WIP: fix(isLegitimatedForUserId): Setup mountpoints to check file access

This fixes workflows on groupfolders, as it will consider access to
files in groupfolders.

It also fixes false positives where access to files was limited by other
means not taken into account before, e.g. access control.

Fixes: nextcloud/flow_notifications#71

TODO:
* [ ] Remove obsolete code that uses `shareManager`
* [ ] Maybe also remove check for file owner (?)

Signed-off-by: Jonas <jonas@freesources.org>

apps/workflowengine/lib/Entity/File.php

@@ -26,6 +26,7 @@
  */
 namespace OCA\WorkflowEngine\Entity;
 
+use OC\Files\Config\UserMountCache;
 use OCP\EventDispatcher\Event;
 use OCP\EventDispatcher\GenericEvent;
 use OCP\Files\InvalidPathException;
@@ -77,6 +78,8 @@ class File implements IEntity, IDisplayText, IUrl, IIcon, IContextPortation {
 	private $actingUser = null;
 	/** @var IUserManager */
 	private $userManager;
+	/** @var UserMountCache */
+	private $userMountCache;
 
 	public function __construct(
 		IL10N $l10n,
@@ -86,7 +89,8 @@ public function __construct(
 		ShareManager $shareManager,
 		IUserSession $userSession,
 		ISystemTagManager $tagManager,
-		IUserManager $userManager
+		IUserManager $userManager,
+		UserMountCache $userMountCache
 	) {
 		$this->l10n = $l10n;
 		$this->urlGenerator = $urlGenerator;
@@ -96,6 +100,7 @@ public function __construct(
 		$this->userSession = $userSession;
 		$this->tagManager = $tagManager;
 		$this->userManager = $userManager;
+		$this->userMountCache = $userMountCache;
 	}
 
 	public function getName(): string {
@@ -137,11 +142,32 @@ public function prepareRuleMatcher(IRuleMatcher $ruleMatcher, string $eventName,
 	public function isLegitimatedForUserId(string $uid): bool {
 		try {
 			$node = $this->getNode();
+			// Is owner
 			if ($node->getOwner()->getUID() === $uid) {
 				return true;
 			}
+			// Has access to file
+			$fileId = $node->getId();
+			$mounts = $this->userMountCache->getMountsForFileId($fileId);
+			foreach ($mounts as $mount) {
+				$mountUID = $mount->getUser()->getUID();
+				if ($mountUID !== $uid) {
+					continue;
+				}
+
+				$userFolder = $this->root->getUserFolder($uid);
+				if (!empty($userFolder->getById($fileId))) {
+					return true;
+				}
+			}
+			// Has access to share
+			/*
 			$acl = $this->shareManager->getAccessList($node, true, true);
-			return isset($acl['users']) && array_key_exists($uid, $acl['users']);
+			if (isset($acl['users']) && array_key_exists($uid, $acl['users'])) {
+				return true;
+			}
+			*/
+			return false;
 		} catch (NotFoundException $e) {
 			return false;
 		}