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

// Quote every field per RFC 4180 and double up embedded quotes - simplest
// rule that's correct for names/notes containing commas, quotes, or newlines.
function csvField(value: string): string {
  return `"${value.replace(/"/g, '""')}"`;
}

function csvRow(fields: string[]): string {
  return fields.map(csvField).join(',') + '\r\n';
}

export async function GET(_request: Request, { params }: { params: Promise<{ id: string }> }) {
  const { id } = await params;
  const { event } = await requireEventAccess(id);

  const rsvps = await prisma.rsvp.findMany({ where: { eventId: id }, orderBy: { createdAt: 'asc' } });

  let csv = csvRow(['Name', 'Status', 'Guests', 'Email', 'Phone', 'Note', 'Responded at (UTC)']);
  for (const rsvp of rsvps) {
    csv += csvRow([
      rsvp.guestName,
      rsvp.status,
      String(rsvp.numGuests),
      rsvp.guestEmail ?? '',
      rsvp.guestPhone ?? '',
      rsvp.note,
      rsvp.createdAt.toISOString(),
    ]);
  }

  return new NextResponse(csv, {
    headers: {
      'Content-Type': 'text/csv; charset=utf-8',
      'Content-Disposition': `attachment; filename="${event.slug}-rsvps.csv"`,
    },
  });
}