package seng302.Model;


import javafx.application.Platform;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import seng302.Controllers.RaceController;

import java.util.ArrayList;

/**
 * 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;

    protected int scaleFactor;

    private int SLEEP_TIME = 100; //time in milliseconds to pause in a paced loop
    protected int PRERACE_TIME = 100;//Integer.MAX_VALUE; //time in milliseconds to pause during pre-race
    private boolean timerEnabled = true;

    /**
     * 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.
     */
    public Race(BoatInRace[] boats, ArrayList<Leg> legs, RaceController controller, int scaleFactor) {
        if (boats.length > 0) {
            for (BoatInRace boat : boats) {
                if (boat != null) {
                    boat.setScaledVelocity(boat.getVelocity() * scaleFactor);
                }
            }
        }

        this.startingBoats = FXCollections.observableArrayList(boats);
        this.legs = legs;
        this.legs.add(new Leg("Finish", this.legs.size()));
        this.controller = controller;
        this.scaleFactor = scaleFactor;
    }

    /**
     * Constructor for Race class
     *
     * @param boats boats participating in the race.
     * @param legs  legs that there are in the race.
     */
    public Race(BoatInRace[] boats, ArrayList<Leg> legs, int scaleFactor) {
        if (boats.length > 0) {
            for (BoatInRace boat : boats) {
                if (boat != null) {
                    boat.setScaledVelocity(boat.getVelocity() * scaleFactor);
                }
            }
        }
        this.startingBoats = FXCollections.observableArrayList(boats);
        this.legs = legs;
        this.legs.add(new Leg("Finish", this.legs.size()));
        this.scaleFactor = scaleFactor;
    }


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

    public void disableTimer() {
        timerEnabled = false;
    }

    /**
     * Initialises the boats,
     * Sets the boats' current to the first leg in the race
     */
    private void preRace() {
        //show the boats participating.
        for (int i = 0; i < startingBoats.size(); i++) {
            if (startingBoats.get(i) != null) {
                startingBoats.get(i).setCurrentLeg(legs.get(0));
            }
        }
    }


    /**
     * Prerace timer showing time until the race will begin, as a negative value
     */
    protected void countdownTimer() {
        long currentTime = System.currentTimeMillis();
        long startTime = currentTime + PRERACE_TIME;
        long minutes;
        long currentTimeInSeconds;
        long remainingSeconds;
        long hours;
        long timeLeft;
        long timeLoopEnded;

        while (currentTime <= startTime) {
            timeLeft = startTime - currentTime;
            if (timeLeft == 0 && controller != null) {
                updateTime("Race is starting...");
            } else {
                currentTimeInSeconds = timeLeft / 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));
                }
            }
            try {
                timeLoopEnded = System.currentTimeMillis();
                Thread.sleep(SLEEP_TIME - (timeLoopEnded - currentTime));
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            currentTime = System.currentTimeMillis();
        }
    }

    /**
     * Takes elapsed time in minutes and scales it, converts to hh:mm:ss format
     * @return String formatted race time, scaled
     */
    protected String calcTimer() {
        long minutes;
        long currentTimeInSeconds;
        long remainingSeconds;
        long hours;

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

    /**
     * Updates the GUI race clock
     * @param time
     */
    protected void updateTime(String time) {

        Platform.runLater(() -> {
            controller.setTimer(time);
        });
    }

    /**
     * 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() {

        long timeRaceStarted = System.currentTimeMillis();
        long timeLoopStarted;
        long timeLoopEnded;

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


            for (BoatInRace boat : startingBoats) {
                if (boat != null && !boat.isFinished()) {
                    updatePosition(boat, SLEEP_TIME);
                    checkPosition(boat, totalTimeElapsed);
                }
            }

            if (controller != null) controller.updateMap(startingBoats);
            if (timerEnabled) updateTime(calcTimer());
            try {
                timeLoopEnded = System.currentTimeMillis();
                Thread.sleep(SLEEP_TIME - (timeLoopEnded - timeLoopStarted));
            } catch (InterruptedException e) {
                return;
            }
        }
    }

    /**
     * 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 {
                //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
            FXCollections.sort(startingBoats, (a, b) -> b.getCurrentLeg().getLegNumber() - a.getCurrentLeg().getLegNumber());
        }
    }

    /**
     * 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
     * @param millisecondsElapsed
     */
    protected abstract void updatePosition(BoatInRace boat, int millisecondsElapsed);

}