<?php 

final class registry {
  private static $registry = [];
  protected function __construct() { }

  public static function get(string $name, $key = false) {
    if (isset(self::$registry[strtolower($name)])) {
      $a = self::$registry[strtolower($name)];
      if ($key === false) {
        return $a;
      }
      if (isset($a[$key])) {
        return $a[$key];
      }
    }
    return null;
  }

  public static function set(string $name, $value): bool {
    if (array_key_exists(strtolower($name), self::$registry)) {
      return false;
    }
    self::$registry[strtolower($name)] = $value;
    return true;
  }
}

final class di {
  protected $services = [];
  
  public function register(string $service_name, callable $callable): void {
    $this->services[$service_name] = $callable;
  }
  // Note args may be an object or an array maybe more...!
  public function get_service(string $service_name, $args = []) {
    if (!array_key_exists($service_name, $this->services)) {
      throw new \Exception("The Service: {$service_name} does not exists.");
    }
    return $this->services[$service_name]($args);
  }
  
  public function __set(string $service_name, callable $callable): void {
    $this->register($service_name, $callable);
  }

  public function __get(string $service_name) {
    return $this->get_service($service_name);
  }

  public function list_services_as_array(): array {
    return array_keys($this->services);
  }

  public function list_services_as_string(): string {
    return implode(',', array_keys($this->services));
  }
}

// Initialize our Dependency Injector
registry::set('di', new di());

// Setup php for working with Unicode data, if possible
if (extension_loaded('mbstring')) {
  mb_internal_encoding('UTF-8');
  mb_http_output('UTF-8');
  mb_language('uni');
  setlocale(LC_ALL, "en_US.UTF-8");
}