Reduce terminal auth and analytics stalls

frontend/app/api/analytics/events/route.ts

@@ -7,25 +7,46 @@ import {
   buildProxyExceptionResponse,
   buildUpstreamErrorResponse,
 } from "@/lib/api-proxy";
+import {
+  createProxyTimer,
+  finishProxyTimedResponse,
+} from "@/lib/proxy-timing";
 
 const API_BASE = process.env.POLYWEATHER_API_BASE_URL;
 const ANALYTICS_ENABLED =
   process.env.NEXT_PUBLIC_POLYWEATHER_APP_ANALYTICS !== "false";
+const ANALYTICS_PROXY_TIMEOUT_MS = Math.max(
+  250,
+  Number(process.env.POLYWEATHER_ANALYTICS_PROXY_TIMEOUT_MS || "1500") || 1500,
+);
 
 export async function POST(req: NextRequest) {
+  const timer = createProxyTimer(req, "analytics_events");
   if (!ANALYTICS_ENABLED) {
-    return new NextResponse(null, { status: 204 });
-  }
-
-  if (!API_BASE) {
-    return NextResponse.json(
-      { error: "POLYWEATHER_API_BASE_URL is not configured" },
-      { status: 500 },
+    return finishProxyTimedResponse(
+      new NextResponse(null, { status: 204 }),
+      timer,
+      "disabled",
     );
   }
 
+  if (!API_BASE) {
+    return finishProxyTimedResponse(
+      NextResponse.json(
+        { error: "POLYWEATHER_API_BASE_URL is not configured" },
+        { status: 500 },
+      ),
+      timer,
+      "missing_api_base",
+    );
+  }
+
+  const controller = new AbortController();
+  const timeoutId = setTimeout(() => controller.abort(), ANALYTICS_PROXY_TIMEOUT_MS);
+  let auth: Awaited<ReturnType<typeof buildBackendRequestHeaders>> | null = null;
+
   try {
-    const body = await req.json();
+    const body = await timer.measure("request_read", () => req.json());
     const payload =
       body && typeof body.payload === "object" && body.payload != null
         ? body.payload
@@ -42,30 +63,65 @@ export async function POST(req: NextRequest) {
         referer_header: req.headers.get("referer") || "",
       },
     };
-    const auth = await buildBackendRequestHeaders(req, {
-      includeSupabaseIdentity: false,
-    });
+    auth = await timer.measure("auth_headers", () =>
+      buildBackendRequestHeaders(req, {
+        includeSupabaseIdentity: false,
+      }),
+    );
     const headers = new Headers(auth.headers);
     headers.set("Content-Type", "application/json");
-    const res = await fetch(`${API_BASE}/api/analytics/events`, {
-      method: "POST",
-      headers,
-      body: JSON.stringify(enrichedBody),
-      cache: "no-store",
-    });
+    const res = await timer.measure("backend_fetch", () =>
+      fetch(`${API_BASE}/api/analytics/events`, {
+        method: "POST",
+        headers,
+        body: JSON.stringify(enrichedBody),
+        cache: "no-store",
+        signal: controller.signal,
+      }),
+    );
+    const backendServerTiming = res.headers.get("server-timing") || "";
     if (!res.ok) {
-      const raw = await res.text();
+      const raw = await timer.measure("backend_read", () => res.text());
       const response = buildUpstreamErrorResponse(res.status, raw, {
         detailLimit: 260,
       });
-      return applyAuthResponseCookies(response, auth.response);
+      return finishProxyTimedResponse(
+        applyAuthResponseCookies(response, auth.response),
+        timer,
+        `upstream_${res.status}`,
+        { backendServerTiming },
+      );
     }
-    const data = await res.json();
+    const data = await timer.measure("backend_read", () => res.json());
     const response = NextResponse.json(data);
-    return applyAuthResponseCookies(response, auth.response);
+    return finishProxyTimedResponse(
+      applyAuthResponseCookies(response, auth.response),
+      timer,
+      "ok",
+      { backendServerTiming },
+    );
   } catch (error) {
-    return buildProxyExceptionResponse(error, {
-      publicMessage: "Failed to track analytics event",
-    });
+    const timedOut = controller.signal.aborted;
+    const response = timedOut
+      ? NextResponse.json(
+          {
+            ok: false,
+            accepted: true,
+            dropped: true,
+            reason: "timeout",
+          },
+          { status: 202 },
+        )
+      : buildProxyExceptionResponse(error, {
+          publicMessage: "Failed to track analytics event",
+        });
+    const withCookies = auth ? applyAuthResponseCookies(response, auth.response) : response;
+    return finishProxyTimedResponse(
+      withCookies,
+      timer,
+      timedOut ? "timeout_accepted" : "exception",
+    );
+  } finally {
+    clearTimeout(timeoutId);
   }
 }