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require_once __DIR__ . '/../config/config.php';
require_once __DIR__ . '/../includes/functions.php';
if (!isAdmin()) { header("Location: index.php"); exit; }
header('Content-Type: text/csv; charset=utf-8');
header('Content-Disposition: attachment; filename=customers_export_'.date('Ymd').'.csv');
$output = fopen('php://output', 'w');
fputcsv($output, ['ID', 'Name', 'Email', 'Phone', 'District', 'Status', 'Joined', 'Total Bookings', 'Total Spent']);
$customers = $conn->query("SELECT c.*, (SELECT COUNT(*) FROM bookings WHERE customer_id=c.id) as tbook, (SELECT COALESCE(SUM(total_price),0) FROM bookings WHERE customer_id=c.id AND status NOT IN ('cancelled')) as tspent FROM customers c ORDER BY c.id DESC")->fetch_all(MYSQLI_ASSOC);
foreach ($customers as $c) {
    fputcsv($output, [$c['id'], $c['name'], $c['email'], $c['phone'], $c['district']??'', $c['status']?'Active':'Inactive', $c['created_at'], $c['tbook'], $c['tspent']]);
}
fclose($output);