/*

 * Copyright (c) 2020, Luke Wilde <lukew@serenityos.org>

 * Copyright (c) 2024, circl <circl.lastname@gmail.com>

 *

 * SPDX-License-Identifier: BSD-2-Clause

 */

#include <LibWeb/DOM/EventTarget.h>

#include <LibWeb/DOM/Node.h>

#include <LibWeb/DOM/ShadowRoot.h>

#include <LibWeb/DOM/Utils.h>

namespace Web::DOM {

// https://dom.spec.whatwg.org/#retarget

EventTarget* retarget(EventTarget* a, EventTarget* b)

{

    // To retarget an object A against an object B, repeat these steps until they return an object:

    for (;;) {

        // 1. If one of the following is true then return A.

        // - A is not a node

        if (!is<Node>(a))

            return a;

        // - A’s root is not a shadow root

        auto* a_node = verify_cast<Node>(a);

        auto& a_root = a_node->root();

        if (!is<ShadowRoot>(a_root))

            return a;

        // - B is a node and A’s root is a shadow-including inclusive ancestor of B

        if (is<Node>(b) && a_root.is_shadow_including_inclusive_ancestor_of(verify_cast<Node>(*b)))

            return a;

        // 2. Set A to A’s root’s host.

        auto& a_shadow_root = verify_cast<ShadowRoot>(a_root);

        a = a_shadow_root.host();

    }

}

}