trait ServiceLocatorTrait

trait ServiceLocatorTrait {
    private array $factories;
    private array $loading = [];
    private array $providedTypes;
    
    /**
     * @param array<string, callable> $factories
     */
    public function __construct(array $factories) {
        $this->factories = $factories;
    }
    public function has(string $id) : bool {
        return isset($this->factories[$id]);
    }
    public function get(string $id) : mixed {
        if (!isset($this->factories[$id])) {
            throw $this->createNotFoundException($id);
        }
        if (isset($this->loading[$id])) {
            $ids = array_values($this->loading);
            $ids = \array_slice($this->loading, array_search($id, $ids));
            $ids[] = $id;
            throw $this->createCircularReferenceException($id, $ids);
        }
        $this->loading[$id] = $id;
        try {
            return $this->factories[$id]($this);
        } finally {
            unset($this->loading[$id]);
        }
    }
    public function getProvidedServices() : array {
        if (!isset($this->providedTypes)) {
            $this->providedTypes = [];
            foreach ($this->factories as $name => $factory) {
                if (!\is_callable($factory)) {
                    $this->providedTypes[$name] = '?';
                }
                else {
                    $type = (new \ReflectionFunction($factory))->getReturnType();
                    $this->providedTypes[$name] = $type ? ($type->allowsNull() ? '?' : '') . ($type instanceof \ReflectionNamedType ? $type->getName() : $type) : '?';
                }
            }
        }
        return $this->providedTypes;
    }
    private function createNotFoundException(string $id) : NotFoundExceptionInterface {
        if (!($alternatives = array_keys($this->factories))) {
            $message = 'is empty...';
        }
        else {
            $last = array_pop($alternatives);
            if ($alternatives) {
                $message = sprintf('only knows about the "%s" and "%s" services.', implode('", "', $alternatives), $last);
            }
            else {
                $message = sprintf('only knows about the "%s" service.', $last);
            }
        }
        if ($this->loading) {
            $message = sprintf('The service "%s" has a dependency on a non-existent service "%s". This locator %s', end($this->loading), $id, $message);
        }
        else {
            $message = sprintf('Service "%s" not found: the current service locator %s', $id, $message);
        }
        return new class ($message) extends \InvalidArgumentException implements NotFoundExceptionInterface {

};
    }
    private function createCircularReferenceException(string $id, array $path) : ContainerExceptionInterface {
        return new class (sprintf('Circular reference detected for service "%s", path: "%s".', $id, implode(' -> ', $path))) extends \RuntimeException implements ContainerExceptionInterface {

};
    }

}