import {
  hydrateCart,
  subscribe,
  getSnapshot,
  formatPrice,
} from "/js/cart.js";

function qs(sel, root = document) {
  return root.querySelector(sel);
}

function qsa(sel, root = document) {
  return [...root.querySelectorAll(sel)];
}

function escapeHtml(s) {
  return String(s)
    .replaceAll("&", "&")
    .replaceAll("<", "&lt;")
    .replaceAll(">", "&gt;")
    .replaceAll('"', "&quot;");
}

export function initHeader() {
  hydrateCart();

  const header = qs(".site-header");
  const mega = qs(".mega-panel");
  const backdrop = qs(".mega-backdrop");
  const drawer = qs(".mobile-drawer");
  const badge = qs("[data-cart-count]");
  const cartMenu = qs("[data-cart-menu]");
  const cartTrigger = qs("[data-cart-trigger]");
  const cartPreview = qs("[data-cart-preview]");
  const cartList = qs("[data-cart-preview-list]");
  const cartEmpty = qs("[data-cart-preview-empty]");
  const cartFoot = qs("[data-cart-preview-foot]");
  const cartTotal = qs("[data-cart-preview-total]");

  const fineHover =
    typeof window.matchMedia === "function" &&
    window.matchMedia("(hover: hover) and (pointer: fine)").matches;

  function syncBadge(snap) {
    if (!badge) return;
    badge.textContent = String(snap.itemCount);
    badge.classList.toggle("is-visible", snap.hydrated && snap.itemCount > 0);
  }

  function renderCartPreview(snap) {
    if (!cartList || !cartEmpty || !cartFoot || !cartTotal) return;
    const empty = !snap.items.length;
    cartEmpty.hidden = !empty;
    cartFoot.hidden = empty;
    cartList.hidden = empty;
    cartTotal.textContent = formatPrice(snap.subtotal);

    if (empty) {
      cartList.innerHTML = "";
      return;
    }

    cartList.innerHTML = snap.items
      .slice(0, 8)
      .map((item) => {
        const href = `/products/${escapeHtml(item.slug)}/`;
        const img = item.image
          ? `<img src="${escapeHtml(item.image)}" alt="" width="52" height="66" loading="lazy" />`
          : `<div class="cart-preview-ph" aria-hidden="true"></div>`;
        return `<a class="cart-preview-line" href="${href}">
          ${img}
          <div class="cart-preview-meta">
            <p class="cart-preview-name">${escapeHtml(item.name)}</p>
            <p class="cart-preview-qty">× ${item.quantity.toLocaleString("fa-IR")}</p>
          </div>
          <p class="cart-preview-price">${formatPrice(item.price * item.quantity)}</p>
        </a>`;
      })
      .join("");
  }

  function setCartPreviewOpen(open) {
    if (!cartMenu || !cartPreview || !cartTrigger) return;
    cartMenu.classList.toggle("is-open", open);
    cartPreview.classList.toggle("is-open", open);
    if (open) cartPreview.removeAttribute("hidden");
    else cartPreview.setAttribute("hidden", "");
    cartTrigger.setAttribute("aria-expanded", open ? "true" : "false");
  }

  function closeCartPreview() {
    setCartPreviewOpen(false);
  }

  function openCartPreview() {
    setCartPreviewOpen(true);
  }

  const sideNav = qs(".side-nav");
  const sideNavToggle = qs("[data-side-nav-toggle]");
  const SIDE_NAV_KEY = "kikomiko-side-nav-collapsed";

  function setSideNavCollapsed(collapsed) {
    if (!sideNav || !sideNavToggle) return;
    sideNav.classList.toggle("is-collapsed", collapsed);
    sideNavToggle.setAttribute("aria-expanded", collapsed ? "false" : "true");
    const label = collapsed ? "نمایش منو" : "پنهان کردن منو";
    sideNavToggle.setAttribute("aria-label", label);
    sideNavToggle.setAttribute("title", label);
    try {
      localStorage.setItem(SIDE_NAV_KEY, collapsed ? "1" : "0");
    } catch {
      /* ignore */
    }
    if (collapsed) closeMega();
  }

  function hideDesktopMenu() {
    closeMega();
    setSideNavCollapsed(true);
  }

  subscribe((snap) => {
    syncBadge(snap);
    renderCartPreview(snap);
  });
  const initial = getSnapshot();
  syncBadge(initial);
  renderCartPreview(initial);

  if (cartMenu && cartTrigger && cartPreview) {
    cartTrigger.addEventListener("click", (e) => {
      e.preventDefault();
      e.stopPropagation();
      const open = cartMenu.classList.contains("is-open");
      if (open) closeCartPreview();
      else {
        closeMega();
        openCartPreview();
      }
    });

    if (fineHover) {
      let leaveTimer = 0;
      cartMenu.addEventListener("mouseenter", () => {
        window.clearTimeout(leaveTimer);
        openCartPreview();
      });
      cartMenu.addEventListener("mouseleave", () => {
        leaveTimer = window.setTimeout(closeCartPreview, 180);
      });
    }

    document.addEventListener("click", (e) => {
      if (!(e.target instanceof Element)) return;
      if (!cartMenu.contains(e.target)) closeCartPreview();
    });

    document.addEventListener("keydown", (e) => {
      if (e.key === "Escape") closeCartPreview();
    });
  }

  function closeMega() {
    mega?.classList.remove("is-open");
    mega?.removeAttribute("data-active");
    backdrop?.classList.remove("is-open");
    backdrop?.setAttribute("hidden", "");
    header?.classList.remove("is-open");
    qsa("[data-mega-key]").forEach((b) => b.classList.remove("is-active"));
    qsa("[data-mega-pane]").forEach((pane) => {
      pane.hidden = true;
    });
    // Restore home highlight when on home
    const home = qs('.side-nav-link[href="/"]');
    if (home && (location.pathname === "/" || location.pathname === "/fa")) {
      home.classList.add("is-active");
    }
  }

  function openMega(key) {
    if (!mega) return;
    closeCartPreview();
    // Keep the side panel open while browsing mega categories
    if (sideNav?.classList.contains("is-collapsed")) {
      setSideNavCollapsed(false);
    }
    mega.setAttribute("data-active", key);
    mega.classList.add("is-open");
    header?.classList.add("is-open");
    backdrop?.classList.add("is-open");
    backdrop?.removeAttribute("hidden");
    qsa("[data-mega-pane]").forEach((pane) => {
      pane.hidden = pane.getAttribute("data-mega-pane") !== key;
    });
    qsa(".side-nav-link").forEach((b) => b.classList.remove("is-active"));
    qsa("[data-mega-key]").forEach((b) =>
      b.classList.toggle("is-active", b.getAttribute("data-mega-key") === key)
    );
  }

  qsa("[data-mega-key]").forEach((btn) => {
    btn.addEventListener("click", (e) => {
      e.preventDefault();
      e.stopPropagation();
      const key = btn.getAttribute("data-mega-key");
      if (!key) return;
      const open = mega?.getAttribute("data-active") === key;
      if (open) {
        closeMega();
        return;
      }
      openMega(key);
    });
  });

  // Close mega immediately when any link inside it is chosen
  // (categories, view-all, featured products, collection title).
  mega?.addEventListener(
    "click",
    (e) => {
      const link = e.target instanceof Element ? e.target.closest("a[href]") : null;
      if (!link || !mega.contains(link)) return;
      hideDesktopMenu();
    },
    true
  );

  // Home / offers links in side nav should close mega + collapse panel
  qsa(".side-nav-link[href]").forEach((link) => {
    link.addEventListener("click", () => hideDesktopMenu());
  });

  // Highlight active offers item
  if (location.pathname.startsWith("/offers")) {
    qsa(".side-nav-link").forEach((el) => el.classList.remove("is-active"));
    qs(
      '.side-nav-link[href="/offers/"], .side-nav-link[href="/offers"]'
    )?.classList.add("is-active");
  }

  // Do not use mouseleave — it fights with clicks on mega links.
  backdrop?.addEventListener("click", closeMega);
  qs("[data-mega-close]")?.addEventListener("click", closeMega);

  function closeDrawer(e) {
    e?.preventDefault?.();
    e?.stopPropagation?.();
    drawer?.classList.remove("is-open");
    drawer?.setAttribute("aria-hidden", "true");
    document.body.style.overflow = "";
    qsa("[data-mobile-sub]").forEach((p) => p.classList.remove("is-open"));
    qsa(".mobile-cat").forEach((c) => c.classList.remove("is-expanded"));
  }

  function openDrawer(e) {
    e?.preventDefault?.();
    drawer?.classList.add("is-open");
    drawer?.setAttribute("aria-hidden", "false");
    document.body.style.overflow = "hidden";
    closeMega();
    closeCartPreview();
  }

  qs("[data-menu-open]")?.addEventListener("click", openDrawer);
  qsa("[data-menu-close]").forEach((el) => {
    el.addEventListener("click", closeDrawer);
  });

  qsa("[data-mobile-expand]").forEach((btn) => {
    btn.addEventListener("click", () => {
      const id = btn.getAttribute("data-mobile-expand");
      const panel = qs(`[data-mobile-sub="${id}"]`);
      const cat = btn.closest(".mobile-cat");
      const open = panel?.classList.contains("is-open");
      qsa("[data-mobile-sub]").forEach((p) => p.classList.remove("is-open"));
      qsa(".mobile-cat").forEach((c) => c.classList.remove("is-expanded"));
      if (!open) {
        panel?.classList.add("is-open");
        cat?.classList.add("is-expanded");
      }
    });
  });

  // Highlight current route in the mobile drawer
  const path = window.location.pathname.replace(/\/+$/, "") || "/";
  qsa(".mobile-nav a[href]").forEach((a) => {
    const href = (a.getAttribute("href") || "").replace(/\/+$/, "") || "/";
    if (href === path || (href !== "/" && path.startsWith(href))) {
      a.setAttribute("aria-current", "page");
      a.classList.add("is-active");
    }
  });

  try {
    if (localStorage.getItem(SIDE_NAV_KEY) === "1") {
      setSideNavCollapsed(true);
    }
  } catch {
    /* ignore */
  }

  sideNavToggle?.addEventListener("click", (e) => {
    e.preventDefault();
    e.stopPropagation();
    setSideNavCollapsed(!sideNav?.classList.contains("is-collapsed"));
  });

  document.addEventListener("keydown", (e) => {
    if (e.key === "Escape") {
      closeMega();
      closeDrawer();
      closeCartPreview();
    }
  });
}