package io.swtc.proccessing;

import javax.swing.*;
import java.awt.*;
import java.awt.geom.CubicCurve2D;

/**
 * Acts as a transparent layer over the entire window to draw connections.
 */
public class ConnectionOverlay extends JComponent {
    private final Component source;
    private final Component target;
    private final Color connectionColor;

    public ConnectionOverlay(Component source, Component target, Color color) {
        this.source = source;
        this.target = target;
        this.connectionColor = color;
        setOpaque(false); // Make sure we can see through it
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        if (!source.isShowing() || !target.isShowing()) return;

        Graphics2D g2d = (Graphics2D) g.create();
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

        // 1. Get absolute positions relative to this Overlay
        Point p1 = SwingUtilities.convertPoint(source, 0, 0, this);
        Point p2 = SwingUtilities.convertPoint(target, 0, 0, this);

        int x1, y1, x2, y2, ctrl1X, ctrl2X;

        // Calculate vertical centers
        y1 = p1.y + (source.getHeight() / 2);
        y2 = p2.y + (target.getHeight() / 2);

        // 2. Logic to determine Left/Right orientation
        // If source is to the left of target
        if (p1.x + source.getWidth() < p2.x) {
            x1 = p1.x + source.getWidth(); // Right edge of source
            x2 = p2.x;                     // Left edge of target
        }
        // If source is to the right of target
        else if (p1.x > p2.x + target.getWidth()) {
            x1 = p1.x;                     // Left edge of source
            x2 = p2.x + target.getWidth(); // Right edge of target
        }
        // If they are overlapping horizontally, use centers
        else {
            x1 = p1.x + (source.getWidth() / 2);
            x2 = p2.x + (target.getWidth() / 2);
        }

        // 3. Dynamic Curve "Stiffness"
        // The horizontal distance between the two points determines how far the curve pulls
        int horizontalDist = Math.abs(x1 - x2);
        int offset = Math.max(horizontalDist / 2, 20); // Minimum 20px pull for short distances

        if (x1 < x2) {
            ctrl1X = x1 + offset;
            ctrl2X = x2 - offset;
        } else {
            ctrl1X = x1 - offset;
            ctrl2X = x2 + offset;
        }

        // 4. Draw the Curve
        g2d.setColor(connectionColor);
        g2d.setStroke(new BasicStroke(3f, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));

        // We keep the Y coordinates for controls the same as the endpoints
        // to create that "horizontal entry/exit" look.
        CubicCurve2D curve = new CubicCurve2D.Float(x1, y1, ctrl1X, y1, ctrl2X, y2, x2, y2);
        g2d.draw(curve);

        g2d.dispose();
    }
}