// app/api/users/assign-group/route.ts
import { NextResponse } from 'next/server';
import { prisma } from '@/lib/prisma';

export async function POST(req: Request) {
  try {
    const body = await req.json();
    const { userId, groupId } = body ?? {};

    if (!userId) {
      return NextResponse.json(
        { error: 'userId ist erforderlich.' },
        { status: 400 },
      );
    }

    const normalizedGroupId =
      !groupId || groupId === 'none' ? null : String(groupId);

    await prisma.user.update({
      where: { nwkennung: String(userId) },
      data: { groupId: normalizedGroupId },
    });

    return NextResponse.json({ ok: true });
  } catch (err) {
    console.error('[POST /api/users/assign-group]', err);
    return NextResponse.json(
      { error: 'Interner Serverfehler beim Aktualisieren der Gruppe.' },
      { status: 500 },
    );
  }
}