globalThis.Wegwichtel ??= {};
(function (ns) {
  'use strict';

  class WegwichtelI18n {
    static #languages = new Map([['de', ns.TextsDe.messages]]);
    static #language = 'de';

    static get language() { return this.#language; }

    static register(language, messages) {
      this.#languages.set(language.toLowerCase(), Object.freeze({ ...messages }));
    }

    static setLanguage(language, root = globalThis.document) {
      const requested = String(language).toLowerCase();
      const base = requested.split('-')[0];
      this.#language = 'de';
      if (this.#languages.has(base)) this.#language = base;
      if (this.#languages.has(requested)) this.#language = requested;
      this.apply(root);
      return this.#language;
    }

    static t(key, variables = {}) {
      let value = this.#languages.get(this.#language)?.[key] ?? ns.TextsDe.messages[key];
      if (value == null) throw new RangeError(`Missing translation: ${key}`);
      if (typeof value === 'object') {
        const plural = new Intl.PluralRules(this.#language).select(Number(variables.count));
        value = value[plural] ?? value.other;
      }
      return value.replace(/\{([a-zA-Z0-9_]+)\}/g, (placeholder, name) => {
        if (!Object.hasOwn(variables, name)) return placeholder;
        return String(variables[name] ?? '');
      });
    }

    static apply(root = globalThis.document) {
      if (!root?.querySelectorAll) return;
      if (root.documentElement) root.documentElement.lang = this.#language;
      for (const element of root.querySelectorAll('[data-i18n]')) {
        if (typeof element.getAttribute === 'function') element.textContent = this.t(element.getAttribute('data-i18n'));
      }
      for (const attribute of ['title', 'aria-label', 'placeholder', 'alt']) {
        for (const element of root.querySelectorAll(`[data-i18n-${attribute}]`)) {
          if (typeof element.getAttribute === 'function' && typeof element.setAttribute === 'function') element.setAttribute(attribute, this.t(element.getAttribute(`data-i18n-${attribute}`)));
        }
      }
    }
  }

  ns.I18n = WegwichtelI18n;
  WegwichtelI18n.apply();
}(globalThis.Wegwichtel));