Add basic gateways

config/services.yaml

@@ -14,6 +14,8 @@ services:
     _instanceof:
         App\Library\Economy\Currency\ExchangeInterface:
             tags: ['app.lib.economy.currency.exchange']
+        App\Library\Economy\Payment\GatewayInterface:
+            tags: ['app.lib.economy.payment.gateway']
 
     # makes classes in src/ available to be used as services
     # this creates a service per class whose id is the fully-qualified class name
@@ -34,5 +36,9 @@ services:
         arguments:
             - !tagged 'app.lib.economy.currency.exchange'
 
+    App\Library\Economy\Payment\GatewayLocator:
+        arguments:
+            - !tagged 'app.lib.economy.payment.gateway'
+
     # add more service definitions when explicit configuration is needed
     # please note that last definitions always *replace* previous ones

src/ApiResource/Gateway.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace App\ApiResource;
+
+use ApiPlatform\Metadata as API;
+use App\Library\Economy\Payment\GatewayInterface;
+use App\State\GatewayStateProvider;
+
+/**
+ * Gateways represent external payment services
+ */
+#[API\GetCollection(provider: GatewayStateProvider::class)]
+#[API\Get(provider: GatewayStateProvider::class)]
+class Gateway
+{
+    public function __construct(private readonly GatewayInterface $gateway) {
+    }
+
+    #[API\ApiProperty(identifier: true)]
+    public function getName(): string
+    {
+        return $this->gateway->getName();
+    }
+}

src/Entity/Accounting.php

@@ -15,7 +15,6 @@ use Symfony\Component\Validator\Constraints as Assert;
  * When making relations between Transactions and Accountings you are effectively altering the platform's internal economy.
  */
 #[ORM\Entity(repositoryClass: AccountingRepository::class)]
-#[API\ApiResource()]
 #[API\GetCollection()]
 #[API\Get()]
 #[API\Put()]

src/Entity/Transaction.php

@@ -11,8 +11,10 @@ use Symfony\Component\Validator\Constraints as Assert;
 
 /**
  * Transactions represent a movement of funds inside the platform.\
- * When making relations between Transactions and Accountings you are effectively altering the platform's internal economy.\
- * Transactions cannot be mutated after they are stored.
+ * When making relations between Transactions and Accountings you are effectively altering the platform's internal economy.
+ * \
+ * \
+ * Transactions cannot be mutated after they are stored.\
  * If in need to reverse a Transaction generate a new Transaction reversing the to-be-cancelled one.
  */
 #[ORM\Entity(repositoryClass: TransactionRepository::class)]

src/Library/Economy/AbstractMonetizable.php

@@ -2,6 +2,8 @@
 
 namespace App\Library\Economy;
 
+use ApiPlatform\Metadata as API;
+
 abstract class AbstractMonetizable
 {
     abstract public function getAmount(): int;
@@ -25,6 +27,7 @@ abstract class AbstractMonetizable
         );
     }
 
+    #[API\ApiProperty(readable: false)]
     public function isZero(): bool
     {
         return $this->toBrickMoney()->isZero();

src/Library/Economy/Payment/GatewayInterface.php

@@ -0,0 +1,11 @@
+<?php
+
+namespace App\Library\Economy\Payment;
+
+interface GatewayInterface
+{
+    /**
+     * @return string A short, unique, descriptive string of your gateway
+     */
+    public function getName(): string;
+}

src/Library/Economy/Payment/GatewayLocator.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace App\Library\Economy\Payment;
+
+class GatewayLocator
+{
+    /** @var GatewayInterface[] */
+    private array $gateways;
+
+    public function __construct(iterable $gateways)
+    {
+        /** @var GatewayInterface[] */
+        $gateways = \iterator_to_array($gateways);
+
+        foreach ($gateways as $gateway) {
+            $this->gateways[$gateway->getName()] = $gateway;
+        }
+    }
+
+    /**
+     * @return array<string> List of the available Gateway names
+     */
+    public function getNames(): array
+    {
+        return \array_keys($this->gateways);
+    }
+
+    /**
+     * @return GatewayInterface[]
+     */
+    public function getGateways(): array
+    {
+        return $this->gateways;
+    }
+
+    /**
+     * @param string $name Name of the Gateway interface implementation
+     * @return GatewayInterface
+     * @throws \Exception When the $name does not match to that of an implemented Gateway
+     */
+    public function getGateway(string $name): GatewayInterface
+    {
+        if (!\array_key_exists($name, $this->gateways)) {
+            throw new \Exception("No such Gateway with the name $name");
+        }
+
+        return $this->gateways[$name];
+    }
+}

src/Library/Economy/Payment/StripeGateway.php

@@ -0,0 +1,11 @@
+<?php
+
+namespace App\Library\Economy\Payment;
+
+class StripeGateway implements GatewayInterface
+{
+    public function getName(): string
+    {
+        return 'stripe';
+    }
+}

src/State/GatewayStateProvider.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace App\State;
+
+use ApiPlatform\Metadata as API;
+use ApiPlatform\Metadata\Operation;
+use ApiPlatform\State\ProviderInterface;
+use App\ApiResource\Gateway;
+use App\Library\Economy\Payment\GatewayLocator;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+
+class GatewayStateProvider implements ProviderInterface
+{
+    public function __construct(
+        private GatewayLocator $gateways
+    ) {
+    }
+
+    private function getGateways(): array
+    {
+        $gateways = [];
+        foreach ($this->gateways->getGateways() as $gateway) {
+            $gateways[] = new Gateway($gateway);
+        }
+
+        return $gateways;
+    }
+
+    private function getGateway(string $name): Gateway
+    {
+        try {
+            $gateway = $this->gateways->getGateway($name);
+
+            return new Gateway($gateway);
+        } catch (\Exception $e) {
+            throw new NotFoundHttpException("Not Found");
+        }
+    }
+
+    public function provide(Operation $operation, array $uriVariables = [], array $context = []): object|array|null
+    {
+        switch ($operation::class) {
+            case API\GetCollection::class:
+                return $this->getGateways();
+            case API\Get::class:
+                return $this->getGateway($uriVariables['name']);
+        }
+    }
+}