3. Economy Transaction Processor application service

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

@@ -0,0 +1,26 @@
+<?php
+
+namespace MPWAR\Module\Economy\Application\Service;
+
+use MPWAR\Module\Economy\Domain\AccountOwner;
+use MPWAR\Module\Economy\Domain\AccountRepository;
+use MPWAR\Module\Economy\Domain\VirtualMoney;
+
+final class TransactionProcessor
+{
+    private $repository;
+
+    public function __construct(AccountRepository $repository)
+    {
+        $this->repository = $repository;
+    }
+
+    public function __invoke(AccountOwner $owner, VirtualMoney $money)
+    {
+        $account = $this->repository->search($owner);
+
+        $account->add($money);
+
+        $this->repository->save($account);
+    }
+}

src/MPWAR/Module/Economy/Contract/Exception/VirtualMoneyOperationWithDifferentCurrenciesNotAllowedException.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace MPWAR\Module\Economy\Contract\Exception;
+
+use DomainException;
+
+final class VirtualMoneyOperationWithDifferentCurrenciesNotAllowedException extends DomainException
+{
+    public function __construct()
+    {
+        parent::__construct('Not allowed Virtual Money operation between different currencies');
+
+        $this->code = 'economy_virtual_money_operation_not_valid';
+    }
+}

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

@@ -20,6 +20,15 @@ public function __construct(AccountOwner $owner, VirtualMoney $balance)
         $this->balance = $balance;
     }
 
+    public static function open(AccountOwner $owner)
+    {
+        $account = new self($owner, VirtualMoney::coins(0));
+
+        $account->record(new AccountOpened($owner->value(), new DateTimeImmutable()));
+
+        return $account;
+    }
+
     public function owner()
     {
         return $this->owner;
@@ -30,12 +39,8 @@ public function balance()
         return $this->balance;
     }
 
-    public static function open(AccountOwner $owner)
+    public function add(VirtualMoney $money)
     {
-        $account = new self($owner, VirtualMoney::coins(0));
-
-        $account->record(new AccountOpened($owner->value(), new DateTimeImmutable()));
-
-        return $account;
+        $this->balance = $this->balance()->add($money);
     }
 }

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

@@ -26,6 +26,11 @@ public function value()
         return $this->value;
     }
 
+    public function equals(VirtualCurrency $other)
+    {
+        return $this->value === $other->value;
+    }
+
     private function guard($value)
     {
         if (!in_array($value, self::$allowed)) {

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

@@ -3,6 +3,7 @@
 namespace MPWAR\Module\Economy\Domain;
 
 use MPWAR\Module\Economy\Contract\Exception\VirtualMoneyNotValidException;
+use MPWAR\Module\Economy\Contract\Exception\VirtualMoneyOperationWithDifferentCurrenciesNotAllowedException;
 
 final class VirtualMoney
 {
@@ -22,10 +23,24 @@ public static function coins($amount)
         return new self($amount, VirtualCurrency::coin());
     }
 
+    public function add(VirtualMoney $other)
+    {
+        $this->guardCurrency($other->currency);
+
+        return new self($this->amount + $other->amount, $this->currency);
+    }
+
     private function guard($amount)
     {
         if (!is_int($amount) || 0 > $amount) {
             throw new VirtualMoneyNotValidException($amount);
         }
     }
+
+    private function guardCurrency(VirtualCurrency $other)
+    {
+        if (!$this->currency->equals($other)) {
+            throw new VirtualMoneyOperationWithDifferentCurrenciesNotAllowedException();
+        }
+    }
 }