Next.js Commerce refresh. (#966)

We're making some updates to Next.js Commerce. Everything prior to this commit marks what we're calling [`v1`](https://github.com/vercel/commerce/releases/tag/v1) as a point in time to be able to reference and still use going into the future. The current architecture of Commerce is a multi-vendor, interoperable solution, including:

- [Shopify](https://shopify.vercel.store/)
- [Swell](https://swell.vercel.store/)
- [BigCommerce](https://bigcommerce.vercel.store/)
- [Vendure](https://vendure.vercel.store/)
- [Saleor](https://saleor.vercel.store/)
- [Ordercloud](https://ordercloud.vercel.store/)
- [Spree](https://spree.vercel.store/)
- [Kibo Commerce](https://kibocommerce.vercel.store/)
- [Commerce.js](https://commercejs.vercel.store/)
- [SalesForce Cloud Commerce](https://salesforce-cloud-commerce.vercel.store/)

All features can be toggled on or off, and it's easy to change between commerce providers. To support this, we needed to create a ["commerce metaframework"](d1d9e8c434/packages/commerce/new-provider.md) where providers could confirm to an API spec to add support for Next.js Commerce. While this worked and was successful for `v1`, we have different design goals and ambitions for `v2`.

**What You Need To Know**

- `v1` will not be updated moving forward. If you need to reference `v1`, you will still be able to clone and deploy the version tagged at this release.
- `v2` will be shifting to be a single provider vs. provider agnostic. Other providers are welcome to fork this repository and swap out the underlying `lib/` implementation that connects to the selected commerce provider (Shopify). This architecture was chosen to reduce the surface area of the codebase, remove the intermediate metaframework layer for provider-interoperability, and enable usage with the latest Next.js and React features.
- We will be sharing more about `v2` in the future as we continue to iterate before the marked release.

app/product/[handle]/page.tsx

@@ -0,0 +1,130 @@
+import type { Metadata } from 'next';
+import Link from 'next/link';
+import { notFound } from 'next/navigation';
+import { Suspense } from 'react';
+
+import Grid from 'components/grid';
+import { GridTileImage } from 'components/grid/tile';
+import Footer from 'components/layout/footer';
+import { AddToCart } from 'components/product/add-to-cart';
+import { Gallery } from 'components/product/gallery';
+import { VariantSelector } from 'components/product/variant-selector';
+import Prose from 'components/prose';
+import { HIDDEN_PRODUCT_TAG } from 'lib/constants';
+import { getProduct, getProductRecommendations } from 'lib/shopify';
+import { Image } from 'lib/shopify/types';
+
+export const runtime = 'edge';
+
+export async function generateMetadata({
+  params
+}: {
+  params: { handle: string };
+}): Promise<Metadata> {
+  const product = await getProduct(params.handle);
+
+  if (!product) return notFound();
+
+  const { url, width, height, altText: alt } = product.featuredImage || {};
+  const hide = !product.tags.includes(HIDDEN_PRODUCT_TAG);
+
+  return {
+    title: product.seo.title || product.title,
+    description: product.seo.description || product.description,
+    robots: {
+      index: hide,
+      follow: hide,
+      googleBot: {
+        index: hide,
+        follow: hide
+      }
+    },
+    openGraph: url
+      ? {
+          images: [
+            {
+              url,
+              width,
+              height,
+              alt
+            }
+          ]
+        }
+      : null
+  };
+}
+
+export default async function ProductPage({ params }: { params: { handle: string } }) {
+  const product = await getProduct(params.handle);
+
+  if (!product) return notFound();
+
+  return (
+    <div>
+      <div className="lg:grid lg:grid-cols-6">
+        <div className="lg:col-span-4">
+          <Gallery
+            title={product.title}
+            amount={product.priceRange.maxVariantPrice.amount}
+            currencyCode={product.priceRange.maxVariantPrice.currencyCode}
+            images={product.images.map((image: Image) => ({
+              src: image.url,
+              altText: image.altText
+            }))}
+          />
+        </div>
+
+        <div className="p-6 lg:col-span-2">
+          {/* @ts-expect-error Server Component */}
+          <VariantSelector options={product.options} variants={product.variants} />
+
+          {product.descriptionHtml ? (
+            <Prose className="mb-6 text-sm leading-tight" html={product.descriptionHtml} />
+          ) : null}
+
+          <AddToCart variants={product.variants} availableForSale={product.availableForSale} />
+        </div>
+      </div>
+      <Suspense>
+        {/* @ts-expect-error Server Component */}
+        <RelatedProducts id={product.id} />
+        <Suspense>
+          {/* @ts-expect-error Server Component */}
+          <Footer />
+        </Suspense>
+      </Suspense>
+    </div>
+  );
+}
+
+async function RelatedProducts({ id }: { id: string }) {
+  const relatedProducts = await getProductRecommendations(id);
+
+  if (!relatedProducts) return null;
+
+  return (
+    <div className="px-4 py-8">
+      <div className="mb-4 text-3xl font-bold">Related Products</div>
+      <Grid className="grid-cols-2 lg:grid-cols-5">
+        {relatedProducts.map((product) => {
+          return (
+            <Grid.Item key={product.id} className="animate-fadeIn">
+              <Link
+                aria-label={product.title}
+                className="border-gay-300 group relative block aspect-square overflow-hidden border bg-gray-50"
+                href={`/product/${product.handle}`}
+              >
+                <GridTileImage
+                  alt={product.title}
+                  src={product.featuredImage.url}
+                  width={600}
+                  height={600}
+                />
+              </Link>
+            </Grid.Item>
+          );
+        })}
+      </Grid>
+    </div>
+  );
+}