import {Inset} from "../../core/generated/zenid-types.generated.js";

/**
 * Returns the intersection of two DOMRect objects.
 * If there is no intersection, returns null.
 * 
 * @param a - The first DOMRect
 * @param b - The second DOMRect
 * @returns The intersection DOMRect or null if there is no intersection
 */
export function getViewportIntersection(a: DOMRect, b: DOMRect): DOMRect | null {
    const left = Math.max(a.left, b.left);
    const top = Math.max(a.top, b.top);
    const right = Math.min(a.right, b.right);
    const bottom = Math.min(a.bottom, b.bottom);

    const width = right - left;
    const height = bottom - top;

    if (width <= 0 || height <= 0) return null;

    return new DOMRect(left, top, width, height);
}

/**
 * Calculates the relative position of rect1 with respect to rect2.
 * 
 * @param rect1 - The first DOMRect
 * @param rect2 - The second DOMRect
 * @returns An Inset object representing the relative position
 */
export function getRelativePosition(rect1: DOMRect, rect2: DOMRect): Inset {

    return {
        Top: rect1.top - rect2.top,
        Bottom: rect2.bottom - rect1.bottom,
        Left: rect1.left - rect2.left,
        Right: rect2.right - rect1.right
    };
}