package sample;

import javafx.animation.KeyFrame;
import javafx.animation.KeyValue;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.paint.Color;
import javafx.scene.paint.CycleMethod;
import javafx.scene.paint.LinearGradient;
import javafx.scene.paint.Stop;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Rectangle;
import javafx.scene.shape.StrokeType;
import javafx.stage.Stage;
import javafx.util.Duration;

import static java.lang.Math.random;

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception {
        Group root = new Group();
        Group circles = new Group();
        for (int i = 0; i < 30; i++) {
            Circle circle = new Circle(150, Color.web("white", 0.05));
            circle.setStrokeType(StrokeType.OUTSIDE);
            circle.setStroke(Color.web("white", 0.16));
            circle.setStrokeWidth(4);
            circles.getChildren().add(circle);
        }
        root.getChildren().add(circles);
        Scene scene = new Scene(root, 800, 600, Color.BLACK);
        Rectangle colors = new Rectangle(
                scene.getWidth(),
                scene.getHeight(),
                new LinearGradient(0f, 1f, 1f, 0f, true, CycleMethod.NO_CYCLE, new Stop[] {
                        new Stop(0, Color.web("#f8bd55")),
                        new Stop(0.14, Color.web("#c0fe56")),
                        new Stop(0.28, Color.web("#5dfbc1")),
                        new Stop(0.43, Color.web("#64c2f8")),
                        new Stop(0.57, Color.web("#be4af7")),
                        new Stop(0.71, Color.web("#ed5fc2")),
                        new Stop(0.85, Color.web("#ef504c")),
                        new Stop(1, Color.web("#f2660f")),}));
        colors.widthProperty().bind(scene.widthProperty());
        colors.heightProperty().bind(scene.heightProperty());
        root.getChildren().add(colors);

        Timeline timeline = new Timeline();
        for (Node circle: circles.getChildren()) {
            timeline.getKeyFrames().addAll(
                    new KeyFrame(Duration.ZERO, // set start position at 0
                            new KeyValue(circle.translateXProperty(), random() * 800),
                            new KeyValue(circle.translateYProperty(), random() * 600)
                    ),
                    new KeyFrame(new Duration(40000), // set end position at 40s
                            new KeyValue(circle.translateXProperty(), random() * 800),
                            new KeyValue(circle.translateYProperty(), random() * 600)
                    )
            );
        }
        timeline.play();
        primaryStage.setScene(scene);
        primaryStage.show();
    }

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