6. Publish Account balance changed domain event

src/MPWAR/Module/Economy/Application/Service/TransactionProcessor.php

@@ -2,17 +2,23 @@
 
 namespace MPWAR\Module\Economy\Application\Service;
 
+use iter;
+use MPWAR\Module\Economy\Domain\Account;
 use MPWAR\Module\Economy\Domain\AccountOwner;
 use MPWAR\Module\Economy\Domain\AccountRepository;
 use MPWAR\Module\Economy\Domain\VirtualMoney;
+use SimpleBus\Message\Bus\MessageBus;
+use SimpleBus\Message\Type\Event;
 
 final class TransactionProcessor
 {
     private $repository;
+    private $eventBus;
 
-    public function __construct(AccountRepository $repository)
+    public function __construct(AccountRepository $repository, MessageBus $eventBus)
     {
         $this->repository = $repository;
+        $this->eventBus   = $eventBus;
     }
 
     public function __invoke(AccountOwner $owner, VirtualMoney $money)
@@ -22,5 +28,20 @@ public function __invoke(AccountOwner $owner, VirtualMoney $money)
         $account->add($money);
 
         $this->repository->save($account);
+
+        $this->publishDomainEvents($account);
+    }
+
+    private function publishDomainEvents(Account $account)
+    {
+        iter\apply($this->handleEvent(), $account->recordedMessages());
+        $account->eraseMessages();
+    }
+
+    private function handleEvent()
+    {
+        return function (Event $event) {
+            $this->eventBus->handle($event);
+        };
     }
 }

src/MPWAR/Module/Economy/Contract/DomainEvent/AccountBalanceChanged.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace MPWAR\Module\Economy\Contract\DomainEvent;
+
+use DateTimeImmutable;
+use SimpleBus\Message\Type\Event;
+
+final class AccountBalanceChanged implements Event
+{
+    private $aggregateId;
+    private $occurredOn;
+    private $amount;
+    private $currency;
+
+    public function __construct($aggregateId, $amount, $currency)
+    {
+        $this->aggregateId = $aggregateId;
+        $this->occurredOn  = new DateTimeImmutable();
+        $this->amount      = $amount;
+        $this->currency    = $currency;
+    }
+}

src/MPWAR/Module/Economy/Domain/Account.php

@@ -3,6 +3,7 @@
 namespace MPWAR\Module\Economy\Domain;
 
 use DateTimeImmutable;
+use MPWAR\Module\Economy\Contract\DomainEvent\AccountBalanceChanged;
 use MPWAR\Module\Economy\Contract\DomainEvent\AccountOpened;
 use SimpleBus\Message\Recorder\PrivateMessageRecorderCapabilities;
 use SimpleBus\Message\Recorder\RecordsMessages;
@@ -42,5 +43,9 @@ public function balance()
     public function add(VirtualMoney $money)
     {
         $this->balance = $this->balance()->add($money);
+
+        $this->record(
+            new AccountBalanceChanged($this->owner()->value(), $money->amount(), $money->currency()->value())
+        );
     }
 }

src/MPWAR/Module/Economy/Domain/VirtualMoney.php

@@ -30,6 +30,16 @@ public function add(VirtualMoney $other)
         return new self($this->amount + $other->amount, $this->currency);
     }
 
+    public function amount()
+    {
+        return $this->amount;
+    }
+
+    public function currency()
+    {
+        return $this->currency;
+    }
+
     private function guard($amount)
     {
         if (!is_int($amount) || 0 > $amount) {

src/MPWAR/Module/Economy/Infrastructure/DependencyInjection/economy_services.yml

@@ -30,4 +30,5 @@ services:
     class: MPWAR\Module\Economy\Application\Service\TransactionProcessor
     arguments:
       - @mpwar.economy.infrastructure.account_repository
+      - @event_bus
     public: false