// copy from https://github.com/vuejs/core/blob/main/packages/shared/src/escapeHtml.ts

const escapeRE = /["'&<>]/;

export function escapeHtml(string: unknown): string {
  const str = "" + string;
  const match = escapeRE.exec(str);

  if (!match) {
    return str;
  }

  let html = "";
  let escaped: string;
  let index: number;
  let lastIndex = 0;
  for (index = match.index; index < str.length; index++) {
    switch (str.charCodeAt(index)) {
      case 34: // "
        escaped = "&quot;";
        break;
      case 38: // &
        escaped = "&amp;";
        break;
      case 39: // '
        escaped = "&#39;";
        break;
      case 60: // <
        escaped = "&lt;";
        break;
      case 62: // >
        escaped = "&gt;";
        break;
      default:
        continue;
    }

    if (lastIndex !== index) {
      html += str.slice(lastIndex, index);
    }

    lastIndex = index + 1;
    html += escaped;
  }

  return lastIndex !== index ? html + str.slice(lastIndex, index) : html;
}