"use client";

import { useMemo, useState } from "react";
import type { ApiProduct, ApiVariant } from "@/lib/api";
import { addToCart } from "@/lib/cart";
import { PLACEHOLDER } from "@/lib/data";
import { discountPercent, formatPrice } from "@/lib/format";
import { IconCart } from "./Icons";
import { Media } from "./Media";

type Props = {
  product: ApiProduct;
  variants: ApiVariant[];
};

export function ProductView({ product, variants }: Props) {
  const images = useMemo(() => {
    const urls = [
      product.thumbnailUrl,
      product.image,
      product.thumbnail,
      ...(product.images ?? []).map((item) => item.url),
    ].filter((url): url is string => Boolean(url));
    return [...new Set(urls)];
  }, [product]);

  const [image, setImage] = useState(images[0] || PLACEHOLDER.product);
  const [variantId, setVariantId] = useState(variants[0]?.id);
  const [qty, setQty] = useState(1);
  const [added, setAdded] = useState(false);

  const name = product.nameFa || product.title;
  const variant = variants.find((item) => item.id === variantId) ?? variants[0];
  const price = variant ? (variant.discountedPrice ?? variant.price ?? 0) : (product.store?.minPrice ?? 0);
  const oldPrice = variant?.discountedPrice ? (variant.price ?? undefined) : undefined;
  const stock = variant ? (variant.stockQuantity ?? 0) : product.store?.inStock ? 1 : 0;
  const unavailable = !price || stock === 0;
  const off = discountPercent(price, oldPrice);

  return (
    <div className="grid gap-6 lg:grid-cols-12 items-start">
      <div className="lg:col-span-6">
        <div className="relative overflow-hidden rounded-2xl border border-black/5">
          {off > 0 && (
            <span className="absolute top-3 left-3 z-[2] rounded-full bg-brand px-2.5 py-1.5 font-oswald text-[13px] font-bold leading-none text-white shadow-md">
              {off}%
            </span>
          )}
          <Media src={image} alt={name} className="aspect-square" sizes="560px" priority />
        </div>
        {images.length > 1 && (
          <div className="mt-3 grid grid-cols-6 gap-2">
            {images.map((src, index) => (
              <button
                key={src}
                type="button"
                onClick={() => setImage(src)}
                className={`relative aspect-square overflow-hidden rounded-lg border ${
                  src === image ? "border-brand" : "border-black/10"
                }`}
              >
                <Media src={src} alt={`${name} — تصویر ${(index + 1).toLocaleString("fa-IR")}`} className="size-full" sizes="80px" />
              </button>
            ))}
          </div>
        )}
      </div>

      <div className="rounded-2xl border border-black/5 p-5 md:p-6 lg:col-span-6">
        {product.categoryNameFa && <p className="mb-2 text-xs text-zinc-400">{product.categoryNameFa}</p>}
        <p className="text-xl md:text-2xl font-extrabold leading-9">{name}</p>
        {product.title && product.nameFa && (
          <p dir="ltr" className="mt-1 text-sm text-zinc-400">
            {product.title}
          </p>
        )}

        {variants.length > 1 && (
          <div className="mt-5">
            <p className="mb-2 text-sm text-zinc-500">انتخاب تنوع</p>
            <div className="flex flex-wrap gap-2">
              {variants.map((item) => (
                <button
                  key={item.id}
                  type="button"
                  onClick={() => setVariantId(item.id)}
                  className={`rounded-lg border px-3 py-2 text-sm ${
                    item.id === variant?.id ? "border-brand text-brand" : "border-black/10 text-zinc-600"
                  }`}
                >
                  {item.label || item.selections?.map((selection) => selection.value).join(" / ") || "تنوع"}
                </button>
              ))}
            </div>
          </div>
        )}

        <div className="mt-6">
          {unavailable ? (
            <span className="text-lg text-zinc-400">ناموجود</span>
          ) : (
            <div className="flex flex-col items-start gap-1">
              {oldPrice ? <span className="text-sm font-medium text-brand line-through">{formatPrice(oldPrice)}</span> : null}
              <span className="text-2xl font-extrabold">
                {formatPrice(price)}
                <span className="mr-1 text-sm font-normal">تومان</span>
              </span>
            </div>
          )}
        </div>

        {!unavailable && (
          <div className="mt-6 flex flex-wrap items-center gap-3">
            <div className="flex items-center overflow-hidden rounded-xl border border-black/10">
              <button
                type="button"
                aria-label="کاهش"
                onClick={() => setQty((value) => Math.max(1, value - 1))}
                className="grid size-10 place-items-center text-lg hover:bg-zinc-50"
              >
                −
              </button>
              <span className="min-w-10 text-center text-sm font-bold">{qty.toLocaleString("fa-IR")}</span>
              <button
                type="button"
                aria-label="افزایش"
                onClick={() => setQty((value) => Math.min(stock || 99, value + 1))}
                className="grid size-10 place-items-center text-lg hover:bg-zinc-50"
              >
                +
              </button>
            </div>
            <button
              type="button"
              disabled={!variant?.id}
              onClick={() => {
                if (!variant?.id) return;
                addToCart({
                  id: variant.id,
                  slug: product.slug,
                  name: product.nameFa || product.title,
                  image: images[0] || PLACEHOLDER.product,
                  price,
                  quantity: qty,
                });
                setAdded(true);
              }}
              className="inline-flex flex-1 items-center justify-center gap-2 rounded-xl bg-brand px-5 py-2.5 text-sm text-white hover:bg-[#e51f1f] disabled:opacity-60"
            >
              <IconCart className="w-5 h-5 text-white" />
              {added ? "به سبد اضافه شد" : "افزودن به سبد خرید"}
            </button>
          </div>
        )}
      </div>
    </div>
  );
}