/**
 * @license Copyright (c) 2003-2022, CKSource Holding sp. z o.o. All rights reserved.
 * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
 */
/**
 * @module utils/arestructuresconnected
 */
/* globals EventTarget, Event */
/**
 * Traverses both structures to find out whether there is a reference that is shared between both structures.
 */
export default function areConnectedThroughProperties(obj1, obj2) {
    if (obj1 === obj2 && isObject(obj1)) {
        return true;
    }
    const subNodes1 = getSubNodes(obj1);
    const subNodes2 = getSubNodes(obj2);
    for (const node of subNodes1) {
        if (subNodes2.has(node)) {
            return true;
        }
    }
    return false;
}
/**
 * Traverses JS structure and stores all sub-nodes, including the head node.
 * It walks into each iterable structures with the `try catch` block to omit errors that might be thrown during
 * tree walking. All primitives, functions and built-ins are skipped.
 */
function getSubNodes(head) {
    const nodes = [head];
    // Nodes are stored to prevent infinite looping.
    const subNodes = new Set();
    while (nodes.length > 0) {
        const node = nodes.shift();
        if (subNodes.has(node) || shouldNodeBeSkipped(node)) {
            continue;
        }
        subNodes.add(node);
        // Handle arrays, maps, sets, custom collections that implements `[ Symbol.iterator ]()`, etc.
        if (node[Symbol.iterator]) {
            // The custom editor iterators might cause some problems if the editor is crashed.
            try {
                nodes.push(...node);
            }
            catch (err) {
                // eslint-disable-line no-empty
            }
        }
        else {
            nodes.push(...Object.values(node));
        }
    }
    return subNodes;
}
function shouldNodeBeSkipped(node) {
    const type = Object.prototype.toString.call(node);
    return (type === '[object Number]' ||
        type === '[object Boolean]' ||
        type === '[object String]' ||
        type === '[object Symbol]' ||
        type === '[object Function]' ||
        type === '[object Date]' ||
        type === '[object RegExp]' ||
        node === undefined ||
        node === null ||
        // Skip native DOM objects, e.g. Window, nodes, events, etc.
        node instanceof EventTarget ||
        node instanceof Event);
}
function isObject(structure) {
    return typeof structure === 'object' && structure !== null;
}
