import { NextRequest, NextResponse } from 'next/server';
import { auth } from '@/auth';
import { stripe } from '@/lib/stripe';
import { prisma } from '@/lib/prisma';

export async function POST(req: NextRequest) {
  const session = await auth();
  if (!session?.user?.id) {
    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
  }

  const userId = session.user.id;

  let action = 'portal';
  try {
    const body = await req.json();
    if (body?.action) action = body.action;
  } catch (_) {}

  try {
    const subscription = await prisma.subscription.findUnique({ where: { userId } });
    if (!subscription?.stripeCustomerId) {
      return NextResponse.json({ error: 'No active subscription found' }, { status: 404 });
    }

    const host = req.headers.get('x-forwarded-host') ?? req.headers.get('host') ?? 'localhost:3000';
    const proto = req.headers.get('x-forwarded-proto') ?? 'http';
    const origin = `${proto}://${host}`;

    const portalSession = await stripe.billingPortal.sessions.create({
      customer: subscription.stripeCustomerId,
      return_url: `${origin}/settings/billing`,
    });

    return NextResponse.json({ url: portalSession.url });
  } catch (error) {
    console.error('[billing/portal]', error);
    return NextResponse.json({ error: 'Failed to create portal session' }, { status: 500 });
  }
}