Allow subscription to indicate that a userlimit is reached

Signed-off-by: Morris Jobke <hey@morrisjobke.de>

4 files changed, 104 insertions, 3 deletions

diff --git a/lib/private/Support/Subscription/Registry.php b/lib/private/Support/Subscription/Registry.php
index 3d6a9b09d84..ba9c4099b9b 100644
--- a/lib/private/Support/Subscription/Registry.php
+++ b/lib/private/Support/Subscription/Registry.php
@@ -28,13 +28,16 @@ declare(strict_types=1);
 
 namespace OC\Support\Subscription;
 
+use OC\User\Backend;
 use OCP\AppFramework\QueryException;
 use OCP\IConfig;
 use OCP\IServerContainer;
+use OCP\IUserManager;
 use OCP\Support\Subscription\Exception\AlreadyRegisteredException;
 use OCP\Support\Subscription\IRegistry;
 use OCP\Support\Subscription\ISubscription;
 use OCP\Support\Subscription\ISupportedApps;
+use Psr\Log\LoggerInterface;
 
 class Registry implements IRegistry {
 
@@ -49,10 +52,19 @@ class Registry implements IRegistry {
 
 	/** @var IServerContainer */
 	private $container;
-
-	public function __construct(IConfig $config, IServerContainer $container) {
+	/** @var IUserManager */
+	private $userManager;
+	/** @var LoggerInterface */
+	private $logger;
+
+	public function __construct(IConfig $config,
+								IServerContainer $container,
+								IUserManager $userManager,
+								LoggerInterface $logger) {
 		$this->config = $config;
 		$this->container = $container;
+		$this->userManager = $userManager;
+		$this->logger = $logger;
 	}
 
 	private function getSubscription(): ?ISubscription {
@@ -127,9 +139,76 @@ class Registry implements IRegistry {
 	 * @since 17.0.0
 	 */
 	public function delegateHasExtendedSupport(): bool {
-		if ($this->getSubscription() instanceof ISubscription && method_exists($this->subscription, 'hasExtendedSupport')) {
+		if ($this->getSubscription() instanceof ISubscription) {
 			return $this->getSubscription()->hasExtendedSupport();
 		}
 		return false;
 	}
+
+
+	/**
+	 * Indicates if a hard user limit is reached and no new users should be created
+	 *
+	 * @since 21.0.0
+	 */
+	public function delegateIsHardUserLimitReached(): bool {
+		$subscription = $this->getSubscription();
+		if ($subscription instanceof ISubscription &&
+			$subscription->hasValidSubscription()) {
+			$userLimitReached = $subscription->isHardUserLimitReached();
+			if ($userLimitReached) {
+				$this->notifyAboutReachedUserLimit();
+			}
+			return $userLimitReached;
+		}
+
+		$isOneClickInstance = $this->config->getSystemValueBool('one-click-instance', false);
+
+		if (!$isOneClickInstance) {
+			return false;
+		}
+
+		$userCount = $this->getUserCount();
+		$hardUserLimit = $this->config->getSystemValue('one-click-instance.user-limit', 50);
+
+		$userLimitReached = $userCount >= $hardUserLimit;
+		if ($userLimitReached) {
+			$this->notifyAboutReachedUserLimit();
+		}
+		return $userLimitReached;
+	}
+
+	private function getUserCount(): int {
+		$userCount = 0;
+		$backends = $this->userManager->getBackends();
+		foreach ($backends as $backend) {
+			if ($backend->implementsActions(Backend::COUNT_USERS)) {
+				$backendUsers = $backend->countUsers();
+				if ($backendUsers !== false) {
+					$userCount += $backendUsers;
+				} else {
+					// TODO what if the user count can't be determined?
+					$this->logger->warning('Can not determine user count for ' . get_class($backend), ['app' => 'lib']);
+				}
+			}
+		}
+
+		$disabledUsers = $this->config->getUsersForUserValue('core', 'enabled', 'false');
+		$disabledUsersCount = count($disabledUsers);
+		$userCount = $userCount - $disabledUsersCount;
+
+		if ($userCount < 0) {
+			$userCount = 0;
+
+			// this should never happen
+			$this->logger->warning("Total user count was negative (users: $userCount, disabled: $disabledUsersCount)", ['app' => 'lib']);
+		}
+
+		return $userCount;
+	}
+
+	private function notifyAboutReachedUserLimit() {
+		// TODO notify admin about reached user limit
+		$this->logger->warning('The user limit was reached and the new user was not created', ['app' => 'lib']);
+	}
 }
diff --git a/lib/private/User/Manager.php b/lib/private/User/Manager.php
index 1201a456ce2..1d58c68268c 100644
--- a/lib/private/User/Manager.php
+++ b/lib/private/User/Manager.php
@@ -34,6 +34,7 @@
 
 namespace OC\User;
 
+use OC\HintException;
 use OC\Hooks\PublicEmitter;
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\EventDispatcher\IEventDispatcher;
@@ -42,6 +43,7 @@ use OCP\IGroup;
 use OCP\IUser;
 use OCP\IUserBackend;
 use OCP\IUserManager;
+use OCP\Support\Subscription\IRegistry;
 use OCP\User\Backend\IGetRealUIDBackend;
 use OCP\User\Events\BeforeUserCreatedEvent;
 use OCP\User\Events\UserCreatedEvent;
@@ -297,6 +299,12 @@ class Manager extends PublicEmitter implements IUserManager {
 	 * @return bool|IUser the created user or false
 	 */
 	public function createUser($uid, $password) {
+		// DI injection is not used here as IRegistry needs the user manager itself for user count and thus it would create a cyclic dependency
+		if (\OC::$server->get(IRegistry::class)->delegateIsHardUserLimitReached()) {
+			$l = \OC::$server->getL10N('lib');
+			throw new HintException($l->t('The user limit has been reached and the user was not created.'));
+		}
+
 		$localBackends = [];
 		foreach ($this->backends as $backend) {
 			if ($backend instanceof Database) {
diff --git a/lib/public/Support/Subscription/IRegistry.php b/lib/public/Support/Subscription/IRegistry.php
index f3d6cf2f92c..ab1d00fa823 100644
--- a/lib/public/Support/Subscription/IRegistry.php
+++ b/lib/public/Support/Subscription/IRegistry.php
@@ -78,4 +78,11 @@ interface IRegistry {
 	 * @since 17.0.0
 	 */
 	public function delegateHasExtendedSupport(): bool;
+
+	/**
+	 * Indicates if a hard user limit is reached and no new users should be created
+	 *
+	 * @since 21.0.0
+	 */
+	public function delegateIsHardUserLimitReached(): bool;
 }
diff --git a/lib/public/Support/Subscription/ISubscription.php b/lib/public/Support/Subscription/ISubscription.php
index 83b7509b9fe..9614c0ed77b 100644
--- a/lib/public/Support/Subscription/ISubscription.php
+++ b/lib/public/Support/Subscription/ISubscription.php
@@ -45,4 +45,11 @@ interface ISubscription {
 	 * @since 17.0.0
 	 */
 	public function hasExtendedSupport(): bool;
+
+	/**
+	 * Indicates if a hard user limit is reached and no new users should be created
+	 *
+	 * @since 21.0.0
+	 */
+	public function isHardUserLimitReached(): bool;
 }