SCENT RE-IMAGINED AS CODE.
0.82S GLOBAL TIME-TO-CART.

// Optimistic Edge Storefront Cart Resolver with KV Cache & SWR Invalidation
import { StorefrontClient } from '@themeimpact/edge-shopify';
import { computeOlfactoryHash } from '@ken/fragrance-math';

export default {
  async fetch(request: Request, env: Env): Promise<Response> {
    const { lineItems, currency, locale } = await request.json();
    const cacheKey = `cart:${locale}:${currency}:${computeOlfactoryHash(lineItems)}`;

    // 1. Instant Cache Layer lookup via Cloudflare KV (sub-4ms)
    const cachedCart = await env.EDGE_CART_CACHE.get(cacheKey, { type: 'json' });
    if (cachedCart) {
      return Response.json({ status: 'OPTIMISTIC_EDGE_HIT', cart: cachedCart }, {
        headers: { 'X-Cache-Tier': 'KV_ISOLATE_HIT', 'Server-Timing': 'edge;dur=3.2' }
      });
    }

    // 2. Non-blocking Edge Proxy to Shopify Storefront GraphQL
    const client = new StorefrontClient(env.SHOPIFY_STOREFRONT_TOKEN);
    const mutationResult = await client.cartLinesAdd({ lines: lineItems, buyerIdentity: { countryCode: locale } });

    // 3. Stale-While-Revalidate KV Persistence with zero worker blocking
    env.ctx.waitUntil(env.EDGE_CART_CACHE.put(cacheKey, JSON.stringify(mutationResult), { expirationTtl: 3600 }));

    return Response.json({ status: 'MUTATION_RESOLVED', cart: mutationResult }, {
      headers: { 'X-Cache-Tier': 'DIRECT_STOREFRONT_SYNC', 'Server-Timing': 'upstream;dur=28.4' }
    });
  }
};