harden admin api authorization and add authz regression tests

apps/admin/src/app/api/notifications/__tests__/route-authz.test.ts

@@ -0,0 +1,87 @@
+/**
+ * @jest-environment node
+ */
+
+import { NextRequest } from "next/server";
+import { POST } from "../route";
+
+jest.mock("@clerk/nextjs/server", () => ({
+  auth: jest.fn(),
+}));
+
+jest.mock("@/lib/database", () => ({
+  getDatabase: jest.fn(),
+}));
+
+jest.mock("@/lib/sync-user", () => ({
+  ensureUserSynced: jest.fn(),
+}));
+
+jest.mock("@/lib/logger", () => ({
+  info: jest.fn(),
+  warn: jest.fn(),
+  error: jest.fn(),
+  debug: jest.fn(),
+}));
+
+describe("POST /api/notifications authz", () => {
+  const mockAuth = require("@clerk/nextjs/server").auth as jest.Mock;
+  const mockGetDatabase = require("@/lib/database").getDatabase as jest.Mock;
+  const mockEnsureUserSynced = require("@/lib/sync-user")
+    .ensureUserSynced as jest.Mock;
+
+  const mockDb = {
+    getUserById: jest.fn(),
+    createNotification: jest.fn(),
+  };
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+    mockGetDatabase.mockResolvedValue(mockDb);
+  });
+
+  it("returns 403 for non-staff user", async () => {
+    mockAuth.mockResolvedValue({ userId: "client_1" });
+    mockEnsureUserSynced.mockResolvedValue({
+      id: "client_1",
+      role: "client",
+      gymId: "gym_a",
+    });
+
+    const request = new NextRequest("http://localhost/api/notifications", {
+      method: "POST",
+      body: JSON.stringify({
+        targetUserId: "client_2",
+        title: "Hello",
+        message: "Test",
+        type: "system",
+      }),
+    });
+
+    const response = await POST(request);
+    expect(response.status).toBe(403);
+  });
+
+  it("returns 403 for cross-gym notify by admin", async () => {
+    mockAuth.mockResolvedValue({ userId: "admin_1" });
+    mockEnsureUserSynced.mockResolvedValue({
+      id: "admin_1",
+      role: "admin",
+      gymId: "gym_a",
+    });
+    mockDb.getUserById.mockResolvedValue({ id: "client_2", gymId: "gym_b" });
+
+    const request = new NextRequest("http://localhost/api/notifications", {
+      method: "POST",
+      body: JSON.stringify({
+        targetUserId: "client_2",
+        title: "Hello",
+        message: "Test",
+        type: "system",
+      }),
+    });
+
+    const response = await POST(request);
+    expect(response.status).toBe(403);
+  });
+});

apps/admin/src/app/api/notifications/route.ts

@@ -2,6 +2,7 @@ import { NextRequest, NextResponse } from "next/server";
 import { auth } from "@clerk/nextjs/server";
 import { getDatabase } from "@/lib/database";
 import log from "@/lib/logger";
+import { ensureUserSynced } from "@/lib/sync-user";
 
 /**
  * GET /api/notifications
@@ -84,6 +85,39 @@ export async function POST(req: NextRequest) {
     }
 
     const db = await getDatabase();
+    const currentUser = await ensureUserSynced(userId, db);
+
+    if (!currentUser) {
+      return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+    }
+
+    const canCreateNotifications =
+      currentUser.role === "superAdmin" ||
+      currentUser.role === "admin" ||
+      currentUser.role === "trainer";
+
+    if (!canCreateNotifications) {
+      return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+    }
+
+    const targetUser = await db.getUserById(targetUserId);
+    if (!targetUser) {
+      return NextResponse.json(
+        { error: "Target user not found" },
+        { status: 404 },
+      );
+    }
+
+    if (
+      currentUser.role !== "superAdmin" &&
+      (!currentUser.gymId || targetUser.gymId !== currentUser.gymId)
+    ) {
+      return NextResponse.json(
+        { error: "Forbidden - Cannot notify users from other gyms" },
+        { status: 403 },
+      );
+    }
+
     const notification = await db.createNotification({
       id: crypto.randomUUID(),
       userId: targetUserId,