fix: the image lost after exporting (#3150)

Co-authored-by: Alex Yang <himself65@outlook.com>

packages/workers/src/index.ts

@@ -0,0 +1,63 @@
+const ALLOW_ORIGIN = ['https://affine.pro', 'https://affine.fail'];
+
+function isString(s: any): boolean {
+  return typeof s === 'string' || s instanceof String;
+}
+
+function isOriginAllowed(
+  origin: string,
+  allowedOrigin: string | RegExp | Array<string | RegExp>
+): boolean {
+  if (Array.isArray(allowedOrigin)) {
+    for (let i = 0; i < allowedOrigin.length; ++i) {
+      if (isOriginAllowed(origin, allowedOrigin[i])) {
+        return true;
+      }
+    }
+    return false;
+  } else if (isString(allowedOrigin)) {
+    return origin === allowedOrigin;
+  } else if (allowedOrigin instanceof RegExp) {
+    return allowedOrigin.test(origin);
+  } else {
+    return !!allowedOrigin;
+  }
+}
+
+async function proxyImage(request: Request): Promise<Response> {
+  const url = new URL(request.url);
+  const imageURL = url.searchParams.get('url');
+
+  if (!imageURL) {
+    return new Response('Missing "url" parameter', { status: 400 });
+  }
+
+  const imageRequest = new Request(imageURL, {
+    method: 'GET',
+    headers: request.headers,
+  });
+
+  const response = await fetch(imageRequest);
+  const modifiedResponse = new Response(response.body);
+  modifiedResponse.headers.set('Access-Control-Allow-Origin', '*');
+  modifiedResponse.headers.set('Access-Control-Allow-Methods', 'GET');
+
+  return modifiedResponse;
+}
+
+const handler = {
+  async fetch(request: Request) {
+    if (!isOriginAllowed(request.headers.get('Origin') || '', ALLOW_ORIGIN)) {
+      return new Response('unauthorized', { status: 401 });
+    }
+
+    const url = new URL(request.url);
+    if (url.pathname.startsWith('/proxy/image')) {
+      return await proxyImage(request);
+    }
+
+    return new Response('not found', { status: 404 });
+  },
+};
+
+export default handler;