ThreadCount Community edition

Uniform stock management for healthcare linen rooms. Licensed under the GNU AGPL v3.

app/api/rev/route.ts

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+import { NextRequest, NextResponse } from "next/server";
+import { prisma } from "@/lib/db";
+import { currentUser } from "@/lib/session";
+import { currentStaff } from "@/lib/staffsession";
+
+export const dynamic = "force-dynamic";
+
+/* "Has anything changed?", answered in one integer.
+ *
+ * Every screen in the product already knows how to reload itself — a mutation ends in
+ * router.refresh(). What it could not know was that somebody ELSE had changed something, so a
+ * phone left open on a ward showed whatever the catalogue looked like when it was opened, and a
+ * coordinator adding a garment at the desk had to tell the counter to pull down to refresh.
+ *
+ * The obvious fix — poll the snapshot and diff it — is the expensive one: that is the facility's
+ * catalogue, staff register, stock and history, re-read on a timer by every open device to learn,
+ * almost always, that nothing happened. This returns the counter that the three mutating routes
+ * bump, so the cost of asking is a primary-key lookup, and the cost of the real reload is paid only
+ * when the number has actually moved.
+ *
+ * Both session kinds answer here. A coordinator at the desk and a wearer on a ward are watching the
+ * same facility, and there is nothing in a bare revision number to keep apart — it says that
+ * something changed, never what. Anyone with no session at all gets 401 rather than a number,
+ * because even "this facility is busy" is not ours to hand out.
+ */
+export async function GET(_req: NextRequest) {
+  const user = await currentUser();
+  const facilityId = user?.facilityId || (await currentStaff())?.facilityId;
+  if (!facilityId) return NextResponse.json({ error: "Not signed in" }, { status: 401 });
+
+  const f = await prisma.facility.findUnique({ where: { id: facilityId }, select: { rev: true } });
+  if (!f) return NextResponse.json({ error: "Not signed in" }, { status: 401 });
+
+  // Never from a cache: a stale revision is indistinguishable from nothing having happened, which
+  // is the one wrong answer this endpoint can give.
+  return NextResponse.json({ rev: f.rev }, { headers: { "cache-control": "no-store" } });
+}