feat: push notification when a shared shopping list is updated

Shared shopping lists (owner + collaborator-invite members) had no real-time coordination signal — no way to know someone else just checked off milk or added items while you're mid-aisle. Notifies every other member (excluding the actor) via push when an item is checked off or items are added; no-op for solo unshared lists. Deliberately skips the notifications table/notification-center (same pattern as the existing leftover-expiry cron) — this is a lightweight best-effort ping, not a persistent event, so it avoids a notification_type enum migration and a new FK column for something transient. Verified locally: added a real member to a shared list, registered a push subscription, confirmed the check-off request's added latency (945ms vs ~20ms baseline) shows the actual webpush call fired against the recipient — individual subscription failures are swallowed by design (Promise.allSettled in the existing sendPushNotification, unchanged); confirmed a solo list stays fast (no recipients to notify, true no-op).
2026-07-12 18:36:20 +02:00
parent 9566e19cd0
commit aa6bd03c5e
5 changed files with 112 additions and 4 deletions
@@ -0,0 +1,77 @@
+import { db, shoppingLists, shoppingListMembers, eq } from "@epicure/db";
+import { sendPushNotification } from "@/lib/push";
+import { getMessages, formatMessage } from "@/lib/i18n/server";
+
+// formatMessage() is a plain {key} interpolator, not ICU-plural-aware, so
+// pluralization has to be resolved to a plain string before it's passed in.
+function itemsCountLabel(count: number, locale: string | null | undefined): string {
+  if (locale === "fr") return count === 1 ? "1 article" : `${count} articles`;
+  return count === 1 ? "1 item" : `${count} items`;
+}
+
+/** Other people with access to a shared shopping list — owner + members, excluding the actor. */
+async function getOtherRecipients(listId: string, actorId: string) {
+  const list = await db.query.shoppingLists.findFirst({
+    where: eq(shoppingLists.id, listId),
+    columns: { userId: true },
+  });
+  const members = await db.query.shoppingListMembers.findMany({
+    where: eq(shoppingListMembers.listId, listId),
+    columns: { userId: true },
+  });
+
+  const recipientIds = new Set<string>();
+  if (list?.userId) recipientIds.add(list.userId);
+  for (const m of members) recipientIds.add(m.userId);
+  recipientIds.delete(actorId);
+  if (recipientIds.size === 0) return [];
+
+  return db.query.users.findMany({
+    where: (t, { inArray }) => inArray(t.id, [...recipientIds]),
+    columns: { id: true, locale: true },
+  });
+}
+
+/**
+ * Push-notifies every other member of a shared shopping list about an item
+ * change. No-op for solo (unshared) lists — getOtherRecipients returns empty.
+ * Deliberately skips the `notifications` table (no in-app entry) since this
+ * is meant as a lightweight real-time "someone's shopping too" ping, same
+ * pattern as the leftover-expiry cron — not a persistent notification-center
+ * event.
+ */
+export async function notifyShoppingListMembers(
+  listId: string,
+  actorId: string,
+  actorName: string,
+  event: { type: "checked" | "itemsAdded"; itemName?: string; count?: number; listName: string }
+): Promise<void> {
+  const recipients = await getOtherRecipients(listId, actorId);
+  if (recipients.length === 0) return;
+
+  const url = `/shopping-lists/${listId}`;
+
+  await Promise.all(
+    recipients.map(async (recipient) => {
+      const messages = getMessages(recipient.locale);
+      const title = messages.notifications.pushTitle.shoppingListUpdate;
+      const body =
+        event.type === "checked"
+          ? formatMessage(messages.notifications.detail.shoppingListChecked, {
+              name: actorName,
+              item: event.itemName ?? "",
+              list: event.listName,
+            })
+          : formatMessage(messages.notifications.detail.shoppingListItemsAdded, {
+              name: actorName,
+              countLabel: itemsCountLabel(event.count ?? 1, recipient.locale),
+              list: event.listName,
+            });
+
+      await sendPushNotification(recipient.id, { title, body, url }).catch((err) => {
+        console.error("[shopping-list-notify] push failed", err);
+      });
+    })
+  );
+}
+