Implement YAML config loader

src/Config/Loaders/YamlConfigLoader.php

@@ -0,0 +1,48 @@
+<?php
+declare(strict_types=1);
+
+namespace MailAccountAdmin\Config\Loaders;
+
+use MailAccountAdmin\Config\AppConfig;
+
+class YamlConfigLoader implements ConfigLoaderInterface
+{
+    private string $filePath;
+
+    public function __construct(string $filePath)
+    {
+        assert(file_exists($filePath));
+
+        $this->filePath = $filePath;
+    }
+
+    public function loadConfig(): AppConfig
+    {
+        // Parse yml config file
+        $parsedConfig = yaml_parse_file($this->filePath);
+
+        // Check datatypes
+        assert(is_array($parsedConfig));
+        assert(!isset($parsedConfig['twig']) || is_array($parsedConfig['twig']));
+        assert(!isset($parsedConfig['database']) || is_array($parsedConfig['database']));
+
+        return AppConfig::createFromArray([
+            // App settings
+            'appTitle' => $parsedConfig['appTitle'] ?? null,
+            'environment' => $parsedConfig['environment'] ?? null,
+            'debug' => (bool)$parsedConfig['debug'] ?? null,
+            'timezone' => $parsedConfig['timezone'] ?? null,
+            'dateTimeFormat' => $parsedConfig['dateTimeFormat'] ?? null,
+
+            // Twig settings
+            'twigCacheDir' => $parsedConfig['twig']['cacheDir'] ?? null,
+
+            // Database settings
+            'databaseHost' => $parsedConfig['database']['host'] ?? null,
+            'databasePort' => (int)$parsedConfig['database']['port'] ?? null,
+            'databaseName' => $parsedConfig['database']['name'] ?? null,
+            'databaseUsername' => $parsedConfig['database']['username'] ?? null,
+            'databasePassword' => $parsedConfig['database']['password'] ?? null,
+        ]);
+    }
+}