import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.border.*;
import java.util.*;
import java.text.*;

public class AccelCar extends JPanel {
    
    // Simulation variables: acceleration, velocity, distance.
    double a = 0;
    double v = 0;
    double x = 20;

    // Start and end x values.
    int start = 20;
    int end = 300;

    // Time-related variables.
    int time;
    int sleepTime = 100;
    int timeStep = sleepTime;
    int timeLimit = 60000; // 60 seconds

    // score = time-taken + 2*v*v + penalty
    double score;
    double penalty;

    // If an external controller is given.
    Function controller = null;

    // Animation and GUI stuff.
    boolean stopped = true;
    String terminateMsg = "";
    DecimalFormat df = new DecimalFormat ("##.##");
    JSlider slider;


    public AccelCar (Function controller) 
    {
	this.controller = controller;
    }
    

    void start ()
    {
	Thread t = new Thread () {
		public void run () 
		{
		    simulateWithAnimation ();
		}
	    };
	t.start ();
    }


    void simulateWithAnimation ()
    {
        init ();
        stopped = false;
	runSimulation ();
        terminateMsg = computeScore ();
	System.out.println (terminateMsg);
        repaint ();
    }


    // Without animation.

    double simulate ()
    {
        init ();
        stopped = true;
	runSimulation ();
        computeScore ();
	System.out.println ("Final score: " + df.format(score));
        return score;
    }


    void init ()
    {
	// Initialize variables.
	a = 0;
	v = 0;
	x = start;
	time = 0;
	score = 0;
        penalty = 0;
	terminateMsg = "SCORE:                  ";
    }
    


    void runSimulation ()
    {

	while (! stopped) {
	    try {
		Thread.sleep (sleepTime);
	    }
	    catch (InterruptedException e) {
	    }

            nextStep ();

	    if (time > timeLimit) {
		stopped = true;
		System.out.println ("FAILED: exceeded time limit");
                penalty = 2*timeLimit;
		return;
	    }

	    if (x < start) {
		stopped = true;
		System.out.println ("FAILED: Reversed past start");
                penalty = 2*timeLimit;
		return;
	    }
	    else if (x > end) {
		stopped = true;
                penalty = 0;
		break;
	    }

	    // Redraw.
	    repaint ();
	}

    }


    void nextStep ()
    {
	    // Update clock.
	    time += timeStep;

	    // Move.
	    if (controller != null) {
		a = controller.get (x);
	    }
            else {
                // Read from slider.
                a = (double) slider.getValue ();
            }
            
	    double delT = (double) timeStep / 1000.0;  // seconds.

	    v = v + delT * a;
            x = x + delT * v;

    }
    

    String computeScore ()
    {
	score = penalty + time + 2.0 * v * v;
        return "SCORE: " + df.format(score);
    }


    public void paintComponent (Graphics g)
    {
	super.paintComponent (g);

	Dimension D = this.getSize ();

	// Background.
	g.setColor (Color.white);
	g.fillRect (0,0, D.width, D.height);

	// Drawline.
	g.setColor (Color.lightGray);
	g.drawLine (start, 100, end, 100);

	g.setColor (Color.red);
	g.fillOval ((int)x-10, 100-10, 20, 20);

	// Status:
	g.setColor (Color.black);
	g.setFont (new Font ("Serif", Font.BOLD, 20));
	int seconds = time / 1000;
	int millis = time % 1000;
	String clockStr = "" + seconds + ":" + millis;
	g.drawString (clockStr, 300, 20);
	g.setColor (Color.red);
	g.drawString (terminateMsg, 10, 250);
    }


    void reset ()
    {
	if (controller == null) {
	    slider.setValue (0);
	}
	this.start ();
    }



    ////////////////////////////////////////////////////////////////////////
    // GUI code


    JPanel makeBottomPanel ()
    {
	JPanel panel = new JPanel ();

	JButton resetB = new JButton ("Reset");
	resetB.addActionListener (
	   new ActionListener () {
		   public void actionPerformed (ActionEvent a)
		   {
		       reset ();
		   }
           }
        );
	panel.add (resetB);
	panel.add (new JLabel ("      "));
	panel.add (new JLabel ("Accelerator: "));
	
	slider = new JSlider (-10, 10, 0);
	slider.setMajorTickSpacing(10);
	slider.setMinorTickSpacing(1);
	slider.setPaintTicks(true);
	slider.setPaintLabels(true);
	panel.add (slider);

	if (controller != null) {
	    slider.setEnabled (false);
	}

        panel.add (new JLabel ("        "));
	JButton quitB = new JButton ("Quit");
	quitB.addActionListener (
	   new ActionListener () {
		   public void actionPerformed (ActionEvent a)
		   {
		       System.exit(0);
		   }
           }
        );
	panel.add (quitB);

        return panel;
    }


    void makeFrame ()
    {
        JFrame frame = new JFrame ();
        frame.setSize (800, 600);
        frame.setTitle ("Acceleration model");
        Container cPane = frame.getContentPane();
        cPane.add (makeBottomPanel(), BorderLayout.SOUTH);
        cPane.add (this, BorderLayout.CENTER);
        frame.setVisible (true);
    }


    ////////////////////////////////////////////////////////////////////////
    // static methods


    public static double tryControl (Function controller)
    {
	AccelCar accel = new AccelCar (controller);
	double score = accel.simulate ();
	return score;
    }

    public static void animateControl (Function controller)
    {
	AccelCar a = new AccelCar (controller);
        a.makeFrame ();
    }

    public static void main (String[] argv)
    {
	AccelCar a = new AccelCar (null);
        a.makeFrame ();
    }

}