const HTTP_EQUIV = "http-equiv";
const REFRESH = "refresh";

const isHttpEquiv = ({ attrs }) =>
  HTTP_EQUIV in attrs && attrs[HTTP_EQUIV].toLowerCase() === REFRESH;

const filter = {
  "*": { itemtype: true },
  a: { href: true, ping: true },
  applet: {
    archive: true,
    code: true,
    codebase: true,
    object: true,
    src: true,
  },
  area: { href: true, ping: true },
  audio: { src: true },
  base: { href: true },
  blockquote: { cite: true },
  body: { background: true },
  button: { formaction: true },
  del: { cite: true },
  embed: { src: true },
  form: { action: true },
  frame: { longdesc: true, src: true },
  head: { profile: true },
  html: { manifest: true },
  iframe: { longdesc: true, src: true },
  img: { longdesc: true, src: true, srcset: true },
  input: { formaction: true, src: true },
  ins: { cite: true },
  link: { href: true },
  menuitem: { icon: true },
  meta: { content: isHttpEquiv },
  module: { href: true },
  object: { codebase: true, data: true },
  q: { cite: true },
  script: { src: true },
  source: { src: true, srcset: true },
  table: { background: true },
  tbody: { background: true },
  td: { background: true },
  tfoot: { background: true },
  th: { background: true },
  thead: { background: true },
  tr: { background: true },
  track: { src: true },
  video: { poster: true, src: true },
};

module.exports = filter;