workshop-value-object-or-not-quiz-3

workshop-value-object-or-not-quiz-3.php

final class Money
{
    private string $amount;
    private string $currency;

    public function __construct(private string $amount, private string $currency)
    {
        if (!is_numeric($amount)) {
            throw new InvalidAmountException::notNumeric($amount);
        }

        if (!in_array(strtoupper($currency), ['EUR', 'USD'])) {
            throw new InvalidCurrencyException::notInTheAcceptedCurrencies($currency);
        }

        $this->amount = $amount;
        $this->currency = $currency;
    }

    public function amount(): string
    {
        return $this->amount;
    }

    public function currency(): string
    {
        return $this->currency;
    }

    public function equals(Money $other): bool
    {
        return $this->amount === $other->amount() &&
            $this->currency === $other->currency();
    }

    public function add(Money $other): Money
    {
        if ($this->currency !== $other->currency()) {
            throw new InvalidCurrencyException::notEquals($this->currency, $other->currency());
        }

        $sum = bcadd($this->amount, $other->amount(), 2);

        return new self($sum, $this->currency);
    }
}