water/server/app/miniapi/service/BalanceService.php

<?php

declare(strict_types=1);

namespace app\miniapi\service;

use app\miniapi\model\MiniEnterpriseBalance;

final class BalanceService
{
    public static function cents(int $enterprise): int
    {
        return (int) (MiniEnterpriseBalance::query()->where('enterprise_id', $enterprise)->value('balance_cents') ?? 0);
    }

    public static function locked(int $enterprise): MiniEnterpriseBalance
    {
        $balance = MiniEnterpriseBalance::query()->where('enterprise_id', $enterprise)->lockForUpdate()->first();
        if ($balance) {
            return $balance;
        }

        MiniEnterpriseBalance::query()->insert([
            'enterprise_id' => $enterprise,
            'balance_cents' => 0,
            'created_at' => date('Y-m-d H:i:s'),
            'updated_at' => date('Y-m-d H:i:s'),
        ]);

        return MiniEnterpriseBalance::query()->where('enterprise_id', $enterprise)->lockForUpdate()->firstOrFail();
    }
}