// @flow
import type { Window } from '../types';
declare function getWindow(node: Node | Window): Window;

export default function getWindow(node) {
  if (node == null) {
    return window;
  }

  if (node.toString() !== '[object Window]') {
    const ownerDocument = node.ownerDocument;
    return ownerDocument ? ownerDocument.defaultView || window : window;
  }

  return node;
}