bot-28/app/Services/Agent/AgentExchangeRate.php

<?php

namespace App\Services\Agent;

use Illuminate\Support\Facades\DB;

/** 代理充值、提现沿用会员 USDT 的汇率口径：充值用 exchange_rate_rmb，提现再加 exchange_rate_difference。 */
final class AgentExchangeRate
{
    public static function recharge(): string
    {
        return self::value('exchange_rate_rmb', '1');
    }

    public static function withdraw(): string
    {
        return bcadd(self::recharge(), self::value('exchange_rate_difference', '0'), 4);
    }

    private static function value(string $field, string $default): string
    {
        $value = DB::table('config')->where('field', $field)->value('val');
        $value = is_numeric($value) ? (string) $value : $default;
        return bcadd($value, '0', 4);
    }
}