PHP code example of elegant-bro / money

    
        
<?php
require_once('vendor/autoload.php');

/* Start to develop here. Best regards https://php-download.com/ */

    

elegant-bro / money example snippets

declare(strict_types=1);

use ElegantBro\Money\Currencies\USD;
use ElegantBro\Money\Currency;
use ElegantBro\Money\Money;

final class UserBalance implements Money
{
    /**
     * @var string
     */
    private $userId;
    
    /**
     * @var PDO 
     */
    private $pdo;
     
    public function __construct(string $userId, PDO $pdo)
    {  
        $this->userId = $userId;
        $this->pdo = $pdo;
    } 

    public function amount(): string
    {
        $stmt = $this->pdo->prepare('SELECT SUM(debit - credit) FROM balances WHERE user_id = ?');
        $stmt->execute([$this->userId]);
        
        return $stmt->fetchColumn();
    }
    
    public function currency(): Currency
    {
        return new USD();
    }
    
    public function scale(): int
    {
        return 2;
    }
}

declare(strict_types=1);

use ElegantBro\Money\Currencies\USD;
use ElegantBro\Money\Currency;
use ElegantBro\Money\Money;

final class TwoDollars implements Money
{
    public function amount(): string
    {
        return '2';
    }
    
    public function currency(): Currency
    {
        return new USD();
    }
    
    public function scale(): int
    {
        return 2;
    }

}

declare(strict_types=1);

use ElegantBro\Money\ArrayLot;
use ElegantBro\Money\Money;
use ElegantBro\Money\Operations\MaxOf;
use ElegantBro\Money\Operations\Multiplied;
use ElegantBro\Money\Wrapper;

final class Tax extends Wrapper
{
    public function __construct(Money $origin, Money $minTax)
    {  
        $this->is(
            new MaxOf(
                new ArrayLot(
                    Multiplied::keepScale($origin, '0.1'),
                    $minTax
                ),
                $origin->scale()
            )
        );
    }
}

// on the client side
$tax = new Tax(
    new UserBalance($uuid, $pdo),
    new TwoDollars()
);

declare(strict_types=1);

use Money/Money;

class MoneyHelper
{
    public static function tax(Money $amount, Money $minTax): Money
    {
        return Money::max(
            $amount->multiply('0.1'),
            $minTax
        );
    }
    
    // usually helpers contain dozens of static methods
}

// on the client side
$tax = MoneyHelper::tax(
    $userBalance, // you should fetch user balance from the database before
    Money::USD(200)
);