From a0e91fbf7b4b69d9239bafb866dd5c7362a5b2c6 Mon Sep 17 00:00:00 2001
From: Jonathan Treffler <jonathan.treffler@verdigado.com>
Date: Wed, 24 Jan 2024 20:57:47 +0100
Subject: [PATCH] added DiffTaskResultService, including revert logic

---
 lib/Exceptions/AlreadyRevertedException.php   |   9 ++
 .../ChangesMadeSinceDiffException.php         |   9 ++
 lib/Service/DiffTaskResultService.php         | 145 ++++++++++++++++++
 3 files changed, 163 insertions(+)
 create mode 100644 lib/Exceptions/AlreadyRevertedException.php
 create mode 100644 lib/Exceptions/ChangesMadeSinceDiffException.php
 create mode 100644 lib/Service/DiffTaskResultService.php

diff --git a/lib/Exceptions/AlreadyRevertedException.php b/lib/Exceptions/AlreadyRevertedException.php
new file mode 100644
index 0000000..24a2ff7
--- /dev/null
+++ b/lib/Exceptions/AlreadyRevertedException.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace OCA\GroupfolderFilesystemSnapshots\Exceptions;
+
+class AlreadyRevertedException extends \RuntimeException {
+	public function __construct(string $message = 'Diff task result has already been reverted.') {
+		parent::__construct($message);
+	}
+}
diff --git a/lib/Exceptions/ChangesMadeSinceDiffException.php b/lib/Exceptions/ChangesMadeSinceDiffException.php
new file mode 100644
index 0000000..ba27abe
--- /dev/null
+++ b/lib/Exceptions/ChangesMadeSinceDiffException.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace OCA\GroupfolderFilesystemSnapshots\Exceptions;
+
+class ChangesMadeSinceDiffException extends \RuntimeException {
+	public function __construct(string $message = 'Conflicting changes have been made to the files, since the restore process started') {
+		parent::__construct($message);
+	}
+}
diff --git a/lib/Service/DiffTaskResultService.php b/lib/Service/DiffTaskResultService.php
new file mode 100644
index 0000000..399185b
--- /dev/null
+++ b/lib/Service/DiffTaskResultService.php
@@ -0,0 +1,145 @@
+<?php
+namespace OCA\GroupfolderFilesystemSnapshots\Service;
+
+use Exception;
+
+use OCP\AppFramework\Db\DoesNotExistException;
+use OCP\AppFramework\Db\MultipleObjectsReturnedException;
+
+use OCA\GroupfolderFilesystemSnapshots\Exceptions\NotFoundException;
+use OCA\GroupfolderFilesystemSnapshots\Exceptions\AlreadyRevertedException;
+use OCA\GroupfolderFilesystemSnapshots\Exceptions\ChangesMadeSinceDiffException;
+
+use OCA\GroupfolderFilesystemSnapshots\Db\DiffTaskResult;
+use OCA\GroupfolderFilesystemSnapshots\Db\DiffTaskResultMapper;
+use OCA\GroupfolderFilesystemSnapshots\Db\DiffTaskMapper;
+use OCA\GroupfolderFilesystemSnapshots\Manager\PathManager;
+
+class DiffTaskResultService {
+
+    private DiffTaskResultMapper $mapper;
+	private DiffTaskMapper $diffTaskMapper;
+	private PathManager $pathManager;
+
+    public function __construct(DiffTaskResultMapper $mapper, DiffTaskMapper $diffTaskMapper, PathManager $pathManager){
+        $this->mapper = $mapper;
+		$this->diffTaskMapper = $diffTaskMapper;
+		$this->pathManager = $pathManager;
+    }
+
+    /**
+     * @return DiffTaskResult[]
+     */
+    public function findAll(int $taskId): array {
+        return $this->mapper->findAll($taskId);
+    }
+
+    /**
+     * @return never
+     */
+    private function handleException ($e, $criteria) {
+        if ($e instanceof DoesNotExistException ||
+            $e instanceof MultipleObjectsReturnedException) {
+            throw new NotFoundException($e->getMessage(), $criteria);
+        } else {
+            throw $e;
+        }
+    }
+
+    public function find(int $id): DiffTaskResult {
+        try {
+            return $this->mapper->find($id);
+        } catch(Exception $e) {
+            $this->handleException($e, ["id" => $id]);
+        }
+    }
+
+	public function revert(int $id, string $userId) {
+		$diffTaskResult = $this->find($id);
+
+		if($diffTaskResult->getReverted()) {
+			throw new AlreadyRevertedException;
+		}
+
+		$taskId = $diffTaskResult->getTaskId();
+		$diffTask = $this->diffTaskMapper->find($taskId, $userId);
+
+		$snapshotPath = $this->pathManager->getGroupFolderSnapshotDirectory($diffTask->getGroupfolderId(), $diffTask->getRelativePath(), $diffTask->getSnapshotId());
+		
+		$gruenerFolder = $this->pathManager->getGroupfolderMountById($diffTask->getGroupfolderId())->get($diffTask->getRelativePath());
+
+		switch($diffTaskResult->getType()) {
+			case "CREATION":
+				$currentFile = $this->getSubfolderMustExist($gruenerFolder, $diffTaskResult->getCurrentPath());
+				$currentFile->delete();
+				break;
+			case "RENAME":
+				$currentFile = $this->getSubfolderMustExist($gruenerFolder, $diffTaskResult->getCurrentPath());
+				$beforeDirectory = $this->getOrCreateSubdirectoryByFilepath($gruenerFolder, $diffTaskResult->getBeforePath());
+
+				$currentFile->move($beforeDirectory->getPath() . DIRECTORY_SEPARATOR . basename($diffTaskResult->getBeforePath()));
+				break;
+			case "DELETION":
+				$beforeFileFilesystemPath = $snapshotPath . DIRECTORY_SEPARATOR . $diffTaskResult->getBeforePath();
+
+				$beforeDirectory = $this->getOrCreateSubdirectoryByFilepath($gruenerFolder, $diffTaskResult->getBeforePath());
+				$restoredFile = $beforeDirectory->newFile(basename($diffTaskResult->getBeforePath()));
+
+				$this->copyFilesystemFileToNextcloudFile($beforeFileFilesystemPath, $restoredFile);
+				break;
+			case "EDIT":
+				$currentFile = $this->getSubfolderMustExist($gruenerFolder, $diffTaskResult->getCurrentPath());
+				$beforeFileFilesystemPath = $snapshotPath . DIRECTORY_SEPARATOR . $diffTaskResult->getBeforePath();
+
+				$this->copyFilesystemFileToNextcloudFile($beforeFileFilesystemPath, $currentFile);
+				break;
+			default:
+				throw new \Exception;
+		}
+
+		return $this->mapper->markReverted($id);
+	}
+
+	private function getSubfolderMustExist(\OCP\Files\Folder $parent, string $path) {
+		if($parent->nodeExists($path)) {
+			return $parent->get($path);
+		} else {
+			throw new ChangesMadeSinceDiffException;
+		}
+	}
+
+	private function getOrCreateSubdirectoryByFilepath(\OCP\Files\Folder $parent, string $filepath) {
+		$pathSplit = explode('/', trim($filepath, '/'));
+		array_pop($pathSplit);
+
+		$beforeDirectory = $parent;
+		foreach($pathSplit as $subdir) {
+			if($beforeDirectory->nodeExists($subdir)) {
+				$temp = $beforeDirectory->get($subdir);
+				if($temp instanceof \OCP\Files\Folder) {
+					$beforeDirectory = $temp;
+				} else {
+					throw new ChangesMadeSinceDiffException;
+				}
+			} else {
+				$beforeDirectory = $beforeDirectory->newFolder($subdir);
+			}
+		}
+
+		return $beforeDirectory;
+	}
+
+	private function copyFilesystemFileToNextcloudFile(string $filesystemPath, \OCP\Files\File $nextcloudFile) {
+		$snapshotFileStream = fopen($filesystemPath, 'r');
+		$snapshotFileMtime = filemtime($filesystemPath);
+
+		$restoredFileStream = $nextcloudFile->fopen('w');
+
+		stream_copy_to_stream($snapshotFileStream, $restoredFileStream);
+
+		fclose($snapshotFileStream);
+		fclose($restoredFileStream);
+
+		$nextcloudFile->touch($snapshotFileMtime);
+	}
+}
\ No newline at end of file