package seng302.Model;


import javafx.animation.AnimationTimer;
import javafx.application.Platform;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import org.geotools.referencing.GeodeticCalculator;
import seng302.Controllers.RaceController;
import seng302.GPSCoordinate;

import java.awt.geom.Point2D;
import java.util.ArrayList;
import java.util.Random;

/**
 * Parent class for races
 * Created by fwy13 on 3/03/17.
 */
public abstract class Race implements Runnable {
    //protected BoatInRace[] startingBoats;
    protected ObservableList<BoatInRace> startingBoats;
    protected ArrayList<Leg> legs;
    protected RaceController controller;
    protected int boatsFinished = 0;
    protected long totalTimeElapsed;
    private int dnfChance = 1; //%percentage chance a boat fails at each checkpoint

    private int lastFPS = 20;


    protected int scaleFactor;

    private int SLEEP_TIME = 100; //time in milliseconds to pause in a paced loop
    protected int PRERACE_TIME = 120000; //time in milliseconds to pause during pre-race
    private boolean timerEnabled = true; //boolean to determine if timer is ran

    /**
     * Initailiser for Race
     *
     * @param boats Takes in an array of boats that are participating in the race.
     * @param legs  Number of marks in order that the boats pass in order to complete the race.
     * @param controller race controller
     * @param scaleFactor for race
     */
    public Race(BoatInRace[] boats, ArrayList<Leg> legs, RaceController controller, int scaleFactor) {

        this.startingBoats = FXCollections.observableArrayList(boats);
        this.legs = legs;
        this.legs.add(new Leg("Finish", this.legs.size()));
        this.controller = controller;
        this.scaleFactor = scaleFactor;
        if (startingBoats != null && startingBoats.size() > 0) {
            initialiseBoats();
        }
    }

    /**
     * Sets the chance each boat has of failing at a gate or marker
     * @param chance percentage chance a boat has of failing per checkpoint.
     */
    protected void setDnfChance(int chance) {
        if (chance >= 0 && chance <= 100) {
            dnfChance = chance;
        }
    }


    public void initialiseBoats() {

        Leg officialStart = legs.get(0);
        String name = officialStart.getName();
        Marker endMarker = officialStart.getEndMarker();

        BoatInRace.setTrackPointTimeInterval(BoatInRace.getBaseTrackPointTimeInterval() / scaleFactor);

        ArrayList<Marker> startMarkers = getSpreadStartingPositions();
        for (int i = 0; i < startingBoats.size(); i++) {
            BoatInRace boat = startingBoats.get(i);
            if (boat != null) {
                boat.setScaledVelocity(boat.getVelocity() * scaleFactor);
                Leg startLeg = new Leg(name, 0);
                boat.setCurrentPosition(startMarkers.get(i).getAverageGPSCoordinate());
                startLeg.setStartMarker(startMarkers.get(i));
                startLeg.setEndMarker(endMarker);
                startLeg.calculateDistance();
                boat.setCurrentLeg(startLeg);

            }
        }
    }

    /**
     * Runnable for the thread.
     */
    public void run() {
        setControllerListeners();
        initialiseBoats();
        if (timerEnabled) countdownTimer();
        //simulateRace();
    }

    /**
     * Disable the timer
     */
    public void disableTimer() {
        timerEnabled = false;
    }


    /**
     * Countdown timer until race starts. Use PRERACE_TIME to set countdown duration.
     */
    protected void countdownTimer() {
        new AnimationTimer() {
            long currentTime = System.currentTimeMillis();
            long startTime = currentTime + (PRERACE_TIME/scaleFactor);
            long minutes;
            long currentTimeInSeconds;
            long remainingSeconds;
            long hours;
            long timeLeft;

            @Override
            public void handle(long arg0) {
                    timeLeft = startTime - currentTime;
                    if (timeLeft <= 0 && controller != null) {
                        updateTime("Race is starting...");
                        stop();
                        simulateRace();
                    } else {
                        currentTimeInSeconds = (timeLeft*scaleFactor) / 1000;
                        minutes = currentTimeInSeconds / 60;
                        remainingSeconds = currentTimeInSeconds % 60;
                        hours = minutes / 60;
                        minutes = minutes % 60;
                        if (controller != null) {
                            updateTime(String.format("Race clock: -%02d:%02d:%02d", hours, minutes, remainingSeconds));
                        }
                    }
                    currentTime = System.currentTimeMillis();
            }
        }.start();
    }

    /**
     * Takes total time elapsed and format to hour:minute:second
     *
     * @return Formatted time as string
     */
    protected String calcTimer() {
        long minutes;
        long currentTimeInSeconds;
        long remainingSeconds;
        long hours;

        currentTimeInSeconds = (totalTimeElapsed * scaleFactor) / 1000;
        minutes = currentTimeInSeconds / 60;
        remainingSeconds = currentTimeInSeconds % 60;
        hours = minutes / 60;
        minutes = minutes % 60;
        return String.format("Race clock: %02d:%02d:%02d", hours, minutes, remainingSeconds);
    }

    /**
     * Updates the calculated time to the timer label
     *
     * @param time The calculated time from calcTimer() method
     */
    protected void updateTime(String time) {
        Platform.runLater(() -> {
            controller.setTimer(time);
        });
    }

    /**
     * Update the calculated fps to the fps label
     *
     * @param fps The new calculated fps value
     */
    private void updateFPS(int fps) {
        Platform.runLater(() -> {
            controller.setFrames("FPS: " + fps);
        });
    }

    private boolean doNotFinish() {
        Random rand = new Random();
        return rand.nextInt(100) < dnfChance;
    }

    /**
     * Starts the Race Simulation, playing the race start to finish with the timescale.
     * This prints the boats participating, the order that the events occur in time order, and the respective information of the events.
     */
    private void simulateRace() {

        System.setProperty("javafx.animation.fullspeed", "true");

        for (BoatInRace boat : startingBoats) {
            boat.setStarted(true);
        }

        new AnimationTimer() {

            long timeRaceStarted = System.currentTimeMillis(); //start time of loop
            int fps = 0; //init fps value
            long timeCurrent = System.currentTimeMillis(); //current time

            @Override
            public void handle(long arg0) {

                if (boatsFinished < startingBoats.size()) {
                    totalTimeElapsed = System.currentTimeMillis() - timeRaceStarted;

                    for (BoatInRace boat : startingBoats) {
                        if (boat != null && !boat.isFinished()) {
                            boat.addTrackPoint(boat.getCurrentPosition());
                            updatePosition(boat, Math.round(1000 / lastFPS) > 20 ? 15 : Math.round(1000 / lastFPS));
                            checkPosition(boat, totalTimeElapsed);
                        }
                    }

//                    if (controller != null) controller.updateMap(startingBoats);
                    if (timerEnabled)
                        updateTime(calcTimer());
                }
                controller.updateMap(startingBoats);
//                } else {
//                    //Exit animation timer
//                    updateTime(calcTimer());
//                    updateFPS(0); //race ended so fps = 0
//                    stop(); //exit animation timer
//                }
                fps++;
                if ((System.currentTimeMillis() - timeCurrent) > 1000) {
                    updateFPS(fps);
                    lastFPS = fps;
                    fps = 0;
                    timeCurrent = System.currentTimeMillis();
                }

            }

        }.start();
    }

    /**
     * Checks the position of the boat, this updates the boats current position.
     *
     * @param boat        Boat that the postion is to be updated for.
     * @param timeElapsed Time that has elapse since the start of the the race.
     * @see BoatInRace
     */
    protected void checkPosition(BoatInRace boat, long timeElapsed) {
        if (boat.getDistanceTravelledInLeg() > boat.getCurrentLeg().getDistance()) {
            //boat has passed onto new leg
            if (boat.getCurrentLeg().getName().equals("Finish")) {
                //boat has finished
                boatsFinished++;
                boat.setFinished(true);
                boat.setTimeFinished(timeElapsed);
            } else if (doNotFinish()) {
                boatsFinished++;
                boat.setFinished(true);
                boat.setCurrentLeg(new Leg("DNF", -1));
                boat.setVelocity(0);
                boat.setScaledVelocity(0);
            } else {
                //Calculate how much the boat overshot the marker by
                boat.setDistanceTravelledInLeg(boat.getDistanceTravelledInLeg() - boat.getCurrentLeg().getDistance());
                //Move boat on to next leg
                Leg nextLeg = legs.get(boat.getCurrentLeg().getLegNumber() + 1);

                boat.setCurrentLeg(nextLeg);
                //Add overshoot distance into the distance travelled for the next leg
                boat.setDistanceTravelledInLeg(boat.getDistanceTravelledInLeg());
            }
            //Update the boat display table in the GUI to reflect the leg change
            updatePositions();
        }
    }

    /**
     * Update position of boats in race, no position if on starting leg or DNF.
     */
    private void updatePositions() {
        FXCollections.sort(startingBoats, (a, b) -> b.getCurrentLeg().getLegNumber() - a.getCurrentLeg().getLegNumber());
        for(BoatInRace boat: startingBoats) {
            if(boat != null) {
                boat.setPosition(Integer.toString(startingBoats.indexOf(boat) + 1));
                if (boat.getCurrentLeg().getName().equals("DNF") || boat.getCurrentLeg().getLegNumber() == 0)
                    boat.setPosition("-");
            }
        }
    }

    /**
     * Update call for the controller.
     */
    protected void setControllerListeners() {
        if (controller != null) controller.setInfoTable(this);
    }

    /**
     * Returns the boats that have started the race.
     *
     * @return ObservableList of BoatInRace class that participated in the race.
     * @see ObservableList
     * @see BoatInRace
     */
    public ObservableList<BoatInRace> getStartingBoats() {
        return startingBoats;
    }

    /**
     * Updates the boat's gps coordinates depending on time elapsed
     *
     * @param boat to be updated
     * @param millisecondsElapsed time since last update
     */
    protected abstract void updatePosition(BoatInRace boat, int millisecondsElapsed);

    /**
     * Creates a list of starting positions for the different boats, so they do not appear cramped at the start line
     *
     * @return list of starting positions
     */
    public ArrayList<Marker> getSpreadStartingPositions() {

        int nBoats = startingBoats.size();
        Marker marker = legs.get(0).getStartMarker();

        GeodeticCalculator initialCalc = new GeodeticCalculator();
        initialCalc.setStartingGeographicPoint(marker.getMark1().getLongitude(), marker.getMark1().getLatitude());
        initialCalc.setDestinationGeographicPoint(marker.getMark2().getLongitude(), marker.getMark2().getLatitude());

        double azimuth = initialCalc.getAzimuth();
        double distanceBetweenMarkers = initialCalc.getOrthodromicDistance();
        double distanceBetweenBoats = distanceBetweenMarkers / (nBoats + 1);

        GeodeticCalculator positionCalc = new GeodeticCalculator();
        positionCalc.setStartingGeographicPoint(marker.getMark1().getLongitude(), marker.getMark1().getLatitude());
        ArrayList<Marker> positions = new ArrayList<>();

        for (int i = 0; i < nBoats; i++) {
            positionCalc.setDirection(azimuth, distanceBetweenBoats);
            Point2D position = positionCalc.getDestinationGeographicPoint();
            positions.add(new Marker(new GPSCoordinate(position.getY(), position.getX())));

            positionCalc = new GeodeticCalculator();
            positionCalc.setStartingGeographicPoint(position);
        }
        return positions;
    }
}