<?php 

namespace App\Core;

class Config {
    private static $instance = null;
    private array $settings = [];

    private function __construct() {
        // Map environment variables to internal keys with optional defaults
        $this->settings = [
            'db' => [
                'host' => $_ENV['DB_HOST'] ?? 'localhost',
                'name' => $_ENV['DB_NAME'] ?? 'my_app',
                'user' => $_ENV['DB_USER'] ?? 'root',
                'pass' => $_ENV['DB_PASS'] ?? '',
            ],
            'app' => [
                'name'  => $_ENV['APP_NAME'] ?? 'Vanilla PHP App',
                'env'   => $_ENV['APP_ENV'] ?? 'production',
                'debug' => ($_ENV['APP_DEBUG'] ?? 'false') === 'true',
                'url'   => $_ENV['APP_URL'] ?? 'http://localhost',
            ],
            'mail' => [
                'host' => $_ENV['MAIL_HOST'] ?? 'smtp.mailtrap.io',
                'port' => $_ENV['MAIL_PORT'] ?? 2525,
            ]
        ];
    }

    public static function get(string $key, $default = null) {
        if (self::$instance === null) {
            self::$instance = new self();
        }

        // Support dot notation (e.g., 'db.host')
        $keys = explode('.', $key);
        $value = self::$instance->settings;

        foreach ($keys as $k) {
            if (!isset($value[$k])) {
                return $default;
            }
            $value = $value[$k];
        }

        return $value;
    }
}

?>