nextcloud / server

lib/private/Share20/DefaultShareProvider.php

Indentation +1398 added lines, -1398 removed lines

@@ -62,1438 +62,1438 @@
  */
 class DefaultShareProvider implements IShareProvider {
 
-	// Special share type for user modified group shares
-	public const SHARE_TYPE_USERGROUP = 2;
-
-	/** @var IDBConnection */
-	private $dbConn;
-
-	/** @var IUserManager */
-	private $userManager;
-
-	/** @var IGroupManager */
-	private $groupManager;
-
-	/** @var IRootFolder */
-	private $rootFolder;
-
-	/** @var IMailer */
-	private $mailer;
-
-	/** @var Defaults */
-	private $defaults;
-
-	/** @var IL10N */
-	private $l;
-
-	/** @var IURLGenerator */
-	private $urlGenerator;
-
-	/**
-	 * DefaultShareProvider constructor.
-	 *
-	 * @param IDBConnection $connection
-	 * @param IUserManager $userManager
-	 * @param IGroupManager $groupManager
-	 * @param IRootFolder $rootFolder
-	 * @param IMailer $mailer ;
-	 * @param Defaults $defaults
-	 * @param IL10N $l
-	 * @param IURLGenerator $urlGenerator
-	 */
-	public function __construct(
-			IDBConnection $connection,
-			IUserManager $userManager,
-			IGroupManager $groupManager,
-			IRootFolder $rootFolder,
-			IMailer $mailer,
-			Defaults $defaults,
-			IL10N $l,
-			IURLGenerator $urlGenerator) {
-		$this->dbConn = $connection;
-		$this->userManager = $userManager;
-		$this->groupManager = $groupManager;
-		$this->rootFolder = $rootFolder;
-		$this->mailer = $mailer;
-		$this->defaults = $defaults;
-		$this->l = $l;
-		$this->urlGenerator = $urlGenerator;
-	}
-
-	/**
-	 * Return the identifier of this provider.
-	 *
-	 * @return string Containing only [a-zA-Z0-9]
-	 */
-	public function identifier() {
-		return 'ocinternal';
-	}
-
-	/**
-	 * Share a path
-	 *
-	 * @param \OCP\Share\IShare $share
-	 * @return \OCP\Share\IShare The share object
-	 * @throws ShareNotFound
-	 * @throws \Exception
-	 */
-	public function create(\OCP\Share\IShare $share) {
-		$qb = $this->dbConn->getQueryBuilder();
-
-		$qb->insert('share');
-		$qb->setValue('share_type', $qb->createNamedParameter($share->getShareType()));
-
-		if ($share->getShareType() === \OCP\Share::SHARE_TYPE_USER) {
-			//Set the UID of the user we share with
-			$qb->setValue('share_with', $qb->createNamedParameter($share->getSharedWith()));
-			$qb->setValue('accepted', $qb->createNamedParameter(IShare::STATUS_PENDING));
-
-			//If an expiration date is set store it
-			if ($share->getExpirationDate() !== null) {
-				$qb->setValue('expiration', $qb->createNamedParameter($share->getExpirationDate(), 'datetime'));
-			}
-		} elseif ($share->getShareType() === \OCP\Share::SHARE_TYPE_GROUP) {
-			//Set the GID of the group we share with
-			$qb->setValue('share_with', $qb->createNamedParameter($share->getSharedWith()));
-
-			//If an expiration date is set store it
-			if ($share->getExpirationDate() !== null) {
-				$qb->setValue('expiration', $qb->createNamedParameter($share->getExpirationDate(), 'datetime'));
-			}
-		} elseif ($share->getShareType() === \OCP\Share::SHARE_TYPE_LINK) {
-			//set label for public link
-			$qb->setValue('label', $qb->createNamedParameter($share->getLabel()));
-			//Set the token of the share
-			$qb->setValue('token', $qb->createNamedParameter($share->getToken()));
-
-			//If a password is set store it
-			if ($share->getPassword() !== null) {
-				$qb->setValue('password', $qb->createNamedParameter($share->getPassword()));
-			}
-
-			$qb->setValue('password_by_talk', $qb->createNamedParameter($share->getSendPasswordByTalk(), IQueryBuilder::PARAM_BOOL));
-
-			//If an expiration date is set store it
-			if ($share->getExpirationDate() !== null) {
-				$qb->setValue('expiration', $qb->createNamedParameter($share->getExpirationDate(), 'datetime'));
-			}
-
-			if (method_exists($share, 'getParent')) {
-				$qb->setValue('parent', $qb->createNamedParameter($share->getParent()));
-			}
-		} else {
-			throw new \Exception('invalid share type!');
-		}
-
-		// Set what is shares
-		$qb->setValue('item_type', $qb->createParameter('itemType'));
-		if ($share->getNode() instanceof \OCP\Files\File) {
-			$qb->setParameter('itemType', 'file');
-		} else {
-			$qb->setParameter('itemType', 'folder');
-		}
-
-		// Set the file id
-		$qb->setValue('item_source', $qb->createNamedParameter($share->getNode()->getId()));
-		$qb->setValue('file_source', $qb->createNamedParameter($share->getNode()->getId()));
-
-		// set the permissions
-		$qb->setValue('permissions', $qb->createNamedParameter($share->getPermissions()));
-
-		// Set who created this share
-		$qb->setValue('uid_initiator', $qb->createNamedParameter($share->getSharedBy()));
-
-		// Set who is the owner of this file/folder (and this the owner of the share)
-		$qb->setValue('uid_owner', $qb->createNamedParameter($share->getShareOwner()));
-
-		// Set the file target
-		$qb->setValue('file_target', $qb->createNamedParameter($share->getTarget()));
-
-		// Set the time this share was created
-		$qb->setValue('stime', $qb->createNamedParameter(time()));
-
-		// insert the data and fetch the id of the share
-		$this->dbConn->beginTransaction();
-		$qb->execute();
-		$id = $this->dbConn->lastInsertId('*PREFIX*share');
-
-		// Now fetch the inserted share and create a complete share object
-		$qb = $this->dbConn->getQueryBuilder();
-		$qb->select('*')
-			->from('share')
-			->where($qb->expr()->eq('id', $qb->createNamedParameter($id)));
-
-		$cursor = $qb->execute();
-		$data = $cursor->fetch();
-		$this->dbConn->commit();
-		$cursor->closeCursor();
-
-		if ($data === false) {
-			throw new ShareNotFound();
-		}
-
-		$mailSendValue = $share->getMailSend();
-		$data['mail_send'] = ($mailSendValue === null) ? true : $mailSendValue;
-
-		$share = $this->createShare($data);
-		return $share;
-	}
-
-	/**
-	 * Update a share
-	 *
-	 * @param \OCP\Share\IShare $share
-	 * @return \OCP\Share\IShare The share object
-	 * @throws ShareNotFound
-	 * @throws \OCP\Files\InvalidPathException
-	 * @throws \OCP\Files\NotFoundException
-	 */
-	public function update(\OCP\Share\IShare $share) {
-		$originalShare = $this->getShareById($share->getId());
-
-		if ($share->getShareType() === \OCP\Share::SHARE_TYPE_USER) {
-			/*
+    // Special share type for user modified group shares
+    public const SHARE_TYPE_USERGROUP = 2;
+
+    /** @var IDBConnection */
+    private $dbConn;
+
+    /** @var IUserManager */
+    private $userManager;
+
+    /** @var IGroupManager */
+    private $groupManager;
+
+    /** @var IRootFolder */
+    private $rootFolder;
+
+    /** @var IMailer */
+    private $mailer;
+
+    /** @var Defaults */
+    private $defaults;
+
+    /** @var IL10N */
+    private $l;
+
+    /** @var IURLGenerator */
+    private $urlGenerator;
+
+    /**
+     * DefaultShareProvider constructor.
+     *
+     * @param IDBConnection $connection
+     * @param IUserManager $userManager
+     * @param IGroupManager $groupManager
+     * @param IRootFolder $rootFolder
+     * @param IMailer $mailer ;
+     * @param Defaults $defaults
+     * @param IL10N $l
+     * @param IURLGenerator $urlGenerator
+     */
+    public function __construct(
+            IDBConnection $connection,
+            IUserManager $userManager,
+            IGroupManager $groupManager,
+            IRootFolder $rootFolder,
+            IMailer $mailer,
+            Defaults $defaults,
+            IL10N $l,
+            IURLGenerator $urlGenerator) {
+        $this->dbConn = $connection;
+        $this->userManager = $userManager;
+        $this->groupManager = $groupManager;
+        $this->rootFolder = $rootFolder;
+        $this->mailer = $mailer;
+        $this->defaults = $defaults;
+        $this->l = $l;
+        $this->urlGenerator = $urlGenerator;
+    }
+
+    /**
+     * Return the identifier of this provider.
+     *
+     * @return string Containing only [a-zA-Z0-9]
+     */
+    public function identifier() {
+        return 'ocinternal';
+    }
+
+    /**
+     * Share a path
+     *
+     * @param \OCP\Share\IShare $share
+     * @return \OCP\Share\IShare The share object
+     * @throws ShareNotFound
+     * @throws \Exception
+     */
+    public function create(\OCP\Share\IShare $share) {
+        $qb = $this->dbConn->getQueryBuilder();
+
+        $qb->insert('share');
+        $qb->setValue('share_type', $qb->createNamedParameter($share->getShareType()));
+
+        if ($share->getShareType() === \OCP\Share::SHARE_TYPE_USER) {
+            //Set the UID of the user we share with
+            $qb->setValue('share_with', $qb->createNamedParameter($share->getSharedWith()));
+            $qb->setValue('accepted', $qb->createNamedParameter(IShare::STATUS_PENDING));
+
+            //If an expiration date is set store it
+            if ($share->getExpirationDate() !== null) {
+                $qb->setValue('expiration', $qb->createNamedParameter($share->getExpirationDate(), 'datetime'));
+            }
+        } elseif ($share->getShareType() === \OCP\Share::SHARE_TYPE_GROUP) {
+            //Set the GID of the group we share with
+            $qb->setValue('share_with', $qb->createNamedParameter($share->getSharedWith()));
+
+            //If an expiration date is set store it
+            if ($share->getExpirationDate() !== null) {
+                $qb->setValue('expiration', $qb->createNamedParameter($share->getExpirationDate(), 'datetime'));
+            }
+        } elseif ($share->getShareType() === \OCP\Share::SHARE_TYPE_LINK) {
+            //set label for public link
+            $qb->setValue('label', $qb->createNamedParameter($share->getLabel()));
+            //Set the token of the share
+            $qb->setValue('token', $qb->createNamedParameter($share->getToken()));
+
+            //If a password is set store it
+            if ($share->getPassword() !== null) {
+                $qb->setValue('password', $qb->createNamedParameter($share->getPassword()));
+            }
+
+            $qb->setValue('password_by_talk', $qb->createNamedParameter($share->getSendPasswordByTalk(), IQueryBuilder::PARAM_BOOL));
+
+            //If an expiration date is set store it
+            if ($share->getExpirationDate() !== null) {
+                $qb->setValue('expiration', $qb->createNamedParameter($share->getExpirationDate(), 'datetime'));
+            }
+
+            if (method_exists($share, 'getParent')) {
+                $qb->setValue('parent', $qb->createNamedParameter($share->getParent()));
+            }
+        } else {
+            throw new \Exception('invalid share type!');
+        }
+
+        // Set what is shares
+        $qb->setValue('item_type', $qb->createParameter('itemType'));
+        if ($share->getNode() instanceof \OCP\Files\File) {
+            $qb->setParameter('itemType', 'file');
+        } else {
+            $qb->setParameter('itemType', 'folder');
+        }
+
+        // Set the file id
+        $qb->setValue('item_source', $qb->createNamedParameter($share->getNode()->getId()));
+        $qb->setValue('file_source', $qb->createNamedParameter($share->getNode()->getId()));
+
+        // set the permissions
+        $qb->setValue('permissions', $qb->createNamedParameter($share->getPermissions()));
+
+        // Set who created this share
+        $qb->setValue('uid_initiator', $qb->createNamedParameter($share->getSharedBy()));
+
+        // Set who is the owner of this file/folder (and this the owner of the share)
+        $qb->setValue('uid_owner', $qb->createNamedParameter($share->getShareOwner()));
+
+        // Set the file target
+        $qb->setValue('file_target', $qb->createNamedParameter($share->getTarget()));
+
+        // Set the time this share was created
+        $qb->setValue('stime', $qb->createNamedParameter(time()));
+
+        // insert the data and fetch the id of the share
+        $this->dbConn->beginTransaction();
+        $qb->execute();
+        $id = $this->dbConn->lastInsertId('*PREFIX*share');
+
+        // Now fetch the inserted share and create a complete share object
+        $qb = $this->dbConn->getQueryBuilder();
+        $qb->select('*')
+            ->from('share')
+            ->where($qb->expr()->eq('id', $qb->createNamedParameter($id)));
+
+        $cursor = $qb->execute();
+        $data = $cursor->fetch();
+        $this->dbConn->commit();
+        $cursor->closeCursor();
+
+        if ($data === false) {
+            throw new ShareNotFound();
+        }
+
+        $mailSendValue = $share->getMailSend();
+        $data['mail_send'] = ($mailSendValue === null) ? true : $mailSendValue;
+
+        $share = $this->createShare($data);
+        return $share;
+    }
+
+    /**
+     * Update a share
+     *
+     * @param \OCP\Share\IShare $share
+     * @return \OCP\Share\IShare The share object
+     * @throws ShareNotFound
+     * @throws \OCP\Files\InvalidPathException
+     * @throws \OCP\Files\NotFoundException
+     */
+    public function update(\OCP\Share\IShare $share) {
+        $originalShare = $this->getShareById($share->getId());
+
+        if ($share->getShareType() === \OCP\Share::SHARE_TYPE_USER) {
+            /*
 			 * We allow updating the recipient on user shares.
 			 */
-			$qb = $this->dbConn->getQueryBuilder();
-			$qb->update('share')
-				->where($qb->expr()->eq('id', $qb->createNamedParameter($share->getId())))
-				->set('share_with', $qb->createNamedParameter($share->getSharedWith()))
-				->set('uid_owner', $qb->createNamedParameter($share->getShareOwner()))
-				->set('uid_initiator', $qb->createNamedParameter($share->getSharedBy()))
-				->set('permissions', $qb->createNamedParameter($share->getPermissions()))
-				->set('item_source', $qb->createNamedParameter($share->getNode()->getId()))
-				->set('file_source', $qb->createNamedParameter($share->getNode()->getId()))
-				->set('expiration', $qb->createNamedParameter($share->getExpirationDate(), IQueryBuilder::PARAM_DATE))
-				->set('note', $qb->createNamedParameter($share->getNote()))
-				->set('accepted', $qb->createNamedParameter($share->getStatus()))
-				->execute();
-		} elseif ($share->getShareType() === \OCP\Share::SHARE_TYPE_GROUP) {
-			$qb = $this->dbConn->getQueryBuilder();
-			$qb->update('share')
-				->where($qb->expr()->eq('id', $qb->createNamedParameter($share->getId())))
-				->set('uid_owner', $qb->createNamedParameter($share->getShareOwner()))
-				->set('uid_initiator', $qb->createNamedParameter($share->getSharedBy()))
-				->set('permissions', $qb->createNamedParameter($share->getPermissions()))
-				->set('item_source', $qb->createNamedParameter($share->getNode()->getId()))
-				->set('file_source', $qb->createNamedParameter($share->getNode()->getId()))
-				->set('expiration', $qb->createNamedParameter($share->getExpirationDate(), IQueryBuilder::PARAM_DATE))
-				->set('note', $qb->createNamedParameter($share->getNote()))
-				->execute();
-
-			/*
+            $qb = $this->dbConn->getQueryBuilder();
+            $qb->update('share')
+                ->where($qb->expr()->eq('id', $qb->createNamedParameter($share->getId())))
+                ->set('share_with', $qb->createNamedParameter($share->getSharedWith()))
+                ->set('uid_owner', $qb->createNamedParameter($share->getShareOwner()))
+                ->set('uid_initiator', $qb->createNamedParameter($share->getSharedBy()))
+                ->set('permissions', $qb->createNamedParameter($share->getPermissions()))
+                ->set('item_source', $qb->createNamedParameter($share->getNode()->getId()))
+                ->set('file_source', $qb->createNamedParameter($share->getNode()->getId()))
+                ->set('expiration', $qb->createNamedParameter($share->getExpirationDate(), IQueryBuilder::PARAM_DATE))
+                ->set('note', $qb->createNamedParameter($share->getNote()))
+                ->set('accepted', $qb->createNamedParameter($share->getStatus()))
+                ->execute();
+        } elseif ($share->getShareType() === \OCP\Share::SHARE_TYPE_GROUP) {
+            $qb = $this->dbConn->getQueryBuilder();
+            $qb->update('share')
+                ->where($qb->expr()->eq('id', $qb->createNamedParameter($share->getId())))
+                ->set('uid_owner', $qb->createNamedParameter($share->getShareOwner()))
+                ->set('uid_initiator', $qb->createNamedParameter($share->getSharedBy()))
+                ->set('permissions', $qb->createNamedParameter($share->getPermissions()))
+                ->set('item_source', $qb->createNamedParameter($share->getNode()->getId()))
+                ->set('file_source', $qb->createNamedParameter($share->getNode()->getId()))
+                ->set('expiration', $qb->createNamedParameter($share->getExpirationDate(), IQueryBuilder::PARAM_DATE))
+                ->set('note', $qb->createNamedParameter($share->getNote()))
+                ->execute();
+
+            /*
 			 * Update all user defined group shares
 			 */
-			$qb = $this->dbConn->getQueryBuilder();
-			$qb->update('share')
-				->where($qb->expr()->eq('parent', $qb->createNamedParameter($share->getId())))
-				->andWhere($qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP)))
-				->set('uid_owner', $qb->createNamedParameter($share->getShareOwner()))
-				->set('uid_initiator', $qb->createNamedParameter($share->getSharedBy()))
-				->set('item_source', $qb->createNamedParameter($share->getNode()->getId()))
-				->set('file_source', $qb->createNamedParameter($share->getNode()->getId()))
-				->set('expiration', $qb->createNamedParameter($share->getExpirationDate(), IQueryBuilder::PARAM_DATE))
-				->set('note', $qb->createNamedParameter($share->getNote()))
-				->execute();
-
-			/*
+            $qb = $this->dbConn->getQueryBuilder();
+            $qb->update('share')
+                ->where($qb->expr()->eq('parent', $qb->createNamedParameter($share->getId())))
+                ->andWhere($qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP)))
+                ->set('uid_owner', $qb->createNamedParameter($share->getShareOwner()))
+                ->set('uid_initiator', $qb->createNamedParameter($share->getSharedBy()))
+                ->set('item_source', $qb->createNamedParameter($share->getNode()->getId()))
+                ->set('file_source', $qb->createNamedParameter($share->getNode()->getId()))
+                ->set('expiration', $qb->createNamedParameter($share->getExpirationDate(), IQueryBuilder::PARAM_DATE))
+                ->set('note', $qb->createNamedParameter($share->getNote()))
+                ->execute();
+
+            /*
 			 * Now update the permissions for all children that have not set it to 0
 			 */
-			$qb = $this->dbConn->getQueryBuilder();
-			$qb->update('share')
-				->where($qb->expr()->eq('parent', $qb->createNamedParameter($share->getId())))
-				->andWhere($qb->expr()->neq('permissions', $qb->createNamedParameter(0)))
-				->set('permissions', $qb->createNamedParameter($share->getPermissions()))
-				->execute();
-		} elseif ($share->getShareType() === \OCP\Share::SHARE_TYPE_LINK) {
-			$qb = $this->dbConn->getQueryBuilder();
-			$qb->update('share')
-				->where($qb->expr()->eq('id', $qb->createNamedParameter($share->getId())))
-				->set('password', $qb->createNamedParameter($share->getPassword()))
-				->set('password_by_talk', $qb->createNamedParameter($share->getSendPasswordByTalk(), IQueryBuilder::PARAM_BOOL))
-				->set('uid_owner', $qb->createNamedParameter($share->getShareOwner()))
-				->set('uid_initiator', $qb->createNamedParameter($share->getSharedBy()))
-				->set('permissions', $qb->createNamedParameter($share->getPermissions()))
-				->set('item_source', $qb->createNamedParameter($share->getNode()->getId()))
-				->set('file_source', $qb->createNamedParameter($share->getNode()->getId()))
-				->set('token', $qb->createNamedParameter($share->getToken()))
-				->set('expiration', $qb->createNamedParameter($share->getExpirationDate(), IQueryBuilder::PARAM_DATE))
-				->set('note', $qb->createNamedParameter($share->getNote()))
-				->set('label', $qb->createNamedParameter($share->getLabel()))
-				->set('hide_download', $qb->createNamedParameter($share->getHideDownload() ? 1 : 0), IQueryBuilder::PARAM_INT)
-				->execute();
-		}
-
-		if ($originalShare->getNote() !== $share->getNote() && $share->getNote() !== '') {
-			$this->propagateNote($share);
-		}
-
-
-		return $share;
-	}
-
-	/**
-	 * Accept a share.
-	 *
-	 * @param IShare $share
-	 * @param string $recipient
-	 * @return IShare The share object
-	 * @since 9.0.0
-	 */
-	public function acceptShare(IShare $share, string $recipient): IShare {
-		if ($share->getShareType() === IShare::TYPE_GROUP) {
-			$group = $this->groupManager->get($share->getSharedWith());
-			$user = $this->userManager->get($recipient);
-
-			if (is_null($group)) {
-				throw new ProviderException('Group "' . $share->getSharedWith() . '" does not exist');
-			}
-
-			if (!$group->inGroup($user)) {
-				throw new ProviderException('Recipient not in receiving group');
-			}
-
-			// Try to fetch user specific share
-			$qb = $this->dbConn->getQueryBuilder();
-			$stmt = $qb->select('*')
-				->from('share')
-				->where($qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP)))
-				->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($recipient)))
-				->andWhere($qb->expr()->eq('parent', $qb->createNamedParameter($share->getId())))
-				->andWhere($qb->expr()->orX(
-					$qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
-					$qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
-				))
-				->execute();
-
-			$data = $stmt->fetch();
-			$stmt->closeCursor();
-
-			/*
+            $qb = $this->dbConn->getQueryBuilder();
+            $qb->update('share')
+                ->where($qb->expr()->eq('parent', $qb->createNamedParameter($share->getId())))
+                ->andWhere($qb->expr()->neq('permissions', $qb->createNamedParameter(0)))
+                ->set('permissions', $qb->createNamedParameter($share->getPermissions()))
+                ->execute();
+        } elseif ($share->getShareType() === \OCP\Share::SHARE_TYPE_LINK) {
+            $qb = $this->dbConn->getQueryBuilder();
+            $qb->update('share')
+                ->where($qb->expr()->eq('id', $qb->createNamedParameter($share->getId())))
+                ->set('password', $qb->createNamedParameter($share->getPassword()))
+                ->set('password_by_talk', $qb->createNamedParameter($share->getSendPasswordByTalk(), IQueryBuilder::PARAM_BOOL))
+                ->set('uid_owner', $qb->createNamedParameter($share->getShareOwner()))
+                ->set('uid_initiator', $qb->createNamedParameter($share->getSharedBy()))
+                ->set('permissions', $qb->createNamedParameter($share->getPermissions()))
+                ->set('item_source', $qb->createNamedParameter($share->getNode()->getId()))
+                ->set('file_source', $qb->createNamedParameter($share->getNode()->getId()))
+                ->set('token', $qb->createNamedParameter($share->getToken()))
+                ->set('expiration', $qb->createNamedParameter($share->getExpirationDate(), IQueryBuilder::PARAM_DATE))
+                ->set('note', $qb->createNamedParameter($share->getNote()))
+                ->set('label', $qb->createNamedParameter($share->getLabel()))
+                ->set('hide_download', $qb->createNamedParameter($share->getHideDownload() ? 1 : 0), IQueryBuilder::PARAM_INT)
+                ->execute();
+        }
+
+        if ($originalShare->getNote() !== $share->getNote() && $share->getNote() !== '') {
+            $this->propagateNote($share);
+        }
+
+
+        return $share;
+    }
+
+    /**
+     * Accept a share.
+     *
+     * @param IShare $share
+     * @param string $recipient
+     * @return IShare The share object
+     * @since 9.0.0
+     */
+    public function acceptShare(IShare $share, string $recipient): IShare {
+        if ($share->getShareType() === IShare::TYPE_GROUP) {
+            $group = $this->groupManager->get($share->getSharedWith());
+            $user = $this->userManager->get($recipient);
+
+            if (is_null($group)) {
+                throw new ProviderException('Group "' . $share->getSharedWith() . '" does not exist');
+            }
+
+            if (!$group->inGroup($user)) {
+                throw new ProviderException('Recipient not in receiving group');
+            }
+
+            // Try to fetch user specific share
+            $qb = $this->dbConn->getQueryBuilder();
+            $stmt = $qb->select('*')
+                ->from('share')
+                ->where($qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP)))
+                ->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($recipient)))
+                ->andWhere($qb->expr()->eq('parent', $qb->createNamedParameter($share->getId())))
+                ->andWhere($qb->expr()->orX(
+                    $qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
+                    $qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
+                ))
+                ->execute();
+
+            $data = $stmt->fetch();
+            $stmt->closeCursor();
+
+            /*
 			 * Check if there already is a user specific group share.
 			 * If there is update it (if required).
 			 */
-			if ($data === false) {
-				$id = $this->createUserSpecificGroupShare($share, $recipient);
-			} else {
-				$id = $data['id'];
-			}
-		} elseif ($share->getShareType() === IShare::TYPE_USER) {
-			if ($share->getSharedWith() !== $recipient) {
-				throw new ProviderException('Recipient does not match');
-			}
-
-			$id = $share->getId();
-		} else {
-			throw new ProviderException('Invalid shareType');
-		}
-
-		$qb = $this->dbConn->getQueryBuilder();
-		$qb->update('share')
-			->set('accepted', $qb->createNamedParameter(IShare::STATUS_ACCEPTED))
-			->where($qb->expr()->eq('id', $qb->createNamedParameter($id)))
-			->execute();
-
-		return $share;
-	}
-
-	/**
-	 * Get all children of this share
-	 * FIXME: remove once https://github.com/owncloud/core/pull/21660 is in
-	 *
-	 * @param \OCP\Share\IShare $parent
-	 * @return \OCP\Share\IShare[]
-	 */
-	public function getChildren(\OCP\Share\IShare $parent) {
-		$children = [];
-
-		$qb = $this->dbConn->getQueryBuilder();
-		$qb->select('*')
-			->from('share')
-			->where($qb->expr()->eq('parent', $qb->createNamedParameter($parent->getId())))
-			->andWhere(
-				$qb->expr()->in(
-					'share_type',
-					$qb->createNamedParameter([
-						\OCP\Share::SHARE_TYPE_USER,
-						\OCP\Share::SHARE_TYPE_GROUP,
-						\OCP\Share::SHARE_TYPE_LINK,
-					], IQueryBuilder::PARAM_INT_ARRAY)
-				)
-			)
-			->andWhere($qb->expr()->orX(
-				$qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
-				$qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
-			))
-			->orderBy('id');
-
-		$cursor = $qb->execute();
-		while ($data = $cursor->fetch()) {
-			$children[] = $this->createShare($data);
-		}
-		$cursor->closeCursor();
-
-		return $children;
-	}
-
-	/**
-	 * Delete a share
-	 *
-	 * @param \OCP\Share\IShare $share
-	 */
-	public function delete(\OCP\Share\IShare $share) {
-		$qb = $this->dbConn->getQueryBuilder();
-		$qb->delete('share')
-			->where($qb->expr()->eq('id', $qb->createNamedParameter($share->getId())));
-
-		/*
+            if ($data === false) {
+                $id = $this->createUserSpecificGroupShare($share, $recipient);
+            } else {
+                $id = $data['id'];
+            }
+        } elseif ($share->getShareType() === IShare::TYPE_USER) {
+            if ($share->getSharedWith() !== $recipient) {
+                throw new ProviderException('Recipient does not match');
+            }
+
+            $id = $share->getId();
+        } else {
+            throw new ProviderException('Invalid shareType');
+        }
+
+        $qb = $this->dbConn->getQueryBuilder();
+        $qb->update('share')
+            ->set('accepted', $qb->createNamedParameter(IShare::STATUS_ACCEPTED))
+            ->where($qb->expr()->eq('id', $qb->createNamedParameter($id)))
+            ->execute();
+
+        return $share;
+    }
+
+    /**
+     * Get all children of this share
+     * FIXME: remove once https://github.com/owncloud/core/pull/21660 is in
+     *
+     * @param \OCP\Share\IShare $parent
+     * @return \OCP\Share\IShare[]
+     */
+    public function getChildren(\OCP\Share\IShare $parent) {
+        $children = [];
+
+        $qb = $this->dbConn->getQueryBuilder();
+        $qb->select('*')
+            ->from('share')
+            ->where($qb->expr()->eq('parent', $qb->createNamedParameter($parent->getId())))
+            ->andWhere(
+                $qb->expr()->in(
+                    'share_type',
+                    $qb->createNamedParameter([
+                        \OCP\Share::SHARE_TYPE_USER,
+                        \OCP\Share::SHARE_TYPE_GROUP,
+                        \OCP\Share::SHARE_TYPE_LINK,
+                    ], IQueryBuilder::PARAM_INT_ARRAY)
+                )
+            )
+            ->andWhere($qb->expr()->orX(
+                $qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
+                $qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
+            ))
+            ->orderBy('id');
+
+        $cursor = $qb->execute();
+        while ($data = $cursor->fetch()) {
+            $children[] = $this->createShare($data);
+        }
+        $cursor->closeCursor();
+
+        return $children;
+    }
+
+    /**
+     * Delete a share
+     *
+     * @param \OCP\Share\IShare $share
+     */
+    public function delete(\OCP\Share\IShare $share) {
+        $qb = $this->dbConn->getQueryBuilder();
+        $qb->delete('share')
+            ->where($qb->expr()->eq('id', $qb->createNamedParameter($share->getId())));
+
+        /*
 		 * If the share is a group share delete all possible
 		 * user defined groups shares.
 		 */
-		if ($share->getShareType() === \OCP\Share::SHARE_TYPE_GROUP) {
-			$qb->orWhere($qb->expr()->eq('parent', $qb->createNamedParameter($share->getId())));
-		}
-
-		$qb->execute();
-	}
-
-	/**
-	 * Unshare a share from the recipient. If this is a group share
-	 * this means we need a special entry in the share db.
-	 *
-	 * @param IShare $share
-	 * @param string $recipient UserId of recipient
-	 * @throws BackendError
-	 * @throws ProviderException
-	 */
-	public function deleteFromSelf(IShare $share, $recipient) {
-		if ($share->getShareType() === IShare::TYPE_GROUP) {
-			$group = $this->groupManager->get($share->getSharedWith());
-			$user = $this->userManager->get($recipient);
-
-			if (is_null($group)) {
-				throw new ProviderException('Group "' . $share->getSharedWith() . '" does not exist');
-			}
-
-			if (!$group->inGroup($user)) {
-				throw new ProviderException('Recipient not in receiving group');
-			}
-
-			// Try to fetch user specific share
-			$qb = $this->dbConn->getQueryBuilder();
-			$stmt = $qb->select('*')
-				->from('share')
-				->where($qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP)))
-				->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($recipient)))
-				->andWhere($qb->expr()->eq('parent', $qb->createNamedParameter($share->getId())))
-				->andWhere($qb->expr()->orX(
-					$qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
-					$qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
-				))
-				->execute();
-
-			$data = $stmt->fetch();
-
-			/*
+        if ($share->getShareType() === \OCP\Share::SHARE_TYPE_GROUP) {
+            $qb->orWhere($qb->expr()->eq('parent', $qb->createNamedParameter($share->getId())));
+        }
+
+        $qb->execute();
+    }
+
+    /**
+     * Unshare a share from the recipient. If this is a group share
+     * this means we need a special entry in the share db.
+     *
+     * @param IShare $share
+     * @param string $recipient UserId of recipient
+     * @throws BackendError
+     * @throws ProviderException
+     */
+    public function deleteFromSelf(IShare $share, $recipient) {
+        if ($share->getShareType() === IShare::TYPE_GROUP) {
+            $group = $this->groupManager->get($share->getSharedWith());
+            $user = $this->userManager->get($recipient);
+
+            if (is_null($group)) {
+                throw new ProviderException('Group "' . $share->getSharedWith() . '" does not exist');
+            }
+
+            if (!$group->inGroup($user)) {
+                throw new ProviderException('Recipient not in receiving group');
+            }
+
+            // Try to fetch user specific share
+            $qb = $this->dbConn->getQueryBuilder();
+            $stmt = $qb->select('*')
+                ->from('share')
+                ->where($qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP)))
+                ->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($recipient)))
+                ->andWhere($qb->expr()->eq('parent', $qb->createNamedParameter($share->getId())))
+                ->andWhere($qb->expr()->orX(
+                    $qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
+                    $qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
+                ))
+                ->execute();
+
+            $data = $stmt->fetch();
+
+            /*
 			 * Check if there already is a user specific group share.
 			 * If there is update it (if required).
 			 */
-			if ($data === false) {
-				$id = $this->createUserSpecificGroupShare($share, $recipient);
-				$permissions = $share->getPermissions();
-			} else {
-				$permissions = $data['permissions'];
-				$id = $data['id'];
-			}
-
-			if ($permissions !== 0) {
-				// Update existing usergroup share
-				$qb = $this->dbConn->getQueryBuilder();
-				$qb->update('share')
-					->set('permissions', $qb->createNamedParameter(0))
-					->where($qb->expr()->eq('id', $qb->createNamedParameter($id)))
-					->execute();
-			}
-		} elseif ($share->getShareType() === IShare::TYPE_USER) {
-			if ($share->getSharedWith() !== $recipient) {
-				throw new ProviderException('Recipient does not match');
-			}
-
-			// We can just delete user and link shares
-			$this->delete($share);
-		} else {
-			throw new ProviderException('Invalid shareType');
-		}
-	}
-
-	protected function createUserSpecificGroupShare(IShare $share, string $recipient): int {
-		$type = $share->getNodeType();
-
-		$qb = $this->dbConn->getQueryBuilder();
-		$qb->insert('share')
-			->values([
-				'share_type' => $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP),
-				'share_with' => $qb->createNamedParameter($recipient),
-				'uid_owner' => $qb->createNamedParameter($share->getShareOwner()),
-				'uid_initiator' => $qb->createNamedParameter($share->getSharedBy()),
-				'parent' => $qb->createNamedParameter($share->getId()),
-				'item_type' => $qb->createNamedParameter($type),
-				'item_source' => $qb->createNamedParameter($share->getNodeId()),
-				'file_source' => $qb->createNamedParameter($share->getNodeId()),
-				'file_target' => $qb->createNamedParameter($share->getTarget()),
-				'permissions' => $qb->createNamedParameter($share->getPermissions()),
-				'stime' => $qb->createNamedParameter($share->getShareTime()->getTimestamp()),
-			])->execute();
-
-		return $qb->getLastInsertId();
-	}
-
-	/**
-	 * @inheritdoc
-	 *
-	 * For now this only works for group shares
-	 * If this gets implemented for normal shares we have to extend it
-	 */
-	public function restore(IShare $share, string $recipient): IShare {
-		$qb = $this->dbConn->getQueryBuilder();
-		$qb->select('permissions')
-			->from('share')
-			->where(
-				$qb->expr()->eq('id', $qb->createNamedParameter($share->getId()))
-			);
-		$cursor = $qb->execute();
-		$data = $cursor->fetch();
-		$cursor->closeCursor();
-
-		$originalPermission = $data['permissions'];
-
-		$qb = $this->dbConn->getQueryBuilder();
-		$qb->update('share')
-			->set('permissions', $qb->createNamedParameter($originalPermission))
-			->where(
-				$qb->expr()->eq('parent', $qb->createNamedParameter($share->getParent()))
-			)->andWhere(
-				$qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP))
-			)->andWhere(
-				$qb->expr()->eq('share_with', $qb->createNamedParameter($recipient))
-			);
-
-		$qb->execute();
-
-		return $this->getShareById($share->getId(), $recipient);
-	}
-
-	/**
-	 * @inheritdoc
-	 */
-	public function move(\OCP\Share\IShare $share, $recipient) {
-		if ($share->getShareType() === \OCP\Share::SHARE_TYPE_USER) {
-			// Just update the target
-			$qb = $this->dbConn->getQueryBuilder();
-			$qb->update('share')
-				->set('file_target', $qb->createNamedParameter($share->getTarget()))
-				->where($qb->expr()->eq('id', $qb->createNamedParameter($share->getId())))
-				->execute();
-		} elseif ($share->getShareType() === \OCP\Share::SHARE_TYPE_GROUP) {
-
-			// Check if there is a usergroup share
-			$qb = $this->dbConn->getQueryBuilder();
-			$stmt = $qb->select('id')
-				->from('share')
-				->where($qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP)))
-				->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($recipient)))
-				->andWhere($qb->expr()->eq('parent', $qb->createNamedParameter($share->getId())))
-				->andWhere($qb->expr()->orX(
-					$qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
-					$qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
-				))
-				->setMaxResults(1)
-				->execute();
-
-			$data = $stmt->fetch();
-			$stmt->closeCursor();
-
-			if ($data === false) {
-				// No usergroup share yet. Create one.
-				$qb = $this->dbConn->getQueryBuilder();
-				$qb->insert('share')
-					->values([
-						'share_type' => $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP),
-						'share_with' => $qb->createNamedParameter($recipient),
-						'uid_owner' => $qb->createNamedParameter($share->getShareOwner()),
-						'uid_initiator' => $qb->createNamedParameter($share->getSharedBy()),
-						'parent' => $qb->createNamedParameter($share->getId()),
-						'item_type' => $qb->createNamedParameter($share->getNodeType()),
-						'item_source' => $qb->createNamedParameter($share->getNodeId()),
-						'file_source' => $qb->createNamedParameter($share->getNodeId()),
-						'file_target' => $qb->createNamedParameter($share->getTarget()),
-						'permissions' => $qb->createNamedParameter($share->getPermissions()),
-						'stime' => $qb->createNamedParameter($share->getShareTime()->getTimestamp()),
-					])->execute();
-			} else {
-				// Already a usergroup share. Update it.
-				$qb = $this->dbConn->getQueryBuilder();
-				$qb->update('share')
-					->set('file_target', $qb->createNamedParameter($share->getTarget()))
-					->where($qb->expr()->eq('id', $qb->createNamedParameter($data['id'])))
-					->execute();
-			}
-		}
-
-		return $share;
-	}
-
-	public function getSharesInFolder($userId, Folder $node, $reshares) {
-		$qb = $this->dbConn->getQueryBuilder();
-		$qb->select('*')
-			->from('share', 's')
-			->andWhere($qb->expr()->orX(
-				$qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
-				$qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
-			));
-
-		$qb->andWhere($qb->expr()->orX(
-			$qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_USER)),
-			$qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_GROUP)),
-			$qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_LINK))
-		));
-
-		/**
-		 * Reshares for this user are shares where they are the owner.
-		 */
-		if ($reshares === false) {
-			$qb->andWhere($qb->expr()->eq('uid_initiator', $qb->createNamedParameter($userId)));
-		} else {
-			$qb->andWhere(
-				$qb->expr()->orX(
-					$qb->expr()->eq('uid_owner', $qb->createNamedParameter($userId)),
-					$qb->expr()->eq('uid_initiator', $qb->createNamedParameter($userId))
-				)
-			);
-		}
-
-		$qb->innerJoin('s', 'filecache' ,'f', $qb->expr()->eq('s.file_source', 'f.fileid'));
-		$qb->andWhere($qb->expr()->eq('f.parent', $qb->createNamedParameter($node->getId())));
-
-		$qb->orderBy('id');
-
-		$cursor = $qb->execute();
-		$shares = [];
-		while ($data = $cursor->fetch()) {
-			$shares[$data['fileid']][] = $this->createShare($data);
-		}
-		$cursor->closeCursor();
-
-		return $shares;
-	}
-
-	/**
-	 * @inheritdoc
-	 */
-	public function getSharesBy($userId, $shareType, $node, $reshares, $limit, $offset) {
-		$qb = $this->dbConn->getQueryBuilder();
-		$qb->select('*')
-			->from('share')
-			->andWhere($qb->expr()->orX(
-				$qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
-				$qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
-			));
-
-		$qb->andWhere($qb->expr()->eq('share_type', $qb->createNamedParameter($shareType)));
-
-		/**
-		 * Reshares for this user are shares where they are the owner.
-		 */
-		if ($reshares === false) {
-			$qb->andWhere($qb->expr()->eq('uid_initiator', $qb->createNamedParameter($userId)));
-		} else {
-			if ($node === null) {
-				$qb->andWhere(
-					$qb->expr()->orX(
-						$qb->expr()->eq('uid_owner', $qb->createNamedParameter($userId)),
-						$qb->expr()->eq('uid_initiator', $qb->createNamedParameter($userId))
-					)
-				);
-			}
-		}
-
-		if ($node !== null) {
-			$qb->andWhere($qb->expr()->eq('file_source', $qb->createNamedParameter($node->getId())));
-		}
-
-		if ($limit !== -1) {
-			$qb->setMaxResults($limit);
-		}
-
-		$qb->setFirstResult($offset);
-		$qb->orderBy('id');
-
-		$cursor = $qb->execute();
-		$shares = [];
-		while ($data = $cursor->fetch()) {
-			$shares[] = $this->createShare($data);
-		}
-		$cursor->closeCursor();
-
-		return $shares;
-	}
-
-	/**
-	 * @inheritdoc
-	 */
-	public function getShareById($id, $recipientId = null) {
-		$qb = $this->dbConn->getQueryBuilder();
-
-		$qb->select('*')
-			->from('share')
-			->where($qb->expr()->eq('id', $qb->createNamedParameter($id)))
-			->andWhere(
-				$qb->expr()->in(
-					'share_type',
-					$qb->createNamedParameter([
-						\OCP\Share::SHARE_TYPE_USER,
-						\OCP\Share::SHARE_TYPE_GROUP,
-						\OCP\Share::SHARE_TYPE_LINK,
-					], IQueryBuilder::PARAM_INT_ARRAY)
-				)
-			)
-			->andWhere($qb->expr()->orX(
-				$qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
-				$qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
-			));
-
-		$cursor = $qb->execute();
-		$data = $cursor->fetch();
-		$cursor->closeCursor();
-
-		if ($data === false) {
-			throw new ShareNotFound();
-		}
-
-		try {
-			$share = $this->createShare($data);
-		} catch (InvalidShare $e) {
-			throw new ShareNotFound();
-		}
-
-		// If the recipient is set for a group share resolve to that user
-		if ($recipientId !== null && $share->getShareType() === \OCP\Share::SHARE_TYPE_GROUP) {
-			$share = $this->resolveGroupShares([$share], $recipientId)[0];
-		}
-
-		return $share;
-	}
-
-	/**
-	 * Get shares for a given path
-	 *
-	 * @param \OCP\Files\Node $path
-	 * @return \OCP\Share\IShare[]
-	 */
-	public function getSharesByPath(Node $path) {
-		$qb = $this->dbConn->getQueryBuilder();
-
-		$cursor = $qb->select('*')
-			->from('share')
-			->andWhere($qb->expr()->eq('file_source', $qb->createNamedParameter($path->getId())))
-			->andWhere(
-				$qb->expr()->orX(
-					$qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_USER)),
-					$qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_GROUP))
-				)
-			)
-			->andWhere($qb->expr()->orX(
-				$qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
-				$qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
-			))
-			->execute();
-
-		$shares = [];
-		while ($data = $cursor->fetch()) {
-			$shares[] = $this->createShare($data);
-		}
-		$cursor->closeCursor();
-
-		return $shares;
-	}
-
-	/**
-	 * Returns whether the given database result can be interpreted as
-	 * a share with accessible file (not trashed, not deleted)
-	 */
-	private function isAccessibleResult($data) {
-		// exclude shares leading to deleted file entries
-		if ($data['fileid'] === null || $data['path'] === null) {
-			return false;
-		}
-
-		// exclude shares leading to trashbin on home storages
-		$pathSections = explode('/', $data['path'], 2);
-		// FIXME: would not detect rare md5'd home storage case properly
-		if ($pathSections[0] !== 'files'
-				&& in_array(explode(':', $data['storage_string_id'], 2)[0], ['home', 'object'])) {
-			return false;
-		}
-		return true;
-	}
-
-	/**
-	 * @inheritdoc
-	 */
-	public function getSharedWith($userId, $shareType, $node, $limit, $offset) {
-		/** @var Share[] $shares */
-		$shares = [];
-
-		if ($shareType === \OCP\Share::SHARE_TYPE_USER) {
-			//Get shares directly with this user
-			$qb = $this->dbConn->getQueryBuilder();
-			$qb->select('s.*',
-				'f.fileid', 'f.path', 'f.permissions AS f_permissions', 'f.storage', 'f.path_hash',
-				'f.parent AS f_parent', 'f.name', 'f.mimetype', 'f.mimepart', 'f.size', 'f.mtime', 'f.storage_mtime',
-				'f.encrypted', 'f.unencrypted_size', 'f.etag', 'f.checksum'
-			)
-				->selectAlias('st.id', 'storage_string_id')
-				->from('share', 's')
-				->leftJoin('s', 'filecache', 'f', $qb->expr()->eq('s.file_source', 'f.fileid'))
-				->leftJoin('f', 'storages', 'st', $qb->expr()->eq('f.storage', 'st.numeric_id'));
-
-			// Order by id
-			$qb->orderBy('s.id');
-
-			// Set limit and offset
-			if ($limit !== -1) {
-				$qb->setMaxResults($limit);
-			}
-			$qb->setFirstResult($offset);
-
-			$qb->where($qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_USER)))
-				->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($userId)))
-				->andWhere($qb->expr()->orX(
-					$qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
-					$qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
-				));
-
-			// Filter by node if provided
-			if ($node !== null) {
-				$qb->andWhere($qb->expr()->eq('file_source', $qb->createNamedParameter($node->getId())));
-			}
-
-			$cursor = $qb->execute();
-
-			while ($data = $cursor->fetch()) {
-				if ($this->isAccessibleResult($data)) {
-					$shares[] = $this->createShare($data);
-				}
-			}
-			$cursor->closeCursor();
-		} elseif ($shareType === \OCP\Share::SHARE_TYPE_GROUP) {
-			$user = $this->userManager->get($userId);
-			$allGroups = $this->groupManager->getUserGroups($user);
-
-			/** @var Share[] $shares2 */
-			$shares2 = [];
-
-			$start = 0;
-			while (true) {
-				$groups = array_slice($allGroups, $start, 100);
-				$start += 100;
-
-				if ($groups === []) {
-					break;
-				}
-
-				$qb = $this->dbConn->getQueryBuilder();
-				$qb->select('s.*',
-					'f.fileid', 'f.path', 'f.permissions AS f_permissions', 'f.storage', 'f.path_hash',
-					'f.parent AS f_parent', 'f.name', 'f.mimetype', 'f.mimepart', 'f.size', 'f.mtime', 'f.storage_mtime',
-					'f.encrypted', 'f.unencrypted_size', 'f.etag', 'f.checksum'
-				)
-					->selectAlias('st.id', 'storage_string_id')
-					->from('share', 's')
-					->leftJoin('s', 'filecache', 'f', $qb->expr()->eq('s.file_source', 'f.fileid'))
-					->leftJoin('f', 'storages', 'st', $qb->expr()->eq('f.storage', 'st.numeric_id'))
-					->orderBy('s.id')
-					->setFirstResult(0);
-
-				if ($limit !== -1) {
-					$qb->setMaxResults($limit - count($shares));
-				}
-
-				// Filter by node if provided
-				if ($node !== null) {
-					$qb->andWhere($qb->expr()->eq('file_source', $qb->createNamedParameter($node->getId())));
-				}
-
-
-				$groups = array_filter($groups, function ($group) {
-					return $group instanceof IGroup;
-				});
-				$groups = array_map(function (IGroup $group) {
-					return $group->getGID();
-				}, $groups);
-
-				$qb->andWhere($qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_GROUP)))
-					->andWhere($qb->expr()->in('share_with', $qb->createNamedParameter(
-						$groups,
-						IQueryBuilder::PARAM_STR_ARRAY
-					)))
-					->andWhere($qb->expr()->orX(
-						$qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
-						$qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
-					));
-
-				$cursor = $qb->execute();
-				while ($data = $cursor->fetch()) {
-					if ($offset > 0) {
-						$offset--;
-						continue;
-					}
-
-					if ($this->isAccessibleResult($data)) {
-						$shares2[] = $this->createShare($data);
-					}
-				}
-				$cursor->closeCursor();
-			}
-
-			/*
+            if ($data === false) {
+                $id = $this->createUserSpecificGroupShare($share, $recipient);
+                $permissions = $share->getPermissions();
+            } else {
+                $permissions = $data['permissions'];
+                $id = $data['id'];
+            }
+
+            if ($permissions !== 0) {
+                // Update existing usergroup share
+                $qb = $this->dbConn->getQueryBuilder();
+                $qb->update('share')
+                    ->set('permissions', $qb->createNamedParameter(0))
+                    ->where($qb->expr()->eq('id', $qb->createNamedParameter($id)))
+                    ->execute();
+            }
+        } elseif ($share->getShareType() === IShare::TYPE_USER) {
+            if ($share->getSharedWith() !== $recipient) {
+                throw new ProviderException('Recipient does not match');
+            }
+
+            // We can just delete user and link shares
+            $this->delete($share);
+        } else {
+            throw new ProviderException('Invalid shareType');
+        }
+    }
+
+    protected function createUserSpecificGroupShare(IShare $share, string $recipient): int {
+        $type = $share->getNodeType();
+
+        $qb = $this->dbConn->getQueryBuilder();
+        $qb->insert('share')
+            ->values([
+                'share_type' => $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP),
+                'share_with' => $qb->createNamedParameter($recipient),
+                'uid_owner' => $qb->createNamedParameter($share->getShareOwner()),
+                'uid_initiator' => $qb->createNamedParameter($share->getSharedBy()),
+                'parent' => $qb->createNamedParameter($share->getId()),
+                'item_type' => $qb->createNamedParameter($type),
+                'item_source' => $qb->createNamedParameter($share->getNodeId()),
+                'file_source' => $qb->createNamedParameter($share->getNodeId()),
+                'file_target' => $qb->createNamedParameter($share->getTarget()),
+                'permissions' => $qb->createNamedParameter($share->getPermissions()),
+                'stime' => $qb->createNamedParameter($share->getShareTime()->getTimestamp()),
+            ])->execute();
+
+        return $qb->getLastInsertId();
+    }
+
+    /**
+     * @inheritdoc
+     *
+     * For now this only works for group shares
+     * If this gets implemented for normal shares we have to extend it
+     */
+    public function restore(IShare $share, string $recipient): IShare {
+        $qb = $this->dbConn->getQueryBuilder();
+        $qb->select('permissions')
+            ->from('share')
+            ->where(
+                $qb->expr()->eq('id', $qb->createNamedParameter($share->getId()))
+            );
+        $cursor = $qb->execute();
+        $data = $cursor->fetch();
+        $cursor->closeCursor();
+
+        $originalPermission = $data['permissions'];
+
+        $qb = $this->dbConn->getQueryBuilder();
+        $qb->update('share')
+            ->set('permissions', $qb->createNamedParameter($originalPermission))
+            ->where(
+                $qb->expr()->eq('parent', $qb->createNamedParameter($share->getParent()))
+            )->andWhere(
+                $qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP))
+            )->andWhere(
+                $qb->expr()->eq('share_with', $qb->createNamedParameter($recipient))
+            );
+
+        $qb->execute();
+
+        return $this->getShareById($share->getId(), $recipient);
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function move(\OCP\Share\IShare $share, $recipient) {
+        if ($share->getShareType() === \OCP\Share::SHARE_TYPE_USER) {
+            // Just update the target
+            $qb = $this->dbConn->getQueryBuilder();
+            $qb->update('share')
+                ->set('file_target', $qb->createNamedParameter($share->getTarget()))
+                ->where($qb->expr()->eq('id', $qb->createNamedParameter($share->getId())))
+                ->execute();
+        } elseif ($share->getShareType() === \OCP\Share::SHARE_TYPE_GROUP) {
+
+            // Check if there is a usergroup share
+            $qb = $this->dbConn->getQueryBuilder();
+            $stmt = $qb->select('id')
+                ->from('share')
+                ->where($qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP)))
+                ->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($recipient)))
+                ->andWhere($qb->expr()->eq('parent', $qb->createNamedParameter($share->getId())))
+                ->andWhere($qb->expr()->orX(
+                    $qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
+                    $qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
+                ))
+                ->setMaxResults(1)
+                ->execute();
+
+            $data = $stmt->fetch();
+            $stmt->closeCursor();
+
+            if ($data === false) {
+                // No usergroup share yet. Create one.
+                $qb = $this->dbConn->getQueryBuilder();
+                $qb->insert('share')
+                    ->values([
+                        'share_type' => $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP),
+                        'share_with' => $qb->createNamedParameter($recipient),
+                        'uid_owner' => $qb->createNamedParameter($share->getShareOwner()),
+                        'uid_initiator' => $qb->createNamedParameter($share->getSharedBy()),
+                        'parent' => $qb->createNamedParameter($share->getId()),
+                        'item_type' => $qb->createNamedParameter($share->getNodeType()),
+                        'item_source' => $qb->createNamedParameter($share->getNodeId()),
+                        'file_source' => $qb->createNamedParameter($share->getNodeId()),
+                        'file_target' => $qb->createNamedParameter($share->getTarget()),
+                        'permissions' => $qb->createNamedParameter($share->getPermissions()),
+                        'stime' => $qb->createNamedParameter($share->getShareTime()->getTimestamp()),
+                    ])->execute();
+            } else {
+                // Already a usergroup share. Update it.
+                $qb = $this->dbConn->getQueryBuilder();
+                $qb->update('share')
+                    ->set('file_target', $qb->createNamedParameter($share->getTarget()))
+                    ->where($qb->expr()->eq('id', $qb->createNamedParameter($data['id'])))
+                    ->execute();
+            }
+        }
+
+        return $share;
+    }
+
+    public function getSharesInFolder($userId, Folder $node, $reshares) {
+        $qb = $this->dbConn->getQueryBuilder();
+        $qb->select('*')
+            ->from('share', 's')
+            ->andWhere($qb->expr()->orX(
+                $qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
+                $qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
+            ));
+
+        $qb->andWhere($qb->expr()->orX(
+            $qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_USER)),
+            $qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_GROUP)),
+            $qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_LINK))
+        ));
+
+        /**
+         * Reshares for this user are shares where they are the owner.
+         */
+        if ($reshares === false) {
+            $qb->andWhere($qb->expr()->eq('uid_initiator', $qb->createNamedParameter($userId)));
+        } else {
+            $qb->andWhere(
+                $qb->expr()->orX(
+                    $qb->expr()->eq('uid_owner', $qb->createNamedParameter($userId)),
+                    $qb->expr()->eq('uid_initiator', $qb->createNamedParameter($userId))
+                )
+            );
+        }
+
+        $qb->innerJoin('s', 'filecache' ,'f', $qb->expr()->eq('s.file_source', 'f.fileid'));
+        $qb->andWhere($qb->expr()->eq('f.parent', $qb->createNamedParameter($node->getId())));
+
+        $qb->orderBy('id');
+
+        $cursor = $qb->execute();
+        $shares = [];
+        while ($data = $cursor->fetch()) {
+            $shares[$data['fileid']][] = $this->createShare($data);
+        }
+        $cursor->closeCursor();
+
+        return $shares;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function getSharesBy($userId, $shareType, $node, $reshares, $limit, $offset) {
+        $qb = $this->dbConn->getQueryBuilder();
+        $qb->select('*')
+            ->from('share')
+            ->andWhere($qb->expr()->orX(
+                $qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
+                $qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
+            ));
+
+        $qb->andWhere($qb->expr()->eq('share_type', $qb->createNamedParameter($shareType)));
+
+        /**
+         * Reshares for this user are shares where they are the owner.
+         */
+        if ($reshares === false) {
+            $qb->andWhere($qb->expr()->eq('uid_initiator', $qb->createNamedParameter($userId)));
+        } else {
+            if ($node === null) {
+                $qb->andWhere(
+                    $qb->expr()->orX(
+                        $qb->expr()->eq('uid_owner', $qb->createNamedParameter($userId)),
+                        $qb->expr()->eq('uid_initiator', $qb->createNamedParameter($userId))
+                    )
+                );
+            }
+        }
+
+        if ($node !== null) {
+            $qb->andWhere($qb->expr()->eq('file_source', $qb->createNamedParameter($node->getId())));
+        }
+
+        if ($limit !== -1) {
+            $qb->setMaxResults($limit);
+        }
+
+        $qb->setFirstResult($offset);
+        $qb->orderBy('id');
+
+        $cursor = $qb->execute();
+        $shares = [];
+        while ($data = $cursor->fetch()) {
+            $shares[] = $this->createShare($data);
+        }
+        $cursor->closeCursor();
+
+        return $shares;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function getShareById($id, $recipientId = null) {
+        $qb = $this->dbConn->getQueryBuilder();
+
+        $qb->select('*')
+            ->from('share')
+            ->where($qb->expr()->eq('id', $qb->createNamedParameter($id)))
+            ->andWhere(
+                $qb->expr()->in(
+                    'share_type',
+                    $qb->createNamedParameter([
+                        \OCP\Share::SHARE_TYPE_USER,
+                        \OCP\Share::SHARE_TYPE_GROUP,
+                        \OCP\Share::SHARE_TYPE_LINK,
+                    ], IQueryBuilder::PARAM_INT_ARRAY)
+                )
+            )
+            ->andWhere($qb->expr()->orX(
+                $qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
+                $qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
+            ));
+
+        $cursor = $qb->execute();
+        $data = $cursor->fetch();
+        $cursor->closeCursor();
+
+        if ($data === false) {
+            throw new ShareNotFound();
+        }
+
+        try {
+            $share = $this->createShare($data);
+        } catch (InvalidShare $e) {
+            throw new ShareNotFound();
+        }
+
+        // If the recipient is set for a group share resolve to that user
+        if ($recipientId !== null && $share->getShareType() === \OCP\Share::SHARE_TYPE_GROUP) {
+            $share = $this->resolveGroupShares([$share], $recipientId)[0];
+        }
+
+        return $share;
+    }
+
+    /**
+     * Get shares for a given path
+     *
+     * @param \OCP\Files\Node $path
+     * @return \OCP\Share\IShare[]
+     */
+    public function getSharesByPath(Node $path) {
+        $qb = $this->dbConn->getQueryBuilder();
+
+        $cursor = $qb->select('*')
+            ->from('share')
+            ->andWhere($qb->expr()->eq('file_source', $qb->createNamedParameter($path->getId())))
+            ->andWhere(
+                $qb->expr()->orX(
+                    $qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_USER)),
+                    $qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_GROUP))
+                )
+            )
+            ->andWhere($qb->expr()->orX(
+                $qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
+                $qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
+            ))
+            ->execute();
+
+        $shares = [];
+        while ($data = $cursor->fetch()) {
+            $shares[] = $this->createShare($data);
+        }
+        $cursor->closeCursor();
+
+        return $shares;
+    }
+
+    /**
+     * Returns whether the given database result can be interpreted as
+     * a share with accessible file (not trashed, not deleted)
+     */
+    private function isAccessibleResult($data) {
+        // exclude shares leading to deleted file entries
+        if ($data['fileid'] === null || $data['path'] === null) {
+            return false;
+        }
+
+        // exclude shares leading to trashbin on home storages
+        $pathSections = explode('/', $data['path'], 2);
+        // FIXME: would not detect rare md5'd home storage case properly
+        if ($pathSections[0] !== 'files'
+                && in_array(explode(':', $data['storage_string_id'], 2)[0], ['home', 'object'])) {
+            return false;
+        }
+        return true;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function getSharedWith($userId, $shareType, $node, $limit, $offset) {
+        /** @var Share[] $shares */
+        $shares = [];
+
+        if ($shareType === \OCP\Share::SHARE_TYPE_USER) {
+            //Get shares directly with this user
+            $qb = $this->dbConn->getQueryBuilder();
+            $qb->select('s.*',
+                'f.fileid', 'f.path', 'f.permissions AS f_permissions', 'f.storage', 'f.path_hash',
+                'f.parent AS f_parent', 'f.name', 'f.mimetype', 'f.mimepart', 'f.size', 'f.mtime', 'f.storage_mtime',
+                'f.encrypted', 'f.unencrypted_size', 'f.etag', 'f.checksum'
+            )
+                ->selectAlias('st.id', 'storage_string_id')
+                ->from('share', 's')
+                ->leftJoin('s', 'filecache', 'f', $qb->expr()->eq('s.file_source', 'f.fileid'))
+                ->leftJoin('f', 'storages', 'st', $qb->expr()->eq('f.storage', 'st.numeric_id'));
+
+            // Order by id
+            $qb->orderBy('s.id');
+
+            // Set limit and offset
+            if ($limit !== -1) {
+                $qb->setMaxResults($limit);
+            }
+            $qb->setFirstResult($offset);
+
+            $qb->where($qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_USER)))
+                ->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($userId)))
+                ->andWhere($qb->expr()->orX(
+                    $qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
+                    $qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
+                ));
+
+            // Filter by node if provided
+            if ($node !== null) {
+                $qb->andWhere($qb->expr()->eq('file_source', $qb->createNamedParameter($node->getId())));
+            }
+
+            $cursor = $qb->execute();
+
+            while ($data = $cursor->fetch()) {
+                if ($this->isAccessibleResult($data)) {
+                    $shares[] = $this->createShare($data);
+                }
+            }
+            $cursor->closeCursor();
+        } elseif ($shareType === \OCP\Share::SHARE_TYPE_GROUP) {
+            $user = $this->userManager->get($userId);
+            $allGroups = $this->groupManager->getUserGroups($user);
+
+            /** @var Share[] $shares2 */
+            $shares2 = [];
+
+            $start = 0;
+            while (true) {
+                $groups = array_slice($allGroups, $start, 100);
+                $start += 100;
+
+                if ($groups === []) {
+                    break;
+                }
+
+                $qb = $this->dbConn->getQueryBuilder();
+                $qb->select('s.*',
+                    'f.fileid', 'f.path', 'f.permissions AS f_permissions', 'f.storage', 'f.path_hash',
+                    'f.parent AS f_parent', 'f.name', 'f.mimetype', 'f.mimepart', 'f.size', 'f.mtime', 'f.storage_mtime',
+                    'f.encrypted', 'f.unencrypted_size', 'f.etag', 'f.checksum'
+                )
+                    ->selectAlias('st.id', 'storage_string_id')
+                    ->from('share', 's')
+                    ->leftJoin('s', 'filecache', 'f', $qb->expr()->eq('s.file_source', 'f.fileid'))
+                    ->leftJoin('f', 'storages', 'st', $qb->expr()->eq('f.storage', 'st.numeric_id'))
+                    ->orderBy('s.id')
+                    ->setFirstResult(0);
+
+                if ($limit !== -1) {
+                    $qb->setMaxResults($limit - count($shares));
+                }
+
+                // Filter by node if provided
+                if ($node !== null) {
+                    $qb->andWhere($qb->expr()->eq('file_source', $qb->createNamedParameter($node->getId())));
+                }
+
+
+                $groups = array_filter($groups, function ($group) {
+                    return $group instanceof IGroup;
+                });
+                $groups = array_map(function (IGroup $group) {
+                    return $group->getGID();
+                }, $groups);
+
+                $qb->andWhere($qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_GROUP)))
+                    ->andWhere($qb->expr()->in('share_with', $qb->createNamedParameter(
+                        $groups,
+                        IQueryBuilder::PARAM_STR_ARRAY
+                    )))
+                    ->andWhere($qb->expr()->orX(
+                        $qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
+                        $qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
+                    ));
+
+                $cursor = $qb->execute();
+                while ($data = $cursor->fetch()) {
+                    if ($offset > 0) {
+                        $offset--;
+                        continue;
+                    }
+
+                    if ($this->isAccessibleResult($data)) {
+                        $shares2[] = $this->createShare($data);
+                    }
+                }
+                $cursor->closeCursor();
+            }
+
+            /*
 			 * Resolve all group shares to user specific shares
 			 */
-			$shares = $this->resolveGroupShares($shares2, $userId);
-		} else {
-			throw new BackendError('Invalid backend');
-		}
-
-
-		return $shares;
-	}
-
-	/**
-	 * Get a share by token
-	 *
-	 * @param string $token
-	 * @return \OCP\Share\IShare
-	 * @throws ShareNotFound
-	 */
-	public function getShareByToken($token) {
-		$qb = $this->dbConn->getQueryBuilder();
-
-		$cursor = $qb->select('*')
-			->from('share')
-			->where($qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_LINK)))
-			->andWhere($qb->expr()->eq('token', $qb->createNamedParameter($token)))
-			->andWhere($qb->expr()->orX(
-				$qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
-				$qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
-			))
-			->execute();
-
-		$data = $cursor->fetch();
-
-		if ($data === false) {
-			throw new ShareNotFound();
-		}
-
-		try {
-			$share = $this->createShare($data);
-		} catch (InvalidShare $e) {
-			throw new ShareNotFound();
-		}
-
-		return $share;
-	}
-
-	/**
-	 * Create a share object from an database row
-	 *
-	 * @param mixed[] $data
-	 * @return \OCP\Share\IShare
-	 * @throws InvalidShare
-	 */
-	private function createShare($data) {
-		$share = new Share($this->rootFolder, $this->userManager);
-		$share->setId((int)$data['id'])
-			->setShareType((int)$data['share_type'])
-			->setPermissions((int)$data['permissions'])
-			->setTarget($data['file_target'])
-			->setNote($data['note'])
-			->setMailSend((bool)$data['mail_send'])
-			->setStatus((int)$data['accepted'])
-			->setLabel($data['label']);
-
-		$shareTime = new \DateTime();
-		$shareTime->setTimestamp((int)$data['stime']);
-		$share->setShareTime($shareTime);
-
-		if ($share->getShareType() === \OCP\Share::SHARE_TYPE_USER) {
-			$share->setSharedWith($data['share_with']);
-			$user = $this->userManager->get($data['share_with']);
-			if ($user !== null) {
-				$share->setSharedWithDisplayName($user->getDisplayName());
-			}
-		} elseif ($share->getShareType() === \OCP\Share::SHARE_TYPE_GROUP) {
-			$share->setSharedWith($data['share_with']);
-		} elseif ($share->getShareType() === \OCP\Share::SHARE_TYPE_LINK) {
-			$share->setPassword($data['password']);
-			$share->setSendPasswordByTalk((bool)$data['password_by_talk']);
-			$share->setToken($data['token']);
-		}
-
-		$share->setSharedBy($data['uid_initiator']);
-		$share->setShareOwner($data['uid_owner']);
-
-		$share->setNodeId((int)$data['file_source']);
-		$share->setNodeType($data['item_type']);
-
-		if ($data['expiration'] !== null) {
-			$expiration = \DateTime::createFromFormat('Y-m-d H:i:s', $data['expiration']);
-			$share->setExpirationDate($expiration);
-		}
-
-		if (isset($data['f_permissions'])) {
-			$entryData = $data;
-			$entryData['permissions'] = $entryData['f_permissions'];
-			$entryData['parent'] = $entryData['f_parent'];
-			$share->setNodeCacheEntry(Cache::cacheEntryFromData($entryData,
-				\OC::$server->getMimeTypeLoader()));
-		}
-
-		$share->setProviderId($this->identifier());
-		$share->setHideDownload((int)$data['hide_download'] === 1);
-
-		return $share;
-	}
-
-	/**
-	 * @param Share[] $shares
-	 * @param $userId
-	 * @return Share[] The updates shares if no update is found for a share return the original
-	 */
-	private function resolveGroupShares($shares, $userId) {
-		$result = [];
-
-		$start = 0;
-		while (true) {
-			/** @var Share[] $shareSlice */
-			$shareSlice = array_slice($shares, $start, 100);
-			$start += 100;
-
-			if ($shareSlice === []) {
-				break;
-			}
-
-			/** @var int[] $ids */
-			$ids = [];
-			/** @var Share[] $shareMap */
-			$shareMap = [];
-
-			foreach ($shareSlice as $share) {
-				$ids[] = (int)$share->getId();
-				$shareMap[$share->getId()] = $share;
-			}
-
-			$qb = $this->dbConn->getQueryBuilder();
-
-			$query = $qb->select('*')
-				->from('share')
-				->where($qb->expr()->in('parent', $qb->createNamedParameter($ids, IQueryBuilder::PARAM_INT_ARRAY)))
-				->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($userId)))
-				->andWhere($qb->expr()->orX(
-					$qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
-					$qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
-				));
-
-			$stmt = $query->execute();
-
-			while ($data = $stmt->fetch()) {
-				$shareMap[$data['parent']]->setPermissions((int)$data['permissions']);
-				$shareMap[$data['parent']]->setStatus((int)$data['accepted']);
-				$shareMap[$data['parent']]->setTarget($data['file_target']);
-				$shareMap[$data['parent']]->setParent($data['parent']);
-			}
-
-			$stmt->closeCursor();
-
-			foreach ($shareMap as $share) {
-				$result[] = $share;
-			}
-		}
-
-		return $result;
-	}
-
-	/**
-	 * A user is deleted from the system
-	 * So clean up the relevant shares.
-	 *
-	 * @param string $uid
-	 * @param int $shareType
-	 */
-	public function userDeleted($uid, $shareType) {
-		$qb = $this->dbConn->getQueryBuilder();
-
-		$qb->delete('share');
-
-		if ($shareType === \OCP\Share::SHARE_TYPE_USER) {
-			/*
+            $shares = $this->resolveGroupShares($shares2, $userId);
+        } else {
+            throw new BackendError('Invalid backend');
+        }
+
+
+        return $shares;
+    }
+
+    /**
+     * Get a share by token
+     *
+     * @param string $token
+     * @return \OCP\Share\IShare
+     * @throws ShareNotFound
+     */
+    public function getShareByToken($token) {
+        $qb = $this->dbConn->getQueryBuilder();
+
+        $cursor = $qb->select('*')
+            ->from('share')
+            ->where($qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_LINK)))
+            ->andWhere($qb->expr()->eq('token', $qb->createNamedParameter($token)))
+            ->andWhere($qb->expr()->orX(
+                $qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
+                $qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
+            ))
+            ->execute();
+
+        $data = $cursor->fetch();
+
+        if ($data === false) {
+            throw new ShareNotFound();
+        }
+
+        try {
+            $share = $this->createShare($data);
+        } catch (InvalidShare $e) {
+            throw new ShareNotFound();
+        }
+
+        return $share;
+    }
+
+    /**
+     * Create a share object from an database row
+     *
+     * @param mixed[] $data
+     * @return \OCP\Share\IShare
+     * @throws InvalidShare
+     */
+    private function createShare($data) {
+        $share = new Share($this->rootFolder, $this->userManager);
+        $share->setId((int)$data['id'])
+            ->setShareType((int)$data['share_type'])
+            ->setPermissions((int)$data['permissions'])
+            ->setTarget($data['file_target'])
+            ->setNote($data['note'])
+            ->setMailSend((bool)$data['mail_send'])
+            ->setStatus((int)$data['accepted'])
+            ->setLabel($data['label']);
+
+        $shareTime = new \DateTime();
+        $shareTime->setTimestamp((int)$data['stime']);
+        $share->setShareTime($shareTime);
+
+        if ($share->getShareType() === \OCP\Share::SHARE_TYPE_USER) {
+            $share->setSharedWith($data['share_with']);
+            $user = $this->userManager->get($data['share_with']);
+            if ($user !== null) {
+                $share->setSharedWithDisplayName($user->getDisplayName());
+            }
+        } elseif ($share->getShareType() === \OCP\Share::SHARE_TYPE_GROUP) {
+            $share->setSharedWith($data['share_with']);
+        } elseif ($share->getShareType() === \OCP\Share::SHARE_TYPE_LINK) {
+            $share->setPassword($data['password']);
+            $share->setSendPasswordByTalk((bool)$data['password_by_talk']);
+            $share->setToken($data['token']);
+        }
+
+        $share->setSharedBy($data['uid_initiator']);
+        $share->setShareOwner($data['uid_owner']);
+
+        $share->setNodeId((int)$data['file_source']);
+        $share->setNodeType($data['item_type']);
+
+        if ($data['expiration'] !== null) {
+            $expiration = \DateTime::createFromFormat('Y-m-d H:i:s', $data['expiration']);
+            $share->setExpirationDate($expiration);
+        }
+
+        if (isset($data['f_permissions'])) {
+            $entryData = $data;
+            $entryData['permissions'] = $entryData['f_permissions'];
+            $entryData['parent'] = $entryData['f_parent'];
+            $share->setNodeCacheEntry(Cache::cacheEntryFromData($entryData,
+                \OC::$server->getMimeTypeLoader()));
+        }
+
+        $share->setProviderId($this->identifier());
+        $share->setHideDownload((int)$data['hide_download'] === 1);
+
+        return $share;
+    }
+
+    /**
+     * @param Share[] $shares
+     * @param $userId
+     * @return Share[] The updates shares if no update is found for a share return the original
+     */
+    private function resolveGroupShares($shares, $userId) {
+        $result = [];
+
+        $start = 0;
+        while (true) {
+            /** @var Share[] $shareSlice */
+            $shareSlice = array_slice($shares, $start, 100);
+            $start += 100;
+
+            if ($shareSlice === []) {
+                break;
+            }
+
+            /** @var int[] $ids */
+            $ids = [];
+            /** @var Share[] $shareMap */
+            $shareMap = [];
+
+            foreach ($shareSlice as $share) {
+                $ids[] = (int)$share->getId();
+                $shareMap[$share->getId()] = $share;
+            }
+
+            $qb = $this->dbConn->getQueryBuilder();
+
+            $query = $qb->select('*')
+                ->from('share')
+                ->where($qb->expr()->in('parent', $qb->createNamedParameter($ids, IQueryBuilder::PARAM_INT_ARRAY)))
+                ->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($userId)))
+                ->andWhere($qb->expr()->orX(
+                    $qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
+                    $qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
+                ));
+
+            $stmt = $query->execute();
+
+            while ($data = $stmt->fetch()) {
+                $shareMap[$data['parent']]->setPermissions((int)$data['permissions']);
+                $shareMap[$data['parent']]->setStatus((int)$data['accepted']);
+                $shareMap[$data['parent']]->setTarget($data['file_target']);
+                $shareMap[$data['parent']]->setParent($data['parent']);
+            }
+
+            $stmt->closeCursor();
+
+            foreach ($shareMap as $share) {
+                $result[] = $share;
+            }
+        }
+
+        return $result;
+    }
+
+    /**
+     * A user is deleted from the system
+     * So clean up the relevant shares.
+     *
+     * @param string $uid
+     * @param int $shareType
+     */
+    public function userDeleted($uid, $shareType) {
+        $qb = $this->dbConn->getQueryBuilder();
+
+        $qb->delete('share');
+
+        if ($shareType === \OCP\Share::SHARE_TYPE_USER) {
+            /*
 			 * Delete all user shares that are owned by this user
 			 * or that are received by this user
 			 */
 
-			$qb->where($qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_USER)));
+            $qb->where($qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_USER)));
 
-			$qb->andWhere(
-				$qb->expr()->orX(
-					$qb->expr()->eq('uid_owner', $qb->createNamedParameter($uid)),
-					$qb->expr()->eq('share_with', $qb->createNamedParameter($uid))
-				)
-			);
-		} elseif ($shareType === \OCP\Share::SHARE_TYPE_GROUP) {
-			/*
+            $qb->andWhere(
+                $qb->expr()->orX(
+                    $qb->expr()->eq('uid_owner', $qb->createNamedParameter($uid)),
+                    $qb->expr()->eq('share_with', $qb->createNamedParameter($uid))
+                )
+            );
+        } elseif ($shareType === \OCP\Share::SHARE_TYPE_GROUP) {
+            /*
 			 * Delete all group shares that are owned by this user
 			 * Or special user group shares that are received by this user
 			 */
-			$qb->where(
-				$qb->expr()->andX(
-					$qb->expr()->orX(
-						$qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_GROUP)),
-						$qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP))
-					),
-					$qb->expr()->eq('uid_owner', $qb->createNamedParameter($uid))
-				)
-			);
-
-			$qb->orWhere(
-				$qb->expr()->andX(
-					$qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP)),
-					$qb->expr()->eq('share_with', $qb->createNamedParameter($uid))
-				)
-			);
-		} elseif ($shareType === \OCP\Share::SHARE_TYPE_LINK) {
-			/*
+            $qb->where(
+                $qb->expr()->andX(
+                    $qb->expr()->orX(
+                        $qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_GROUP)),
+                        $qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP))
+                    ),
+                    $qb->expr()->eq('uid_owner', $qb->createNamedParameter($uid))
+                )
+            );
+
+            $qb->orWhere(
+                $qb->expr()->andX(
+                    $qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP)),
+                    $qb->expr()->eq('share_with', $qb->createNamedParameter($uid))
+                )
+            );
+        } elseif ($shareType === \OCP\Share::SHARE_TYPE_LINK) {
+            /*
 			 * Delete all link shares owned by this user.
 			 * And all link shares initiated by this user (until #22327 is in)
 			 */
-			$qb->where($qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_LINK)));
-
-			$qb->andWhere(
-				$qb->expr()->orX(
-					$qb->expr()->eq('uid_owner', $qb->createNamedParameter($uid)),
-					$qb->expr()->eq('uid_initiator', $qb->createNamedParameter($uid))
-				)
-			);
-		} else {
-			\OC::$server->getLogger()->logException(new \InvalidArgumentException('Default share provider tried to delete all shares for type: ' . $shareType));
-			return;
-		}
-
-		$qb->execute();
-	}
-
-	/**
-	 * Delete all shares received by this group. As well as any custom group
-	 * shares for group members.
-	 *
-	 * @param string $gid
-	 */
-	public function groupDeleted($gid) {
-		/*
+            $qb->where($qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_LINK)));
+
+            $qb->andWhere(
+                $qb->expr()->orX(
+                    $qb->expr()->eq('uid_owner', $qb->createNamedParameter($uid)),
+                    $qb->expr()->eq('uid_initiator', $qb->createNamedParameter($uid))
+                )
+            );
+        } else {
+            \OC::$server->getLogger()->logException(new \InvalidArgumentException('Default share provider tried to delete all shares for type: ' . $shareType));
+            return;
+        }
+
+        $qb->execute();
+    }
+
+    /**
+     * Delete all shares received by this group. As well as any custom group
+     * shares for group members.
+     *
+     * @param string $gid
+     */
+    public function groupDeleted($gid) {
+        /*
 		 * First delete all custom group shares for group members
 		 */
-		$qb = $this->dbConn->getQueryBuilder();
-		$qb->select('id')
-			->from('share')
-			->where($qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_GROUP)))
-			->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($gid)));
-
-		$cursor = $qb->execute();
-		$ids = [];
-		while ($row = $cursor->fetch()) {
-			$ids[] = (int)$row['id'];
-		}
-		$cursor->closeCursor();
-
-		if (!empty($ids)) {
-			$chunks = array_chunk($ids, 100);
-			foreach ($chunks as $chunk) {
-				$qb->delete('share')
-					->where($qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP)))
-					->andWhere($qb->expr()->in('parent', $qb->createNamedParameter($chunk, IQueryBuilder::PARAM_INT_ARRAY)));
-				$qb->execute();
-			}
-		}
-
-		/*
+        $qb = $this->dbConn->getQueryBuilder();
+        $qb->select('id')
+            ->from('share')
+            ->where($qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_GROUP)))
+            ->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($gid)));
+
+        $cursor = $qb->execute();
+        $ids = [];
+        while ($row = $cursor->fetch()) {
+            $ids[] = (int)$row['id'];
+        }
+        $cursor->closeCursor();
+
+        if (!empty($ids)) {
+            $chunks = array_chunk($ids, 100);
+            foreach ($chunks as $chunk) {
+                $qb->delete('share')
+                    ->where($qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP)))
+                    ->andWhere($qb->expr()->in('parent', $qb->createNamedParameter($chunk, IQueryBuilder::PARAM_INT_ARRAY)));
+                $qb->execute();
+            }
+        }
+
+        /*
 		 * Now delete all the group shares
 		 */
-		$qb = $this->dbConn->getQueryBuilder();
-		$qb->delete('share')
-			->where($qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_GROUP)))
-			->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($gid)));
-		$qb->execute();
-	}
-
-	/**
-	 * Delete custom group shares to this group for this user
-	 *
-	 * @param string $uid
-	 * @param string $gid
-	 */
-	public function userDeletedFromGroup($uid, $gid) {
-		/*
+        $qb = $this->dbConn->getQueryBuilder();
+        $qb->delete('share')
+            ->where($qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_GROUP)))
+            ->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($gid)));
+        $qb->execute();
+    }
+
+    /**
+     * Delete custom group shares to this group for this user
+     *
+     * @param string $uid
+     * @param string $gid
+     */
+    public function userDeletedFromGroup($uid, $gid) {
+        /*
 		 * Get all group shares
 		 */
-		$qb = $this->dbConn->getQueryBuilder();
-		$qb->select('id')
-			->from('share')
-			->where($qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_GROUP)))
-			->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($gid)));
-
-		$cursor = $qb->execute();
-		$ids = [];
-		while ($row = $cursor->fetch()) {
-			$ids[] = (int)$row['id'];
-		}
-		$cursor->closeCursor();
-
-		if (!empty($ids)) {
-			$chunks = array_chunk($ids, 100);
-			foreach ($chunks as $chunk) {
-				/*
+        $qb = $this->dbConn->getQueryBuilder();
+        $qb->select('id')
+            ->from('share')
+            ->where($qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_GROUP)))
+            ->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($gid)));
+
+        $cursor = $qb->execute();
+        $ids = [];
+        while ($row = $cursor->fetch()) {
+            $ids[] = (int)$row['id'];
+        }
+        $cursor->closeCursor();
+
+        if (!empty($ids)) {
+            $chunks = array_chunk($ids, 100);
+            foreach ($chunks as $chunk) {
+                /*
 				 * Delete all special shares wit this users for the found group shares
 				 */
-				$qb->delete('share')
-					->where($qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP)))
-					->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($uid)))
-					->andWhere($qb->expr()->in('parent', $qb->createNamedParameter($chunk, IQueryBuilder::PARAM_INT_ARRAY)));
-				$qb->execute();
-			}
-		}
-	}
-
-	/**
-	 * @inheritdoc
-	 */
-	public function getAccessList($nodes, $currentAccess) {
-		$ids = [];
-		foreach ($nodes as $node) {
-			$ids[] = $node->getId();
-		}
-
-		$qb = $this->dbConn->getQueryBuilder();
-
-		$or = $qb->expr()->orX(
-			$qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_USER)),
-			$qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_GROUP)),
-			$qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_LINK))
-		);
-
-		if ($currentAccess) {
-			$or->add($qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP)));
-		}
-
-		$qb->select('id', 'parent', 'share_type', 'share_with', 'file_source', 'file_target', 'permissions')
-			->from('share')
-			->where(
-				$or
-			)
-			->andWhere($qb->expr()->in('file_source', $qb->createNamedParameter($ids, IQueryBuilder::PARAM_INT_ARRAY)))
-			->andWhere($qb->expr()->orX(
-				$qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
-				$qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
-			));
-		$cursor = $qb->execute();
-
-		$users = [];
-		$link = false;
-		while ($row = $cursor->fetch()) {
-			$type = (int)$row['share_type'];
-			if ($type === \OCP\Share::SHARE_TYPE_USER) {
-				$uid = $row['share_with'];
-				$users[$uid] = isset($users[$uid]) ? $users[$uid] : [];
-				$users[$uid][$row['id']] = $row;
-			} elseif ($type === \OCP\Share::SHARE_TYPE_GROUP) {
-				$gid = $row['share_with'];
-				$group = $this->groupManager->get($gid);
-
-				if ($group === null) {
-					continue;
-				}
-
-				$userList = $group->getUsers();
-				foreach ($userList as $user) {
-					$uid = $user->getUID();
-					$users[$uid] = isset($users[$uid]) ? $users[$uid] : [];
-					$users[$uid][$row['id']] = $row;
-				}
-			} elseif ($type === \OCP\Share::SHARE_TYPE_LINK) {
-				$link = true;
-			} elseif ($type === self::SHARE_TYPE_USERGROUP && $currentAccess === true) {
-				$uid = $row['share_with'];
-				$users[$uid] = isset($users[$uid]) ? $users[$uid] : [];
-				$users[$uid][$row['id']] = $row;
-			}
-		}
-		$cursor->closeCursor();
-
-		if ($currentAccess === true) {
-			$users = array_map([$this, 'filterSharesOfUser'], $users);
-			$users = array_filter($users);
-		} else {
-			$users = array_keys($users);
-		}
-
-		return ['users' => $users, 'public' => $link];
-	}
-
-	/**
-	 * For each user the path with the fewest slashes is returned
-	 * @param array $shares
-	 * @return array
-	 */
-	protected function filterSharesOfUser(array $shares) {
-		// Group shares when the user has a share exception
-		foreach ($shares as $id => $share) {
-			$type = (int) $share['share_type'];
-			$permissions = (int) $share['permissions'];
-
-			if ($type === self::SHARE_TYPE_USERGROUP) {
-				unset($shares[$share['parent']]);
-
-				if ($permissions === 0) {
-					unset($shares[$id]);
-				}
-			}
-		}
-
-		$best = [];
-		$bestDepth = 0;
-		foreach ($shares as $id => $share) {
-			$depth = substr_count($share['file_target'], '/');
-			if (empty($best) || $depth < $bestDepth) {
-				$bestDepth = $depth;
-				$best = [
-					'node_id' => $share['file_source'],
-					'node_path' => $share['file_target'],
-				];
-			}
-		}
-
-		return $best;
-	}
-
-	/**
-	 * propagate notes to the recipients
-	 *
-	 * @param IShare $share
-	 * @throws \OCP\Files\NotFoundException
-	 */
-	private function propagateNote(IShare $share) {
-		if ($share->getShareType() === \OCP\Share::SHARE_TYPE_USER) {
-			$user = $this->userManager->get($share->getSharedWith());
-			$this->sendNote([$user], $share);
-		} elseif ($share->getShareType() === \OCP\Share::SHARE_TYPE_GROUP) {
-			$group = $this->groupManager->get($share->getSharedWith());
-			$groupMembers = $group->getUsers();
-			$this->sendNote($groupMembers, $share);
-		}
-	}
-
-	/**
-	 * send note by mail
-	 *
-	 * @param array $recipients
-	 * @param IShare $share
-	 * @throws \OCP\Files\NotFoundException
-	 */
-	private function sendNote(array $recipients, IShare $share) {
-		$toList = [];
-
-		foreach ($recipients as $recipient) {
-			/** @var IUser $recipient */
-			$email = $recipient->getEMailAddress();
-			if ($email) {
-				$toList[$email] = $recipient->getDisplayName();
-			}
-		}
-
-		if (!empty($toList)) {
-			$filename = $share->getNode()->getName();
-			$initiator = $share->getSharedBy();
-			$note = $share->getNote();
-
-			$initiatorUser = $this->userManager->get($initiator);
-			$initiatorDisplayName = ($initiatorUser instanceof IUser) ? $initiatorUser->getDisplayName() : $initiator;
-			$initiatorEmailAddress = ($initiatorUser instanceof IUser) ? $initiatorUser->getEMailAddress() : null;
-			$plainHeading = $this->l->t('%1$s shared »%2$s« with you and wants to add:', [$initiatorDisplayName, $filename]);
-			$htmlHeading = $this->l->t('%1$s shared »%2$s« with you and wants to add', [$initiatorDisplayName, $filename]);
-			$message = $this->mailer->createMessage();
-
-			$emailTemplate = $this->mailer->createEMailTemplate('defaultShareProvider.sendNote');
-
-			$emailTemplate->setSubject($this->l->t('»%s« added a note to a file shared with you', [$initiatorDisplayName]));
-			$emailTemplate->addHeader();
-			$emailTemplate->addHeading($htmlHeading, $plainHeading);
-			$emailTemplate->addBodyText(htmlspecialchars($note), $note);
-
-			$link = $this->urlGenerator->linkToRouteAbsolute('files.viewcontroller.showFile', ['fileid' => $share->getNode()->getId()]);
-			$emailTemplate->addBodyButton(
-				$this->l->t('Open »%s«', [$filename]),
-				$link
-			);
-
-
-			// The "From" contains the sharers name
-			$instanceName = $this->defaults->getName();
-			$senderName = $this->l->t(
-				'%1$s via %2$s',
-				[
-					$initiatorDisplayName,
-					$instanceName
-				]
-			);
-			$message->setFrom([\OCP\Util::getDefaultEmailAddress($instanceName) => $senderName]);
-			if ($initiatorEmailAddress !== null) {
-				$message->setReplyTo([$initiatorEmailAddress => $initiatorDisplayName]);
-				$emailTemplate->addFooter($instanceName . ' - ' . $this->defaults->getSlogan());
-			} else {
-				$emailTemplate->addFooter();
-			}
-
-			if (count($toList) === 1) {
-				$message->setTo($toList);
-			} else {
-				$message->setTo([]);
-				$message->setBcc($toList);
-			}
-			$message->useTemplate($emailTemplate);
-			$this->mailer->send($message);
-		}
-	}
-
-	public function getAllShares(): iterable {
-		$qb = $this->dbConn->getQueryBuilder();
-
-		$qb->select('*')
-			->from('share')
-			->where(
-				$qb->expr()->orX(
-					$qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share\IShare::TYPE_USER)),
-					$qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share\IShare::TYPE_GROUP)),
-					$qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share\IShare::TYPE_LINK))
-				)
-			);
-
-		$cursor = $qb->execute();
-		while ($data = $cursor->fetch()) {
-			try {
-				$share = $this->createShare($data);
-			} catch (InvalidShare $e) {
-				continue;
-			}
-
-			yield $share;
-		}
-		$cursor->closeCursor();
-	}
+                $qb->delete('share')
+                    ->where($qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP)))
+                    ->andWhere($qb->expr()->eq('share_with', $qb->createNamedParameter($uid)))
+                    ->andWhere($qb->expr()->in('parent', $qb->createNamedParameter($chunk, IQueryBuilder::PARAM_INT_ARRAY)));
+                $qb->execute();
+            }
+        }
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function getAccessList($nodes, $currentAccess) {
+        $ids = [];
+        foreach ($nodes as $node) {
+            $ids[] = $node->getId();
+        }
+
+        $qb = $this->dbConn->getQueryBuilder();
+
+        $or = $qb->expr()->orX(
+            $qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_USER)),
+            $qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_GROUP)),
+            $qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share::SHARE_TYPE_LINK))
+        );
+
+        if ($currentAccess) {
+            $or->add($qb->expr()->eq('share_type', $qb->createNamedParameter(self::SHARE_TYPE_USERGROUP)));
+        }
+
+        $qb->select('id', 'parent', 'share_type', 'share_with', 'file_source', 'file_target', 'permissions')
+            ->from('share')
+            ->where(
+                $or
+            )
+            ->andWhere($qb->expr()->in('file_source', $qb->createNamedParameter($ids, IQueryBuilder::PARAM_INT_ARRAY)))
+            ->andWhere($qb->expr()->orX(
+                $qb->expr()->eq('item_type', $qb->createNamedParameter('file')),
+                $qb->expr()->eq('item_type', $qb->createNamedParameter('folder'))
+            ));
+        $cursor = $qb->execute();
+
+        $users = [];
+        $link = false;
+        while ($row = $cursor->fetch()) {
+            $type = (int)$row['share_type'];
+            if ($type === \OCP\Share::SHARE_TYPE_USER) {
+                $uid = $row['share_with'];
+                $users[$uid] = isset($users[$uid]) ? $users[$uid] : [];
+                $users[$uid][$row['id']] = $row;
+            } elseif ($type === \OCP\Share::SHARE_TYPE_GROUP) {
+                $gid = $row['share_with'];
+                $group = $this->groupManager->get($gid);
+
+                if ($group === null) {
+                    continue;
+                }
+
+                $userList = $group->getUsers();
+                foreach ($userList as $user) {
+                    $uid = $user->getUID();
+                    $users[$uid] = isset($users[$uid]) ? $users[$uid] : [];
+                    $users[$uid][$row['id']] = $row;
+                }
+            } elseif ($type === \OCP\Share::SHARE_TYPE_LINK) {
+                $link = true;
+            } elseif ($type === self::SHARE_TYPE_USERGROUP && $currentAccess === true) {
+                $uid = $row['share_with'];
+                $users[$uid] = isset($users[$uid]) ? $users[$uid] : [];
+                $users[$uid][$row['id']] = $row;
+            }
+        }
+        $cursor->closeCursor();
+
+        if ($currentAccess === true) {
+            $users = array_map([$this, 'filterSharesOfUser'], $users);
+            $users = array_filter($users);
+        } else {
+            $users = array_keys($users);
+        }
+
+        return ['users' => $users, 'public' => $link];
+    }
+
+    /**
+     * For each user the path with the fewest slashes is returned
+     * @param array $shares
+     * @return array
+     */
+    protected function filterSharesOfUser(array $shares) {
+        // Group shares when the user has a share exception
+        foreach ($shares as $id => $share) {
+            $type = (int) $share['share_type'];
+            $permissions = (int) $share['permissions'];
+
+            if ($type === self::SHARE_TYPE_USERGROUP) {
+                unset($shares[$share['parent']]);
+
+                if ($permissions === 0) {
+                    unset($shares[$id]);
+                }
+            }
+        }
+
+        $best = [];
+        $bestDepth = 0;
+        foreach ($shares as $id => $share) {
+            $depth = substr_count($share['file_target'], '/');
+            if (empty($best) || $depth < $bestDepth) {
+                $bestDepth = $depth;
+                $best = [
+                    'node_id' => $share['file_source'],
+                    'node_path' => $share['file_target'],
+                ];
+            }
+        }
+
+        return $best;
+    }
+
+    /**
+     * propagate notes to the recipients
+     *
+     * @param IShare $share
+     * @throws \OCP\Files\NotFoundException
+     */
+    private function propagateNote(IShare $share) {
+        if ($share->getShareType() === \OCP\Share::SHARE_TYPE_USER) {
+            $user = $this->userManager->get($share->getSharedWith());
+            $this->sendNote([$user], $share);
+        } elseif ($share->getShareType() === \OCP\Share::SHARE_TYPE_GROUP) {
+            $group = $this->groupManager->get($share->getSharedWith());
+            $groupMembers = $group->getUsers();
+            $this->sendNote($groupMembers, $share);
+        }
+    }
+
+    /**
+     * send note by mail
+     *
+     * @param array $recipients
+     * @param IShare $share
+     * @throws \OCP\Files\NotFoundException
+     */
+    private function sendNote(array $recipients, IShare $share) {
+        $toList = [];
+
+        foreach ($recipients as $recipient) {
+            /** @var IUser $recipient */
+            $email = $recipient->getEMailAddress();
+            if ($email) {
+                $toList[$email] = $recipient->getDisplayName();
+            }
+        }
+
+        if (!empty($toList)) {
+            $filename = $share->getNode()->getName();
+            $initiator = $share->getSharedBy();
+            $note = $share->getNote();
+
+            $initiatorUser = $this->userManager->get($initiator);
+            $initiatorDisplayName = ($initiatorUser instanceof IUser) ? $initiatorUser->getDisplayName() : $initiator;
+            $initiatorEmailAddress = ($initiatorUser instanceof IUser) ? $initiatorUser->getEMailAddress() : null;
+            $plainHeading = $this->l->t('%1$s shared »%2$s« with you and wants to add:', [$initiatorDisplayName, $filename]);
+            $htmlHeading = $this->l->t('%1$s shared »%2$s« with you and wants to add', [$initiatorDisplayName, $filename]);
+            $message = $this->mailer->createMessage();
+
+            $emailTemplate = $this->mailer->createEMailTemplate('defaultShareProvider.sendNote');
+
+            $emailTemplate->setSubject($this->l->t('»%s« added a note to a file shared with you', [$initiatorDisplayName]));
+            $emailTemplate->addHeader();
+            $emailTemplate->addHeading($htmlHeading, $plainHeading);
+            $emailTemplate->addBodyText(htmlspecialchars($note), $note);
+
+            $link = $this->urlGenerator->linkToRouteAbsolute('files.viewcontroller.showFile', ['fileid' => $share->getNode()->getId()]);
+            $emailTemplate->addBodyButton(
+                $this->l->t('Open »%s«', [$filename]),
+                $link
+            );
+
+
+            // The "From" contains the sharers name
+            $instanceName = $this->defaults->getName();
+            $senderName = $this->l->t(
+                '%1$s via %2$s',
+                [
+                    $initiatorDisplayName,
+                    $instanceName
+                ]
+            );
+            $message->setFrom([\OCP\Util::getDefaultEmailAddress($instanceName) => $senderName]);
+            if ($initiatorEmailAddress !== null) {
+                $message->setReplyTo([$initiatorEmailAddress => $initiatorDisplayName]);
+                $emailTemplate->addFooter($instanceName . ' - ' . $this->defaults->getSlogan());
+            } else {
+                $emailTemplate->addFooter();
+            }
+
+            if (count($toList) === 1) {
+                $message->setTo($toList);
+            } else {
+                $message->setTo([]);
+                $message->setBcc($toList);
+            }
+            $message->useTemplate($emailTemplate);
+            $this->mailer->send($message);
+        }
+    }
+
+    public function getAllShares(): iterable {
+        $qb = $this->dbConn->getQueryBuilder();
+
+        $qb->select('*')
+            ->from('share')
+            ->where(
+                $qb->expr()->orX(
+                    $qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share\IShare::TYPE_USER)),
+                    $qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share\IShare::TYPE_GROUP)),
+                    $qb->expr()->eq('share_type', $qb->createNamedParameter(\OCP\Share\IShare::TYPE_LINK))
+                )
+            );
+
+        $cursor = $qb->execute();
+        while ($data = $cursor->fetch()) {
+            try {
+                $share = $this->createShare($data);
+            } catch (InvalidShare $e) {
+                continue;
+            }
+
+            yield $share;
+        }
+        $cursor->closeCursor();
+    }
 }