How would you implement a simple session management system using cookies in Next.js?

You generate a unique session identifier when a user logs in, store that identifier along with the user's data in a database or cache, save the identifier itself in a secure cookie, and then look up the session on each request by reading that cookie and matching it against your stored sessions.

async function getSession() {
  const cookieStore = await cookies();
  const sessionId = cookieStore.get('sessionId')?.value;
  if (!sessionId) return null;
  return await db.session.findUnique({ where: { id: sessionId } });
}