function ownKeys(e, r) { var t = Object.keys(e); if (Object.getOwnPropertySymbols) { var o = Object.getOwnPropertySymbols(e); r && (o = o.filter(function (r) { return Object.getOwnPropertyDescriptor(e, r).enumerable; })), t.push.apply(t, o); } return t; }
function _objectSpread(e) { for (var r = 1; r < arguments.length; r++) { var t = null != arguments[r] ? arguments[r] : {}; r % 2 ? ownKeys(Object(t), !0).forEach(function (r) { _defineProperty(e, r, t[r]); }) : Object.getOwnPropertyDescriptors ? Object.defineProperties(e, Object.getOwnPropertyDescriptors(t)) : ownKeys(Object(t)).forEach(function (r) { Object.defineProperty(e, r, Object.getOwnPropertyDescriptor(t, r)); }); } return e; }
function _defineProperty(obj, key, value) { key = _toPropertyKey(key); if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
function _toPropertyKey(t) { var i = _toPrimitive(t, "string"); return "symbol" == typeof i ? i : String(i); }
function _toPrimitive(t, r) { if ("object" != typeof t || !t) return t; var e = t[Symbol.toPrimitive]; if (void 0 !== e) { var i = e.call(t, r || "default"); if ("object" != typeof i) return i; throw new TypeError("@@toPrimitive must return a primitive value."); } return ("string" === r ? String : Number)(t); }
const BOOK = new Set(['book', 'inbook', 'bookinbook', 'suppbook']);
const BOOK_PART = new Set(['inbook', 'bookinbook', 'suppbook']);
const COLLECTION = new Set(['collection', 'reference', 'incollection', 'inreference', 'suppcollection']);
const COLLECTION_PART = new Set(['incollection', 'inreference', 'suppcollection']);
const PROCEEDINGS = new Set(['proceedings', 'inproceedings']);
const PROCEEDINGS_PART = new Set(['inproceedings']);
const PERIODICAL_PART = new Set(['article', 'suppperiodical']);
const TITLE_MAP = {
  mvbook: ['main', BOOK],
  mvcollection: ['main', COLLECTION],
  mvreference: ['main', COLLECTION],
  mvproceedings: ['main', PROCEEDINGS],
  book: ['book', BOOK_PART],
  collection: ['book', COLLECTION_PART],
  reference: ['book', COLLECTION_PART],
  proceedings: ['book', PROCEEDINGS_PART],
  periodical: ['journal', PERIODICAL_PART]
};
export function crossref(target, entry, registry) {
  if (entry.crossref in registry) {
    const parent = registry[entry.crossref];
    if (parent.properties === entry) {
      return entry;
    }
    const data = _objectSpread({}, crossref(parent.type, parent.properties, registry));
    delete data.ids;
    delete data.crossref;
    delete data.xref;
    delete data.entryset;
    delete data.entrysubtype;
    delete data.execute;
    delete data.label;
    delete data.options;
    delete data.presort;
    delete data.related;
    delete data.relatedoptions;
    delete data.relatedstring;
    delete data.relatedtype;
    delete data.shortand;
    delete data.shortandintro;
    delete data.sortkey;
    if ((parent.type === 'mvbook' || parent.type === 'book') && BOOK_PART.has(target)) {
      data.bookauthor = data.author;
    }
    if (parent.type in TITLE_MAP) {
      const [prefix, targets] = TITLE_MAP[parent.type];
      if (targets.has(target)) {
        data[prefix + 'title'] = data.title;
        data[prefix + 'subtitle'] = data.subtitle;
        if (prefix !== 'journal') {
          data[prefix + 'titleaddon'] = data.titleaddon;
        }
        delete data.title;
        delete data.subtitle;
        delete data.titleaddon;
        delete data.shorttitle;
        delete data.sorttitle;
        delete data.indextitle;
        delete data.indexsorttitle;
      }
    }
    return Object.assign(data, entry);
  }
  return entry;
}