC65i
            long imei = IMEI_BASE_TC65I_V11 + unitId;
            if (validateImei(imei)) {
                return imei;
            }

            // Try TC65 v2.8
            imei = IMEI_BASE_TC65_V28 + ((unitId + 0xA8180) & 0xFFFFFF);
            if (validateImei(imei)) {
                return imei;
            }

            // Try TC65 v2.0
            imei = IMEI_BASE_TC65_V20 + unitId;
            if (validateImei(imei)) {
                return imei;
            }

        }

        return unitId;
    }

    private static final int DEFAULT_SELECTOR = 0x0002FC;

    private static final int EVENT_DATA = 119;

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

        ChannelBuffer buf = (ChannelBuffer) msg;

        buf.readUnsignedByte(); // marker
        int version = buf.readUnsignedByte();

        String imei;
        if ((version & 0x80) != 0) {
            imei = String.valueOf((buf.readUnsignedInt() << (3 * 8)) | buf.readUnsignedMedium());
        } else {
            imei = String.valueOf(imeiFromUnitId(buf.readUnsignedMedium()));
        }

        buf.readUnsignedShort(); // length

        // Selector
        int selector = DEFAULT_SELECTOR; // default selector
        if ((version & 0x40) != 0) {
            selector = buf.readUnsignedMedium();
        }

        // Create new position
        Position position = new Position();
        position.setProtocol(getProtocolName());
        if (!identify(imei, channel)) {
            return null;
        }

        position.setDeviceId(getDeviceId());

        // Event
        int event = buf.readUnsignedByte();
        position.set(Event.KEY_EVENT, event);
        buf.readUnsignedByte();

        // Validity
        if ((selector & 0x0008) != 0) {
            position.setValid((buf.readUnsignedByte() & 0x40) != 0);
        } else {
            return null; // no location data
        }

        // Time
        if ((selector & 0x0004) != 0) {
            buf.skipBytes(4); // snapshot time
        }

        // Location
        if ((selector & 0x0008) != 0) {
            position.setTime(new Date(buf.readUnsignedInt() * 1000));
            position.setLatitude(buf.readInt() / 1000000.0);
            position.setLongitude(buf.readInt() / 1000000.0);
            position.set(Event.KEY_SATELLITES, buf.readUnsignedByte());
        }

        // Speed and heading
        if ((selector & 0x0010) != 0) {
            position.setSpeed(UnitsConverter.knotsFromKph(buf.readUnsignedByte()));
            buf.readUnsignedByte(); // maximum speed
            position.setCourse(buf.readUnsignedByte() * 2.0);
        }

        // Input
        if ((selector & 0x0040) != 0) {
            position.set(Event.KEY_INPUT, buf.readUnsignedByte());
        }

        // ADC
        if ((selector & 0x0020) != 0) {
            position.set(Event.PREFIX_ADC + 1, buf.readUnsignedShort());
            position.set(Event.PREFIX_ADC + 2, buf.readUnsignedShort());
            position.set(Event.PREFIX_ADC + 3, buf.readUnsignedShort());
            position.set(Event.PREFIX_ADC + 4, buf.readUnsignedShort());
        }

        // Power
        if ((selector & 0x8000) != 0) {
            position.set(Event.KEY_POWER, buf.readUnsignedShort() / 1000.0);
            position.set(Event.KEY_BATTERY, buf.readUnsignedShort());
        }

        // Pulse rate 1
        if ((selector & 0x10000) != 0) {
            buf.readUnsignedShort();
            buf.readUnsignedInt();
        }

        // Pulse rate 2
        if ((selector & 0x20000) != 0) {
            buf.readUnsignedShort();
            buf.readUnsignedInt();
        }

        // Trip 1
        if ((selector & 0x0080) != 0) {
            position.set("trip1", buf.readUnsignedInt());
        }

        // Trip 2
        if ((selector & 0x0100) != 0) {
            position.set("trip2", buf.readUnsignedInt());
        }

        // Output
        if ((selector & 0x0040) != 0) {
            position.set(Event.KEY_OUTPUT, buf.readUnsignedByte());
        }

        // Button
        if ((selector & 0x0200) != 0) {
            buf.skipBytes(6);
        }

        // Keypad
        if ((selector & 0x0400) != 0) {
            buf.readUnsignedByte();
        }

        // Altitude
        if ((selector & 0x0800) != 0) {
            position.setAltitude(buf.readShort());
        }

        // Snapshot counter
        if ((selector & 0x2000) != 0) {
            buf.readUnsignedShort();
        }

        // State flags
        if ((selector & 0x4000) != 0) {
            buf.skipBytes(8);
        }

        // Cell info
        if ((selector & 0x80000) != 0) {
            buf.skipBytes(11);
        }

        // Event specific data
        if ((selector & 0x1000) != 0) {
            switch (event) {
                case 2:
                case 40:
                    buf.readUnsignedByte();
                    break;
                case 9:
                    buf.readUnsignedMedium();
                    break;
                case 31:
                case 32:
                    buf.readUnsignedShort();
                    break;
                case 38:
                    buf.skipBytes(4 * 9);
                    break;
                case 113:
                    buf.readUnsignedInt();
                    buf.readUnsignedByte();
                    break;
                case 121:
                case 142:
                    buf.readLong();
                    break;
                case 130:
                    buf.readUnsignedInt(); // incorrect
                    break;
            }
        }

        if (Context.getConfig().getBoolean(getProtocolName() + ".can") &&
                buf.readable() && (selector & 0x1000) != 0 && event == EVENT_DATA) {

            buf.readUnsignedMedium(); // packet identifier
            buf.readUnsignedByte(); // version
            int count = buf.readUnsignedByte();
            buf.readUnsignedByte(); // batch count
            buf.readUnsignedShort(); // selector bit
            buf.readUnsignedInt(); // timestamp

            buf.skipBytes(8);

            ArrayList<ChannelBuffer> values = new ArrayList<>(count);

            for (int i = 0; i < count; i++) {
                values.add(buf.readBytes(8));
            }

            for (int i = 0; i < count; i++) {
                ChannelBuffer value = values.get(i);
                switch (buf.readInt()) {
                    case 0x20D:
                        position.set(Event.KEY_RPM, ChannelBuffers.swapShort(value.readShort()));
                        position.set("diesel-temperature", ChannelBuffers.swapShort(value.readShort()) * 0.1);
                        position.set("battery-voltage", ChannelBuffers.swapShort(value.readShort()) * 0.01);
                        position.set("supply-air-temp-dep1", ChannelBuffers.swapShort(value.readShort()) * 0.1);
                        break;
                    case 0x30D:
                        position.set("active-alarm", ChannelBufferTools.readHexString(value, 16));
                        break;
                    case 0x40C:
                        position.set("air-temp-dep1", ChannelBuffers.swapShort(value.readShort()) * 0.1);
                        position.set("air-temp-dep2", ChannelBuffers.swapShort(value.readShort()) * 0.1);
                        break;
                    case 0x40D:
                        position.set("cold-unit-state", ChannelBufferTools.readHexString(value, 16));
                        break;
                    case 0x50C:
                        position.set("defrost-temp-dep1", ChannelBuffers.swapShort(value.readShort()) * 0.1);
                        position.set("defrost-temp-dep2", ChannelBuffers.swapShort(value.readShort()) * 0.1);
                        break;
                    case 0x50D:
                        position.set("condenser-pressure", ChannelBuffers.swapShort(value.readShort()) * 0.1);
                        position.set("suction-pressure", ChannelBuffers.swapShort(value.readShort()) * 0.1);
                        break;
                    case 0x58C:
                        value.readByte();
                        value.readShort(); // index
                        switch (value.readByte()) {
                            case 0x01:
                                position.set("setpoint-zone1", ChannelBuffers.swapInt(value.readInt()) * 0.1);
                                break;
                            case 0x02:
                                position.set("setpoint-zone2", ChannelBuffers.swapInt(value.readInt()) * 0.1);
                                break;
                            case 0x05:
                                position.set("unit-type", ChannelBuffers.swapInt(value.readInt()));
                                break;
                            case 0x13:
                                position.set("diesel-hours", ChannelBuffers.swapInt(value.readInt()) / 60 / 60);
                                break;
                            case 0x14:
                                position.set("electric-hours", ChannelBuffers.swapInt(value.readInt()) / 60 / 60);
                                break;
                            case 0x17:
                                position.set("service-indicator", ChannelBuffers.swapInt(value.readInt()));
                                break;
                            case 0x18:
                                position.set("software-version", ChannelBuffers.swapInt(value.readInt()) * 0.01);
                                break;
                        }
                        break;
                }
            }
        }

        return position;
    }

}