package pr1;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.util.Random;

import javax.swing.JPanel;

@SuppressWarnings("serial")
public class SemiPongPanel extends JPanel implements BallHandler, MouseMotionListener {

   private static Random rand = new Random();

   private final int STRING_X = 10;
   private final int STRING_Y = 15;
   private final int STRING_DELTA_Y = 15;
   private final int STRING_BOTTOM_PAD = 5;
   private final int NUM_BALLS = 20;
   private final int BALL_X = 50;
   private final int BALL_Y = 100;
   private final int BALL_RADIUS = 10;
   private final int SECONDS_PER_BALL = 2;
   private final int FRAMES_PER_SECOND = 10;
   private final int MIN_X_VELOCITY = 10;
   private final int MAX_X_VELOCITY = 100;
   private final int MIN_Y_VELOCITY = -100;
   private final int MAX_Y_VELOCITY = 100;
   private final int PADDLE_X_INIT = 300;
   private final int PADDLE_TOP_INIT  = 50;
   private final int PADDLE_LENGTH_INIT = 50;
   private final Color BACKGROUND_COLOR = Color.lightGray;
   private final Color BALL_COLOR = Color.red;
   private Ball[] balls;
   private int ballsFired = 0;
   private int ballsToLeft = 0;
   private int ballsToRight = 0;
   private int collisionCount = 0;
   private BallPhysics physics;
   private int paddleTop = PADDLE_TOP_INIT;
   private int paddleLength = PADDLE_LENGTH_INIT;
   private int paddleX = PADDLE_X_INIT;
   private int tickCounter = 0;

   public SemiPongPanel(int w, int h) {
      setPreferredSize(new Dimension(w, h));
      physics = new BallPhysics(this, this, FRAMES_PER_SECOND);
      balls = new Ball[NUM_BALLS];
      for (int i = 0; i < balls.length; i++) {
         balls[i] = new Ball(BALL_X, BALL_Y, BALL_RADIUS,
               randomRange(MIN_X_VELOCITY, MAX_X_VELOCITY),
               randomRange(MIN_Y_VELOCITY, MAX_Y_VELOCITY), BALL_COLOR);
      }
      physics.setBallHandler(this);
      addMouseMotionListener(this);
   }

   public void paintComponent(Graphics g) {
      Rectangle bounds = getBounds();
      g.setColor(BACKGROUND_COLOR);
      g.fillRect(0, 0, bounds.width, bounds.height);
      g.setColor(Color.black);
      g.drawString("Semi-Pong Part 6 by S. Robbins", STRING_X, STRING_Y);
      g.drawString("Balls Remaiing: " + (balls.length - ballsFired), STRING_X, STRING_Y
            + STRING_DELTA_Y);
      g.drawString("Balls To Left: " + ballsToLeft, STRING_X, STRING_Y + 2
            * STRING_DELTA_Y);
      g.drawString("Balls To Right: " + ballsToRight, STRING_X, STRING_Y + 3
            * STRING_DELTA_Y);
      g.drawString("Collisions: " + collisionCount, STRING_X, STRING_Y + 4
            * STRING_DELTA_Y);
      if (balls.length == ballsToLeft + ballsToRight)
         g.setColor(Color.red);
      g.drawString("Score: " + (2*ballsToLeft - ballsToRight + collisionCount),
            STRING_X,  bounds.height - STRING_BOTTOM_PAD);
      g.setColor(BALL_COLOR);
      g.drawOval(BALL_X-BALL_RADIUS,BALL_Y-BALL_RADIUS,2*BALL_RADIUS,2*BALL_RADIUS);
      for (int i = 0; i < ballsFired; i++)
         balls[i].draw(g);
      g.setColor(Color.black);
      g.drawLine(paddleX, paddleTop, paddleX, paddleTop + paddleLength);
   }

   private static double randomRange(double low, double high) {
      return low + (high - low) * rand.nextDouble();
   }

   @Override
   public void collided(Ball b1, Ball b2) {
      collisionCount++;
   }

   @Override
   public void handleBall(Ball b) {
      double x = b.getX();
      double r = b.getRadius();
      double vx = b.getVelocityX();
      double y = b.getY();
      if ((x+r < paddleX) || (x-r > paddleX))
         return;
      if ((y+r < paddleTop) || (y-r > paddleTop+paddleLength))
         return;
      if (vx < 0)
         return;
      b.setVelocityX(-vx);
      b.setX(2*(paddleX-r)-x);
   }

   @Override
   public void handleTick() {
      tickCounter++;
      if (tickCounter % SECONDS_PER_BALL != 0)
         return;
      if (ballsFired < balls.length) {
         physics.addBall(balls[ballsFired]);
         ballsFired++;
      }
   }

   @Override
   public void hitLeftWall(Ball b) {
      ballsToLeft++;
      hideBall(b);
   }

   @Override
   public void hitRightWall(Ball b) {
      ballsToRight++;
      hideBall(b);
   }
   
   private void hideBall(Ball b) {
      b.setVelocityX(0);
      b.setVelocityY(0);
      b.setX(-b.getRadius()-1);
   }

   @Override
   public void mouseDragged(MouseEvent e) {
   }

   @Override
   public void mouseMoved(MouseEvent e) {
      int height = getBounds().height;
      int newPaddleTop = e.getY() - paddleLength;
      if (newPaddleTop < 0)
         newPaddleTop = 0;
      if (newPaddleTop + paddleLength > height)
         newPaddleTop = height - paddleTop;
      paddleTop = newPaddleTop;
   }
   
}