Ein Bankkonto mit Geschäftsregeln

<?php declare(strict_types=1);

namespace spriebsch\tfd\softwareArchitecture\eventBased\eventSourcing\enforcingAccount;

use RuntimeException;

final class Account
{
    public function __construct(
        private readonly AccountId $id,
        private readonly Currency $currency,
        private Money $balance
    ) {
        $this->ensureSameCurrency($balance);
        $this->ensureNotNegative($balance);
    }

    public function id(): AccountId
    {
        return $this->id;
    }

    public function setBalance(Money $balance): void
    {
        $this->ensureSameCurrency($balance);
        $this->ensureNotNegative($balance);

        $this->balance = $balance;
    }

    public function balance(): Money
    {
        return $this->balance;
    }

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

    private function ensureSameCurrency(Money $money): void
    {
        if ($this->currency !== $money->currency()) {
            throw new RuntimeException('Currency mismatch');
        };
    }

    private function ensureNotNegative(Money $money): void
    {
        if ($money->amountInCents() < 0) {
            throw new RuntimeException('Negative balance');
        }
    }
}