class ServiceLocator

class ServiceLocator implements ServiceCollectionInterface {
    use ServiceLocatorTrait {
        get as private doGet;
    }
    private ?string $externalId = null;
    private ?Container $container = null;
    public function get(string $id) : mixed {
        if (!$this->externalId) {
            return $this->doGet($id);
        }
        try {
            return $this->doGet($id);
        } catch (RuntimeException $e) {
            $what = \sprintf('service "%s" required by "%s"', $id, $this->externalId);
            $message = preg_replace('/service "\\.service_locator\\.[^"]++"/', $what, $e->getMessage());
            if ($e->getMessage() === $message) {
                $message = \sprintf('Cannot resolve %s: %s', $what, $message);
            }
            $r = new \ReflectionProperty($e, 'message');
            $r->setValue($e, $message);
            throw $e;
        }
    }
    public function __invoke(string $id) : mixed {
        return isset($this->factories[$id]) ? $this->get($id) : null;
    }
    
    /**
     * @internal
     */
    public function withContext(string $externalId, Container $container) : static {
        $locator = clone $this;
        $locator->externalId = $externalId;
        $locator->container = $container;
        return $locator;
    }
    public function count() : int {
        return \count($this->getProvidedServices());
    }
    public function getIterator() : \Traversable {
        foreach ($this->getProvidedServices() as $id => $config) {
            (yield $id => $this->get($id));
        }
    }
    private function createNotFoundException(string $id) : NotFoundExceptionInterface {
        if ($this->loading) {
            $msg = \sprintf('The service "%s" has a dependency on a non-existent service "%s". This locator %s', end($this->loading), $id, $this->formatAlternatives());
            return new ServiceNotFoundException($id, end($this->loading) ?: null, null, [], $msg);
        }
        $class = debug_backtrace(\DEBUG_BACKTRACE_PROVIDE_OBJECT | \DEBUG_BACKTRACE_IGNORE_ARGS, 4);
        $class = isset($class[3]['object']) ? $class[3]['object']::class : null;
        $externalId = $this->externalId ?: $class;
        $msg = [];
        $msg[] = \sprintf('Service "%s" not found:', $id);
        if (!$this->container) {
            $class = null;
        }
        elseif ($this->container
            ->has($id) || isset($this->container
            ->getRemovedIds()[$id])) {
            $msg[] = 'even though it exists in the app\'s container,';
        }
        else {
            try {
                $this->container
                    ->get($id);
                $class = null;
            } catch (ServiceNotFoundException $e) {
                if ($e->getAlternatives()) {
                    $msg[] = \sprintf('did you mean %s? Anyway,', $this->formatAlternatives($e->getAlternatives(), 'or'));
                }
                else {
                    $class = null;
                }
            }
        }
        if ($externalId) {
            $msg[] = \sprintf('the container inside "%s" is a smaller service locator that %s', $externalId, $this->formatAlternatives());
        }
        else {
            $msg[] = \sprintf('the current service locator %s', $this->formatAlternatives());
        }
        if (!$class) {
            // no-op
        }
        elseif (is_subclass_of($class, ServiceSubscriberInterface::class)) {
            $msg[] = \sprintf('Unless you need extra laziness, try using dependency injection instead. Otherwise, you need to declare it using "%s::getSubscribedServices()".', preg_replace('/([^\\\\]++\\\\)++/', '', $class));
        }
        else {
            $msg[] = 'Try using dependency injection instead.';
        }
        return new ServiceNotFoundException($id, end($this->loading) ?: null, null, [], implode(' ', $msg));
    }
    private function createCircularReferenceException(string $id, array $path) : ContainerExceptionInterface {
        return new ServiceCircularReferenceException($id, $path);
    }
    private function formatAlternatives(?array $alternatives = null, string $separator = 'and') : string {
        $format = '"%s"%s';
        if (null === $alternatives) {
            if (!($alternatives = array_keys($this->factories))) {
                return 'is empty...';
            }
            $format = \sprintf('only knows about the %s service%s.', $format, 1 < \count($alternatives) ? 's' : '');
        }
        $last = array_pop($alternatives);
        return \sprintf($format, $alternatives ? implode('", "', $alternatives) : $last, $alternatives ? \sprintf(' %s "%s"', $separator, $last) : '');
    }

}