"use client";

import Image from "next/image";
import Link from "next/link";
import { usePathname, useSearchParams } from "next/navigation";
import { ChevronDown, Heart, LayoutGrid, Menu, MessageCircle, PackageCheck, ShoppingCart, UserRound } from "lucide-react";
import { Suspense, useEffect, useMemo, useRef, useState } from "react";
import { PredictiveSearch } from "@/components/search/predictive-search";
import { Button } from "@/components/ui/button";
import { Dialog, DialogContent } from "@/components/ui/dialog";
import { Sheet, SheetContent, SheetDescription, SheetHeader, SheetTitle } from "@/components/ui/sheet";
import type { Category, Product } from "@/lib/headless/types";
import { useCartStore } from "@/store/cart-store";
import { useWishlistStore } from "@/store/wishlist-store";

type CategoryNode = Category & { children: Category[] };

function buildCategoryTree(categories: Category[]): CategoryNode[] {
  return categories
    .filter((category) => !category.parentId)
    .map((root) => ({
      ...root,
      children: categories.filter((category) => category.parentId === root.id),
    }));
}

export function Navbar({ products, categories }: { products: Product[]; categories: Category[] }) {
  const [menuOpen, setMenuOpen] = useState(false);
  const [accountOpen, setAccountOpen] = useState(false);
  const items = useCartStore((state) => state.items);
  const cartHydrated = useCartStore((state) => state.hasHydrated);
  const openCart = useCartStore((state) => state.openCart);
  const wishlistProducts = useWishlistStore((state) => state.products);
  const wishlistHydrated = useWishlistStore((state) => state.hasHydrated);
  const openWishlist = useWishlistStore((state) => state.openWishlist);
  const count = cartHydrated ? items.reduce((sum, item) => sum + item.quantity, 0) : 0;
  const wishlistCount = wishlistHydrated ? wishlistProducts.length : 0;

  const tree = useMemo(() => buildCategoryTree(categories), [categories]);
  // Derivado de los productos reales (no de un endpoint de colecciones):
  // solo aparecen colecciones que de verdad tienen productos hoy.
  const collections = useMemo(
    () => [...new Set(products.map((product) => product.collection).filter(Boolean))],
    [products],
  );

  return (
    <header className="sticky top-0 z-40 border-b border-slate-200/80 bg-white/95 shadow-sm backdrop-blur-xl">
      <div className="bg-gradient-to-r from-amber-300 via-yellow-200 to-lime-200 px-4 py-2 text-center text-xs font-black text-slate-950 sm:text-sm">
        Paga tus compras a cuotas · Envíos nacionales · <span className="underline decoration-2 underline-offset-2">Compra segura con ARI</span>
      </div>

      <div className="relative overflow-visible bg-white">
        <div className="pointer-events-none absolute inset-x-0 top-0 h-1 bg-gradient-to-r from-cyan-400 via-violet-500 to-fuchsia-500" />
        <div className="mx-auto grid max-w-7xl grid-cols-[72px_1fr_auto] items-center gap-4 px-4 py-4 lg:grid-cols-[92px_minmax(420px,1fr)_auto] lg:gap-8">
          <Link href="/" className="relative size-16 overflow-hidden rounded-full border-2 border-slate-900 bg-black shadow-lg lg:size-20">
            <Image src="/images/brand/logo-ari.png" alt="ARI Shopping" fill priority sizes="80px" className="object-cover" />
          </Link>
          <PredictiveSearch products={products} />
          <div className="flex items-center gap-2">
            <Button variant="outline" size="icon" aria-label="Mi cuenta" className="hidden border-slate-300 bg-white text-slate-900 hover:border-violet-400 hover:bg-violet-50 sm:inline-flex" onClick={() => setAccountOpen(true)}><UserRound /></Button>
            <Button variant="outline" size="icon" aria-label={`Favoritos: ${wishlistCount}`} className="relative hidden border-slate-300 bg-white text-slate-900 hover:border-fuchsia-400 hover:bg-fuchsia-50 sm:inline-flex" onClick={openWishlist}>
              <Heart />
              {wishlistCount > 0 && <span className="absolute -right-1.5 -top-1.5 grid size-5 place-items-center rounded-full bg-violet-600 text-[10px] font-black text-white">{wishlistCount}</span>}
            </Button>
            <Button variant="magenta" size="icon" onClick={openCart} aria-label={`Carrito con ${count} productos`} className="relative shadow-lg shadow-fuchsia-500/20">
              <ShoppingCart />
              <span className="absolute -right-2 -top-2 grid size-6 place-items-center rounded-full bg-yellow-300 text-[11px] font-black text-slate-950">{count}</span>
            </Button>
          </div>
        </div>
      </div>

      <Suspense fallback={<DesktopCategoryNavigationFallback tree={tree} onOpenMenu={() => setMenuOpen(true)} />}>
        <DesktopCategoryNavigation tree={tree} onOpenMenu={() => setMenuOpen(true)} />
      </Suspense>

      <Sheet open={menuOpen} onOpenChange={setMenuOpen}>
        <SheetContent side="left" className="max-w-sm">
          <SheetHeader>
            <SheetTitle>Explora ARI</SheetTitle>
            <SheetDescription>Categorías y colecciones del catálogo.</SheetDescription>
          </SheetHeader>
          <div className="flex-1 overflow-y-auto p-6">
            <p className="mb-3 text-xs font-black uppercase tracking-[.16em] text-fuchsia-600">Categorías</p>
            <div className="grid gap-2">
              <Suspense fallback={<MobileCategoryLinksFallback tree={tree} onNavigate={() => setMenuOpen(false)} />}>
                <MobileCategoryLinks tree={tree} onNavigate={() => setMenuOpen(false)} />
              </Suspense>
            </div>
            {collections.length > 0 && (
              <>
                <p className="mb-3 mt-8 text-xs font-black uppercase tracking-[.16em] text-violet-600">Colecciones</p>
                <div className="flex flex-wrap gap-2">
                  {collections.map((collection) => <Link key={collection} href={`/catalog?collection=${encodeURIComponent(collection)}`} onClick={() => setMenuOpen(false)} className="rounded-full bg-slate-100 px-4 py-2 text-sm font-bold hover:bg-violet-100 hover:text-violet-700">{collection}</Link>)}
                </div>
              </>
            )}
            <div className="mt-8 grid grid-cols-2 gap-3 sm:hidden">
              <Button variant="outline" onClick={() => { setMenuOpen(false); setAccountOpen(true); }}><UserRound className="size-4" />Cuenta</Button>
              <Button variant="outline" onClick={() => { setMenuOpen(false); openWishlist(); }}><Heart className="size-4" />Favoritos</Button>
            </div>
          </div>
        </SheetContent>
      </Sheet>

      <Dialog open={accountOpen} onOpenChange={setAccountOpen}>
        <DialogContent className="max-w-lg p-7">
          <div className="pr-10">
            <span className="text-xs font-black uppercase tracking-[.16em] text-violet-600">Atención personalizada</span>
            <h2 className="mt-3 text-3xl font-black">Tu cuenta ARI</h2>
            <p className="mt-3 text-sm leading-6 text-slate-600">El inicio de sesión quedará conectado al backend headless. Mientras tanto, puedes gestionar pedidos y disponibilidad directamente por WhatsApp.</p>
            <div className="mt-6 grid gap-3">
              <Button asChild variant="magenta" size="lg"><a href={process.env.NEXT_PUBLIC_WHATSAPP_URL ?? "https://wa.link/rvcqqc"} target="_blank" rel="noopener noreferrer"><MessageCircle />Hablar con ARI</a></Button>
              <Button asChild variant="outline"><Link href="/catalog" onClick={() => setAccountOpen(false)}><PackageCheck />Ver mis opciones de compra</Link></Button>
            </div>
          </div>
        </DialogContent>
      </Dialog>
    </header>
  );
}

function useCategoryNavigationState() {
  const pathname = usePathname();
  const searchParams = useSearchParams();
  const currentCategory = searchParams.get("category") ?? "";
  const isCatalog = pathname === "/catalog";

  return {
    isAllActive: isCatalog && !currentCategory,
    isActive: (name: string) => isCatalog && currentCategory === name,
  };
}

function pillClass(active: boolean): string {
  return `shrink-0 rounded-full px-4 py-2 text-sm font-extrabold transition ${
    active
      ? "bg-gradient-to-r from-cyan-500 to-violet-500 text-white shadow-lg shadow-violet-950/30"
      : "text-white/90 hover:bg-gradient-to-r hover:from-cyan-500 hover:to-violet-500 hover:text-white"
  }`;
}

function mobileLinkClass(active: boolean): string {
  return `rounded-2xl border px-4 py-3 font-extrabold transition ${
    active
      ? "border-violet-500 bg-violet-50 text-violet-700"
      : "border-slate-200 hover:border-cyan-400 hover:bg-cyan-50"
  }`;
}

function DesktopCategoryNavigation({ tree, onOpenMenu }: { tree: CategoryNode[]; onOpenMenu: () => void }) {
  const { isActive, isAllActive } = useCategoryNavigationState();
  return <CategoryNavBar tree={tree} onOpenMenu={onOpenMenu} isActive={isActive} isAllActive={isAllActive} />;
}

function DesktopCategoryNavigationFallback({ tree, onOpenMenu }: { tree: CategoryNode[]; onOpenMenu: () => void }) {
  return <CategoryNavBar tree={tree} onOpenMenu={onOpenMenu} isActive={() => false} isAllActive={false} />;
}

function CategoryNavBar({
  tree,
  onOpenMenu,
  isActive,
  isAllActive,
}: {
  tree: CategoryNode[];
  onOpenMenu: () => void;
  isActive: (name: string) => boolean;
  isAllActive: boolean;
}) {
  return (
    <nav className="border-b-4 border-fuchsia-500 bg-slate-950 text-white">
      <div className="mx-auto flex max-w-7xl items-center gap-1 px-4 py-2">
        <Button
          variant="ghost"
          size="icon"
          onClick={onOpenMenu}
          aria-label="Abrir menú principal"
          className="mr-2 shrink-0 text-white hover:bg-white/10"
        >
          <Menu />
        </Button>

        <DepartmentsMegaMenu tree={tree} isActive={isActive} />

        <Link href="/catalog" prefetch={false} aria-current={isAllActive ? "page" : undefined} className={pillClass(isAllActive)}>
          Todo
        </Link>
      </div>
    </nav>
  );
}

function DepartmentsMegaMenu({ tree, isActive }: { tree: CategoryNode[]; isActive: (name: string) => boolean }) {
  const [open, setOpen] = useState(false);
  const containerRef = useRef<HTMLDivElement>(null);

  useEffect(() => {
    if (!open) return;
    function handlePointerDown(event: PointerEvent) {
      if (containerRef.current && !containerRef.current.contains(event.target as Node)) setOpen(false);
    }
    function handleKeyDown(event: KeyboardEvent) {
      if (event.key === "Escape") setOpen(false);
    }
    document.addEventListener("pointerdown", handlePointerDown);
    document.addEventListener("keydown", handleKeyDown);
    return () => {
      document.removeEventListener("pointerdown", handlePointerDown);
      document.removeEventListener("keydown", handleKeyDown);
    };
  }, [open]);

  return (
    <div ref={containerRef} className="relative shrink-0" onMouseEnter={() => setOpen(true)} onMouseLeave={() => setOpen(false)}>
      <button
        type="button"
        onClick={() => setOpen((value) => !value)}
        aria-expanded={open}
        aria-haspopup="true"
        className={`flex items-center gap-1.5 ${pillClass(open)}`}
      >
        <LayoutGrid className="size-4" />
        Departamentos
        <ChevronDown className={`size-3.5 opacity-70 transition-transform ${open ? "rotate-180" : ""}`} />
      </button>

      {open && (
        <div className="absolute left-0 top-full z-50 mt-1 w-[min(92vw,64rem)] rounded-2xl border border-slate-800 bg-slate-950 p-6 shadow-2xl">
          <div className="grid grid-cols-2 gap-x-6 gap-y-5 sm:grid-cols-3 lg:grid-cols-6">
            {tree.map((root) => (
              <div key={root.id}>
                <Link
                  href={`/catalog?category=${encodeURIComponent(root.name)}`}
                  prefetch={false}
                  aria-current={isActive(root.name) ? "page" : undefined}
                  onClick={() => setOpen(false)}
                  className={`block text-sm font-black uppercase tracking-wide transition ${
                    isActive(root.name) ? "text-fuchsia-400" : "text-white hover:text-fuchsia-400"
                  }`}
                >
                  {root.name}
                </Link>
                {root.children.length > 0 && (
                  <ul className="mt-2.5 grid gap-1.5">
                    {root.children.map((child) => (
                      <li key={child.id}>
                        <Link
                          href={`/catalog?category=${encodeURIComponent(child.name)}`}
                          prefetch={false}
                          aria-current={isActive(child.name) ? "page" : undefined}
                          onClick={() => setOpen(false)}
                          className={`block text-sm transition ${isActive(child.name) ? "font-bold text-violet-300" : "text-white/70 hover:text-white"}`}
                        >
                          {child.name}
                        </Link>
                      </li>
                    ))}
                  </ul>
                )}
              </div>
            ))}
          </div>
        </div>
      )}
    </div>
  );
}

function MobileCategoryLinks({ tree, onNavigate }: { tree: CategoryNode[]; onNavigate: () => void }) {
  const { isActive, isAllActive } = useCategoryNavigationState();

  return (
    <>
      <Link
        href="/catalog"
        prefetch={false}
        aria-current={isAllActive ? "page" : undefined}
        onClick={onNavigate}
        className={mobileLinkClass(isAllActive)}
      >
        Todo el catálogo
      </Link>

      {tree.map((root) => (
        <div key={root.id} className="contents">
          <Link
            href={`/catalog?category=${encodeURIComponent(root.name)}`}
            prefetch={false}
            aria-current={isActive(root.name) ? "page" : undefined}
            onClick={onNavigate}
            className={mobileLinkClass(isActive(root.name))}
          >
            {root.name}
          </Link>
          {root.children.map((child) => (
            <Link
              key={child.id}
              href={`/catalog?category=${encodeURIComponent(child.name)}`}
              prefetch={false}
              aria-current={isActive(child.name) ? "page" : undefined}
              onClick={onNavigate}
              className={`${mobileLinkClass(isActive(child.name))} ml-4 text-sm`}
            >
              {child.name}
            </Link>
          ))}
        </div>
      ))}
    </>
  );
}

function MobileCategoryLinksFallback({ tree, onNavigate }: { tree: CategoryNode[]; onNavigate: () => void }) {
  return (
    <>
      <Link href="/catalog" prefetch={false} onClick={onNavigate} className={mobileLinkClass(false)}>
        Todo el catálogo
      </Link>

      {tree.map((root) => (
        <div key={root.id} className="contents">
          <Link href={`/catalog?category=${encodeURIComponent(root.name)}`} prefetch={false} onClick={onNavigate} className={mobileLinkClass(false)}>
            {root.name}
          </Link>
          {root.children.map((child) => (
            <Link
              key={child.id}
              href={`/catalog?category=${encodeURIComponent(child.name)}`}
              prefetch={false}
              onClick={onNavigate}
              className={`${mobileLinkClass(false)} ml-4 text-sm`}
            >
              {child.name}
            </Link>
          ))}
        </div>
      ))}
    </>
  );
}