import { type NextRequest, NextResponse } from 'next/server';
import { requireAdminApi } from '@/lib/auth/admin-guard';
import { getTunnelsList } from '@/lib/admin/list';
import { logAdminAction } from '@/lib/auth/audit';
import { toCsv, EXPORT_MAX_ROWS } from '@/lib/admin/csv';

export const runtime = 'nodejs';
export const dynamic = 'force-dynamic';

export async function GET(req: NextRequest) {
  const auth = await requireAdminApi();
  if (!auth.ok) return auth.response;

  const url = new URL(req.url);
  const search = url.searchParams.get('search') ?? '';
  const status = url.searchParams.get('status');
  const sort = url.searchParams.get('sort');
  const order = url.searchParams.get('order');

  try {
    // Respect search/status/sort but pull the full matching set (capped).
    // SECURITY: the tunnel token is NEVER selected or exported.
    const { tunnels } = await getTunnelsList({
      page: 1,
      perPage: EXPORT_MAX_ROWS,
      search,
      status,
      sort,
      order,
    });

    const header = [
      'user_id',
      'owner_email',
      'subdomain',
      'is_active',
      'bytes_used',
      'quota_bytes',
      'usage_pct',
      'last_seen_at',
      'created_at',
    ];
    const rows = tunnels.map((t) => [
      t.user_id,
      t.owner_email ?? '',
      t.subdomain,
      t.is_active ? 'true' : 'false',
      t.bytes_used,
      t.quota_bytes,
      t.usage_pct.toFixed(1),
      t.last_seen_at ?? '',
      t.created_at,
    ]);

    const csv = toCsv(header, rows);

    await logAdminAction(auth.user, {
      action: 'tunnel.export',
      target_type: 'tunnel',
      details: { count: rows.length, capped: rows.length >= EXPORT_MAX_ROWS },
    });

    return new NextResponse(csv, {
      status: 200,
      headers: {
        'Content-Type': 'text/csv; charset=utf-8',
        'Content-Disposition': 'attachment; filename="tunnels.csv"',
        'Cache-Control': 'no-store',
        Pragma: 'no-cache',
      },
    });
  } catch (e) {
    console.error('admin tunnels export failed', e);
    return NextResponse.json(
      { error: 'internal error' },
      { status: 500, headers: { 'Cache-Control': 'no-store' } },
    );
  }
}