package ceccs;

import javafx.animation.AnimationTimer;
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.input.KeyEvent;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

public class Pong extends Application {

    double gameHeight = 500;
    double gameWidth = 1000;
    double padOffset = 5;
    Ball ball;
    Paddle padL, padR;
    boolean downPressedL, upPressedL, downPressedR, upPressedR;

    @Override
    public void start(Stage primaryStage) throws Exception {

        ball = new Ball(490, 240, -.5, 0);
        padL = new Paddle(padOffset, gameHeight/2 - padL.height/2);
        padR = new Paddle(gameWidth - padR.width - padOffset, gameHeight/2 - padL.height/2);
        Pane pane = new Pane();
        pane.getChildren().addAll(ball.rectangle, padL.rectangle, padR.rectangle);
        Scene scene = new Scene(pane, gameWidth, gameHeight);
        primaryStage.setScene(scene);
        primaryStage.setTitle("PONG");
        primaryStage.setResizable(false);
        primaryStage.show();

        ball.updateGraphics();
        padL.updateGraphics();
        padR.updateGraphics();

        scene.setOnKeyPressed(new EventHandler<KeyEvent>() {
            @Override
            public void handle(KeyEvent event) {
                switch(event.getCode()){
                    case W:
                        upPressedL = true;
                        break;
                    case S:
                        downPressedL = true;
                        break;
                    case DOWN:
                        downPressedR = true;
                        break;
                    case UP:
                        upPressedR = true;
                        break;
                }
            }
        });

        scene.setOnKeyReleased(new EventHandler<KeyEvent>() {
            @Override
            public void handle(KeyEvent event) {
                switch(event.getCode()){
                    case W:
                        upPressedL = false;
                        break;
                    case S:
                        downPressedL = false;
                        break;
                    case DOWN:
                        downPressedR = false;
                        break;
                    case UP:
                        upPressedR = false;
                        break;
                }
            }
        });

        AnimationTimer timer = new AnimationTimer() {
            @Override
            public void handle(long now) {
                //input updates
                checkInput();

                //physics updates
                padL.updatePosition();
                padR.updatePosition();
                ball.updatePosition();
                checkGameBounds();
                checkLeftPaddle();

                //graphics updates
                ball.updateGraphics();
                padL.updateGraphics();
                padR.updateGraphics();

            }
        };
        timer.start();


    }

    public static void main(String[] args){
        launch(args);
    }

    void checkGameBounds(){
        if (ball.y >= (gameHeight - ball.size) || (ball.y < 0)){
            ball.reflectY();
        }

        // Left and Right side reflections disabled
        /*
            if (ball.x >= (gameWidth - ball.size) || (ball.x < 0)) {
            ball.reflectX();
            }
         */
    }

    void checkLeftPaddle(){
        double ballLeft = ball.x;
        double ballRight = ball.x + ball.size;
        double ballTop = ball.y;
        double ballBottom = ball.y + ball.size;

        double padLeft = padL.x;
        double padRight = padL.x + padL.width;
        double padTop = padL.y;
        double padBottom = padL.y + padL.height;

        double xOverlap = Math.min(ballRight, padRight) - Math.max(ballLeft, padLeft);
        double yOverlap = Math.min(ballBottom, padBottom) - Math.max(ballTop, padTop);

        if (xOverlap > 0 && yOverlap > 0) {
            // Collision Detected!
            padL.rectangle.setFill(Color.RED);
        } else {
            padL.rectangle.setFill(Color.BLACK);
        }
    }

    void checkInput(){
        // left paddle
        if(downPressedL && !upPressedL){
            padL.vy = padL.speed;
        }else if(upPressedL && !downPressedL){
            padL.vy = -padL.speed;
        } else {
            padL.vy = 0;
        }

        // right paddle
        if(downPressedR && !upPressedR){
            padR.vy = padR.speed;
        }else if(upPressedR && !downPressedR){
            padR.vy = -padR.speed;
        } else {
            padR.vy = 0;
        }

    }
}

package ceccs;

import javafx.scene.shape.Rectangle;

public class Ball {
    double x, y, vx, vy, size;
    Rectangle rectangle;

    Ball(double startX, double startY, double startVx, double startVy){
        x = startX;
        y = startY;
        vx = startVx;
        vy = startVy;
        size = 20;
        rectangle = new Rectangle(size, size);
    }

    void updateGraphics(){
        rectangle.setX(x);
        rectangle.setY(y);
    }

    void updatePosition(){
        x = x + vx;
        y = y + vy;
    }

    void reflectX(){
        x = x - vx;
        vx = -1 * vx;
    }

    void reflectY(){
        y = y - vy;
        vy = -1 * vy;
    }
}

package ceccs;

import javafx.scene.shape.Rectangle;

public class Paddle {
    double x, y, vy;
    Rectangle rectangle;

    static double speed = 2;
    static double width = 20;
    static double height = 100;

    Paddle(double startX, double startY){
        x = startX;
        y = startY;
        rectangle = new Rectangle(startX, startX, width, height);
    }

    void updateGraphics(){
        rectangle.setX(x);
        rectangle.setY(y);
    }

    void updatePosition(){
        y = y + vy;
    }
}