(function attachBackgroundRegistrationEmailState(root, factory) {
  root.MultiPageRegistrationEmailState = factory();
})(typeof self !== 'undefined' ? self : globalThis, function createBackgroundRegistrationEmailStateModule() {
  const DEFAULT_REGISTRATION_EMAIL_STATE = Object.freeze({
    current: '',
    previous: '',
    source: '',
    updatedAt: 0,
  });

  function createRegistrationEmailStateHelpers() {
    function normalizeEmailValue(value) {
      return String(value || '').trim();
    }

    function cloneDefaultRegistrationEmailState() {
      return {
        current: DEFAULT_REGISTRATION_EMAIL_STATE.current,
        previous: DEFAULT_REGISTRATION_EMAIL_STATE.previous,
        source: DEFAULT_REGISTRATION_EMAIL_STATE.source,
        updatedAt: DEFAULT_REGISTRATION_EMAIL_STATE.updatedAt,
      };
    }

    function normalizeRegistrationEmailState(value, fallbackEmail = '') {
      const fallback = normalizeEmailValue(fallbackEmail);
      const candidate = value && typeof value === 'object' && !Array.isArray(value)
        ? value
        : null;
      const current = normalizeEmailValue(candidate?.current || fallback);
      const previous = normalizeEmailValue(candidate?.previous || current || fallback);
      const source = String(candidate?.source || '').trim();
      const updatedAt = Number(candidate?.updatedAt) || 0;
      return {
        current,
        previous,
        source,
        updatedAt: updatedAt > 0 ? updatedAt : 0,
      };
    }

    function getRegistrationEmailState(state = {}) {
      return normalizeRegistrationEmailState(state?.registrationEmailState, state?.email);
    }

    function buildRegistrationEmailStateUpdates(state = {}, options = {}) {
      const currentState = getRegistrationEmailState(state);
      const currentEmail = normalizeEmailValue(options.currentEmail);
      const preservePrevious = Boolean(options.preservePrevious);
      const source = String(options.source || '').trim();
      const nextState = cloneDefaultRegistrationEmailState();

      nextState.current = currentEmail;
      nextState.previous = currentEmail || (preservePrevious ? currentState.previous : '');
      nextState.source = currentEmail
        ? (source || currentState.source)
        : (preservePrevious ? currentState.source : '');
      nextState.updatedAt = currentEmail || (preservePrevious && currentState.previous)
        ? Date.now()
        : 0;

      return {
        email: currentEmail || null,
        registrationEmailState: nextState,
      };
    }

    function getRegistrationEmailBaseline(state = {}, options = {}) {
      const currentState = getRegistrationEmailState(state);
      const preferredEmail = normalizeEmailValue(options.preferredEmail);
      const fallbackEmail = normalizeEmailValue(options.fallbackEmail);
      return preferredEmail || currentState.current || currentState.previous || fallbackEmail || '';
    }

    return {
      DEFAULT_REGISTRATION_EMAIL_STATE: cloneDefaultRegistrationEmailState(),
      buildRegistrationEmailStateUpdates,
      getRegistrationEmailBaseline,
      getRegistrationEmailState,
      normalizeRegistrationEmailState,
    };
  }

  return {
    createRegistrationEmailStateHelpers,
  };
});