"use client";
import { useState, useMemo, useEffect } from "react";
import { motion, AnimatePresence } from "motion/react";
import {
  ArrowRight,
  Calculator as CalcIcon,
  ChevronLeft,
  ShieldCheck,
  CheckCircle2,
  Clock,
  FlaskConical,
  Stethoscope,
  Info,
  CalendarDays,
  Dog,
  Gamepad2,
  X,
  Plus,
  Minus,
  Bell,
  Sparkles,
  ChevronRight,
  ChevronDown,
  Activity,
  Heart,
  Zap,
  Flame,
  Star,
  Users,
  ShoppingBag
} from "lucide-react";

const ICON_MAP: Record<string, any> = {
  Sparkles,
  Activity,
  ShieldCheck,
  Heart,
  Zap,
  Flame,
  Star,
  Users
};
import { toPersian, cn } from "../lib/utils";
import { Product, PRODUCTS } from "../lib/data/products";
import { productService } from "../lib/services/productService";
import { SCIENTIFIC_TERMS } from "../lib/data/scientificTerms";
import { useSettingsStore } from "../lib/store/settingsStore";
import { create } from "zustand";
import { useCartStore } from "../lib/store/cartStore";
import { usePetStore } from "../lib/store/usePetStore";
import { toast } from "sonner";

interface CalculatorState {
  petType: "young" | "adult";
  weight: number;
  setPetType: (type: "young" | "adult") => void;
  setWeight: (weight: number) => void;
}

const useCalculatorStore = create<CalculatorState>((set) => ({
  petType: "young",
  weight: 10,
  setPetType: (petType) => set({ petType }),
  setWeight: (weight) => set({ weight }),
}));

import Tooltip from "./Tooltip";
import SafeImage from "./SafeImage";

import { useRouter } from 'next/navigation';

export default function ProductPage({ productSlug }: { productSlug: string }) {
  const router = useRouter();
  const [product, setProduct] = useState<Product | null>(null);
  const [isLoading, setIsLoading] = useState(true);
  const [activeTab, setActiveTab] = useState<"specs" | "feeding" | "notes">("specs");
  const [showRefillModal, setShowRefillModal] = useState(false);
  const [itemQuantity, setItemQuantity] = useState(1);
  const [allProducts, setAllProducts] = useState<Product[]>([]);
  const [isMounted, setIsMounted] = useState(false);

  useEffect(() => {
    setIsMounted(true);
    productService.getProducts({ limit: 999 })
      .then((res) => {
        const products = res.data;
        setAllProducts(products);
        const found = products.find(p => p.slug === productSlug || p.id === productSlug);
        setProduct(found || null);
      })
      .catch(err => console.error("Error fetching products in ProductPage:", err))
      .finally(() => setIsLoading(false));
  }, [productSlug]);
  const { pets, getActivePet } = usePetStore();
  const activePet = getActivePet();
  const { petType, weight, setPetType, setWeight } = useCalculatorStore();
  const { addItem } = useCartStore();
  const scientificTerms = useSettingsStore(state => state.scientificTerms);
  const termKeys = useMemo(() => {
    return Array.from(new Set([
      ...Object.keys(scientificTerms),
      ...Object.keys(SCIENTIFIC_TERMS)
    ]));
  }, [scientificTerms]);

  // Re-hydrate product to ensure methods like calculateDosage exist
  const fullProduct = useMemo(() => {
    if (!product) return null;
    const apiProduct = allProducts.find(p => p.id === product.id) || product;
    if (!apiProduct) return null;
    const staticProduct = PRODUCTS.find(p => p.id === apiProduct.id || p.artNo === apiProduct.artNo);
    if (staticProduct) {
      return {
        ...apiProduct,
        calculateDosage: staticProduct.calculateDosage
      };
    }
    if (typeof apiProduct.calculateDosage !== 'function') {
      return {
        ...apiProduct,
        calculateDosage: (w: number, y: boolean) => {
          return {
            quantity: 1,
            unit: apiProduct.unit || "قرص",
            description: "مصرف روزانه بر اساس دستور پزشک"
          };
        }
      };
    }
    return apiProduct;
  }, [product, allProducts]);

  useEffect(() => {
    if (activePet) {
      setWeight(activePet.weight);
      setPetType(activePet.age <= 1 ? "young" : "adult");
    }
  }, [activePet, setWeight, setPetType]);

  const calculation = useMemo(() => {
    if (!fullProduct || typeof fullProduct.calculateDosage !== 'function') return null;
    const result = fullProduct.calculateDosage(weight, petType === "young");
    const duration = Math.floor(fullProduct.packageSize / result.quantity);

    return {
      dailyDose: result.quantity,
      duration: duration || 0,
      unit: result.unit,
      description: result.description
    };
  }, [fullProduct, petType, weight]);

  // Suggest quantity inside useEffect to avoid render-phase state update
  useEffect(() => {
    const duration = calculation?.duration ?? 0;
    const suggestedQty = (duration < 30 && duration > 0) ? 2 : 1;
    setItemQuantity(suggestedQty);
  }, [calculation?.duration]);

  if (isLoading) return <div className="min-h-screen flex items-center justify-center">Loading...</div>;
  if (!product || !fullProduct || !calculation) return <div className="min-h-screen flex items-center justify-center">محصول یافت نشد</div>;

  return (
    <div className="min-h-screen bg-medical-gray-50 pt-2 pb-20 px-4 md:px-0" dir="rtl">
      <div className="max-w-7xl mx-auto">
        {/* Mobile Header with Back Button */}
        <div className="flex items-center justify-between mb-6 md:hidden">
          <button
            onClick={() => router.back()}
            className="p-3 bg-white border border-medical-gray-200 rounded-2xl text-medical-gray-700 shadow-sm flex items-center gap-2 font-vazir text-sm font-bold"
          >
            <ChevronRight className="w-5 h-5" />
            بازگشت
          </button>
          <div className="text-[10px] font-black text-canina-blue bg-canina-blue/5 px-4 py-2 rounded-xl font-vazir whitespace-nowrap">
            کانینا ایران
          </div>
        </div>

        {/* Breadcrumbs */}
        <nav className="hidden md:flex items-center gap-2 text-sm font-semibold text-medical-gray-600 mb-10 overflow-x-auto whitespace-nowrap py-3 border-b border-medical-gray-100">
          <button
            onClick={() => router.push('/')}
            className="hover:text-canina-blue transition-colors font-vazir cursor-pointer"
          >
            خانه
          </button>
          <ChevronLeft className="w-3.5 h-3.5 flex-shrink-0 text-medical-gray-300" />
          <button
            onClick={() => router.push(`/shop?category=${product.categorySlug}`)}
            className="hover:text-canina-blue cursor-pointer font-vazir"
          >
            {product.category}
          </button>
          <ChevronLeft className="w-3.5 h-3.5 flex-shrink-0 text-medical-gray-300" />
          <span className="text-canina-blue font-vazir whitespace-nowrap font-bold">{product.name}</span>
        </nav>

        {/* Global Single Grid Layout - Aligns Sticky Buy Box at the Top */}
        <div className="grid lg:grid-cols-12 gap-12 items-start">
          
          {/* Right/Main Content Column (lg:col-span-8) */}
          <div className="lg:col-span-8 space-y-12">
            
            {/* Above the Fold Grid */}
            <div className="grid md:grid-cols-12 gap-12 items-start">
              {/* Right Column: Product Image Frame (md:col-span-5) */}
              <div className="md:col-span-5 w-full">
                <motion.div
                  initial={{ opacity: 0, scale: 0.95 }}
                  animate={{ opacity: 1, scale: 1 }}
                  className="bg-white rounded-[2.5rem] border border-medical-gray-200 shadow-xl relative group overflow-hidden h-[380px] flex items-center justify-center p-8"
                >
                  <div className="absolute top-6 left-6 flex flex-col gap-2 z-10">
                    <div className="px-3 py-1 bg-green-500 text-white rounded-full text-[10px] font-black uppercase tracking-widest flex items-center gap-1 font-vazir shadow-sm">
                      <CheckCircle2 className="w-3 h-3" />
                      موجود در انبار
                    </div>
                    <div className="px-3 py-1 bg-canina-blue text-white rounded-full text-[10px] font-black uppercase tracking-widest font-vazir whitespace-nowrap shadow-sm">
                      گرید دارویی اختصاصی
                    </div>
                  </div>
                  <SafeImage
                    src={product.image}
                    alt={product.name}
                    className="w-full h-full"
                    imgClassName="max-h-[300px] w-auto object-contain drop-shadow-2xl group-hover:scale-105 transition-transform duration-700 mx-auto my-auto"
                  />
                </motion.div>
              </div>

              {/* Left Column: Product Title & Description (md:col-span-7) */}
              <div className="md:col-span-7 space-y-6">
                <div>
                  <div className="flex flex-wrap items-center gap-3 mb-4">
                    <div className="px-3 py-1 bg-canina-blue text-white rounded-full text-[10px] font-black uppercase tracking-widest font-vazir whitespace-nowrap shadow-sm">
                      استاندارد صنعتی آلمان
                    </div>
                    {product.specialBadge && (
                      <div className="px-3 py-1 bg-medical-gray-900 text-white rounded-full text-[10px] font-black uppercase tracking-widest font-vazir whitespace-nowrap shadow-sm">
                        {product.specialBadge}
                      </div>
                    )}
                  </div>
                  <div className="flex flex-col gap-2 mb-4">
                    <h1 dir="rtl" className="text-2xl md:text-3xl lg:text-4xl font-black text-medical-gray-900 leading-tight font-vazir text-right">
                      {product.nameFa || product.name}
                    </h1>
                    {product.nameEn && (
                      <h2 dir="ltr" className="text-base md:text-lg text-slate-400 font-bold italic font-sans text-left">
                        {product.nameEn}
                      </h2>
                    )}
                  </div>
                  <p className="text-xl text-canina-blue font-bold italic opacity-70 leading-relaxed max-w-2xl font-vazir mb-6 text-right" dir="rtl">
                    {isMounted && pets.length > 0 ? (
                      product.optimisticTemplate?.replace("[PetName]", activePet?.name || "").replace("[OnSet]", product.onSetOfAction || "به زودی")
                    ) : (
                      product.scientificTagline
                    )}
                  </p>
                  {fullProduct.shortDescription && (
                    <p className="text-lg text-medical-gray-600 font-bold leading-relaxed max-w-3xl font-vazir border-r-4 border-canina-blue pr-6 py-2 bg-canina-blue/5 rounded-l-2xl">
                      {fullProduct.shortDescription}
                    </p>
                  )}
                </div>
              </div>
            </div>
            {/* ─── Symptoms / Therapeutic Indications Section ─── */}
            {fullProduct.symptoms && fullProduct.symptoms.length > 0 && (
              <section className="bg-canina-blue/[0.03] border border-canina-blue/10 rounded-[2rem] p-6 md:p-8 space-y-4">
                <div className="flex items-center gap-3">
                  <div className="w-9 h-9 bg-canina-blue/10 text-canina-blue rounded-xl flex items-center justify-center">
                    <Stethoscope className="w-5 h-5" />
                  </div>
                  <h3 className="text-base font-black text-medical-gray-900 font-vazir">علائم و موارد درمانی مرتبط</h3>
                </div>
                <p className="text-[12px] text-medical-gray-400 font-vazir font-bold">این محصول برای رفع علائم زیر توسط دامپزشکان توصیه می‌شود:</p>
                <div className="flex flex-wrap gap-2">
                  {fullProduct.symptoms.map((symptom: string, idx: number) => (
                    <a
                      key={idx}
                      href={`/shop?symptom=${encodeURIComponent(symptom)}`}
                      className="inline-flex items-center gap-1.5 px-3.5 py-1.5 rounded-full text-[11px] font-bold bg-white border border-canina-blue/20 text-canina-blue hover:bg-canina-blue hover:text-white hover:border-canina-blue transition-all shadow-sm cursor-pointer font-vazir whitespace-nowrap"
                    >
                      <span className="w-1.5 h-1.5 rounded-full bg-current opacity-60" />
                      {symptom}
                    </a>
                  ))}
                </div>
              </section>
            )}

            {/* Key Benefits Section */}
            {fullProduct.keyBenefits && fullProduct.keyBenefits.length > 0 && (
              <section className="space-y-8 pt-6 border-t border-medical-gray-100">
                <div className="flex items-center gap-4">
                  <div className="w-12 h-12 bg-canina-blue text-white rounded-2xl flex items-center justify-center shadow-lg">
                    <Star className="w-6 h-6" />
                  </div>
                  <h3 className="text-3xl font-black text-medical-gray-900 italic font-vazir">چرا {fullProduct.name}؟</h3>
                </div>
                <div className="grid md:grid-cols-3 gap-6">
                  {fullProduct.keyBenefits.map((benefit, i) => {
                    const Icon = ICON_MAP[benefit.icon] || CheckCircle2;
                    return (
                      <div key={i} className="bg-white border border-medical-gray-200 rounded-[2.5rem] p-8 shadow-sm hover:shadow-xl hover:-translate-y-1 transition-all group overflow-hidden relative">
                        <div className="absolute -top-10 -left-10 w-24 h-24 bg-canina-blue/5 rounded-full group-hover:scale-150 transition-transform duration-700" />
                        <div className="w-12 h-12 bg-medical-gray-50 rounded-2xl flex items-center justify-center text-canina-blue mb-6 group-hover:bg-canina-blue group-hover:text-white transition-all">
                          <Icon className="w-6 h-6" />
                        </div>
                        <h4 className="text-xl font-black text-medical-gray-900 mb-2 font-vazir">{benefit.title}</h4>
                        <p className="text-sm text-medical-gray-500 font-bold font-vazir">{benefit.description}</p>
                      </div>
                    );
                  })}
                </div>
              </section>
            )}

            {/* Comprehensive Product Description Section (Below the fold) */}
            {fullProduct.description && (
              <section className="bg-white border border-medical-gray-200 rounded-[2.5rem] p-8 md:p-10 shadow-md space-y-6">
                <div className="flex items-center gap-4">
                  <div className="w-12 h-12 bg-canina-blue text-white rounded-2xl flex items-center justify-center shadow-lg">
                    <Info className="w-6 h-6" />
                  </div>
                  <h3 className="text-2xl font-black text-medical-gray-900 italic font-vazir">توضیحات و معرفی محصول</h3>
                </div>
                <div className="text-base text-medical-gray-600 font-medium leading-loose font-vazir space-y-4 pt-4 border-t border-medical-gray-100">
                  {fullProduct.description.split('\n').filter(Boolean).map((para, pIdx) => (
                    <p key={pIdx}>{para.trim()}</p>
                  ))}
                </div>
              </section>
            )}

            {/* Smart Dosage Calculator Utility Section */}
            <section className="bg-white rounded-[2.5rem] border border-medical-gray-200 p-8 md:p-10 shadow-md space-y-8">
              <div className="flex items-center gap-4">
                <div className="w-12 h-12 bg-canina-blue text-white rounded-2xl flex items-center justify-center shadow-lg">
                  <Clock className="w-6 h-6" />
                </div>
                <div>
                  <h3 className="text-2xl font-black text-medical-gray-900 italic font-vazir">ماشین حساب هوشمند مصرف</h3>
                  <p className="text-xs text-medical-gray-400 font-bold font-vazir mt-1">تخمین دقیق دوز روزانه و ماندگاری هر بسته بر اساس مشخصات پت شما</p>
                </div>
              </div>

              <div className="grid md:grid-cols-2 gap-8 items-center">
                {/* Manual Slider Inputs */}
                <div className="bg-medical-gray-50 rounded-[2rem] p-6 border border-medical-gray-100 space-y-6">
                  <div className="flex items-center justify-between">
                    <span className="text-xs font-black text-medical-gray-500 font-vazir">وزن پت (کیلوگرم)</span>
                    <span className="text-lg font-black text-canina-blue font-vazir">{toPersian(weight)} ک‌گ</span>
                  </div>
                  <input
                    type="range"
                    min="1" max="100"
                    value={weight}
                    onChange={(e) => setWeight(parseInt(e.target.value))}
                    className="w-full h-2 bg-medical-gray-200 rounded-lg appearance-none cursor-pointer accent-canina-blue [&::-webkit-slider-thumb]:w-6 [&::-webkit-slider-thumb]:h-6 [&::-webkit-slider-thumb]:rounded-full [&::-webkit-slider-thumb]:bg-canina-blue [&::-webkit-slider-thumb]:appearance-none"
                  />
                  
                  <div className="space-y-2">
                    <span className="text-[10px] font-black text-medical-gray-400 font-vazir">سن حیوان</span>
                    <div className="flex gap-2">
                      <button onClick={() => setPetType("young")} className={`flex-1 py-3 rounded-xl text-xs font-black transition-all border ${petType === "young" ? 'bg-canina-blue border-canina-blue text-white shadow-lg' : 'bg-white border-medical-gray-200 text-medical-gray-400'}`}>جوان</button>
                      <button onClick={() => setPetType("adult")} className={`flex-1 py-3 rounded-xl text-xs font-black transition-all border ${petType === "adult" ? 'bg-canina-blue border-canina-blue text-white shadow-lg' : 'bg-white border-medical-gray-200 text-medical-gray-400'}`}>بالغ</button>
                    </div>
                  </div>
                </div>

                {/* Calculation Results Output */}
                <div className="bg-canina-blue rounded-[2rem] p-8 text-white border-b-8 border-white/20 shadow-2xl flex flex-col justify-between h-full min-h-[220px]">
                  <div className="flex items-center gap-2 mb-4 opacity-90 border-b border-white/10 pb-3">
                    <Sparkles className="w-4 h-4 text-white" />
                    <span className="text-[10px] font-bold uppercase tracking-widest font-vazir text-white">تخمین هوش مصنوعی (AI Advice)</span>
                  </div>
                  <div className="flex items-center justify-between">
                    <div>
                      <div className="text-3xl font-black font-vazir text-white">{toPersian(calculation.duration)} روز</div>
                      <div className="text-[10px] font-bold text-white/80 font-vazir whitespace-nowrap mt-1">تخمین اتمام مصرف بسته</div>
                    </div>
                    <div className="text-left">
                      <div className="text-2xl font-black font-vazir text-white">{toPersian(calculation.dailyDose)}</div>
                      <div className="text-[10px] font-bold text-white/80 font-vazir whitespace-nowrap mt-1">دوز روزانه ({calculation.unit === 'g' ? 'گرم' : calculation.unit})</div>
                    </div>
                  </div>
                  <p className="text-[11px] text-white/60 font-bold font-vazir mt-6 leading-relaxed">
                    * دوزها تخمینی هستند؛ توصیه می‌شود برای مصرف دقیق کاتالوگ محصول را مطالعه کنید.
                  </p>
                </div>
              </div>
            </section>

            {/* Ingredients Section */}
            <section className="space-y-8">
              <div className="flex items-center gap-4">
                <div className="w-12 h-12 bg-canina-blue text-white rounded-2xl flex items-center justify-center shadow-lg">
                  <FlaskConical className="w-6 h-6" />
                </div>
                <h3 className="text-3xl font-black text-medical-gray-900 italic font-vazir">ترکیبات و آنالیز علمی</h3>
              </div>

              <div className="space-y-10">
                {/* Ingredients Cards */}
                <div className="bg-white rounded-[2.5rem] p-8 md:p-10 border border-medical-gray-200 shadow-md">
                  <h4 className="text-xs font-black text-medical-gray-400 uppercase tracking-widest mb-6 font-vazir">مواد تشکیل‌دهنده برتر</h4>
                  <div className="flex flex-wrap gap-3">
                    {product.main_ingredients.map((ing, idx) => {
                      const termKey = termKeys.find(key => {
                        const termObj = scientificTerms[key] || SCIENTIFIC_TERMS[key];
                        const termName = termObj?.term || key;
                        const ingClean = ing.toLowerCase();
                        const keyClean = key.toLowerCase();
                        const termNameClean = termName.toLowerCase();
                        return ingClean.includes(keyClean) || 
                               keyClean.includes(ingClean) || 
                               ingClean.includes(termNameClean) || 
                               termNameClean.includes(ingClean);
                      });
                      return (
                        <div key={idx} className="bg-medical-gray-50 border border-medical-gray-100 px-5 py-3 rounded-2xl flex items-center gap-3 group hover:border-canina-blue/30 transition-all">
                          <span className="text-sm font-bold text-medical-gray-700 font-vazir">
                            {termKey ? (
                              <Tooltip termKey={termKey} onWikiNavigate={(id) => router.push(`/wiki?term=${id}`)}>
                                {ing}
                              </Tooltip>
                            ) : ing}
                          </span>
                          <Sparkles className="w-3 h-3 text-canina-blue opacity-40 group-hover:opacity-100 transition-opacity" />
                        </div>
                      );
                    })}
                  </div>
                </div>

                {/* Analysis Cards Grid */}
                {Object.keys(product.analysis).length > 0 && (
                  <div className="space-y-6">
                    <div className="text-[10px] font-black text-medical-gray-400 uppercase tracking-widest mb-4 font-vazir">تخمین اتمام بسته (هوش مصنوعی)</div>
                    <div className="grid grid-cols-2 gap-4">
                      {Object.entries(product.analysis).map(([key, value]) => (
                        <div key={key} className="bg-canina-blue text-white p-8 rounded-[2.5rem] border-b-2 border-white/20 shadow-xl group hover:scale-[1.02] transition-all duration-300">
                          <div className="text-[10px] font-black text-white/80 uppercase tracking-widest mb-3 font-vazir whitespace-nowrap">{key}</div>
                          <div className="text-3xl font-black font-vazir tracking-tighter text-white">{toPersian(value)}</div>
                        </div>
                      ))}
                    </div>
                  </div>
                )}
              </div>
            </section>

            {/* Feeding / Usage Instructions Section (Dynamic Header based on product category) */}
            <section className="bg-white border border-medical-gray-200 rounded-[2.5rem] p-8 md:p-10 shadow-md">
              <div className="flex items-center gap-4 mb-8">
                <div className="w-12 h-12 bg-canina-blue text-white rounded-2xl flex items-center justify-center shadow-lg">
                  <CalendarDays className="w-6 h-6" />
                </div>
                <h3 className="text-2xl font-black text-medical-gray-900 italic font-vazir">
                  {product.categorySlug === 'special-care' || product.name.toLowerCase().includes('pfotenpflege') || product.name.toLowerCase().includes('augenpflege')
                    ? 'دستورالعمل و نحوه استفاده موضعی' 
                    : 'توصیه غذایی و نحوه مصرف'}
                </h3>
              </div>
              <p className="text-medical-gray-700 leading-relaxed text-sm md:text-base font-medium font-vazir">
                {product.feedingAdvice}
              </p>
            </section>

            {/* Specialist Note */}
            {product.specialist && (
              <section className="bg-white rounded-[2.5rem] p-8 md:p-10 border border-medical-gray-200 shadow-md">
                <div className="flex flex-col md:flex-row gap-10 items-start">
                  <img
                    src={product.specialist.image}
                    alt={product.specialist.name}
                    className="w-32 h-32 rounded-[2rem] object-cover border-4 border-medical-gray-50 shadow-xl"
                  />
                  <div className="flex-1">
                    <div className="inline-flex items-center gap-2 px-3 py-1 bg-medical-gray-900 text-white rounded-full text-[10px] font-black uppercase tracking-widest mb-4 font-vazir whitespace-nowrap">
                      <Stethoscope className="w-3 h-3" />
                      مورد تأیید دامپزشکان
                    </div>
                    <h4 className="text-2xl font-black text-medical-gray-900 mb-1 font-vazir">{product.specialist.name}</h4>
                    <p className="text-sm font-bold text-canina-blue mb-6 font-vazir">{product.specialist.title}</p>
                    <p className="text-base text-medical-gray-600 leading-relaxed italic font-vazir">
                      "{product.specialist.message}"
                    </p>
                  </div>
                </div>
              </section>
            )}

            {/* Specialized Landing Banner */}
            <section>
              <div
                className="relative bg-canina-blue rounded-[2.5rem] p-12 overflow-hidden group cursor-pointer border border-medical-gray-200 shadow-md"
                onClick={() => toast.info("بزودی: صفحه فرود تخصصی این محصول در حال آماده‌سازی است")}
              >
                <div className="absolute top-0 right-0 w-full h-full bg-[url('https://www.transparenttextures.com/patterns/cubes.png')] opacity-10" />
                <div className="absolute -bottom-20 -left-20 w-80 h-80 bg-white/10 rounded-full blur-3xl group-hover:bg-white/20 transition-all duration-700" />

                <div className="relative z-10 flex flex-col md:flex-row items-center justify-between gap-8">
                  <div className="text-center md:text-right">
                    <h3 className="text-3xl lg:text-4xl font-black text-white mb-4 italic">مشاهده بررسی تخصصی و نتایج درمانی</h3>
                    <p className="text-white/80 font-bold font-vazir max-w-lg">
                      گزارش‌های علمی، ویدیوهای آموزشی و تجربیات واقعی دیگر صاحبان پت در لندینگ‌پیج اختصاصی این محصول.
                    </p>
                  </div>
                  <div className="bg-white text-canina-blue px-8 py-4 rounded-2xl font-black shadow-2xl hover:scale-105 transition-transform flex items-center gap-3">
                    ورود به آزمایشگاه علمی
                    <ArrowRight className="w-5 h-5 rotate-180" />
                  </div>
                </div>
              </div>
            </section>

            {/* FAQ Section */}
            {product.faqs && product.faqs.length > 0 && (
              <section className="pt-10">
                <div className="flex items-center gap-4 mb-10">
                  <div className="w-12 h-12 bg-blue-100 text-canina-blue rounded-2xl flex items-center justify-center">
                    <Info className="w-6 h-6" />
                  </div>
                  <h3 className="text-3xl font-black text-medical-gray-900 italic font-vazir">پاسخ به ابهامات شما</h3>
                </div>
                <div className="grid md:grid-cols-1 gap-4">
                  {product.faqs.map((faq, i) => (
                    <details key={i} className="group bg-white border border-medical-gray-200 rounded-[2rem] overflow-hidden hover:border-canina-blue/30 transition-all">
                      <summary className="flex items-center justify-between p-6 cursor-pointer list-none">
                        <span className="font-bold text-medical-gray-900 font-vazir">{faq.question}</span>
                        <ChevronDown className="w-5 h-5 text-canina-blue group-open:rotate-180 transition-transform" />
                      </summary>
                      <div className="px-6 pb-6 text-sm text-medical-gray-500 font-medium leading-relaxed font-vazir border-t border-medical-gray-50 pt-4">
                        {faq.answer}
                      </div>
                    </details>
                  ))}
                </div>
              </section>
            )}
          </div>

          {/* Sticky Sidebar (Clean Buy Box) - Sticky starts at the top, level with the title */}
          <div className="lg:col-span-4 lg:sticky lg:top-28 space-y-8">
            <div className="bg-white rounded-[2.5rem] border-2 border-medical-gray-100 p-8 shadow-2xl relative overflow-hidden">
              <div className="absolute top-0 right-0 w-24 h-24 bg-canina-blue/5 rounded-full -mr-12 -mt-12" />

              <div className="text-[10px] font-black text-medical-gray-400 uppercase tracking-widest mb-1 font-vazir">قیمت نهایی محصول</div>
              <div className="text-4xl font-black font-vazir text-medical-gray-900 tracking-tighter mb-8">
                {toPersian(product.price)}
              </div>

              <div className="flex gap-4 mb-6">
                {/* Quantity Selector - 40% Width */}
                <div className="flex items-center gap-4 bg-medical-gray-50 border border-medical-gray-100 rounded-2xl p-2 h-16 w-[40%]">
                  <button
                    onClick={() => setItemQuantity(Math.max(1, itemQuantity - 1))}
                    className="w-10 h-10 flex items-center justify-center rounded-xl bg-white text-medical-gray-900 border border-medical-gray-200 hover:bg-canina-blue hover:text-white hover:border-canina-blue transition-all shadow-sm"
                  >
                    <Minus className="w-4 h-4" />
                  </button>
                  <span className="text-xl font-black text-medical-gray-900 flex-1 text-center font-vazir">
                    {toPersian(itemQuantity)}
                  </span>
                  <button
                    onClick={() => setItemQuantity(itemQuantity + 1)}
                    className="w-10 h-10 flex items-center justify-center rounded-xl bg-white text-medical-gray-900 border border-medical-gray-200 hover:bg-canina-blue hover:text-white hover:border-canina-blue transition-all shadow-sm"
                  >
                    <Plus className="w-4 h-4" />
                  </button>
                </div>

                {/* Add to Cart Button - 60% Width */}
                <button
                  onClick={() => {
                    addItem(product, itemQuantity, { quantity: calculation.dailyDose, unit: calculation.unit });
                    toast.success(`${toPersian(itemQuantity)} عدد ${product.name} به سبد خرید اضافه شد`);
                  }}
                  className="w-[60%] flex items-center justify-center gap-1.5 px-4 bg-medical-gray-900 text-white rounded-2xl h-16 font-black text-sm hover:bg-canina-blue transition-all shadow-xl shadow-black/10 font-vazir whitespace-nowrap"
                >
                  <ShoppingBag className="w-5 h-5 mb-1" />
                  افزودن به سبد خرید
                </button>
              </div>

              <div className="mt-6 flex flex-col gap-3 border-t border-medical-gray-50 pt-6">
                <div className="flex items-center gap-2 text-xs font-bold text-medical-gray-500 font-vazir">
                  <ShieldCheck className="w-4 h-4 text-green-500" />
                  ضمانت اصالت محصول (Made in Germany)
                </div>
                <div className="flex items-center gap-2 text-xs font-bold text-medical-gray-500 font-vazir">
                  <Clock className="w-4 h-4 text-canina-blue" />
                  آماده ارسال (تحویل حداکثر ۴۸ ساعت)
                </div>
              </div>
            </div>

            {/* expected results box */}
            {product.expectedResults && product.expectedResults.length > 0 && (
              <div className="bg-white rounded-[2.5rem] border border-medical-gray-200 p-8 shadow-md">
                <h4 className="text-[10px] font-black text-medical-gray-400 uppercase tracking-widest mb-6 font-vazir">تغییرات قابل انتظار</h4>
                <div className="space-y-4">
                  {product.expectedResults.map((res, i) => {
                    const Icon = ICON_MAP[res.icon] || Sparkles;
                    return (
                      <div key={i} className="flex items-center gap-4 group">
                        <div className="w-10 h-10 bg-medical-gray-50 rounded-xl flex items-center justify-center text-canina-blue group-hover:bg-canina-blue group-hover:text-white transition-all">
                          <Icon className="w-5 h-5" />
                        </div>
                        <span className="text-xs font-bold text-medical-gray-700 font-vazir">{res.text}</span>
                      </div>
                    );
                  })}
                </div>
              </div>
            )}
          </div>
        </div>

        {/* Smart Cross-sell: Recommended Combinations */}
        {product.relatedProducts && product.relatedProducts.length > 0 && (
          <section className="mt-32 pt-20 border-t border-medical-gray-200">
            <div className="flex flex-col items-center text-center mb-16 px-4">
              <div className="inline-flex items-center gap-2 px-4 py-2 bg-canina-blue/5 border border-canina-blue/10 rounded-full text-canina-blue text-xs font-black uppercase tracking-widest mb-6 font-vazir whitespace-nowrap">
                <Sparkles className="w-4 h-4" />
                فرمولاسیون ترکیبی هم‌افزا (Synergy Blend)
              </div>
              <h2 className="text-3xl lg:text-5xl font-black text-medical-gray-900 leading-tight">
                اثربخشی <span className="text-canina-blue italic">دوبرابر</span> با ترکیب هوشمند
              </h2>
            </div>

            <div className="grid lg:grid-cols-2 gap-8">
              {product.relatedProducts.map(relId => {
                const relProduct = allProducts.find(p => p.id === relId);
                if (!relProduct) return null;
                return (
                  <motion.div
                    key={relId}
                    initial={{ opacity: 0, y: 20 }}
                    whileInView={{ opacity: 1, y: 0 }}
                    viewport={{ once: true }}
                    className="bg-white rounded-[3rem] p-8 border border-medical-gray-200 flex flex-col md:flex-row gap-8 items-center cursor-pointer hover:shadow-2xl transition-all"
                    onClick={() => router.push(`/shop/${relProduct.id}`)}
                  >
                    <div className="w-40 h-40 bg-medical-gray-50 rounded-[2rem] p-4 flex items-center justify-center">
                      <SafeImage src={relProduct.image} alt={relProduct.name} className="w-full h-full drop-shadow-xl" imgClassName="object-contain" />
                    </div>
                    <div className="flex-1 text-center md:text-right">
                      <h4 className="text-xl font-black text-medical-gray-900 mb-2">{relProduct.name}</h4>
                      <p className="text-sm text-medical-gray-500 mb-6">{relProduct.description}</p>
                      <div className="flex items-center justify-center md:justify-start gap-4">
                        <span className="text-lg font-black text-canina-blue">{relProduct.price}</span>
                        <ArrowRight className="w-4 h-4 text-medical-gray-300" />
                      </div>
                    </div>
                    <div className="w-px h-24 bg-medical-gray-100 hidden md:block" />
                    <div className="flex items-center justify-center gap-1 group">
                      <span className="text-xs font-black text-medical-gray-400 group-hover:text-canina-blue transition-colors">مشاهده محصول مکمل</span>
                      <ChevronLeft className="w-4 h-4 text-medical-gray-300 group-hover:text-canina-blue group-hover:-translate-x-1 transition-all rtl:group-hover:translate-x-1" />
                    </div>
                  </motion.div>
                );
              })}
            </div>
          </section>
        )}
      </div>

      {/* Refill Automation Popup */}
      <AnimatePresence>
        {showRefillModal && (
          <div className="fixed inset-0 z-[100] flex items-center justify-center p-4">
            <motion.div
              initial={{ opacity: 0 }}
              animate={{ opacity: 1 }}
              exit={{ opacity: 0 }}
              onClick={() => setShowRefillModal(false)}
              className="absolute inset-0 bg-medical-gray-900/60 backdrop-blur-md"
            />
            <motion.div
              initial={{ opacity: 0, scale: 0.9, y: 20 }}
              animate={{ opacity: 1, scale: 1, y: 0 }}
              exit={{ opacity: 0, scale: 0.9, y: 20 }}
              className="bg-white w-full max-w-lg rounded-[3rem] p-10 relative z-10 shadow-2xl overflow-hidden"
            >
              <div className="absolute top-0 left-0 w-full h-2 bg-gradient-to-r from-canina-blue via-blue-400 to-canina-blue" />
              <button
                onClick={() => setShowRefillModal(false)}
                className="absolute top-6 left-6 text-medical-gray-400 hover:text-medical-gray-600 transition-colors"
              >
                <X className="w-6 h-6" />
              </button>

              <div className="text-center">
                <div className="w-20 h-20 bg-canina-blue/10 rounded-[2rem] flex items-center justify-center mx-auto mb-8">
                  <Bell className="w-10 h-10 text-canina-blue animate-bounce" />
                </div>
                <h3 className="text-3xl font-black text-medical-gray-900 mb-4 leading-tight italic">سیستم یادآوری هوشمند</h3>
                <div className="bg-medical-gray-50 border border-medical-gray-100 rounded-3xl p-6 mb-8 text-right">
                  <p className="text-medical-gray-700 leading-relaxed font-medium font-vazir">
                    بر اساس وزن <span className="text-canina-blue font-bold">{toPersian(weight)} کیلوگرمی</span> {activePet ? `برای ${activePet.name}` : 'سگ شما'}، این بسته {toPersian(product.packageSize)} تایی دقیقاً <span className="text-canina-blue font-bold">{toPersian(calculation.duration)} روز</span> دیگر تمام می‌شود.
                  </p>
                  <div className="mt-4 flex items-center gap-2 text-xs font-bold text-medical-gray-500 font-vazir">
                    <ShieldCheck className="w-4 h-4 text-green-500" />
                    آیا مایلید سیستم ۵ روز قبل از اتمام، به شما پیامک یادآوری ارسال کند؟
                  </div>
                </div>

                <div className="flex flex-col gap-3">
                  <button
                    onClick={() => setShowRefillModal(false)}
                    className="w-full bg-canina-blue text-white py-5 rounded-2xl font-black text-lg hover:shadow-xl hover:shadow-canina-blue/20 transition-all flex items-center justify-center gap-2"
                  >
                    <CheckCircle2 className="w-5 h-5" />
                    بله، پیامک یادآوری فعال شود
                  </button>
                  <button
                    onClick={() => setShowRefillModal(false)}
                    className="w-full py-4 text-medical-gray-400 font-bold text-sm hover:text-medical-gray-600 transition-colors"
                  >
                    خیر، فقط محصول را به سبد خرید اضافه کن
                  </button>
                </div>
              </div>
            </motion.div>
          </div>
        )}
      </AnimatePresence>
    </div>
  );
}