import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.NodeOrientation;
import javafx.geometry.Point2D;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.input.MouseButton;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.BorderPane;
import javafx.scene.paint.Color;
import javafx.scene.shape.LineTo;
import javafx.scene.shape.MoveTo;
import javafx.scene.shape.Path;
import javafx.scene.shape.PathElement;
import javafx.scene.text.HitInfo;
import javafx.scene.text.Text;
import javafx.scene.text.TextFlow;
import javafx.stage.Stage;

public class TextFlowExtraSpaceSample extends Application {

    private TextFlow flow;
    private Path caret;
    private Path range;

    @Override
    public void start(Stage stage) throws Exception {
        flow = new TextFlow(
                t("Arabic: ", Color.RED),
                t("العربية", Color.GREEN),
                new Text("\n"),
                t("Hebrew :", Color.BLUE),
                t("עברית", Color.BLACK));
        flow.setStyle("-fx-font-size:400%");
        flow.addEventFilter(MouseEvent.MOUSE_PRESSED, this::handleMousePress);

        caret = new Path();
        caret.setManaged(false);
        caret.setStroke(Color.MAGENTA);
        caret.setStrokeWidth(1);
        caret.setMouseTransparent(true);

        range = new Path();
        range.setManaged(false);
        range.setStroke(null);
        range.setFill(Color.rgb(255, 0, 0, 0.2));
        range.setMouseTransparent(true);

        BorderPane bp = new BorderPane(flow);
        bp.getChildren().addAll(caret, range);

        Scene scene = new Scene(bp);
        scene.setNodeOrientation(NodeOrientation.RIGHT_TO_LEFT);

        stage.setScene(scene);
        stage.setTitle("TextFlow RTL");
//        stage.setWidth(220);
        stage.setWidth(500);
        stage.setHeight(300);
        stage.show();

        Platform.runLater(() -> {
            updateRange();
        });
    }

    private void updateRange() {
        int len = getTextLength(flow);
        PathElement[] pe = flow.rangeShape(0, len);
        //System.out.println("range=" + dump(pe));
        range.getElements().setAll(pe);
    }

    private int getTextLength(TextFlow f) {
        int len = 0;
        for (Node n : f.getChildren()) {
            if (n instanceof Text t) {
                len += t.getText().length();
            }
        }
        return len;
    }

    private static Text t(String text, Color c) {
        Text t = new Text(text);
        t.setFill(c);
        t.setUnderline(true);
        return t;
    }

    private void handleMousePress(MouseEvent ev) {
        System.out.println("x: " + ev.getX() + " y:" + ev.getY());
        Point2D p = new Point2D(ev.getX(), ev.getY());
        HitInfo h = flow.hitTest(p);
        System.out.println("hit=" + h);

        PathElement[] pe = flow.caretShape(h.getCharIndex(), h.isLeading());
        System.out.println("caret=" + dump(pe));
        caret.getElements().setAll(pe);
        updateRange();
    }

    /** dumps the path element array to a compact human-readable string */
    public static String dump(PathElement[] elements) {
        StringBuilder sb = new StringBuilder();
        if (elements == null) {
            sb.append("null");
        } else {
            for (PathElement em : elements) {
                if (em instanceof MoveTo p) {
                    sb.append('M');
                    sb.append(r(p.getX()));
                    sb.append(',');
                    sb.append(r(p.getY()));
                    sb.append(' ');
                } else if (em instanceof LineTo p) {
                    sb.append('L');
                    sb.append(r(p.getX()));
                    sb.append(',');
                    sb.append(r(p.getY()));
                    sb.append(' ');
                } else {
                    sb.append(em);
                    sb.append(' ');
                }
            }
        }
        return sb.toString();
    }

    private static int r(double x) {
        return (int)Math.round(x);
    }
}