package bugs.performance.triangles;

import javafx.animation.AnimationTimer;
import javafx.application.Application;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Bounds;
import javafx.geometry.Pos;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.control.ToggleButton;
import javafx.scene.control.ToolBar;
import javafx.scene.input.ScrollEvent;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.Pane;
import javafx.scene.layout.StackPane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Polygon;
import javafx.scene.shape.Rectangle;
import javafx.scene.shape.Shape;
import javafx.stage.Stage;

/**
 * Run with -Dprism.order=j2d for best performance :-(
 */
public class TrianglePerformanceTest extends Application {
	
	private final static double WIDTH = 800;
	private final static double HEIGHT = 800;
	private final static double SIZE = 100;

    private final StackPane graphicsPane = new StackPane();
    private final Pane drawingPane = new Pane();
    private final Group graphics = new Group();
    
    private ToolBar toolBar;
    private TextField numElemSelection;
    private TextField frameRate;
    private ToggleButton triRectButton;
    private ToggleButton animButton;
    
	private int numElements = 1000;
	private boolean showRectangles = false;
    
    private class MyAnimationTimer extends AnimationTimer {
        private final static long SECONDS_TO_NANOS = 1_000_000_000;       
    	private long previousTimeNanos = 0;
    	private boolean active = false;
		@Override
    	public void start() {
    		super.start();
    		this.active = true;
    	}
		@Override
    	public void stop() {
    		super.stop();
    		this.active = false;
    	}
		@Override
		public void handle(long nowNanos) {
			if (previousTimeNanos > 0) {
				long deltaNanos = nowNanos - previousTimeNanos;
				if (deltaNanos > 0) {
					frameRate.setText(String.format("%d", SECONDS_TO_NANOS/deltaNanos));
				}
			}
			previousTimeNanos = nowNanos;
			
			double angle = 10 * ((double)nowNanos / SECONDS_TO_NANOS);
			graphics.setRotate(angle);
		}
		public boolean isActive() {
			return active;
		}
	};
	
	MyAnimationTimer timer = new MyAnimationTimer();
	
	@Override
	public void start(Stage stage) throws Exception {
        stage.setTitle(getClass().getSimpleName());
        
        BorderPane root = new BorderPane();
        
        if (true) { // if 'false' crashes application
	        Rectangle clip = new Rectangle();
	        clip.widthProperty().bind(drawingPane.widthProperty());
	        clip.heightProperty().bind(drawingPane.heightProperty());
	        drawingPane.setClip(clip);
        }
        drawingPane.getChildren().add(graphics);
        
        graphicsPane.getChildren().add(drawingPane);
        
        toolBar = new ToolBar();
        root.setTop(toolBar);
        root.setCenter(graphicsPane);
    	
        drawingPane.setOnScroll(new EventHandler<ScrollEvent>() {
			@Override
			public void handle(ScrollEvent e) {
    			double val = e.getDeltaY();		
    			if (val < 0) {
    				graphics.setScaleX(graphics.getScaleX()*0.8);
    				graphics.setScaleY(graphics.getScaleY()*0.8);
    			} else {
    				graphics.setScaleX(graphics.getScaleX()*1.2);
    				graphics.setScaleY(graphics.getScaleY()*1.2);
    			}
			}
        });
    	    	    	
        {
            // Number of elements:
	        Label label = new Label("Num. Elem.:");
	        numElemSelection = new TextField();
	        numElemSelection.setAlignment(Pos.BASELINE_RIGHT);
	        numElemSelection.setPrefColumnCount(4);
	        numElemSelection.setText(String.valueOf(numElements));
	        numElemSelection.setOnAction(resetConfigActionHandler);
	        toolBar.getItems().addAll(label, numElemSelection);
        }
        
        {
            // Frame rate:
	        Label label = new Label("Frame rate:");
	        frameRate = new TextField();
	        frameRate.setAlignment(Pos.BASELINE_RIGHT);
	        frameRate.setPrefColumnCount(3);
	        frameRate.setEditable(false);
	        toolBar.getItems().addAll(label, frameRate);
        }
        
        toolBar.getItems().add(new Label("   "));
        
        {
            // Triangles/Rectangles toggle button:
        	triRectButton = new ToggleButton("Triangles/Rectangles");
        	triRectButton.setSelected(false);
        	triRectButton.setOnAction(resetConfigActionHandler);
	        toolBar.getItems().add(triRectButton);
        }
        
        {
            // Start/Stop animation toggle button:
        	animButton = new ToggleButton("Start/Stop Animation");
        	animButton.setSelected(false);
        	animButton.setOnAction(animationActionHandler);
	        toolBar.getItems().add(animButton);
        }
        
        Scene scene = new Scene(root, WIDTH, HEIGHT); 
        stage.setScene(scene);
        stage.show();
        
        // Crashes application if the listener is attached to the graphicsPane. It works with the drawingPane.
        graphicsPane.boundsInLocalProperty().addListener(new ChangeListener<Bounds>() {			
			@Override
			public void changed(ObservableValue<? extends Bounds> observable, Bounds oldValue, Bounds newValue) {
				resetConfig();
			}
		});
        
        resetConfig();		
	}
	
    private EventHandler<ActionEvent> resetConfigActionHandler = new EventHandler<ActionEvent>() {
		@Override
		public void handle(ActionEvent e) {
			resetConfig();
		}	
    };
    
    private EventHandler<ActionEvent> animationActionHandler = new EventHandler<ActionEvent>() {
		@Override
		public void handle(ActionEvent e) {
			boolean showAnimation = animButton.isSelected();
			if (showAnimation != timer.isActive()) {
				if (showAnimation) {
					timer.start();
				} else {
					timer.stop();
				}
			}
		}	
    };
    
    private void resetConfig() {
        try {
        	timer.stop();
			numElements = Math.abs(Integer.valueOf(numElemSelection.getText()));
			showRectangles = triRectButton.isSelected();
			boolean showAnimation = animButton.isSelected();
			updateGraphics();
			if (showAnimation) {
				timer.start();
			} else {
				timer.stop();
			}
		} catch (NumberFormatException e) {
			System.err.println("Illegal value for number of elements: " + numElemSelection.getText());
		}
    }
    
	private void updateGraphics() {
		graphics.getChildren().clear();
		graphics.setRotate(0.0);
		graphics.setScaleX(1.0);
		graphics.setScaleY(1.0);

        for (int i = 0; i < numElements; i++) {
        	addShape(graphics, drawingPane.getWidth(), drawingPane.getHeight(), showRectangles);
        }
	}
	
	private void addShape(Group graphics, double width, double height, boolean showRectangles) {
        final double px0 = Math.random() * width;
        final double py0 = Math.random() * height;
        final double px1 = px0 - SIZE/2 + Math.random() * SIZE;
        final double py1 = py0 - SIZE/2 + Math.random() * SIZE;
        final double px2 = px0 - SIZE/2 + Math.random() * SIZE;
        final double py2 = py0 - SIZE/2 + Math.random() * SIZE;
        
        Shape shape;
        
        if (!showRectangles) {
	        shape = new Polygon(px0, py0, px1, py1, px2, py2);
        } else {	        
	        double boundsX = Math.min(Math.min(px0, px1), px2);
	        double boundsY = Math.min(Math.min(py0, py1), py2);
	        double boundsWidth = Math.max(Math.max(px0, px1), px2) - boundsX;
	        double boundsHeight = Math.max(Math.max(py0, py1), py2) - boundsY;	        
	        shape = new Rectangle(boundsX, boundsY, boundsWidth, boundsHeight);
        }

        shape.setFill(randomColor());
        shape.setStroke(null);
        graphics.getChildren().add(shape);
	}
	
	private Color randomColor() {
		return new Color(Math.random(), Math.random(), Math.random(), 1.0);
	}
	
	public static void main(String[] args) {
		launch(args);
	}

}