retention

src/lib/analyticsActivity.ts

@@ -0,0 +1,41 @@
+import { db } from '@/lib/db';
+
+/**
+ * Records that a signed-in user looked at their own scan numbers.
+ *
+ * This exists because "inactive" cannot be answered from anything else we
+ * store. A session can stay alive for weeks without the user ever opening their
+ * analytics, so a login timestamp would call someone active who has not seen a
+ * number in a month. PostHog cannot answer it either - capture there is gated on
+ * cookie consent and runs client-side, so it covers an unknown subset.
+ *
+ * Written server-side, on the endpoint that serves the numbers. That endpoint is
+ * the single choke point for both the analytics page and the dashboard.
+ */
+
+/** Repeat views inside this window do not cause another write. */
+const THROTTLE_MS = 60 * 60 * 1000;
+
+export function touchAnalyticsView(userId: string): void {
+  const now = new Date();
+  const staleBefore = new Date(now.getTime() - THROTTLE_MS);
+
+  // updateMany, not update: the throttle lives in the WHERE clause, so a repeat
+  // view inside the window matches no rows instead of racing a read.
+  db.user
+    .updateMany({
+      where: {
+        id: userId,
+        OR: [
+          { lastAnalyticsViewAt: null },
+          { lastAnalyticsViewAt: { lt: staleBefore } },
+        ],
+      },
+      data: { lastAnalyticsViewAt: now },
+    })
+    .catch((error) => {
+      // Fire and forget. Analytics must still render if this write fails - it
+      // also fails harmlessly if the column has not been added yet.
+      console.error('Failed to record analytics view:', error);
+    });
+}