'use client';

import Link from 'next/link';
import Image from 'next/image';
import { useState } from 'react';
import { Check, ShoppingCart } from 'lucide-react';
import BlurHashImage from '@/components/ui/BlurHashImage';
import { ProductResponse } from '@/services/api/catalogService';
import { useCartStore } from '@/store/cartStore';
import { formatCatalogPriceLabel, formatCurrency, getImageUrl } from '@/lib/utils';

interface QuickComparisonTableProps {
  products: ProductResponse[];
}

function priceLabel(product: ProductResponse): string {
  const label = formatCatalogPriceLabel(product);
  return label === formatCurrency(0) ? '—' : label;
}

function productImage(product: ProductResponse): string {
  return getImageUrl(product.images?.[0]?.image_url || product.variants?.[0]?.images?.[0]?.image_url);
}

function extraAttributes(product: ProductResponse): { label: string; values: string[] }[] {
  const buckets: Record<string, { label: string; values: Set<string> }> = {};

  (product.variants || []).forEach((variant) => {
    (variant.attributes || []).forEach((attr) => {
      const raw = attr.attribute_name || attr.attribute_code || '';
      const value = String(attr.attribute_value || '').trim();
      if (!raw || !value) return;
      const key = raw.trim().toLowerCase().replace(/[\s-]+/g, '_');
      if (!buckets[key]) {
        let label = raw.replace(/[_-]+/g, ' ').replace(/\b\w/g, (c) => c.toUpperCase());
        if (['qul', 'qual'].includes(key)) label = 'Quality';
        else if (['clr'].includes(key)) label = 'Color';
        else if (['str'].includes(key)) label = 'Storage';
        buckets[key] = {
          label,
          values: new Set(),
        };
      }
      buckets[key].values.add(value);
    });
  });

  return Object.values(buckets)
    .map((item) => ({
      label: item.label,
      values: Array.from(item.values),
    }))
    .slice(0, 3);
}

function ctaKind(product: ProductResponse): 'view' | 'cart' {
  return (product.variants?.length || 0) > 1 ? 'view' : 'cart';
}

export function QuickComparisonTable({ products }: QuickComparisonTableProps) {
  const addToCart = useCartStore((state) => state.addToCart);
  const [addedId, setAddedId] = useState<string | null>(null);

  if (!products.length) return null;

  const handleAdd = async (product: ProductResponse) => {
    const variant = product.variants?.[0];
    if (!variant) return;
    await addToCart(product, variant, 1);
    setAddedId(product.product_id);
    setTimeout(() => setAddedId(null), 1800);
  };

  const labelCls =
    'sticky left-0 z-10 w-[150px] min-w-[150px] px-4 py-4 text-[13px] font-medium text-gray-500 text-left align-middle bg-[#f3f4f6]';
  const cellCls = 'px-5 py-4 min-w-[170px] align-middle text-center';

  return (
    <section className="mb-10">
      <h3 className="text-[20px] font-semibold text-gray-800 mb-4 tracking-tight">Quick Comparison</h3>
      <div className="overflow-x-auto rounded-md border border-gray-200">
        <table className="w-full border-collapse min-w-[860px]">
          <thead>
            <tr className="bg-white">
              <th className={labelCls} />
              {products.map((prod) => {
                const img = productImage(prod);
                return (
                  <th key={prod.product_id} className={`${cellCls} font-normal bg-white`}>
                    <Link
                      href={`/products/${prod.slug}`}
                      className="block text-[13px] font-medium text-gray-700 leading-snug hover:text-primary line-clamp-2 min-h-[36px] mb-3"
                    >
                      {prod.name}
                    </Link>
                    <Link
                      href={`/products/${prod.slug}`}
                      className="w-[92px] h-[92px] mx-auto bg-white border border-gray-200 rounded-md p-2 flex items-center justify-center hover:border-primary/40 transition-colors"
                    >
                      <BlurHashImage
                        src={img}
                        alt={prod.name}
                        width={84}
                        height={84}
                        className="max-h-full max-w-full object-contain"
                      />
                    </Link>
                  </th>
                );
              })}
            </tr>
          </thead>
          <tbody>
            <tr className="bg-[#f8f8f8]">
              <td className={labelCls}>Price</td>
              {products.map((prod) => (
                <td key={prod.product_id} className={`${cellCls} text-[14px] font-bold text-gray-900`}>
                  {priceLabel(prod)}
                </td>
              ))}
            </tr>

            <tr className="bg-white">
              <td className={labelCls}>Add to cart</td>
              {products.map((prod) => {
                const kind = ctaKind(prod);
                const justAdded = addedId === prod.product_id;
                return (
                  <td key={prod.product_id} className={cellCls}>
                    {kind === 'view' ? (
                      <Link
                        href={`/products/${prod.slug}`}
                        className="inline-flex items-center justify-center min-w-[120px] bg-primary hover:bg-primary-hover text-white text-[13px] font-semibold px-4 py-2.5 rounded-md transition-colors"
                      >
                        View Products
                      </Link>
                    ) : (
                      <button
                        type="button"
                        onClick={() => void handleAdd(prod)}
                        className="inline-flex items-center justify-center gap-1.5 min-w-[120px] bg-primary hover:bg-primary-hover text-white text-[13px] font-semibold px-4 py-2.5 rounded-md transition-colors cursor-pointer"
                      >
                        {justAdded ? <Check size={14} /> : <ShoppingCart size={14} />}
                        {justAdded ? 'Added' : 'Add To Cart'}
                      </button>
                    )}
                  </td>
                );
              })}
            </tr>

            <tr className="bg-[#f8f8f8]">
              <td className={`${labelCls} align-top`}>Additional information</td>
              {products.map((prod) => {
                const attrs = extraAttributes(prod);
                return (
                  <td key={prod.product_id} className={`${cellCls} align-top text-[12px] leading-relaxed`}>
                    {attrs.length === 0 ? (
                      <span className="text-gray-300">—</span>
                    ) : (
                      <div className="space-y-1.5 text-left inline-block">
                        {attrs.map((attr) => (
                          <div key={attr.label}>
                            <span className="text-gray-700 font-medium">{attr.label}: </span>
                            {attr.values.map((value, i) => (
                              <span key={value}>
                                <Link href={`/products/${prod.slug}`} className="text-primary hover:underline">
                                  {value}
                                </Link>
                                {i < attr.values.length - 1 ? <span className="text-gray-400">, </span> : null}
                              </span>
                            ))}
                          </div>
                        ))}
                      </div>
                    )}
                  </td>
                );
              })}
            </tr>
          </tbody>
        </table>
      </div>
    </section>
  );
}