import { NextResponse } from 'next/server';
import { prisma } from '@/lib/prisma';

export async function POST(req: Request) {
  try {
    const body = await req.json();

    // 🔹 BULK: { names: string[], canEditDevices?: boolean }
    if (Array.isArray(body?.names)) {
      const rawNames = body.names as unknown[];

      const trimmedNames = rawNames
        .filter((n): n is string => typeof n === 'string')
        .map((n) => n.trim())
        .filter((n) => n.length > 0);

      const uniqueNames = Array.from(new Set(trimmedNames));

      const defaultCanEditDevices = Boolean(body.canEditDevices ?? false);

      const groups = [];
      for (const name of uniqueNames) {
        const trimmedName = name.trim();
        const isTEG = trimmedName.toUpperCase() === 'TEG';

        // 👇 TEG immer true, sonst Default
        const canEdit = isTEG ? true : defaultCanEditDevices;

        const group = await prisma.userGroup.upsert({
          where: { name: trimmedName },
          update: {
            canEditDevices: canEdit,
          },
          create: {
            name: trimmedName,
            canEditDevices: canEdit,
          },
        });

        groups.push({
          id: group.id,
          name: group.name,
          canEditDevices: group.canEditDevices,
        });
      }

      return NextResponse.json({ groups }, { status: 200 });
    }

    // 🔹 SINGLE: { name: string, canEditDevices?: boolean }
    const { name, canEditDevices } = body;

    if (!name || typeof name !== 'string') {
      return NextResponse.json(
        { error: 'Gruppenname ist erforderlich.' },
        { status: 400 },
      );
    }

    const trimmed = name.trim();
    if (!trimmed) {
      return NextResponse.json(
        { error: 'Gruppenname darf nicht leer sein.' },
        { status: 400 },
      );
    }

    const isTEG = trimmed.toUpperCase() === 'TEG';

    // 👇 TEG immer true, sonst Flag aus Request (oder false)
    const flag = isTEG ? true : Boolean(canEditDevices ?? false);

    const group = await prisma.userGroup.upsert({
      where: { name: trimmed },
      update: {
        canEditDevices: flag,
      },
      create: {
        name: trimmed,
        canEditDevices: flag,
      },
    });

    return NextResponse.json(
      {
        id: group.id,
        name: group.name,
        canEditDevices: group.canEditDevices,
      },
      { status: 200 },
    );
  } catch (err) {
    console.error('[POST /api/user-groups]', err);
    return NextResponse.json(
      { error: 'Interner Serverfehler beim Anlegen der User-Gruppe.' },
      { status: 500 },
    );
  }
}