import { unescape } from './escape-html';
import type { HighlightedParts } from '../../types';

const hasAlphanumeric = new RegExp(/\w/i);

export function getHighlightFromSiblings(parts: HighlightedParts[], i: number) {
  const current = parts[i];
  const isNextHighlighted = parts[i + 1]?.isHighlighted || true;
  const isPreviousHighlighted = parts[i - 1]?.isHighlighted || true;

  if (
    !hasAlphanumeric.test(unescape(current.value)) &&
    isPreviousHighlighted === isNextHighlighted
  ) {
    return isPreviousHighlighted;
  }

  return current.isHighlighted;
}