export const getVisibleFocusingElements = () => [].map.call(document.getElementsByName('paymentMethodSelection'), e => e)
  .filter(element => window.getComputedStyle(element, null).display !== 'none' && (<any>element).offsetParent);

export const focusNextEl = target => {
  const focusingElements = getVisibleFocusingElements();
  const currentElementIndex = focusingElements.indexOf(target);
  const nextElementIndex = currentElementIndex >= focusingElements.length - 1 ? 0 : currentElementIndex + 1;
  focusEl(focusingElements[nextElementIndex]);
};

export const focusPrevEl = target => {
  const focusingElements = getVisibleFocusingElements();
  const currentElementIndex = focusingElements.indexOf(target);
  const prevElementIndex = currentElementIndex <= 0 ?
    focusingElements.length - 1 :
    currentElementIndex - 1;
  focusEl(focusingElements[prevElementIndex]);
};

const focusEl = elementToFocus => {
  if (elementToFocus) {
    (<any>elementToFocus).focus();
    (<any>elementToFocus).click();
  }
};