(() => {
  "use strict";

  const embedded = JSON.parse(document.getElementById("docslib-manifest").textContent);
  const config = JSON.parse(document.getElementById("docslib-config").textContent);
  const elements = {
    title: document.getElementById("site-title"),
    tree: document.getElementById("page-tree"),
    content: document.getElementById("content"),
    breadcrumbs: document.getElementById("breadcrumbs"),
    previous: document.getElementById("previous-page"),
    next: document.getElementById("next-page"),
    status: document.getElementById("update-status"),
    searchDialog: document.getElementById("search-dialog"),
    searchInput: document.getElementById("search-input"),
    searchResults: document.getElementById("search-results"),
    themeIcon: document.getElementById("theme-icon"),
    headerButtons: document.getElementById("header-buttons"),
    headerActions: document.getElementById("header-actions"),
    headerActionsAnchor: document.getElementById("header-actions-anchor"),
    openActions: document.getElementById("open-actions"),
    workspace: document.querySelector(".workspace"),
  };
  let manifest = embedded;
  let currentNumber = null;
  const mobileLayout = matchMedia("(max-width: 800px)");

  const dbPromise = new Promise((resolve, reject) => {
    if (!window.indexedDB) return reject(new Error("IndexedDB unavailable"));
    const request = indexedDB.open("docslib-cache", 1);
    request.onupgradeneeded = () => request.result.createObjectStore("manifests");
    request.onsuccess = () => resolve(request.result);
    request.onerror = () => reject(request.error);
  });

  async function cacheGet() {
    const db = await dbPromise;
    return new Promise((resolve, reject) => {
      const request = db.transaction("manifests", "readonly").objectStore("manifests").get(config.cacheKey);
      request.onsuccess = () => resolve(request.result);
      request.onerror = () => reject(request.error);
    });
  }

  async function cachePut(value) {
    const db = await dbPromise;
    return new Promise((resolve, reject) => {
      const transaction = db.transaction("manifests", "readwrite");
      transaction.objectStore("manifests").put(value, config.cacheKey);
      transaction.oncomplete = resolve;
      transaction.onerror = () => reject(transaction.error);
    });
  }

  function manifestIdentity(value = manifest) {
    const updated = String(value.updated_at || "")
      .replace("T", " ")
      .replace(/\.\d+(?=Z|[+-])/, "")
      .replace("+00:00", "Z");
    const revision = String(value.revision || "").slice(0, 8);
    return [updated, revision].filter(Boolean).join(" · ") || "—";
  }

  function setStatus(state = "", detail = "") {
    elements.status.className = `update-status ${state}`.trim();
    elements.status.querySelector("span").textContent = manifestIdentity();
    elements.status.title = detail || String(manifest.revision || "");
  }

  function routeNumber() {
    const match = location.hash.match(/^#\/page\/(.+)$/);
    return match ? decodeURIComponent(match[1]) : null;
  }

  function navigate(number, replace = false) {
    const hash = `#/page/${encodeURIComponent(number)}`;
    if (replace) history.replaceState(null, "", hash);
    else if (location.hash !== hash) location.hash = hash;
    renderPage(number);
    document.body.classList.remove("sidebar-open");
    document.body.classList.remove("actions-open");
  }

  function placeHeaderActions() {
    if (mobileLayout.matches) {
      if (elements.headerActions.parentElement !== document.body) document.body.append(elements.headerActions);
    } else {
      if (elements.headerActions.previousElementSibling !== elements.headerActionsAnchor) {
        elements.headerActionsAnchor.after(elements.headerActions);
      }
      document.body.classList.remove("actions-open");
    }
  }

  function makeTree() {
    elements.tree.replaceChildren();
    const root = { children: new Map(), page: null };
    manifest.pages.forEach((page) => {
      let node = root;
      page.number.split(".").forEach((part) => {
        if (!node.children.has(part)) node.children.set(part, { children: new Map(), page: null });
        node = node.children.get(part);
      });
      node.page = page;
    });
    const appendNodes = (parent, node) => {
      node.children.forEach((child) => {
        const group = document.createElement("div");
        group.className = "tree-group";
        if (child.page) {
          const button = document.createElement("button");
          button.className = "tree-link";
          button.dataset.page = child.page.number;
          const number = document.createElement("span");
          number.className = "tree-number";
          number.textContent = child.page.number;
          const title = document.createElement("span");
          title.className = "tree-title";
          title.textContent = child.page.title;
          button.append(number, title);
          button.addEventListener("click", () => navigate(child.page.number));
          group.append(button);
        }
        if (child.children.size) {
          const nested = document.createElement("div");
          nested.className = "tree-children";
          appendNodes(nested, child);
          group.append(nested);
        }
        parent.append(group);
      });
    };
    appendNodes(elements.tree, root);
  }

  function assetDataUri(name) {
    const asset = manifest.assets && manifest.assets[name];
    return asset ? `data:${asset.mime};base64,${asset.data}` : "";
  }

  function hydrateAssets() {
    elements.content.querySelectorAll("[data-docslib-asset]").forEach((element) => {
      const name = element.dataset.docslibAsset;
      const uri = assetDataUri(name);
      if (uri && element.tagName === "IMG") element.src = uri;
      else if (!uri) {
        element.setAttribute("title", name);
        element.classList.add("missing-asset");
      }
    });
  }

  function renderPage(number) {
    if (!manifest.pages.length) {
      elements.content.replaceChildren();
      elements.previous.disabled = elements.next.disabled = true;
      return;
    }
    let index = manifest.pages.findIndex((page) => page.number === number);
    if (index < 0) index = 0;
    const page = manifest.pages[index];
    currentNumber = page.number;
    if (routeNumber() !== page.number) history.replaceState(null, "", `#/page/${encodeURIComponent(page.number)}`);
    document.title = `${page.title} · ${manifest.title}`;
    elements.content.innerHTML = page.content || "";
    hydrateAssets();
    elements.content.querySelectorAll("a[href^='#/page/']").forEach((link) => {
      link.addEventListener("click", (event) => {
        if (event.button !== 0 || event.metaKey || event.ctrlKey || event.shiftKey || event.altKey) return;
        event.preventDefault();
        navigate(decodeURIComponent(link.hash.slice(7)));
      });
    });
    elements.tree.querySelectorAll(".tree-link").forEach((button) => button.classList.toggle("active", button.dataset.page === page.number));
    elements.headerButtons.querySelectorAll("[data-page]").forEach((button) => {
      const target = button.dataset.page;
      button.classList.toggle("active", page.number === target || page.number.startsWith(`${target}.`));
    });
    elements.breadcrumbs.replaceChildren();
    const numberParts = page.number.split(".");
    numberParts.forEach((_, partIndex) => {
      const candidate = manifest.pages.find((item) => item.number === numberParts.slice(0, partIndex + 1).join("."));
      if (candidate) {
        const crumb = document.createElement("span");
        crumb.textContent = candidate.title;
        elements.breadcrumbs.append(crumb);
      }
    });
    setupNavButton(elements.previous, manifest.pages[index - 1], "←");
    setupNavButton(elements.next, manifest.pages[index + 1], "→");
    elements.content.focus({ preventScroll: true });
    elements.workspace.scrollTo({ top: 0, behavior: "instant" });
  }

  function setupNavButton(button, page, direction) {
    button.disabled = !page;
    button.replaceChildren();
    if (!page) return;
    const small = document.createElement("small");
    small.textContent = direction;
    const title = document.createElement("span");
    title.textContent = page.title;
    button.append(small, title);
    button.onclick = () => navigate(page.number);
  }

  function renderHeaderButtons() {
    elements.headerButtons.replaceChildren();
    const buttons = (manifest.ui && manifest.ui.header_buttons) || [];
    buttons.forEach((button) => {
      if (!button.label || (!button.href && !button.page)) return;
      const link = document.createElement("a");
      link.className = "header-link";
      link.textContent = button.label;
      if (button.page) {
        link.href = `#/page/${encodeURIComponent(button.page)}`;
        link.dataset.page = button.page;
        link.addEventListener("click", (event) => {
          if (event.button !== 0 || event.metaKey || event.ctrlKey || event.shiftKey || event.altKey) return;
          event.preventDefault();
          navigate(button.page);
        });
      } else {
        link.href = button.href;
      }
      if (!button.page && button.target === "_blank") {
        link.target = "_blank";
        link.rel = "noopener noreferrer";
      }
      link.addEventListener("click", () => document.body.classList.remove("actions-open"));
      elements.headerButtons.append(link);
    });
    elements.openActions.hidden = buttons.length === 0;
  }

  function renderAll() {
    document.documentElement.lang = "und";
    elements.title.textContent = manifest.title;
    makeTree();
    renderHeaderButtons();
    renderPage(routeNumber() || currentNumber || (manifest.pages[0] && manifest.pages[0].number));
    setStatus();
  }

  function plainText(html) {
    const node = document.createElement("div");
    node.innerHTML = html;
    return (node.textContent || "").replace(/\s+/g, " ").trim();
  }

  function search(query) {
    const needle = query.trim().toLocaleLowerCase();
    const matches = !needle ? manifest.pages : manifest.pages.filter((page) =>
      `${page.number} ${page.title} ${plainText(page.content)}`.toLocaleLowerCase().includes(needle)
    );
    elements.searchResults.replaceChildren();
    matches.slice(0, 30).forEach((page) => {
      const button = document.createElement("button");
      button.className = "search-result";
      const title = document.createElement("strong");
      title.textContent = `${page.number}  ${page.title}`;
      const excerpt = document.createElement("span");
      excerpt.textContent = plainText(page.content).slice(0, 150) || "—";
      button.append(title, excerpt);
      button.addEventListener("click", () => {
        elements.searchDialog.close();
        navigate(page.number);
      });
      elements.searchResults.append(button);
    });
    if (!matches.length) elements.searchResults.innerHTML = '<div class="empty-state">∅</div>';
  }

  function openSearch() {
    if (!elements.searchDialog.open) elements.searchDialog.showModal();
    elements.searchInput.value = "";
    search("");
    setTimeout(() => elements.searchInput.focus(), 0);
  }

  function applyTheme(theme) {
    document.documentElement.dataset.theme = theme;
    elements.themeIcon.textContent = theme === "dark" ? "☀" : "◐";
    localStorage.setItem("docslib-theme", theme);
  }

  async function syncManifest({ reload = true } = {}) {
    setStatus("syncing");
    try {
      const response = await fetch(config.manifestUrl, { cache: "no-store" });
      if (!response.ok) throw new Error(`HTTP ${response.status}`);
      const remote = await response.json();
      if (!remote.schema_version || !Array.isArray(remote.pages)) throw new Error("Invalid manifest");
      if (remote.revision !== manifest.revision || remote.updated_at !== manifest.updated_at) {
        await cachePut(remote).catch(() => {});
        manifest = remote;
        if (reload) {
          sessionStorage.setItem("docslib-updated", remote.revision || remote.updated_at);
          location.reload();
          return;
        }
        renderAll();
        setStatus();
      } else {
        setStatus();
      }
    } catch (error) {
      setStatus("error", String(error));
      console.warn("SharedDocsLib update check failed:", error);
    }
  }

  async function pollLive() {
    try {
      const response = await fetch(config.liveUrl, { cache: "no-store" });
      if (!response.ok) return;
      const live = await response.json();
      if (live.error) setStatus("error", live.error);
      else if (live.revision && live.revision !== manifest.revision) await syncManifest({ reload: false });
    } catch (_) { /* The normal manifest remains usable when the dev server stops. */ }
  }

  async function start() {
    applyTheme(localStorage.getItem("docslib-theme") || (matchMedia("(prefers-color-scheme: dark)").matches ? "dark" : "light"));
    try {
      const cached = await cacheGet();
      if (
        cached &&
        cached.schema_version === embedded.schema_version &&
        String(cached.updated_at || "") >= String(embedded.updated_at || "")
      ) manifest = cached;
      else await cachePut(embedded);
    } catch (error) {
      console.warn("SharedDocsLib cache unavailable:", error);
    }
    renderAll();
    if (sessionStorage.getItem("docslib-updated")) sessionStorage.removeItem("docslib-updated");
    syncManifest();
    if (config.livePreview) setInterval(pollLive, 1200);
  }

  document.getElementById("search-button").addEventListener("click", openSearch);
  document.getElementById("close-search").addEventListener("click", () => elements.searchDialog.close());
  elements.searchInput.addEventListener("input", () => search(elements.searchInput.value));
  document.getElementById("theme-button").addEventListener("click", () => applyTheme(document.documentElement.dataset.theme === "dark" ? "light" : "dark"));
  document.getElementById("open-sidebar").addEventListener("click", () => document.body.classList.add("sidebar-open"));
  document.getElementById("close-sidebar").addEventListener("click", () => document.body.classList.remove("sidebar-open"));
  document.getElementById("sidebar-overlay").addEventListener("click", () => document.body.classList.remove("sidebar-open"));
  document.getElementById("open-actions").addEventListener("click", () => document.body.classList.add("actions-open"));
  document.getElementById("close-actions").addEventListener("click", () => document.body.classList.remove("actions-open"));
  document.getElementById("actions-overlay").addEventListener("click", () => document.body.classList.remove("actions-open"));
  if (mobileLayout.addEventListener) mobileLayout.addEventListener("change", placeHeaderActions);
  else mobileLayout.addListener(placeHeaderActions);
  window.addEventListener("hashchange", () => renderPage(routeNumber()));
  window.addEventListener("keydown", (event) => {
    if ((event.ctrlKey || event.metaKey) && event.key.toLowerCase() === "k") { event.preventDefault(); openSearch(); }
    if (event.key === "Escape" && elements.searchDialog.open) elements.searchDialog.close();
  });
  placeHeaderActions();
  start();
})();