"use client";

import React, { useState, useEffect, useCallback, useRef } from "react";
import Link from "next/link";
import Image from "next/image";
import { usePathname, useRouter } from "next/navigation";
import { 
  Home, 
  ShoppingBag, 
  ShoppingCart, 
  Menu, 
  Pill, 
  ShieldCheck, 
  HeartPulse, 
  BookOpen, 
  FileText, 
  Video, 
  Building2, 
  FileHeart, 
  User, 
  Search, 
  ChevronLeft,
  Dog,
  PhoneCall,
  Sparkles,
  ArrowRight
} from "lucide-react";
import { useCartStore } from "../lib/store/cartStore";
import { useUserStore } from "../lib/store/userStore";
import { useUIStore } from "../lib/store/uiStore";
import { useSettingsStore } from "../lib/store/settingsStore";
import { useCatalogMode } from "../lib/useCatalogMode";
import { productService } from "../lib/services/productService";
import { Product } from "../lib/data/products";
import { toPersian } from "../lib/utils";

const SOLUTION_ITEMS = [
  {
    id: "joints",
    title: "مفاصل و استخوان",
    icon: <Pill className="w-5 h-5 text-canina-blue" />,
    solutions: ["لنگیدن", "سختی در بلند شدن", "درد مفاصل", "رشد سریع توله‌سگ", "پاهای پرانتزی", "ضعف تاندون"]
  },
  {
    id: "immune",
    title: "تقویت سیستم ایمنی و گوارش",
    icon: <ShieldCheck className="w-5 h-5 text-emerald-600" />,
    solutions: ["ضعف بعد از بیماری", "بی‌اشتهایی", "بعد از زایمان", "اسهال", "مشکلات گوارشی"]
  },
  {
    id: "energy",
    title: "ویتامین‌ها و انرژی‌بخش‌ها",
    icon: <HeartPulse className="w-5 h-5 text-amber-500" />,
    solutions: ["نفس‌نفس زدن", "خستگی", "سن بالا", "بی‌حالی"]
  },
  {
    id: "special-care",
    title: "مراقبت‌های ویژه (پوست، دندان و چشم)",
    icon: <Sparkles className="w-5 h-5 text-indigo-500" />,
    solutions: ["ریزش مو", "خشکی پوست", "خارش", "جرم دندان", "سوزش چشم"]
  }
];

export default function MobileBottomNav({
  onPrescriptionOpen,
}: {
  onPrescriptionOpen?: () => void;
}) {
  const pathname = usePathname();
  const router = useRouter();

  const [activeSheet, setActiveSheet] = useState<"shop" | "menu" | null>(null);
  const [searchQuery, setSearchQuery] = useState("");
  const [searchResults, setSearchResults] = useState<Product[]>([]);
  const [isSearching, setIsSearching] = useState(false);
  const [isMounted, setIsMounted] = useState(false);

  const isNavigatingBackRef = useRef(false);

  const { getTotalItems } = useCartStore();
  const setCartOpen = useUIStore((state) => state.setCartOpen);
  const setB2BPortalOpen = useUIStore((state) => state.setB2BPortalOpen);
  const isB2BEnabled = useSettingsStore((s) => s.getBoolean('b2bRegistrationOpen', true) && s.getBoolean('b2b_enabled', true));
  const isPrescriptionEnabled = useSettingsStore((s) => s.getText('PRESCRIPTION_UPLOAD_ENABLED', 'true') !== 'false');
  const { isCatalogOnly, allowCart } = useCatalogMode();
  const isCartDisabled = isCatalogOnly && !allowCart;

  const { isLoggedIn, setAuthModalOpen } = useUserStore();

  useEffect(() => {
    setIsMounted(true);
  }, []);

  // Close sheet with history navigation support (Back button dismiss)
  const closeSheet = useCallback(() => {
    if (!activeSheet) return;
    setActiveSheet(null);
    if (typeof window !== "undefined" && window.location.hash === "#sheet") {
      isNavigatingBackRef.current = true;
      window.history.back();
    }
  }, [activeSheet]);

  const openSheet = useCallback((sheet: "shop" | "menu") => {
    setActiveSheet(sheet);
    if (typeof window !== "undefined") {
      window.history.pushState({ mobileSheet: sheet }, "", "#sheet");
    }
  }, []);

  // Handle hardware / browser back button popstate
  useEffect(() => {
    const handlePopState = () => {
      if (isNavigatingBackRef.current) {
        isNavigatingBackRef.current = false;
        return;
      }
      if (activeSheet) {
        setActiveSheet(null);
      }
    };

    window.addEventListener("popstate", handlePopState);
    return () => window.removeEventListener("popstate", handlePopState);
  }, [activeSheet]);

  // Close sheet on route change
  useEffect(() => {
    setActiveSheet(null);
    setSearchQuery("");
    setSearchResults([]);
  }, [pathname]);

  // Live search debounced query
  useEffect(() => {
    if (!searchQuery.trim()) {
      setSearchResults([]);
      setIsSearching(false);
      return;
    }

    const timer = setTimeout(async () => {
      setIsSearching(true);
      try {
        const res = await productService.getProducts({ query: searchQuery.trim(), limit: 6 });
        setSearchResults(res.data || []);
      } catch (err) {
        console.error("Live search failed:", err);
      } finally {
        setIsSearching(false);
      }
    }, 250);

    return () => clearTimeout(timer);
  }, [searchQuery]);

  const handleSearchSubmit = (e: React.FormEvent) => {
    e.preventDefault();
    if (searchQuery.trim()) {
      const q = searchQuery.trim();
      closeSheet();
      router.push(`/shop?search=${encodeURIComponent(q)}`);
    } else {
      closeSheet();
      router.push("/shop");
    }
  };

  const handleAccountClick = () => {
    if (isLoggedIn) {
      router.push("/dashboard");
    } else {
      setAuthModalOpen(true);
    }
  };

  const totalCartItems = isMounted ? getTotalItems() : 0;
  const isHomeActive = pathname === "/";
  const isShopActive = pathname.startsWith("/shop") || activeSheet === "shop";
  const isAccountActive = pathname.startsWith("/dashboard");

  return (
    <>
      {/* 1. SHOP & SOLUTIONS BOTTOM SHEET (Modal for Shop Tab) */}
      {activeSheet === "shop" && (
        <div 
          className="lg:hidden fixed inset-0 z-50 flex items-end justify-center bg-black/50 backdrop-blur-xs font-vazir"
          onClick={closeSheet}
        >
          <div 
            className="w-full max-w-lg bg-white rounded-t-3xl p-5 border-t border-medical-gray-200 shadow-2xl max-h-[85vh] flex flex-col animate-in slide-in-from-bottom duration-200"
            onClick={(e) => e.stopPropagation()}
            dir="rtl"
          >
            {/* Grab handle */}
            <div className="w-10 h-1 bg-medical-gray-200 rounded-full mx-auto mb-3 shrink-0" />

            {/* Header with Direct Shop Link */}
            <div className="flex items-center justify-between pb-3 border-b border-medical-gray-100 mb-3 shrink-0">
              <div className="flex items-center gap-2">
                <div className="p-1.5 bg-canina-blue/10 rounded-xl text-canina-blue">
                  <ShoppingBag className="w-4 h-4" />
                </div>
                <div>
                  <h3 className="font-black text-sm text-medical-gray-900">فروشگاه و راهکارهای دارویی</h3>
                  <p className="text-[10px] text-medical-gray-400">جستجو در داروها، مکمل‌ها و علائم بالینی</p>
                </div>
              </div>
              <button 
                type="button" 
                onClick={closeSheet}
                className="text-xs text-medical-gray-400 hover:text-medical-gray-700 font-bold p-1"
              >
                بستن ✕
              </button>
            </div>

            {/* Search Input */}
            <form onSubmit={handleSearchSubmit} className="relative mb-3 shrink-0">
              <Search className="absolute right-3.5 top-1/2 -translate-y-1/2 w-4 h-4 text-medical-gray-400" />
              <input
                type="text"
                placeholder="جستجوی دارو، ترکیب یا علامت بالینی..."
                value={searchQuery}
                onChange={(e) => setSearchQuery(e.target.value)}
                className="w-full bg-medical-gray-50 border border-medical-gray-200 rounded-xl py-2.5 pr-10 pl-14 text-xs outline-none focus:border-canina-blue font-vazir text-medical-gray-900"
                autoFocus
              />
              <button
                type="submit"
                className="absolute left-1.5 top-1/2 -translate-y-1/2 px-2.5 py-1 bg-canina-blue text-white rounded-lg text-[10px] font-bold"
              >
                جستجو
              </button>
            </form>

            {/* Live Search Results (if typing) */}
            {searchQuery.trim().length > 0 && (
              <div className="mb-3 shrink-0 bg-medical-gray-50 rounded-2xl p-2.5 border border-medical-gray-200 max-h-56 overflow-y-auto">
                <div className="flex items-center justify-between mb-2 px-1">
                  <span className="text-[10px] font-black text-medical-gray-500">
                    {isSearching ? "در حال جستجو..." : `نتایج زنده (${toPersian(searchResults.length)})`}
                  </span>
                  <button
                    type="button"
                    onClick={handleSearchSubmit}
                    className="text-[10px] font-bold text-canina-blue hover:underline flex items-center gap-0.5"
                  >
                    <span>مشاهده همه در فروشگاه</span>
                    <ArrowRight className="w-3 h-3 rotate-180" />
                  </button>
                </div>

                {searchResults.length === 0 && !isSearching ? (
                  <p className="text-center text-xs text-medical-gray-400 py-3">دارویی با این نام یافت نشد</p>
                ) : (
                  <div className="space-y-1.5">
                    {searchResults.map((prod) => (
                      <Link
                        key={prod.id}
                        href={`/products/${prod.slug || prod.id}`}
                        onClick={closeSheet}
                        className="flex items-center gap-2.5 p-2 bg-white rounded-xl border border-medical-gray-100 hover:border-canina-blue transition-all"
                      >
                        {prod.image ? (
                          <Image
                            src={prod.image}
                            alt={prod.name}
                            width={36}
                            height={36}
                            className="w-9 h-9 object-contain rounded-lg shrink-0"
                          />
                        ) : (
                          <div className="w-9 h-9 bg-medical-gray-100 rounded-lg flex items-center justify-center text-medical-gray-400 shrink-0">
                            <Pill className="w-4 h-4" />
                          </div>
                        )}
                        <div className="flex-1 min-w-0 text-right">
                          <div className="text-xs font-bold text-medical-gray-900 truncate">{prod.name}</div>
                          <div className="text-[10px] text-medical-gray-400 truncate">{prod.scientificTagline || prod.category}</div>
                        </div>
                        <div className="text-[11px] font-black text-canina-blue shrink-0">
                          {prod.price}
                        </div>
                      </Link>
                    ))}
                  </div>
                )}
              </div>
            )}

            {/* Direct Link to All Products */}
            <Link
              href="/shop"
              onClick={closeSheet}
              className="w-full flex items-center justify-between p-3 bg-canina-blue text-white rounded-2xl font-black text-xs shadow-md shadow-canina-blue/20 mb-3 shrink-0"
            >
              <div className="flex items-center gap-2">
                <ShoppingBag className="w-4 h-4" />
                <span>مشاهده کاتالوگ و همه محصولات</span>
              </div>
              <ChevronLeft className="w-4 h-4" />
            </Link>

            {/* Prescription Upload Banner CTA if enabled */}
            {isPrescriptionEnabled && (
              <button
                type="button"
                onClick={() => {
                  closeSheet();
                  if (onPrescriptionOpen) {
                    onPrescriptionOpen();
                  }
                }}
                className="w-full flex items-center justify-between p-3 bg-gradient-to-r from-emerald-500 to-teal-600 text-white rounded-2xl font-black text-xs shadow-md shadow-emerald-500/15 mb-3 shrink-0"
              >
                <div className="flex items-center gap-2">
                  <div className="p-1.5 bg-white/20 rounded-xl">
                    <FileHeart className="w-4 h-4 text-white" />
                  </div>
                  <div className="text-right">
                    <div className="text-xs font-black">ثبت و استعلام نسخه دامپزشک</div>
                    <div className="text-[10px] text-emerald-100 font-medium">تامین مستقیم دارو و مکمل‌های اورجینال</div>
                  </div>
                </div>
                <ChevronLeft className="w-4 h-4" />
              </button>
            )}

            {/* 4 Major Clinical Categories with Symptoms */}
            <div className="overflow-y-auto flex-1 space-y-3 py-1 pr-0.5">
              <div className="text-[11px] font-black text-medical-gray-400">دسته‌بندی‌ها و راهکارهای درمانی:</div>
              {SOLUTION_ITEMS.map((item) => (
                <div key={item.id} className="p-3 bg-medical-gray-50/70 border border-medical-gray-100 rounded-2xl">
                  <Link
                    href={`/shop?category=${item.id}`}
                    onClick={closeSheet}
                    className="flex items-center justify-between mb-2"
                  >
                    <div className="flex items-center gap-2">
                      {item.icon}
                      <span className="text-xs font-black text-medical-gray-800">{item.title}</span>
                    </div>
                    <span className="text-[10px] text-canina-blue font-bold flex items-center">
                      مشاهده داروها
                      <ChevronLeft className="w-3 h-3" />
                    </span>
                  </Link>
                  <div className="flex flex-wrap gap-1.5">
                    {item.solutions.map((sol, sIdx) => (
                      <Link
                        key={sIdx}
                        href={`/shop?category=${item.id}&symptom=${encodeURIComponent(sol)}`}
                        onClick={closeSheet}
                        className="px-2.5 py-1 bg-white border border-medical-gray-200/80 rounded-lg text-[10px] font-bold text-medical-gray-600 hover:border-canina-blue hover:text-canina-blue transition-all"
                      >
                        {sol}
                      </Link>
                    ))}
                  </div>
                </div>
              ))}
            </div>
          </div>
        </div>
      )}

      {/* 2. MENU BOTTOM SHEET (Modal for Menu Tab) */}
      {activeSheet === "menu" && (
        <div 
          className="lg:hidden fixed inset-0 z-50 flex items-end justify-center bg-black/50 backdrop-blur-xs font-vazir"
          onClick={closeSheet}
        >
          <div 
            className="w-full max-w-lg bg-white rounded-t-3xl p-5 border-t border-medical-gray-200 shadow-2xl max-h-[85vh] flex flex-col animate-in slide-in-from-bottom duration-200"
            onClick={(e) => e.stopPropagation()}
            dir="rtl"
          >
            {/* Grab handle */}
            <div className="w-10 h-1 bg-medical-gray-200 rounded-full mx-auto mb-3 shrink-0" />

            {/* Header */}
            <div className="flex items-center justify-between pb-3 border-b border-medical-gray-100 mb-3 shrink-0">
              <h3 className="font-black text-sm text-medical-gray-900">منوی بخش‌های کنینا</h3>
              <button 
                type="button" 
                onClick={closeSheet}
                className="text-xs text-medical-gray-400 hover:text-medical-gray-700 font-bold p-1"
              >
                بستن ✕
              </button>
            </div>

            <div className="overflow-y-auto flex-1 space-y-3 py-1">
              {/* Navigation Links Grid */}
              <div className="grid grid-cols-2 gap-2">
                <Link
                  href="/dashboard?tab=pets"
                  onClick={closeSheet}
                  className="flex items-center gap-2.5 p-3.5 bg-medical-gray-50 border border-medical-gray-200/80 rounded-2xl text-xs font-bold text-medical-gray-800 hover:border-canina-blue"
                >
                  <Dog className="w-4 h-4 text-canina-blue" />
                  <span>شناسنامه پت‌ها</span>
                </Link>

                <Link
                  href="/catalog"
                  onClick={closeSheet}
                  className="flex items-center gap-2.5 p-3.5 bg-medical-gray-50 border border-medical-gray-200/80 rounded-2xl text-xs font-bold text-medical-gray-800 hover:border-canina-blue"
                >
                  <BookOpen className="w-4 h-4 text-emerald-600" />
                  <span>کاتالوگ دارویی</span>
                </Link>

                <Link
                  href="/wiki"
                  onClick={closeSheet}
                  className="flex items-center gap-2.5 p-3.5 bg-medical-gray-50 border border-medical-gray-200/80 rounded-2xl text-xs font-bold text-medical-gray-800 hover:border-canina-blue"
                >
                  <FileText className="w-4 h-4 text-amber-500" />
                  <span>دانشنامه علمی</span>
                </Link>

                <Link
                  href="/blog"
                  onClick={closeSheet}
                  className="flex items-center gap-2.5 p-3.5 bg-medical-gray-50 border border-medical-gray-200/80 rounded-2xl text-xs font-bold text-medical-gray-800 hover:border-canina-blue"
                >
                  <HeartPulse className="w-4 h-4 text-rose-500" />
                  <span>مجله سلامت پت</span>
                </Link>

                <Link
                  href="/videos"
                  onClick={closeSheet}
                  className="flex items-center gap-2.5 p-3.5 bg-medical-gray-50 border border-medical-gray-200/80 rounded-2xl text-xs font-bold text-medical-gray-800 hover:border-canina-blue"
                >
                  <Video className="w-4 h-4 text-indigo-500" />
                  <span>ویدیوهای بالینی</span>
                </Link>

                {isB2BEnabled && (
                  <button
                    type="button"
                    onClick={() => {
                      closeSheet();
                      setB2BPortalOpen(true);
                    }}
                    className="flex items-center gap-2.5 p-3.5 bg-medical-gray-50 border border-medical-gray-200/80 rounded-2xl text-xs font-bold text-medical-gray-800 hover:border-canina-blue text-right"
                  >
                    <Building2 className="w-4 h-4 text-teal-600" />
                    <span>خرید عمده (B2B)</span>
                  </button>
                )}
              </div>

              {/* Contact & Support */}
              <div className="pt-2 border-t border-medical-gray-100 space-y-1.5">
                <Link
                  href="/contact"
                  onClick={closeSheet}
                  className="w-full flex items-center justify-between p-3 rounded-xl hover:bg-medical-gray-50 text-xs font-bold text-medical-gray-700"
                >
                  <div className="flex items-center gap-2.5">
                    <PhoneCall className="w-4 h-4 text-canina-blue" />
                    <span>تماس با مرکز پشتیبانی و مشاوره</span>
                  </div>
                  <ChevronLeft className="w-4 h-4 text-medical-gray-300" />
                </Link>
              </div>
            </div>
          </div>
        </div>
      )}

      {/* 3. FIXED 5-TAB APP BOTTOM NAVIGATION BAR */}
      <nav 
        aria-label="منوی ناوبری موبایل"
        className="lg:hidden fixed bottom-0 inset-x-0 z-40 bg-white/95 backdrop-blur-md border-t border-medical-gray-200 shadow-[0_-4px_20px_rgba(0,0,0,0.06)] font-vazir" 
        dir="rtl"
      >
        <div className="max-w-md mx-auto px-2 h-16 flex items-center justify-between select-none">
          
          {/* Tab 1: Home */}
          <Link
            href="/"
            className={`flex flex-col items-center justify-center flex-1 py-1 transition-all ${
              isHomeActive ? "text-canina-blue font-black" : "text-medical-gray-400 font-bold hover:text-medical-gray-700"
            }`}
          >
            <Home className={`w-5 h-5 mb-1 ${isHomeActive ? "text-canina-blue" : "text-medical-gray-400"}`} />
            <span className="text-[10px] leading-none">خانه</span>
          </Link>

          {/* Tab 2: Menu */}
          <button
            type="button"
            onClick={() => {
              if (activeSheet === "menu") closeSheet();
              else openSheet("menu");
            }}
            className={`flex flex-col items-center justify-center flex-1 py-1 transition-all ${
              activeSheet === "menu" ? "text-canina-blue font-black" : "text-medical-gray-400 font-bold hover:text-medical-gray-700"
            }`}
          >
            <Menu className="w-5 h-5 mb-1" />
            <span className="text-[10px] leading-none">منو</span>
          </button>

          {/* Tab 3: Shop (Opens Shop Sheet with Direct Shop Link + Solutions + Symptoms + Live Search) */}
          <button
            type="button"
            onClick={() => {
              if (activeSheet === "shop") closeSheet();
              else openSheet("shop");
            }}
            className={`flex flex-col items-center justify-center flex-1 py-1 transition-all ${
              isShopActive ? "text-canina-blue font-black" : "text-medical-gray-400 font-bold hover:text-medical-gray-700"
            }`}
          >
            <div className="relative mb-1">
              <ShoppingBag className={`w-5 h-5 ${isShopActive ? "text-canina-blue" : "text-medical-gray-400"}`} />
            </div>
            <span className="text-[10px] leading-none">فروشگاه</span>
          </button>

          {/* Tab 4: Cart */}
          {!isCartDisabled && (
            <button
              type="button"
              onClick={() => setCartOpen(true)}
              className="flex flex-col items-center justify-center flex-1 py-1 text-medical-gray-400 font-bold hover:text-medical-gray-700 relative"
            >
              <div className="relative mb-1">
                <ShoppingCart className="w-5 h-5" />
                {totalCartItems > 0 && (
                  <span className="absolute -top-1.5 -right-2 min-w-[16px] h-4 px-1 bg-canina-gold text-canina-dark rounded-full text-[9px] font-black flex items-center justify-center leading-none shadow-xs">
                    {toPersian(totalCartItems)}
                  </span>
                )}
              </div>
              <span className="text-[10px] leading-none">سبد خرید</span>
            </button>
          )}

          {/* Tab 5: Account (Direct to Dashboard if logged in, otherwise opens Auth Modal) */}
          <button
            type="button"
            onClick={handleAccountClick}
            className={`flex flex-col items-center justify-center flex-1 py-1 transition-all ${
              isAccountActive ? "text-canina-blue font-black" : "text-medical-gray-400 font-bold hover:text-medical-gray-700"
            }`}
          >
            <User className={`w-5 h-5 mb-1 ${isAccountActive ? "text-canina-blue" : "text-medical-gray-400"}`} />
            <span className="text-[10px] leading-none">حساب من</span>
          </button>

        </div>
      </nav>
    </>
  );
}