add Settings class and Twig cache settings

src/Dependencies.php

@@ -16,6 +16,19 @@ class Dependencies
     {
         $container = new Container();
 
+        // App settings
+        $container->set(Settings::class, function (): Settings {
+            return new Settings();
+        });
+
+        // Twig template engine
+        $container->set(self::TWIG, function (ContainerInterface $c) {
+            /** @var Settings $settings */
+            $settings = $c->get(Settings::class);
+
+            return Twig::create(self::TWIG_TEMPLATE_DIR, $settings->getTwigSettings());
+        });
+
         // Controllers
         $container->set(HelloWorldController::class, function (ContainerInterface $c) {
             return new HelloWorldController(
@@ -29,12 +42,6 @@ class Dependencies
             return new HelloWorld();
         });
 
-        $container->set(self::TWIG, function (ContainerInterface $c) {
-            // TODO cache
-            $twigSettings = [];
-            return Twig::create(self::TWIG_TEMPLATE_DIR, $twigSettings);
-        });
-
         return $container;
     }
 }

src/Settings.php

@@ -0,0 +1,14 @@
+<?php
+declare(strict_types=1);
+
+namespace NoteCat;
+
+class Settings
+{
+    public function getTwigSettings(): array
+    {
+        return [
+            'cache' => getenv('TWIG_CACHE_DIR') ?? false,
+        ];
+    }
+}