feat: add currency lister

feat: add currency lister

static currency lister

config/services.yaml

@@ -4,6 +4,8 @@
 # Put parameters here that don't need to change on each machine where the app is deployed
 # https://symfony.com/doc/current/best_practices.html#use-parameters-for-application-configuration
 parameters:
+    env(SYMFONY_EXAMPLE_APP_CURRENCIES): '["CZK", "EUR", "USD", "GBP"]'
+    app.currencies: '%env(json:SYMFONY_EXAMPLE_APP_CURRENCIES)%'
 
 services:
     # default configuration for services in *this* file
@@ -21,5 +23,10 @@ services:
             - '../src/Entity/'
             - '../src/Kernel.php'
 
+    App\Service\StaticCurrencyLister:
+        arguments:
+            $available_currencies: '%app.currencies%'
+
+    App\Service\CurrencyListerInterface: '@App\Service\StaticCurrencyLister'
     # add more service definitions when explicit configuration is needed
     # please note that last definitions always *replace* previous ones

src/Service/CurrencyListerInterface.php

@@ -0,0 +1,12 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Service;
+
+interface CurrencyListerInterface
+{
+    /**
+     * @return string[]
+     */
+    public function getCurrencies(): iterable;
+}

src/Service/StaticCurrencyLister.php

@@ -0,0 +1,20 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Service;
+
+/**
+ * Represents currency lister loaded from configuration
+ */
+readonly final class StaticCurrencyLister implements CurrencyListerInterface {
+    /**
+     * @param String[] $available_currencies
+     */
+    public function __construct(private array $available_currencies) {
+    }
+
+    public function getCurrencies(): iterable
+    {
+        return $this->available_currencies;
+    }
+}