/*
 * Copyright 2013 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.util.Calendar;
import java.util.TimeZone;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.traccar.BaseProtocolDecoder;
import org.traccar.ServerManager;
import org.traccar.helper.Log;
import org.traccar.model.Position;

public class MegastekProtocolDecoder extends BaseProtocolDecoder {

    public MegastekProtocolDecoder(ServerManager serverManager) {
        super(serverManager);
    }

    static private Pattern pattern = Pattern.compile(
            "STX," +
            "[^,]+," +                     // Identifier (not IMEI)
            "\\$GPRMC," +
            "(\\d{2})(\\d{2})(\\d{2})\\.\\d+," + // Time (HHMMSS.SSS)
            "([AV])," +                    // Validity
            "(\\d+)(\\d{2}\\.\\d+)," +     // Latitude (DDMM.MMMM)
            "([NS])," +
            "(\\d+)(\\d{2}\\.\\d+)," +     // Longitude (DDDMM.MMMM)
            "([EW])," +
            "(\\d+\\.\\d{2})?," +          // Speed
            "(\\d+\\.\\d{2})?," +          // Course
            "(\\d{2})(\\d{2})(\\d{2})" +   // Date (DDMMYY)
            "[^\\*]+\\*[0-9a-fA-F]{2}," +  // Checksumm
            "[FL]," +                      // Flag
            "([^,]*)," +                   // Alarm
            "imei:(\\d+)," +               // IMEI
            "(\\d+)?," +                   // Satellites
            "(\\d+\\.\\d+)," +             // Altitude
            "Battery=(\\d+)%,," +          // Battery
            "(\\d)?," +                    // Charger
            "(\\d+)," +                    // MCC
            "(\\d+)," +                    // MNC
            "([0-9a-fA-F]+,[0-9a-fA-F]+);" + // Location code
            ".+");                         // Checksumm

    @Override
    protected Object decode(
            ChannelHandlerContext ctx, Channel channel, Object msg)
            throws Exception {

        String sentence = (String) msg;

        // Parse message
        Matcher parser = pattern.matcher(sentence);
        if (!parser.matches()) {
            return null;
        }

        // Create new position
        Position position = new Position();
        StringBuilder extendedInfo = new StringBuilder("<protocol>megastek</protocol>");
        int index = 1;

        // Time
        Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
        time.clear();
        time.set(Calendar.HOUR, Integer.valueOf(parser.group(index++)));
        time.set(Calendar.MINUTE, Integer.valueOf(parser.group(index++)));
        time.set(Calendar.SECOND, Integer.valueOf(parser.group(index++)));

        // Validity
        position.setValid(parser.group(index++).compareTo("A") == 0 ? true : false);

        // Latitude
        Double latitude = Double.valueOf(parser.group(index++));
        latitude += Double.valueOf(parser.group(index++)) / 60;
        if (parser.group(index++).compareTo("S") == 0) latitude = -latitude;
        position.setLatitude(latitude);

        // Longitude
        Double lonlitude = Double.valueOf(parser.group(index++));
        lonlitude += Double.valueOf(parser.group(index++)) / 60;
        if (parser.group(index++).compareTo("W") == 0) lonlitude = -lonlitude;
        position.setLongitude(lonlitude);

        // Speed
        String speed = parser.group(index++);
        if (speed != null) {
            position.setSpeed(Double.valueOf(speed));
        } else {
            position.setSpeed(0.0);
        }

        // Course
        String course = parser.group(index++);
        if (course != null) {
            position.setCourse(Double.valueOf(course));
        } else {
            position.setCourse(0.0);
        }

        // Date
        time.set(Calendar.DAY_OF_MONTH, Integer.valueOf(parser.group(index++)));
        time.set(Calendar.MONTH, Integer.valueOf(parser.group(index++)) - 1);
        time.set(Calendar.YEAR, 2000 + Integer.valueOf(parser.group(index++)));
        position.setTime(time.getTime());

        // Alarm
        extendedInfo.append("<alarm>");
        extendedInfo.append(parser.group(index++));
        extendedInfo.append("</alarm>");

        // IMEI
        String imei = parser.group(index++);
        try {
            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
        } catch(Exception error) {
            Log.warning("Unknown device - " + imei);
            return null;
        }

        // Satellites
        String satellites = parser.group(index++);
        if (satellites != null) {
            extendedInfo.append("<satellites>");
            extendedInfo.append(satellites);
            extendedInfo.append("</satellites>");
        }

        // Altitude
        position.setAltitude(Double.valueOf(parser.group(index++)));

        // Battery
        position.setPower(Double.valueOf(parser.group(index++)));

        // Charger
        String charger = parser.group(index++);
        if (charger != null) {
            extendedInfo.append("<charger>");
            extendedInfo.append(Integer.valueOf(charger) == 1);
            extendedInfo.append("</charger>");
        }

        // MCC
        extendedInfo.append("<mcc>");
        extendedInfo.append(parser.group(index++));
        extendedInfo.append("</mcc>");

        // MNC
        extendedInfo.append("<mnc>");
        extendedInfo.append(parser.group(index++));
        extendedInfo.append("</mnc>");

        // LAC
        extendedInfo.append("<lac>");
        extendedInfo.append(parser.group(index++));
        extendedInfo.append("</lac>");

        // Extended info
        position.setExtendedInfo(extendedInfo.toString());

        return position;
    }

}