Account.php

<?php namespace KBC\Accounts;

use KBC\Accounts\Events\AccountWasDeleted;
use KBC\Accounts\Events\AccountWasOpened;
use KBC\Accounts\Events\MoneyWasWithdrawn;
use KBC\Accounts\Events\MoneyWasDeposited;
use KBC\Core\BaseModel;

final class Account extends BaseModel
{
    private $name;

    private $balance;

    private $id;

    private $closed;

       public static function open($id, Name $name)
    {
        $me = new static();

        $me->apply(new AccountWasOpened($id, $name, 0));
    }

    public function delete()
    {
        $this->apply(new AccountWasDeleted($this->id));
    }

    public function deposit($amount)
    {
        if(!$this->closed)
            throw new  AccountClosed();
            
        $this->apply(new MoneyWasDeposited($this->id, $amount));
    }

    public function withdraw($amount)
    {
        if(!$this->closed)
            throw new  AccountClosed();

        $this->apply(new MoneyWasWithdrawn($this->id, $amount));
    }

    /* Respond to events */
    public  function applyAccountWasOpened(AccountWasOpened $event)
    {
        $state->id = $event->id;
        $state->balance = $event->balance;
        $state->name = $event->name;
    }

    public function applyMoneyWasDeposited(MoneyWasDeposited $event)
    {
        $this->balance += $event->amount;
    }

    public function applyMoneyWasWithdrawn(MoneyWasWithdrawn $event)
    {
        $state->balance -= $event->amount;
    }

    public  function applyAccountWasDeleted(AccountWasDeleted $event)
    {
        $this->closed = true;
    }
}