import java.awt.AWTException;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Robot;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.util.ArrayList;
import java.util.TimerTask;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;


public final class Main extends JPanel implements MouseMotionListener {

    Timer timer;
    int time = 10;
    java.util.Timer taskTimer;
    ArrayList<Point> mousePoints;
    ArrayList<Long> times;
    Robot robot;
    int width, height;
    ArrayList<Point> drawMousePoints;

    public Main(){
        width = 500;
        height = 500;
        drawMousePoints = new ArrayList<>();

        robot = null;
        try{
            robot = new Robot();
        }
        catch(AWTException e){
            System.out.println("The time machine malfunctioned... Reverting to 512 BC");
        }
        mousePoints = new ArrayList<>();
        times = new ArrayList<>();

        taskTimer = new java.util.Timer();

        ActionListener al;
        al = new ActionListener(){
            @Override
            public void actionPerformed(ActionEvent e){
                time--;
                if(time == 0)
                    rewind();
                repaint();
            }
        };
        timer = new Timer(1000, al);
        start();
    }

    @Override
    public void paint(Graphics g){
        g.clearRect(0, 0, width, height);
        g.drawString("Time Machine activiates in: " + time, 15, 50);
        for(int i=0; i<drawMousePoints.size(); i++){
            Point drawMousePoint = drawMousePoints.get(i);
            drawMouse(drawMousePoint.x-getLocationOnScreen().x, drawMousePoint.y-getLocationOnScreen().y, g, Color.BLACK, Color.LIGHT_GRAY, (double)i/drawMousePoints.size());
        }
    }

    public void drawMouse(int x, int y, Graphics g, Color line, Color fill, double alpha){
        Graphics2D g2d = (Graphics2D)g;
        g2d.setColor(new Color(fill.getRed(), fill.getGreen(), fill.getBlue(), (int)Math.max(Math.min(alpha*255, 255), 0)));
        g2d.fillPolygon(new int[]{x, x, x+4, x+8, x+10, x+7, x+12}, new int[]{y, y+16, y+13, y+20, y+19, y+12, y+12}, 7);

        g2d.setColor(new Color(line.getRed(), line.getGreen(), line.getBlue(), (int)Math.max(Math.min(alpha*255, 255), 0)));
        g2d.drawLine(x, y, x, y + 16);
        g2d.drawLine(x, y+16, x+4, y+13);
        g2d.drawLine(x+4, y+13, x+8, y+20);
        g2d.drawLine(x+8, y+20, x+10, y+19);
        g2d.drawLine(x+10, y+19, x+7, y+12);
        g2d.drawLine(x+7, y+12, x+12, y+12);
        g2d.drawLine(x+12, y+12, x, y);
    }

    public void start(){
        timer.start();
        prevTime = System.currentTimeMillis();
        mousePoints.clear();
    }

    public void rewind(){
        timer.stop();
        long timeSum = 0;
        for(int i=0; i<times.size(); i++){
            timeSum += times.get(0);
            final boolean done = i == times.size()-1;
            taskTimer.schedule(new TimerTask(){
                @Override
                public void run(){
                    Point point = mousePoints.remove(0);
                    drawMousePoints.clear();
                    drawMousePoints.addAll(mousePoints.subList(0, Math.min(mousePoints.size(), 30)));
                    robot.mouseMove(point.x, point.y);
                    repaint();
                    if(done)
                        System.exit(0);
                }
            }, timeSum);
        }
    }

    long prevTime = 0;
    public void record(MouseEvent m){
        if(timer.isRunning()){
            long Ttime = System.currentTimeMillis();
            mousePoints.add(new Point(m.getXOnScreen(), m.getYOnScreen()));
            times.add((Ttime-prevTime)/10);
            prevTime = Ttime;
        }
    }

    public static void main(String[] args){

        Main timeMachine = new Main();

        JFrame frame = new JFrame("Time Machine");
        frame.setSize(timeMachine.width, timeMachine.height);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
        frame.addMouseMotionListener(timeMachine);

        frame.add(timeMachine);
    }

    @Override
    public void mouseDragged(MouseEvent m) {
        record(m);
    }

    @Override
    public void mouseMoved(MouseEvent m) {
        record(m);
    }

}