// public/assets/js/lang.js
(function () {
  // ---------------------------------------------
  // 1) Basis-Config aus PHP (app_config.php)
  // ---------------------------------------------
  const usbConfig = window.usbConfig || {};
  const i18nConfig = usbConfig.i18n || {};

  // Map: { de: {code, label, flag}, en: {...}, ... }
  const availableLangs = i18nConfig.available || {};

  // Liste der unterstützten Sprachen als Codes
  const supportedLangs = Object.keys(availableLangs);

  // Aktuelle Sprache (wird unten per getInitialLang() gesetzt)
  let currentLang = "en";

  // Translations-Map (geflacht)
  let translations = {};

  // ---------------------------------------------
  // 2) Helper: Translations flatten
  // ---------------------------------------------
  function flattenTranslations(obj, target = {}) {
    Object.keys(obj || {}).forEach((key) => {
      const val = obj[key];
      if (val && typeof val === "object" && !Array.isArray(val)) {
        flattenTranslations(val, target);
      } else {
        target[key] = val;
      }
    });
    return target;
  }

  // ---------------------------------------------
  // 3) Domain-Platzhalter ersetzen
  // ---------------------------------------------
  function applyDomainPlaceholders(text) {
    if (typeof text !== "string") return text;

    // Primär aus usbConfig.domains, Fallback auf window.appDomains
    const domains = usbConfig.domains || window.appDomains || {};
    const replacements = {
      "{{primary_domain}}": domains.primaryDomain || "usbcheck.it",
      "{{primary_url}}":
        domains.primaryUrl ||
        "https://" + (domains.primaryDomain || "usbcheck.it"),
      "{{fakecheck_domain}}": domains.fakecheckDomain || "ismyusbfake.com",
      "{{fakecheck_url}}":
        domains.fakecheckUrl ||
        "https://" + (domains.fakecheckDomain || "ismyusbfake.com"),
    };

    return Object.keys(replacements).reduce((acc, token) => {
      const value = replacements[token];
      return acc.split(token).join(value);
    }, text);
  }

  // ------------------------------------------------
  // 4) Browsersprache erkennen (2-Buchstaben-Code)
  // ------------------------------------------------
  function detectBrowserLang() {
    const nav = window.navigator || {};
    const candidates = [];

    if (Array.isArray(nav.languages)) {
      candidates.push(...nav.languages);
    }
    if (typeof nav.language === "string") {
      candidates.push(nav.language);
    }
    if (typeof nav.userLanguage === "string") {
      candidates.push(nav.userLanguage);
    }

    for (const raw of candidates) {
      const code = (raw || "").slice(0, 2).toLowerCase();
      if (supportedLangs.includes(code)) {
        return code;
      }
    }
    return null;
  }

  // ---------------------------------------------
  // 5) Initiale Sprache bestimmen
  //
  // Priorität:
  //  a) URL ?lang= (falls gültig)
  //  b) localStorage (explizit gewählte Sprache)
  //  c) Browsersprache
  //  d) 'en', wenn vorhanden
  //  e) erste verfügbare Sprache
  // ---------------------------------------------
  function getInitialLang() {
    const urlParams = new URLSearchParams(window.location.search);
    const paramLang = (urlParams.get("lang") || "").toLowerCase();

    // a) URL-Parameter, wenn gültig
    if (paramLang && supportedLangs.includes(paramLang)) {
      return paramLang;
    }

    // b) localStorage (vom User über Switcher gewählt)
    const stored = (localStorage.getItem("usbcheck_lang") || "").toLowerCase();
    if (stored) {
      if (supportedLangs.includes(stored)) {
        return stored;
      }
      // Ungültigen alten Wert aufräumen
      localStorage.removeItem("usbcheck_lang");
    }

    // c) Browsersprache
    const browserLang = detectBrowserLang();
    if (browserLang) {
      return browserLang;
    }

    // d) Wenn 'en' existiert → nimm 'en'
    if (supportedLangs.includes("en")) {
      return "en";
    }

    // e) Sonst erste verfügbare Sprache
    if (supportedLangs.length > 0) {
      return supportedLangs[0];
    }

    // Worst-Case (sollte nie eintreten)
    return "en";
  }

  // ---------------------------------------------
  // 6) i18n JSON per Fetch laden
  // ---------------------------------------------
  async function loadLangFile(lang) {
    const code = (lang || "").toLowerCase();
    if (!supportedLangs.includes(code)) {
      console.warn("i18n: unsupported language in loadLangFile:", code);
      translations = {};
      return;
    }

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

  // ---------------------------------------------
  // 7) Data-i18n-Texte einsetzen
  // ---------------------------------------------
  function applyTranslations() {
    document.documentElement.setAttribute("lang", currentLang);

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

      // {year}-Platzhalter ersetzen (z. B. footer_copy)
      if (value.includes("{year}")) {
        const year = new Date().getFullYear();
        value = value.replace("{year}", year);
      }

      value = applyDomainPlaceholders(value);

      node.innerHTML = value;
    });
  }

  // ---------------------------------------------
  // 8) Label + Flag im Button aktualisieren
  // ---------------------------------------------
  function updateLangCurrentLabel(lang) {
    const code = (lang || "").toLowerCase();

    const info = availableLangs[code] || {
      code: code || "en",
      label: (code || "en").toUpperCase(),
      flag: "",
    };

    const node =
      document.getElementById("langCurrentLabel") ||
      document.getElementById("langCurrent");
    if (!node) return;

    const flag = info.flag || "";
    const label = info.label || info.code.toUpperCase();

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

  // ---------------------------------------------
  // 9) Sprache setzen (via Switcher)
  //
  // - akzeptiert nur Sprachen aus availableLangs
  // - speichert in localStorage
  // - schreibt ?lang= in die URL
  // - lädt Seite neu, damit PHP + JS synchron sind
  // ---------------------------------------------
  function setLang(lang) {
    const code = (lang || "").toLowerCase();
    if (!supportedLangs.includes(code)) {
      console.warn("Unsupported language:", code, supportedLangs);
      return;
    }

    const url = new URL(window.location.href);
    url.searchParams.set("lang", code);
    localStorage.setItem("usbcheck_lang", code);

    window.location.href = url.toString();
  }

  // ---------------------------------------------
  // 10) DOM Ready
  // ---------------------------------------------
  document.addEventListener("DOMContentLoaded", async function () {
    // Initiale Sprache (kombiniert aus URL, localStorage, Browser)
    currentLang = getInitialLang();
    updateLangCurrentLabel(currentLang);

    // i18n JSON laden & Texte einsetzen
    await loadLangFile(currentLang);
    applyTranslations();

    const langCurrent = document.getElementById("langCurrent");
    const langMenu = document.getElementById("langMenu");

    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 über .lang-pill (Buttons im Dropdown)
    document.addEventListener("click", function (e) {
      const btn = e.target.closest(".lang-pill");
      if (btn) {
        const lang = btn.getAttribute("data-lang");
        if (lang) {
          // Nur wenn data-lang gesetzt ist → JS-gesteuerter Wechsel
          setLang(lang);
          e.preventDefault();
        }
      }
    });
  });
})();