// app/api/admin/update-user-role/route.ts
import { NextResponse } from 'next/server';
import { getServerSession } from 'next-auth';
import { authOptions } from '@/lib/auth-options';
import { prisma } from '@/lib/prisma';

export async function PATCH(req: Request) {
  try {
    const session = await getServerSession(authOptions);
    if (!session?.user?.email) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    // Only superadmins can assign roles
    const role = (session as any)?.user?.role ?? null;
    if (role !== 'superadmin') {
      return NextResponse.json(
        { error: 'Only superadmins can assign roles' },
        { status: 403 }
      );
    }

    const body = await req.json();
    const { userId, newRole } = body;

    if (!userId || !newRole) {
      return NextResponse.json(
        { error: 'userId and newRole required' },
        { status: 400 }
      );
    }

    // Validate newRole
    const validRoles = ['user', 'admin', 'superadmin'];
    if (!validRoles.includes(newRole)) {
      return NextResponse.json(
        { error: `Invalid role. Must be one of: ${validRoles.join(', ')}` },
        { status: 400 }
      );
    }

    // Prevent self-demotion from superadmin
    const currentUser = await prisma.user.findUnique({
      where: { email: session.user.email },
    });

    if (currentUser?.id === userId && newRole !== 'superadmin') {
      return NextResponse.json(
        { error: 'Cannot demote yourself from superadmin' },
        { status: 400 }
      );
    }

    // Update user role
    const updatedUser = await prisma.user.update({
      where: { id: userId },
      data: { role: newRole },
      select: {
        id: true,
        email: true,
        name: true,
        role: true,
      },
    });

    return NextResponse.json({
      message: 'User role updated successfully',
      user: updatedUser,
    });
  } catch (err: any) {
    console.error('update user role error:', err);
    return NextResponse.json(
      { error: err?.message ?? 'server error' },
      { status: 500 }
    );
  }
}