[NOTIF-003] Emit view notifications on public profile views

src/app/[lang]/u/[id]/page.tsx

@@ -10,6 +10,7 @@ import {
 import { ANALYTICS_EVENTS } from '@/lib/analytics/events';
 import { trackEvent } from '@/lib/analytics/track.server';
 import { getCurrentUser } from '@/lib/auth';
+import { notifyProfileView } from '@/lib/notifications/profileView';
 import { PublicProfileClient } from './PublicProfileClient';
 
 export default async function PublicProfileRoute({
@@ -32,11 +33,16 @@ export default async function PublicProfileRoute({
   let currentProfileId: string | undefined;
   let viewerTimezone: string | undefined;
   let viewerUserId: string | undefined;
+  let viewerActor: { name: string; avatarUrl: string | null } | null = null;
 
   if (user) {
     isLoggedIn = true;
     const persistedUser = await upsertDiscordUser(user);
     viewerUserId = persistedUser.id;
+    viewerActor = {
+      name: persistedUser.displayName,
+      avatarUrl: persistedUser.avatarUrl,
+    };
     const viewerProfile = await getProfileByUserId(persistedUser.id);
     currentProfileId = viewerProfile?.profile.id;
     savedProfileIds = await listSavedProfileIds(persistedUser.id);
@@ -54,6 +60,13 @@ export default async function PublicProfileRoute({
     locale: lang,
   });
 
+  if (viewerUserId !== row.profile.userId) {
+    await notifyProfileView({
+      ownerUserId: row.profile.userId,
+      actor: viewerActor,
+    });
+  }
+
   return (
     <PublicProfileClient
       locale={lang}

src/db/notifications.ts

@@ -1,6 +1,6 @@
 import 'server-only';
 
-import { and, desc, eq } from 'drizzle-orm';
+import { and, desc, eq, gte } from 'drizzle-orm';
 import { db } from './client';
 import {
   type NewNotificationRecord,
@@ -58,6 +58,29 @@ export const createNotification = async (values: NewNotificationRecord) => {
   return created;
 };
 
+export const hasRecentViewNotification = async (
+  userId: string,
+  actorName: string | null,
+  windowStart: Date,
+): Promise<boolean> => {
+  const [existing] = await db
+    .select({ id: notifications.id })
+    .from(notifications)
+    .where(
+      and(
+        eq(notifications.userId, userId),
+        eq(notifications.kind, 'view'),
+        actorName === null
+          ? eq(notifications.isGuest, true)
+          : eq(notifications.actorName, actorName),
+        gte(notifications.createdAt, windowStart),
+      ),
+    )
+    .limit(1);
+
+  return existing !== undefined;
+};
+
 export const setNotificationRead = async (
   userId: string,
   notificationId: string,

src/lib/notifications/profileView.ts

@@ -0,0 +1,41 @@
+import 'server-only';
+
+import { createNotification, hasRecentViewNotification } from '@/db';
+
+const VIEW_DEDUPE_WINDOW_MS = 60 * 60 * 1000;
+
+type ProfileViewActor = {
+  name: string;
+  avatarUrl: string | null;
+};
+
+export const notifyProfileView = async ({
+  ownerUserId,
+  actor,
+}: {
+  ownerUserId: string;
+  actor: ProfileViewActor | null;
+}): Promise<void> => {
+  try {
+    const windowStart = new Date(Date.now() - VIEW_DEDUPE_WINDOW_MS);
+    const duplicate = await hasRecentViewNotification(
+      ownerUserId,
+      actor?.name ?? null,
+      windowStart,
+    );
+
+    if (duplicate) {
+      return;
+    }
+
+    await createNotification({
+      userId: ownerUserId,
+      kind: 'view',
+      actorName: actor?.name ?? null,
+      actorAvatarUrl: actor?.avatarUrl ?? null,
+      isGuest: actor === null,
+    });
+  } catch (error) {
+    console.error('profile view notification failed', error);
+  }
+};