commerce/app/sitemap.ts

import { getCollectionProducts, getCollections } from 'lib/fourthwall';
import { validateEnvironmentVariables } from 'lib/utils';
import { MetadataRoute } from 'next';

type Route = {
  url: string;
  lastModified: string;
};

const baseUrl = process.env.NEXT_PUBLIC_VERCEL_URL
  ? `https://${process.env.NEXT_PUBLIC_VERCEL_URL}`
  : 'http://localhost:3000';

export const dynamic = 'force-dynamic';

export default async function sitemap(): Promise<MetadataRoute.Sitemap> {
  validateEnvironmentVariables();

  const routesMap = [''].map((route) => ({
    url: `${baseUrl}${route}`,
    lastModified: new Date().toISOString()
  }));

  const collections = await getCollections();

  const productsPromises = collections.map((collection) => {
    return getCollectionProducts({ collection: collection.handle, currency: 'USD' }).then((products) =>
      products.map((product) => ({
        url: `${baseUrl}/product/${product.handle}`,
        lastModified: product.updatedAt
      }))
    );
  });
  
  let fetchedRoutes: Route[] = [];

  try {
    fetchedRoutes = (await Promise.all([...productsPromises])).flat();
  } catch (error) {
    throw JSON.stringify(error, null, 2);
  }

  return [...routesMap, ...fetchedRoutes];
}