(function (ns) {
  'use strict';

  const entries = Object.freeze([
    ['🍎', 'Apfel'],
    ['🔑', 'Schlüssel'],
    ['🔔', 'Glocke'],
    ['📘', 'Buch'],
    ['🌻', 'Sonnenblume'],
    ['☂️', 'Regenschirm'],
    ['⚽', 'Fußball'],
    ['☕', 'Tasse']
  ].map(([unicode, label]) => Object.freeze({
    unicode,
    label,
    imageUrl: `/images/group-symbols/${unicode}.png`
  })));

  // Presentation selectors must not create different symbols for the same object.
  function normalizeUnicode(value) {
    if (typeof value !== 'string') return null;
    return value.normalize('NFC').replaceAll(/[\uFE0E\uFE0F]/g, '');
  }

  const byUnicode = new Map(entries.map(entry => [normalizeUnicode(entry.unicode), entry]));

  /**
   * Read-only catalogue of the eight approved group-code illustrations.
   * Loading this file only registers the class; it does not create UI or sessions.
   */
  class GroupSymbols {
    static list() {
      return entries;
    }

    /** Returns the immutable motif descriptor, or null for an unknown symbol. */
    static get(unicode) {
      return byUnicode.get(normalizeUnicode(unicode)) ?? null;
    }

    static has(unicode) {
      return this.get(unicode) !== null;
    }

    static imageUrl(unicode) {
      return this.get(unicode)?.imageUrl ?? null;
    }
  }

  ns.GroupSymbols = GroupSymbols;
}(globalThis.Wegwichtel ??= {}));