// public/assets/js/lang.js

(function () {
  const supportedLangs = ["de", "en", "it", "fr"];
  let translations = {};

  // Mapping für Flaggen + Label im Header
  const langMeta = {
    de: { flag: "🇩🇪", label: "DE" },
    en: { flag: "🇬🇧", label: "EN" }, // oder 🇺🇸 wenn dir lieber
    it: { flag: "🇮🇹", label: "IT" },
    fr: { flag: "🇫🇷", label: "FR" }
  };

  function flattenTranslations(obj, prefix = "") {
    const result = {};
    Object.keys(obj).forEach((key) => {
      const value = obj[key];
      const newKey = prefix ? `${prefix}_${key}` : key;

      if (value && typeof value === "object" && !Array.isArray(value)) {
        Object.assign(result, flattenTranslations(value, newKey));
      } else {
        result[newKey] = value;
      }
    });
    return result;
  }

  async function loadLangFile(lang) {
    try {
      const res = await fetch(`/assets/i18n/${lang}.json`, { cache: "no-store" });
      if (!res.ok) throw new Error(`Failed to load /assets/i18n/${lang}.json`);
      const data = await res.json();
      translations = flattenTranslations(data);
    } catch (err) {
      console.error("i18n load error:", err);
      translations = {};
    }
  }

  function getInitialLang() {
    const urlParams = new URLSearchParams(window.location.search);
    const paramLang = urlParams.get("lang");
    if (paramLang && supportedLangs.includes(paramLang)) return paramLang;

    const stored = localStorage.getItem("usbcheck_lang");
    if (stored && supportedLangs.includes(stored)) return stored;

    const navLang = (navigator.language || "en").slice(0, 2).toLowerCase();
    if (supportedLangs.includes(navLang)) return navLang;

    return "en";
  }

  function applyTranslations() {
    document.documentElement.setAttribute("lang", getCurrentLang());

    document.querySelectorAll("[data-i18n]").forEach((node) => {
      const key = node.getAttribute("data-i18n");
      if (!key || !translations[key]) return;

      let value = translations[key];

      // {year}-Placeholder ersetzen (für footer_copy etc.)
      if (typeof value === "string" && value.includes("{year}")) {
        const year = new Date().getFullYear();
        value = value.replace("{year}", year);
      }

      node.innerHTML = value;
    });
  }

  function getCurrentLang() {
    const urlParams = new URLSearchParams(window.location.search);
    const paramLang = urlParams.get("lang");
    if (paramLang && supportedLangs.includes(paramLang)) return paramLang;

    const stored = localStorage.getItem("usbcheck_lang");
    if (stored && supportedLangs.includes(stored)) return stored;

    return "en";
  }

  function updateLangCurrentLabel(lang) {
    const meta = langMeta[lang] || { flag: "", label: lang.toUpperCase() };
    const node = document.getElementById("langCurrentLabel") || document.getElementById("langCurrent");
    if (!node) return;

    if (meta.flag) {
      node.innerHTML = `<span class="mr-1.5">${meta.flag}</span><span>${meta.label}</span>`;
    } else {
      node.textContent = meta.label;
    }
  }

  async function setLang(lang) {
    if (!supportedLangs.includes(lang)) return;

    localStorage.setItem("usbcheck_lang", lang);

    // URL-Parameter ohne Reload aktualisieren
    const url = new URL(window.location.href);
    url.searchParams.set("lang", lang);
    window.history.replaceState({}, "", url.toString());

    await loadLangFile(lang);
    applyTranslations();
    updateLangCurrentLabel(lang);
  }

  document.addEventListener("DOMContentLoaded", async function () {
    const initialLang = getInitialLang();

    // Header-Label initial
    updateLangCurrentLabel(initialLang);

    // Übersetzungen laden und anwenden
    await loadLangFile(initialLang);
    applyTranslations();

    // Dropdown-Elemente
    const langCurrent = document.getElementById("langCurrent");
    const langMenu = document.getElementById("langMenu");

    // Dropdown öffnen/schließen
    if (langCurrent && langMenu) {
      langCurrent.addEventListener("click", function (e) {
        e.stopPropagation();
        langMenu.classList.toggle("hidden");
      });

      document.addEventListener("click", function (e) {
        if (!langMenu.classList.contains("hidden")) {
          if (!langMenu.contains(e.target) && !langCurrent.contains(e.target)) {
            langMenu.classList.add("hidden");
          }
        }
      });

      langMenu.addEventListener("click", function (e) {
        const pill = e.target.closest(".lang-pill");
        if (pill) {
          langMenu.classList.add("hidden");
        }
      });
    }

    // Sprachumschaltung / Klick auf .lang-pill
    document.addEventListener("click", function (e) {
      const btn = e.target.closest(".lang-pill");
      if (btn) {
        const lang = btn.getAttribute("data-lang");
        setLang(lang);
      }
    });

    // Login / Avatar – UI-Dummy wie vorher
    const loginButton = document.getElementById("loginButton");
    const userAvatar = document.getElementById("userAvatar");
    const avatarInitials = document.getElementById("avatarInitials");

    if (loginButton && userAvatar) {
      loginButton.addEventListener("click", function () {
        loginButton.classList.add("hidden");
        userAvatar.classList.remove("hidden");

        if (avatarInitials && !avatarInitials.textContent.trim()) {
          avatarInitials.textContent = "UC";
        }
      });

      userAvatar.addEventListener("click", function () {
        alert("Account-Menü Platzhalter – hier später Profil/Logout etc. einbauen.");
      });
    }
  });
})();