function getEntries(query: string) {
  const entries = Array.from(document.querySelectorAll(query));
  const firstElement = entries[0];
  const lastElement = entries[entries.length - 1];

  return { entries, firstElement, lastElement };
}

/**
 * Helper method to find the next focusable sibling element relative to the
 * specified element.
 *
 * @param {string} query  - Argument that gets passed to document.querySelectorAll
 * @param {HTMLElement} element - Specified element (e.target)
 * @returns {HTMLElement} - element to be focused
 */
export function getNextSibling(
  query: string,
  element: EventTarget
): HTMLElement {
  const { entries, firstElement, lastElement } = getEntries(query);

  if (element === lastElement) {
    return firstElement as HTMLElement;
  }
  const elementIndex = entries.indexOf(element as HTMLElement);
  return entries[elementIndex + 1] as HTMLElement;
}

/**
 * Helper method to find the previous focusable sibling element relative to the
 * specified element.
 *
 * @param {string} query  - Argument that gets passed to document.querySelectorAll
 * @param {HTMLElement} element - Specified element (e.target)
 * @returns {HTMLElement} - element to be focused
 */
export function getPreviousSibling(
  query: string,
  element: EventTarget
): HTMLElement {
  const { entries, firstElement, lastElement } = getEntries(query);

  if (element === firstElement) {
    return lastElement as HTMLElement;
  }
  const elementIndex = entries.indexOf(element as HTMLButtonElement);
  return entries[elementIndex - 1] as HTMLElement;
}