We don't just build websites. We engineer deterministic, zero-latency edge infrastructure.

import { createEdgeRouter, type ExecutionContext } from '@themeimpact/edge-core';
import { streamSSRResponse, cacheControlHeaders } from '@themeimpact/runtime-streaming';

const router = createEdgeRouter({
  regions: ['iad', 'lhr', 'sin', 'nrt', 'fra'],
  maxTtfbTargetMs: 50,
  enableSpeculativePrefetch: true,
});

// Deterministic edge request interceptor
export default {
  async fetch(request: Request, env: Env, ctx: ExecutionContext): Promise<Response> {
    const cache = caches.default;
    const cacheKey = new URL(request.url).toString();
    
    // Tier 1: Check edge cache with stale-while-revalidate
    const cachedResponse = await cache.match(cacheKey);
    if (cachedResponse) {
      ctx.waitUntil(revalidateEdgeOriginIfNeeded(request, env, cachedResponse));
      return cachedResponse;
    }

    // Tier 2: Stream critical DOM chunks immediately to browser
    const { stream, responsePromise } = await streamSSRResponse({
      request,
      budgetKb: 35.0, // Hard limit for critical render tree
      timeoutMs: 450,
    });

    // Background asynchronous cache registration
    ctx.waitUntil(cache.put(cacheKey, responsePromise.clone()));
    return stream;
  }
};