package seng302.models.stream;


import java.io.IOException;
import java.io.StringReader;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Date;
import java.util.Map;
import java.util.TimeZone;
import java.util.TreeMap;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentSkipListMap;
import java.util.concurrent.PriorityBlockingQueue;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import seng302.models.Yacht;
import seng302.models.stream.packets.BoatPositionPacket;
import seng302.models.stream.packets.StreamPacket;

/**
 * The purpose of this class is to take in the stream of divided packets so they can be read
 * and parsed in by turning the byte arrays into useful data. There are two public static hashmaps
 * that are threadsafe so the visualiser can always access the latest speed and position available
 * Created by kre39 on 23/04/17.
 */
public class StreamParser extends Thread{

     public static ConcurrentHashMap<Long, PriorityBlockingQueue<BoatPositionPacket>> markPositions = new ConcurrentHashMap<>();
     public static ConcurrentHashMap<Long, PriorityBlockingQueue<BoatPositionPacket>> boatPositions = new ConcurrentHashMap<>();
     private String threadName;
     private Thread t;
     private static boolean newRaceXmlReceived = false;
     private static boolean raceStarted = false;
     private static XMLParser xmlObject;
     private static boolean raceFinished = false;
     private static boolean streamStatus = false;
     private static long timeSinceStart = -1;
     private static Map<Integer, Yacht> boats = new ConcurrentHashMap<>();
     private static Map<Long, Yacht> boatsPos = new ConcurrentSkipListMap<>();
     private static double windDirection = 0;
     private static Long currentTimeLong;
     private static String currentTimeString;
     private static boolean appRunning;

    /**
     * Used to initialise the thread name and stream parser object so a thread can be executed
     *
     * @param threadName name of the thread
     */
     public StreamParser(String threadName){
         this.threadName = threadName;
     }

    /**
     * Used to within threading so when the stream parser thread runs, it will keep looking for a packet to
     * process until it is unable to find anymore packets
     *
     */
    public void run(){
        appRunning = true;
         try {
             System.out.println("[CLIENT] Start of stream");
             streamStatus = true;
             xmlObject = new XMLParser();
             while (StreamReceiver.packetBuffer == null || StreamReceiver.packetBuffer.size() < 1) {
                 Thread.sleep(1);
             }
             while (appRunning){
                 StreamPacket packet = StreamReceiver.packetBuffer.take();
                 parsePacket(packet);
                 Thread.sleep(1);
                 while (StreamReceiver.packetBuffer.peek() == null) {
                 }
             }
         } catch (Exception e){
             e.printStackTrace();
         }
     }

    /**
     * Used to start the stream parser thread when multithreading
     *
     */
    public void start () {
        System.out.println("[CLIENT] Starting " +  threadName );
        if (t == null) {
            t = new Thread (this, threadName);
            t.start ();
        }
    }

    /**
     * Looks at the type of the packet then sends it to the appropriate parser to extract the
     * specific data associated with that packet type
     *
     * @param packet the packet to be looked at and processed
     */
     private static void parsePacket(StreamPacket packet) {
         try{
             switch (packet.getType()){
                 case HEARTBEAT:
                     extractHeartBeat(packet);
                     break;
                 case RACE_STATUS:
                     extractRaceStatus(packet);
                     break;
                 case DISPLAY_TEXT_MESSAGE:
                     extractDisplayMessage(packet);
                     break;
                 case XML_MESSAGE:
                     newRaceXmlReceived = true;
                     extractXmlMessage(packet);
                     break;
                 case RACE_START_STATUS:
                     extractRaceStartStatus(packet);
                     break;
                 case YACHT_EVENT_CODE:
                     extractYachtEventCode(packet);
                     break;
                 case YACHT_ACTION_CODE:
                     extractYachtActionCode(packet);
                     break;
                 case CHATTER_TEXT:
                     extractChatterText(packet);
                     break;
                 case BOAT_LOCATION:
                     extractBoatLocation(packet);
                     break;
                 case MARK_ROUNDING:
                     extractMarkRounding(packet);
                     break;
                 case COURSE_WIND:
                     extractCourseWind(packet);
                     break;
                 case AVG_WIND:
                     extractAvgWind(packet);
                     break;
                 default:
                     break;
                 //System.out.println(packet.getType().toString());
             }
         }
         catch (NullPointerException e){
             System.out.println("Error parsing packet");
         }
     }

    /**
     * Extracts the seq num used in the heartbeat packet
     *
     * @param packet Packet parsed in to use the payload
     */
    private static void extractHeartBeat(StreamPacket packet) {
        long heartbeat = bytesToLong(packet.getPayload());
    }

    private static String getTimeZoneString() {

        Integer offset = xmlObject.getRegattaXML().getUtcOffset();
        StringBuilder utcOffset = new StringBuilder();
        utcOffset.append("GMT");
        if (offset > 0) {
            utcOffset.append("+");
            utcOffset.append(offset);
        } else if (offset < 0) {
            utcOffset.append("-");
            utcOffset.append(offset);
        }
        return utcOffset.toString();

    }

    /**
     * Extracts the useful race status data from race status type packets. This method will also print to the
     * console the current state of the race (if it has started/finished or is about to start), along side
     * this it'll also display the amount of time since the race has started or time till it starts
     *
     * @param packet Packet parsed in to use the payload
     */
    private static void extractRaceStatus(StreamPacket packet){
        byte[] payload = packet.getPayload();
        int messageVersionNo = payload[0];
        long currentTime = bytesToLong(Arrays.copyOfRange(payload,1,7));
        long raceId = bytesToLong(Arrays.copyOfRange(payload,7,11));
        int raceStatus = payload[11];
        long expectedStartTime = bytesToLong(Arrays.copyOfRange(payload,12,18));
        long windDir = bytesToLong(Arrays.copyOfRange(payload,18,20));
        long windSpeed = bytesToLong(Arrays.copyOfRange(payload,20,22));

        currentTimeLong = currentTime;
        DateFormat format = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss");
        if (xmlObject.getRegattaXML() != null) {
            format.setTimeZone(TimeZone.getTimeZone(getTimeZoneString()));
            currentTimeString = format.format((new Date (currentTime)).getTime());
        }
        long timeTillStart = ((new Date (expectedStartTime)).getTime() - (new Date (currentTime)).getTime())/1000;

        if (timeTillStart > 0) {
            timeSinceStart = timeTillStart;
            //System.out.println("Time till start: " + timeTillStart + " Seconds");
        } else {
            if (raceStatus == 4 || raceStatus == 8){
                raceFinished = true;
                raceStarted = false;
                System.out.println("[CLIENT] Race has finished");
            } else if (!raceStarted){
                raceStarted = true;
                raceFinished = false;
                System.out.println("[CLIENT] Race has started");
            }
            timeSinceStart = timeTillStart;
        }

        double windDirFactor = 0x4000 / 90;   //0x4000 is 90 degrees, 0x8000 is 180 degrees, etc...
        windDirection = windDir / windDirFactor;

        int noBoats = payload[22];
        int raceType = payload[23];
        boatsPos = new TreeMap<>();
        for (int i = 0; i < noBoats; i++){
            long boatStatusSourceID = bytesToLong(Arrays.copyOfRange(payload,24 + (i * 20),28+ (i * 20)));
            Yacht boat = boats.get((int) boatStatusSourceID);
            boat.setBoatStatus((int)payload[28 + (i * 20)]);
            boat.setLegNumber((int)payload[29 + (i * 20)]);
            boat.setPenaltiesAwarded((int)payload[30 + (i * 20)]);
            boat.setPenaltiesServed((int)payload[31 + (i * 20)]);
            Long estTimeAtNextMark = bytesToLong(Arrays.copyOfRange(payload,32 + (i * 20),38+ (i * 20)));
            boat.setEstimateTimeAtNextMark(estTimeAtNextMark);
            Long estTimeAtFinish = bytesToLong(Arrays.copyOfRange(payload,38 + (i * 20),44+ (i * 20)));
            boat.setEstimateTimeAtFinish(estTimeAtFinish);
            boatsPos.put(estTimeAtFinish, boat);
//            String boatStatus = "SourceID: " + boatStatusSourceID;
//            boatStatus += "\nBoat Status: " + (int)payload[28 + (i * 20)];
//            boatStatus += "\nLegNumber: " + (int)payload[29 + (i * 20)];
//            boatStatus += "\nPenaltiesAwarded: " + (int)payload[29 + (i * 20)];
//            boatStatus += "\nPenaltiesServed: " + (int)payload[30 + (i * 20)];
//            boatStatus += "\nEstTimeAtNextMark: " + bytesToLong(Arrays.copyOfRange(payload,31 + (i * 20),37+ (i * 20)));
//            boatStatus += "\nEstTimeAtFinish: " + bytesToLong(Arrays.copyOfRange(payload,37 + (i * 20),43+ (i * 20)));
//            boatStatuses.add(boatStatus);
        }
        if (isRaceStarted()) {
            int pos = 1;
            for (Yacht yacht : boatsPos.values()) {
                yacht.setPosition(String.valueOf(pos));
                pos++;
            }
        } else {
            for (Yacht yacht : boatsPos.values()) {
                yacht.setPosition("-");
            }
        }
    }

    /**
     * Used to extract the messages passed through with the display message packet
     *
     * @param packet Packet parsed in to use the payload
     */
    private static void extractDisplayMessage(StreamPacket packet){
        byte[] payload = packet.getPayload();
        int messageVersionNo = payload[0];
        int numOfLines = payload[3];
        int totalLen = 0;
        for (int i = 0; i < numOfLines; i++){
            int lineNum = payload[4 + totalLen];
            int textLength = payload[5 + totalLen];
            byte[] messageTextBytes = Arrays.copyOfRange(payload,6 + totalLen,6 + textLength + totalLen);
            String messageText = new String(messageTextBytes);
            totalLen += 2 + textLength;
        }
    }

    /**
     * Used to read in the xml data. Will call the specific methods to create the course and boats
     *
     * @param packet Packet parsed in to use the payload
     */
    private static void extractXmlMessage(StreamPacket packet){

        byte[] payload = packet.getPayload();

        int messageType = payload[9];
        long messageLength = bytesToLong(Arrays.copyOfRange(payload,12,14));
        String xmlMessage = new String((Arrays.copyOfRange(payload,14,(int) (14 + messageLength)))).trim();

        //Create XML document Object
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        DocumentBuilder db = null;
        Document doc = null;
        try {
            db = dbf.newDocumentBuilder();
            doc = db.parse(new InputSource(new StringReader(xmlMessage)));
        } catch (ParserConfigurationException | IOException | SAXException e) {
            e.printStackTrace();
        }

        xmlObject.constructXML(doc, messageType);
        if (messageType == 7) {   //7 is the boat XML
            boats = xmlObject.getBoatXML().getCompetingBoats();
        }
        if (messageType == 6) { //6 is race info xml

            newRaceXmlReceived = true;
        }
    }

    /**
     * Extracts the race start status from the packet, currently is unused within the app but
     * is here for potential future use
     *
     * @param packet Packet parsed in to use the payload
     */
    private static void extractRaceStartStatus(StreamPacket packet){
        byte[] payload = packet.getPayload();
        int messageVersionNo = payload[0];
        long timeStamp = bytesToLong(Arrays.copyOfRange(payload,1,7));
        long raceStartTime = bytesToLong(Arrays.copyOfRange(payload,9,15));
        long raceId = bytesToLong(Arrays.copyOfRange(payload,15,19));
        int notificationType = payload[19];
    }

    /**
     * When a yacht event occurs this will parse the byte array to retrieve the necessary info,
     * currently unused
     *
     * @param packet Packet parsed in to use the payload
     */
    private static void extractYachtEventCode(StreamPacket packet){
        byte[] payload = packet.getPayload();
        int messageVersionNo = payload[0];
        long timeStamp = bytesToLong(Arrays.copyOfRange(payload,1,7));
        long raceId = bytesToLong(Arrays.copyOfRange(payload,9,13));
        long subjectId = bytesToLong(Arrays.copyOfRange(payload,13,17));
        long incidentId = bytesToLong(Arrays.copyOfRange(payload,17,21));
        int eventId = payload[21];
    }

    /**
     * When a yacht action occurs this will parse the parse the byte array to retrieve the necessary info,
     * currently unused
     *
     * @param packet Packet parsed in to use the payload
     */
    private static void extractYachtActionCode(StreamPacket packet){
        byte[] payload = packet.getPayload();
        int messageVersionNo = payload[0];
        long timeStamp = bytesToLong(Arrays.copyOfRange(payload,1,7));
        long subjectId = bytesToLong(Arrays.copyOfRange(payload,9,13));
        long incidentId = bytesToLong(Arrays.copyOfRange(payload,13,17));
        int eventId = payload[17];
    }

    /**
     * Strips the message from the chatter text type packets, currently the message is unused
     *
     * @param packet Packet parsed in to use the payload
     */
    private static void extractChatterText(StreamPacket packet){
        byte[] payload = packet.getPayload();
        int messageVersionNo = payload[0];
        int messageType = payload[1];
        int length = payload[2];
        String message = new String(Arrays.copyOfRange(payload,3,3 + length));
    }

    /**
     * Used to breakdown the boatlocation packets so the boat coordinates, id and groundspeed are all used
     * All the other extra data is still being read and translated however is unused.
     *
     * @param packet Packet parsed in to use the payload
     */
    private static void extractBoatLocation(StreamPacket packet){
        byte[] payload = packet.getPayload();

        int deviceType = (int)payload[15];
        long timeValid = bytesToLong(Arrays.copyOfRange(payload,1,7));
        long seq = bytesToLong(Arrays.copyOfRange(payload,11,15));
        long boatId = bytesToLong(Arrays.copyOfRange(payload,7,11));
        long rawLat = bytesToLong(Arrays.copyOfRange(payload,16,20));
        long rawLon = bytesToLong(Arrays.copyOfRange(payload,20,24));
        //Converts the double to a usable lat/lon
        double lat = ((180d * (double)rawLat)/Math.pow(2,31));
        double lon = ((180d *(double)rawLon)/Math.pow(2,31));
        long heading = bytesToLong(Arrays.copyOfRange(payload,28,30));
        double groundSpeed = bytesToLong(Arrays.copyOfRange(payload,38,40))/1000.0;

        //type 1 is a racing yacht and type 3 is a mark, needed for updating positions of the mark and boat
        if (deviceType == 1){
            BoatPositionPacket boatPacket = new BoatPositionPacket(boatId, timeValid, lat, lon, heading, groundSpeed);

            //add a new priority que to the boatPositions HashMap
            if (!boatPositions.containsKey(boatId)){
                boatPositions.put(boatId, new PriorityBlockingQueue<>(256, new Comparator<BoatPositionPacket>() {
                    @Override
                    public int compare(BoatPositionPacket p1, BoatPositionPacket p2) {
                        return (int) (p1.getTimeValid() - p2.getTimeValid());
                    }
                }));
            }
            boatPositions.get(boatId).put(boatPacket);
        } else if (deviceType == 3){
            BoatPositionPacket markPacket = new BoatPositionPacket(boatId, timeValid, lat, lon, heading, groundSpeed);

            //add a new priority que to the boatPositions HashMap
            if (!markPositions.containsKey(boatId)) {
                markPositions.put(boatId,
                    new PriorityBlockingQueue<>(256, new Comparator<BoatPositionPacket>() {
                        @Override
                        public int compare(BoatPositionPacket p1, BoatPositionPacket p2) {
                            return (int) (p1.getTimeValid() - p2.getTimeValid());
                        }
                    }));
            }
            markPositions.get(boatId).put(markPacket);
        }
    }

    /**
     * This packet type is received when a mark or gate is rounded by a boat
     *
     * @param packet The packet containing the payload
     */
    private static void extractMarkRounding(StreamPacket packet){
        byte[] payload = packet.getPayload();
        int messageVersionNo = payload[0];
        long timeStamp = bytesToLong(Arrays.copyOfRange(payload,1,7));
        long raceId = bytesToLong(Arrays.copyOfRange(payload,9,13));
        long subjectId = bytesToLong(Arrays.copyOfRange(payload,13,17));
        int boatStatus = payload[17];
        int roundingSide = payload[18];
        int markType = payload[19];
        int markId = payload[20];

        // assign mark rounding time to boat
        boats.get((int)subjectId).setMarkRoundingTime(timeStamp);
    }

    /**
     * This packet type contains periodic data on the state of the wind
     *
     * @param packet The packet containing the payload
     */
    private static void extractCourseWind(StreamPacket packet){
        byte[] payload = packet.getPayload();
        int messageVersionNo = payload[0];
        int selectedWindId = payload[1];
        int loopCount = payload[2];
        ArrayList<String> windInfo = new ArrayList<>();
        for (int i = 0; i < loopCount; i++){
            String wind = "WindId: " + payload[3 + (20 * i)];
            wind += "\nTime: " + bytesToLong(Arrays.copyOfRange(payload,4 + (20 * i),10 + (20 * i)));
            wind += "\nRaceId: " + bytesToLong(Arrays.copyOfRange(payload,10 + (20 * i),14 + (20 * i)));
            wind += "\nWindDirection: " + bytesToLong(Arrays.copyOfRange(payload,14 + (20 * i),16 + (20 * i)));
            wind += "\nWindSpeed: " + bytesToLong(Arrays.copyOfRange(payload,16 + (20 * i),18 + (20 * i)));
            wind += "\nBestUpWindAngle: " + bytesToLong(Arrays.copyOfRange(payload,18 + (20 * i),20 + (20 * i)));
            wind += "\nBestDownWindAngle: " + bytesToLong(Arrays.copyOfRange(payload,20 + (20 * i),22 + (20 * i)));
            wind += "\nFlags: " + String.format("%8s", Integer.toBinaryString(payload[22 + (20 * i)] & 0xFF)).replace(' ', '0');
            windInfo.add(wind);
        }
    }

    /**
     * This packet conatins the average wind to ground speed
     *
     * @param packet The packet containing the paylaod
     */
    private static void extractAvgWind(StreamPacket packet){
        byte[] payload = packet.getPayload();
        int messageVersionNo = payload[0];
        long timeStamp = bytesToLong(Arrays.copyOfRange(payload,1,7));
        long rawPeriod = bytesToLong(Arrays.copyOfRange(payload,7,9));
        long rawSamplePeriod = bytesToLong(Arrays.copyOfRange(payload,9,11));
        long period2 = bytesToLong(Arrays.copyOfRange(payload,11,13));
        long speed2 = bytesToLong(Arrays.copyOfRange(payload,13,15));
        long period3 = bytesToLong(Arrays.copyOfRange(payload,15,17));
        long speed3 = bytesToLong(Arrays.copyOfRange(payload,17,19));
        long period4 = bytesToLong(Arrays.copyOfRange(payload,19,21));
        long speed4 = bytesToLong(Arrays.copyOfRange(payload,21,23));
    }

    /**
     * takes an array of up to 7 bytes and returns a positive
     * long constructed from the input bytes
     *
     * @return a positive long if there is less than 7 bytes -1 otherwise
     */
    private static long bytesToLong(byte[] bytes){
        long partialLong = 0;
        int index = 0;
        for (byte b: bytes){
            if (index > 6){
                return -1;
            }
            partialLong = partialLong | (b & 0xFFL) << (index * 8);
            index++;
        }
        return partialLong;
    }

    /**
     * returns false if race not started, true otherwise
     *
     * @return race started status
     */
    public static boolean isRaceStarted() {
        return raceStarted;
    }

    /**
     * returns false if stream not connected, true otherwise
     *
     * @return stream started status
     */
    public static boolean isStreamStatus() {
        return streamStatus;
    }

    /**
     * returns race timer
     *
     * @return race timer in long
     */
    public static long getTimeSinceStart() {
        return timeSinceStart;
    }

    /**
     * return false if race not finished, true otherwise
     *
     * @return race finished status
     */
    public static boolean isRaceFinished() {
        return raceFinished;
    }

    /**
     * return a map of boats with sourceID and the boat
     *
     * @return map of boats
     */
    public static Map<Integer, Yacht> getBoats() {
        return boats;
    }


    /**
     * returns the latest updated object from xml parser
     *
     * @return the latest xml object
     */
    public static XMLParser getXmlObject() {
        return xmlObject;
    }

    /**
     * returns the wind direction in degrees
     *
     * @return a double wind direction value
     */
    public static double getWindDirection() {
        return windDirection;
    }

    /**
     * returns stream time in formatted string format
     *
     * @return String of stream time
     */
    public static String getCurrentTimeString() {
        return currentTimeString;
    }

    /**
     * used in boat position since tree map can sort position efficiently.
     *
     * @return a map of time to finish and boat.
     */
    public static Map<Long, Yacht> getBoatsPos() {
        return boatsPos;
    }

    /**
     * returns current time in stream in long
     *
     * @return a long value of current time
     */
    public static Long getCurrentTimeLong() {
        return currentTimeLong;
    }

    public static void appClose(){
        appRunning = false;
        System.out.println("[CLIENT] Shutting down stream parser");
    }

    /**
     * Used to check if a new un-processed xml has been found, if so will return true before
     * toggling off so that the next check will return false.
     *
     * @return the status of if new xml has been received
     */
    public static boolean isNewRaceXmlReceived(){
        if (newRaceXmlReceived){
            newRaceXmlReceived = false;
            return true;
        } else {
            return false;
        }
    }
}