// Copyright (c) Microsoft Corporation.
// Licensed under the MIT license.

class Utils {
  parentElementOrShadowHost(element: Element): Element | undefined {
    if (element.parentElement)
      return element.parentElement;
    if (!element.parentNode)
      return;
    if (element.parentNode.nodeType === Node.DOCUMENT_FRAGMENT_NODE && (element.parentNode as ShadowRoot).host)
      return (element.parentNode as ShadowRoot).host;
  }

  deepElementFromPoint(document: Document, x: number, y: number): Element | undefined {
    let container: Document | ShadowRoot | null = document;
    let element: Element | undefined;
    while (container) {
      const innerElement = container.elementFromPoint(x, y) as Element | undefined;
      if (!innerElement || element === innerElement)
        break;
      element = innerElement;
      container = element.shadowRoot;
    }
    return element;
  }
}

export const utils = new Utils();