/**
 * Runtime label translator for asm_ui_app.
 * Replaces hardcoded English labels/sections using Frappe Translation doctype.
 */
(function () {
  "use strict";

  var API_METHOD =
    "/api/method/translation_tool.api.translations.get_translations";
  var STORAGE_KEY = "i18nextLng";
  var VERSION = "1.0.2";

  var translations = {};
  var isArabic = false;
  var isApplying = false;
  var debounceTimer = null;
  var observer = null;
  var reapplyInterval = null;

  /** Text nodes cannot use .dataset — store originals in WeakMap */
  var textOriginals = new WeakMap();
  var trackedTextNodes = [];

  var ELEMENT_SELECTORS =
    "label, h1, h2, h3, h4, h5, h6, th, legend, nav span, aside span, [role='tab']";

  var SKIP_ANCESTOR_SELECTORS =
    "input, textarea, select, option, script, style, noscript, code, pre";

  var SKIP_VALUE_SELECTORS =
    "td, [data-value], .recharts-wrapper, .toast, [class*='toast']";

  function log() {
    if (window.__TRANSLATION_TOOL_DEBUG__) {
      console.log.apply(
        console,
        ["[translation_tool]"].concat([].slice.call(arguments))
      );
    }
  }

  function getActiveLanguage() {
    try {
      var stored = localStorage.getItem(STORAGE_KEY);
      if (stored) return stored;
    } catch (e) {
      /* ignore */
    }
    return document.documentElement.getAttribute("lang") || "en";
  }

  function shouldTranslate() {
    var lang = getActiveLanguage();
    var dir = document.documentElement.getAttribute("dir");
    return lang === "ar" || dir === "rtl";
  }

  function parentElement(node) {
    return node && node.nodeType === Node.TEXT_NODE ? node.parentElement : node;
  }

  function shouldSkipNode(node) {
    var el = parentElement(node);
    if (!el) return true;
    if (el.closest(SKIP_ANCESTOR_SELECTORS)) return true;
    if (el.closest(SKIP_VALUE_SELECTORS)) return true;
    if (el.closest("[data-tt-skip]")) return true;
    if (el.isContentEditable) return true;
    return false;
  }

  function translateExactText(text) {
    var trimmed = (text || "").trim();
    if (!trimmed) return null;
    return translations[trimmed] || null;
  }

  function restoreOriginals(root) {
    trackedTextNodes.forEach(function (textNode) {
      if (textOriginals.has(textNode) && textNode.parentNode) {
        textNode.textContent = textOriginals.get(textNode);
      }
    });
    trackedTextNodes = [];
    textOriginals = new WeakMap();

    root.querySelectorAll("[data-tt-el-original]").forEach(function (el) {
      el.textContent = el.dataset.ttElOriginal;
      delete el.dataset.ttElOriginal;
    });

    root.querySelectorAll("[data-tt-attr-original]").forEach(function (el) {
      var attr = el.dataset.ttAttrOriginalName;
      if (attr) {
        el.setAttribute(attr, el.dataset.ttAttrOriginal);
      }
      delete el.dataset.ttAttrOriginal;
      delete el.dataset.ttAttrOriginalName;
    });
  }

  function rememberTextNode(textNode, original) {
    if (!textOriginals.has(textNode)) {
      textOriginals.set(textNode, original);
      trackedTextNodes.push(textNode);
    }
  }

  function translateTextNode(textNode) {
    if (!textNode || textNode.nodeType !== Node.TEXT_NODE) return;
    if (shouldSkipNode(textNode)) return;

    var original = textNode.textContent;
    var trimmed = original.trim();
    if (!trimmed) return;

    var translated = translateExactText(trimmed);
    if (!translated) return;

    rememberTextNode(textNode, original);

    var leading = (original.match(/^\s*/) || [""])[0];
    var trailing = (original.match(/\s*$/) || [""])[0];
    textNode.textContent = leading + translated + trailing;
  }

  function translateLeafElement(el) {
    if (!el || el.nodeType !== 1) return;
    if (shouldSkipNode(el)) return;
    if (el.childElementCount > 0) return;

    var original = el.textContent;
    var trimmed = original.trim();
    if (!trimmed) return;

    var translated = translateExactText(trimmed);
    if (!translated) return;

    if (!el.dataset.ttElOriginal) {
      el.dataset.ttElOriginal = original;
    }
    el.textContent = translated;
  }

  function translateAttributes(root) {
    root.querySelectorAll("[placeholder], [title], [aria-label]").forEach(function (el) {
      if (shouldSkipNode(el)) return;

      ["placeholder", "title", "aria-label"].forEach(function (attr) {
        var value = el.getAttribute(attr);
        if (!value) return;

        var trimmed = value.trim();
        var translated = translateExactText(trimmed);
        if (!translated) return;

        if (!el.dataset.ttAttrOriginal) {
          el.dataset.ttAttrOriginal = value;
          el.dataset.ttAttrOriginalName = attr;
        }
        el.setAttribute(attr, translated);
      });
    });
  }

  function walkAndTranslateText(root) {
    var walker = document.createTreeWalker(root, NodeFilter.SHOW_TEXT, null);
    var batch = [];
    var node;
    while ((node = walker.nextNode())) {
      batch.push(node);
    }
    batch.forEach(translateTextNode);
  }

  function applyTranslations(root) {
    if (!isArabic || !Object.keys(translations).length) return;

    isApplying = true;
    try {
      translateAttributes(root);

      root.querySelectorAll(ELEMENT_SELECTORS).forEach(translateLeafElement);

      walkAndTranslateText(root);
    } catch (err) {
      console.error("[translation_tool] applyTranslations error:", err);
    } finally {
      isApplying = false;
    }
  }

  function scheduleApply() {
    if (debounceTimer) clearTimeout(debounceTimer);
    debounceTimer = setTimeout(function () {
      var root = document.getElementById("root");
      if (!root || !isArabic) return;
      applyTranslations(root);
    }, 80);
  }

  function setupObserver() {
    var root = document.getElementById("root");
    if (!root || observer) return;

    observer = new MutationObserver(function () {
      if (isApplying || !isArabic) return;
      scheduleApply();
    });

    observer.observe(root, {
      childList: true,
      subtree: true,
      characterData: true,
    });
  }

  function setupReapplyInterval() {
    if (reapplyInterval) return;
    reapplyInterval = setInterval(function () {
      if (!isArabic) return;
      var root = document.getElementById("root");
      if (root) applyTranslations(root);
    }, 2000);
  }

  function clearReapplyInterval() {
    if (reapplyInterval) {
      clearInterval(reapplyInterval);
      reapplyInterval = null;
    }
  }

  function fetchTranslations(language) {
    var url = API_METHOD + "?language=" + encodeURIComponent(language);
    return fetch(url, {
      method: "GET",
      credentials: "include",
      headers: { Accept: "application/json" },
    })
      .then(function (res) {
        return res.json();
      })
      .then(function (payload) {
        var message = payload.message || payload;
        if (message && message.success && message.translations) {
          return message.translations;
        }
        return {};
      })
      .catch(function (err) {
        console.warn("[translation_tool] Failed to load translations:", err);
        return {};
      });
  }

  function activateArabic() {
    isArabic = true;
    return fetchTranslations("ar").then(function (map) {
      translations = map || {};
      log("Loaded", Object.keys(translations).length, "translations");
      var root = document.getElementById("root");
      if (root) applyTranslations(root);
      setupObserver();
      setupReapplyInterval();
    });
  }

  function deactivateTranslation() {
    isArabic = false;
    translations = {};
    clearReapplyInterval();
    var root = document.getElementById("root");
    if (root) restoreOriginals(root);
  }

  function syncLanguage() {
    if (shouldTranslate()) {
      activateArabic();
    } else {
      deactivateTranslation();
    }
  }

  function watchLanguageChanges() {
    var htmlObserver = new MutationObserver(function () {
      syncLanguage();
    });
    htmlObserver.observe(document.documentElement, {
      attributes: true,
      attributeFilter: ["lang", "dir"],
    });

    window.addEventListener("storage", function (event) {
      if (event.key === STORAGE_KEY) syncLanguage();
    });

    setInterval(function () {
      var active = shouldTranslate();
      if (active !== isArabic) syncLanguage();
    }, 1000);
  }

  function init() {
    if (!document.getElementById("root")) {
      document.addEventListener("DOMContentLoaded", init);
      return;
    }

    watchLanguageChanges();
    syncLanguage();
    log("label_translator initialized v" + VERSION);
  }

  init();
})();