implemented snapshot diff; started work on admin settings

lib/Manager/PathManager.php

@@ -0,0 +1,78 @@
+<?php
+
+namespace OCA\GroupfolderFilesystemSnapshots\Manager;
+
+use OCP\IConfig;
+use OCP\Files\IRootFolder;
+use OCA\GroupFolders\Folder\FolderManager;
+
+class PathManager {
+    private IConfig $config;
+    private IRootFolder $rootFolder;
+    private FolderManager $groupfolderFolderManager;
+
+    const FILESYSTEM_ROOT_PATH = "/srv/nextcloud/files/";
+    const FILESYSTEM_SNAPSHOT_PATH = "/srv/nextcloud/files/.zfs/snapshot/";
+
+    public function __construct(IConfig $config, IRootFolder $rootFolder, FolderManager $manager){
+        $this->config = $config;
+        $this->groupfolderFolderManager = $manager;
+        $this->rootFolder = $rootFolder;
+    }
+
+    public function getFilesystemSnapshotPath() {
+        return self::FILESYSTEM_SNAPSHOT_PATH;
+    }
+
+    // Nextcloud general
+    public function getDataDirectory() {
+        return $this->config->getSystemValue("datadirectory");
+    }
+
+    private function getRootFolderStorageId(): ?int {
+		return $this->rootFolder->getMountPoint()->getNumericStorageId();
+	}
+
+    // Snapshots
+    public function getSnapshotPath(string $snapshotId) {
+        return realpath(self::FILESYSTEM_SNAPSHOT_PATH . DIRECTORY_SEPARATOR . $snapshotId . DIRECTORY_SEPARATOR);
+    }
+
+    public function convertToSnapshotPath(string $filesystemPath, string $snapshotId) {
+        $filesystemPath = realpath($filesystemPath);
+
+        if(!str_starts_with($filesystemPath, self::FILESYSTEM_ROOT_PATH)) {
+            return false;
+        }
+
+        return str_replace(self::FILESYSTEM_ROOT_PATH, $this->getSnapshotPath($snapshotId) . DIRECTORY_SEPARATOR, $filesystemPath);
+    }
+
+    // Groupfolders
+	private function checkIfGroupfolderExists(int $groupfolderId): bool {
+		$storageId = $this->getRootFolderStorageId();
+		if ($storageId === null) {
+			return "storage Id null";
+		}
+
+		$folder = $this->groupfolderFolderManager->getFolder($groupfolderId, $storageId);
+		if ($folder === false) {
+			return "Folder does not exist";
+		}
+        
+		return true;
+	}
+
+    public function getGroupFolderDirectory(int $groupfolderId) {
+        $folderExistsCheck = $this->checkIfGroupfolderExists($groupfolderId);
+		if(!$folderExistsCheck) {
+            return $folderExistsCheck;
+        }
+
+		return realpath($this->getDataDirectory() . DIRECTORY_SEPARATOR . "__groupfolders" . DIRECTORY_SEPARATOR . $groupfolderId . DIRECTORY_SEPARATOR);
+	}
+
+    public function getGroupFolderSnapshotDirectory(int $groupfolderId, string $snapshotId) {
+        return $this->convertToSnapshotPath($this->getGroupFolderDirectory($groupfolderId), $snapshotId);
+    }
+}