use Illuminate\Support\Facades\Cache;

public function getReport() {
    $cacheKey = 'sales_report_daily';
    $expiresAt = now()->endOfDay(); // Cache hết hạn lúc 23:59 hôm nay

    return Cache::remember($cacheKey, $expiresAt, function () {
        return DB::table('sales')
            ->whereDate('created_at', '>=', now()->subDays(30))
            ->get();
    });
}

public function requestReport() {
    $user = auth()->user();
    GenerateBigReport::dispatch($user->id);

    return response()->json(['message' => 'Báo cáo đang được tạo. Bạn sẽ nhận thông báo khi sẵn sàng tải về.']);
}

use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Support\Facades\Storage;

class GenerateBigReport implements ShouldQueue {
    use Queueable;
    public $userId;

    public function __construct($userId) {
        $this->userId = $userId;
    }

    public function handle() {
        $data = DB::table('transactions')->get(); // Dữ liệu lớn ví dụ

        $csv = fopen(storage_path("app/reports/report_{$this->userId}.csv"), 'w');
        fputcsv($csv, ['id', 'amount', 'date']); // Header

        foreach ($data as $row) {
            fputcsv($csv, [$row->id, $row->amount, $row->created_at]);
        }
        fclose($csv);

        // Có thể gửi thông báo tới user khi hoàn thành
    }
}

public function checkReport() {
    $path = "reports/report_" . auth()->id() . ".csv";

    if (Storage::exists($path)) {
        return response()->json([
            'ready' => true,
            'download_url' => Storage::url($path),
        ]);
    }

    return response()->json(['ready' => false]);
}