'use client';

import { useEffect, useRef, useState } from 'react';
import { Loader2, Plus, Search } from 'lucide-react';
import { toast } from 'sonner';
import { storefrontService } from '@/services/api/storefrontService';
import { ProductResponse } from '@/services/api/catalogService';
import { mapProductCardToProductResponse } from '@/utils/productMapper';
import { getCatalogPriceInfo, getImageUrl } from '@/lib/utils';
import { isSameCompareProduct, notifyCompareResult } from '@/lib/compare';
import {
  compareKindLabel,
  detectProductKind,
  formatComparePrice,
  lockedCompareKind,
} from '@/lib/compareSpecs';
import { useCartStore } from '@/store/cartStore';

interface CompareProductPickerProps {
  variant?: 'hero' | 'icon' | 'button';
  replaceProductId?: string;
  defaultOpen?: boolean;
  onAdded?: () => void;
}

export function CompareProductPicker({
  variant = 'icon',
  replaceProductId,
  defaultOpen = false,
  onAdded,
}: CompareProductPickerProps) {
  const compareList = useCartStore((s) => s.compareList);
  const addToCompare = useCartStore((s) => s.addToCompare);
  const replaceCompareProduct = useCartStore((s) => s.replaceCompareProduct);
  const [query, setQuery] = useState('');
  const [results, setResults] = useState<ProductResponse[]>([]);
  const [loading, setLoading] = useState(false);
  const [open, setOpen] = useState(variant === 'hero' || defaultOpen);

  useEffect(() => {
    if (defaultOpen) setOpen(true);
  }, [defaultOpen, replaceProductId]);
  const rootRef = useRef<HTMLDivElement>(null);
  const inputRef = useRef<HTMLInputElement>(null);
  const lockedKind = lockedCompareKind(compareList, replaceProductId);
  const kindLabel = lockedKind ? compareKindLabel(lockedKind) : 'products';

  useEffect(() => {
    if (open) inputRef.current?.focus();
  }, [open]);

  useEffect(() => {
    const q = query.trim();
    if (q.length < 2) {
      setResults([]);
      setLoading(false);
      return;
    }

    setLoading(true);
    const timer = window.setTimeout(async () => {
      try {
        const data = await storefrontService.getLiveSearch(q);
        const products = (data.products || [])
          .map((p) => mapProductCardToProductResponse(p as unknown as Record<string, unknown>))
          .filter((p) => {
            if (!p.product_id) return false;
            const alreadyListed = compareList.some(
              (c) =>
                isSameCompareProduct(c, p) &&
                (!replaceProductId || !isSameCompareProduct(c, replaceProductId))
            );
            if (alreadyListed) return false;
            if (lockedKind && detectProductKind(p) !== lockedKind) return false;
            return true;
          })
          .slice(0, 8);
        setResults(products);
      } catch {
        setResults([]);
      } finally {
        setLoading(false);
      }
    }, 280);

    return () => window.clearTimeout(timer);
  }, [query, compareList, replaceProductId, lockedKind]);

  useEffect(() => {
    if (variant === 'hero') return;
    const onPointer = (event: MouseEvent) => {
      if (!rootRef.current?.contains(event.target as Node)) setOpen(false);
    };
    document.addEventListener('mousedown', onPointer);
    return () => document.removeEventListener('mousedown', onPointer);
  }, [variant]);

  const handleSelect = (product: ProductResponse) => {
    const result = replaceProductId
      ? replaceCompareProduct(replaceProductId, product)
      : addToCompare(product);
    if (!notifyCompareResult(result)) return;
    if (result.ok && !result.already) {
      toast.success(replaceProductId ? 'Product replaced' : 'Added to comparison');
    }
    setQuery('');
    setResults([]);
    if (variant === 'icon') setOpen(false);
    onAdded?.();
  };

  const searchField = (
    <div className="relative w-full">
      <Search className="absolute left-3 top-1/2 -translate-y-1/2 w-4 h-4 text-gray-400" />
      <input
        ref={inputRef}
        type="search"
        value={query}
        onChange={(e) => setQuery(e.target.value)}
        placeholder={lockedKind ? `Search ${kindLabel}` : 'Search product name'}
        className="w-full h-10 pl-9 pr-9 rounded-lg border border-gray-200 bg-white text-[13px] text-gray-800 placeholder:text-gray-400 focus:outline-none focus:border-primary"
      />
      {loading ? (
        <Loader2 className="absolute right-3 top-1/2 -translate-y-1/2 w-4 h-4 text-gray-400 animate-spin" />
      ) : null}
    </div>
  );

  const resultList =
    query.trim().length >= 2 ? (
      <ul className="mt-2 max-h-72 overflow-y-auto">
        {loading && results.length === 0 ? (
          <li className="px-2 py-3 text-[13px] text-gray-400">Searching…</li>
        ) : results.length === 0 ? (
          <li className="px-2 py-3 text-[13px] text-gray-400">
            {lockedKind ? `No matching ${kindLabel}` : 'No matching products'}
          </li>
        ) : (
          results.map((product) => {
            const img = getImageUrl(product.images?.[0]?.image_url);
            const price = getCatalogPriceInfo(product).price;
            return (
              <li key={product.product_id}>
                <button
                  type="button"
                  onClick={() => handleSelect(product)}
                  className="w-full flex items-center gap-3 px-2 py-2 rounded-lg text-left hover:bg-[#f5f8fc] cursor-pointer"
                >
                  <div className="w-11 h-11 shrink-0 rounded-md border border-gray-100 bg-white overflow-hidden">
                    {img ? (
                      // eslint-disable-next-line @next/next/no-img-element
                      <img src={img} alt="" className="w-full h-full object-contain p-1" />
                    ) : (
                      <div className="w-full h-full bg-gray-50" />
                    )}
                  </div>
                  <div className="min-w-0">
                    <p className="text-[13px] font-medium text-[#212121] line-clamp-2">{product.name}</p>
                    {price ? (
                      <p className="text-[12px] font-bold text-[#212121] mt-0.5">
                        {formatComparePrice(price)}
                      </p>
                    ) : null}
                  </div>
                </button>
              </li>
            );
          })
        )}
      </ul>
    ) : null;

  if (variant === 'hero') {
    return (
      <div ref={rootRef} className="w-full max-w-lg mx-auto">
        {searchField}
        {resultList}
      </div>
    );
  }

  return (
    <div ref={rootRef} className="relative">
      <button
        type="button"
        onClick={() => setOpen((v) => !v)}
        aria-label="Add product to compare"
        className={
          variant === 'button'
            ? 'h-9 px-4 rounded-lg bg-primary text-white text-[13px] font-semibold inline-flex items-center gap-1.5 hover:brightness-95 cursor-pointer'
            : 'w-10 h-10 rounded-full bg-primary text-white flex items-center justify-center shadow-sm hover:brightness-95 cursor-pointer'
        }
      >
        <Plus className="w-4 h-4" />
        {variant === 'button' ? 'Add Product' : null}
      </button>
      {open ? (
        <div className="absolute right-0 top-full mt-2 w-[340px] bg-white border border-gray-200 rounded-xl shadow-[0_16px_40px_rgba(16,24,40,0.16)] p-3 z-[80]">
          <p className="text-[13px] font-semibold text-[#212121] mb-2">
            {replaceProductId ? 'Replace product' : 'Add a product'}
          </p>
          {searchField}
          {resultList}
        </div>
      ) : null}
    </div>
  );
}