OCA\Ocr\Service\OcrService

Complexity

Total Complexity

50

Size/Duplication

Total Lines	391
Duplicated Lines	2.05 %

Coupling/Cohesion

Components	1
Dependencies	4

Test Coverage

Coverage

15.53%

Importance

Changes

0

13 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	10	1
C	listLanguages()	0	27	7
C	process()	0	38	7
A	status()	0	14	2
A	complete()	0	14	3
C	handleProcessed()	0	25	7
A	handleFailed()	0	15	3
A	buildNewName()	0	15	2
B	buildFileInfo()	0	20	6
A	checkMimeType()	0	10	4
A	getCorrectPath()	0	12	3
A	sendGearmanJob()	0	23	3
A	handleException()	8	8	2

<?php
/**
 * nextCloud - ocr
 *
 * This file is licensed under the Affero General Public License version 3 or
 * later. See the COPYING file.
 *
 * @author Janis Koehr <janiskoehr@icloud.com>
 * @copyright Janis Koehr 2016
 */

namespace OCA\Ocr\Service;

use Exception;
use OC\Files\View;
use OCA\Ocr\Db\OcrStatus;
use OCA\Ocr\Db\OcrStatusMapper;
use OCP\Files;
use OCP\Files\FileInfo;
use OCP\IConfig;
use OCP\IL10N;
use OCP\ILogger;
use OCP\ITempManager;


/**
 * Class OcrService
 * @package OCA\Ocr\Service
 */
class OcrService {

	/**
	 * @var ILogger
	 */
	private $logger;

	/**
	 * @var ITempManager
	 */
	private $tempM;

	/**
	 * @var IConfig
	 */
	private $config;

	/**
	 * @var GearmanWorkerService
	 */
	private $workerService;

	/**
	 * @var OcrStatusMapper
	 */
	private $statusMapper;

	/**
	 * @var View
	 */
	private $view;

	/**
	 * @var
	 */
	private $userId;

	/**
	 * @var IL10N
	 */
	private $l10n;

	/**
	 * Array of allowed mimetypes for ocr processing
	 */
	const ALLOWED_MIMETYPES = ['application/pdf', 'image/png', 'image/jpeg', 'image/tiff'];

	/**
	 * the correct mimetype for a pdf file
	 */
	const MIMETYPE_PDF = 'application/pdf';

	/**
	 * the only allowed image mimetypes by tesseract
	 */
	const MIMETYPES_IMAGE = ['image/png', 'image/jpeg', 'image/tiff'];

	/**
	 * OcrService constructor.
	 *
	 * @param ITempManager $tempManager
	 * @param IConfig $config
	 * @param GearmanWorkerService $workerService
	 * @param OcrStatusMapper $mapper
	 * @param View $view
	 * @param $userId
	 * @param IL10N $l10n
	 * @param ILogger $logger
	 */
	public function __construct(ITempManager $tempManager, IConfig $config, GearmanWorkerService $workerService, OcrStatusMapper $mapper, View $view, $userId, IL10N $l10n, ILogger $logger) {
		$this->logger = $logger;
		$this->tempM = $tempManager;
		$this->config = $config;
		$this->workerService = $workerService;
		$this->statusMapper = $mapper;
		$this->view = $view;
		$this->userId = $userId;
		$this->l10n = $l10n;
	}

	/**
	 * Gets the list of all available tesseract-ocr languages.
	 *
	 * @return array Languages
	 */
	public function listLanguages() {
		try {
			$success = -1;
			$this->logger->debug('Fetching languages. ', ['app' => 'ocr']);
			exec('tesseract --list-langs 2>&1', $result, $success);
			if ($success === 0 && count($result) > 0) {
				if (is_array($result)) {
					$traineddata = $result;
				} else {
					$traineddata = explode(' ', $result);
				}
				$languages = array();
				foreach ($traineddata as $td) {
					$tdname = trim($td);
					if (strlen($tdname) === 3) {
						array_push($languages, $tdname);
					}
				}
				$this->logger->debug('Fetched languages: ' . json_encode($languages), ['app' => 'ocr']);
				return $languages;
			} else {
				throw new NotFoundException($this->l10n->t('No languages found.'));
			}
		} catch (Exception $e) {
			$this->handleException($e);
		}
	}

	/**
	 * Processes and prepares the files for ocr.
	 * Sends the stuff to the gearman client in order to ocr async.
	 *
	 * @param string $language
	 * @param array $files
	 * @return string
	 */
	public function process($language, $files) {
		try {
			$this->logger->debug('Will now process files: ' . json_encode($files) . ' with language: ' . json_encode($language), ['app' => 'ocr']);
			// Check if files and language not empty
			if (!empty($files) && !empty($language) && in_array($language, $this->listLanguages())) {
				// get the array with full fileinfo
				$fileInfo = $this->buildFileInfo($files);
				foreach ($fileInfo as $fInfo) {
					// Check if filelock existing
					// TODO: FileLock maybe \OC\Files\View::lockFile()
					// get new name for saving purpose
					$newName = $this->buildNewName($fInfo);

					// create a temp file for ocr processing purposes
					$tempFile = $this->tempM->getTemporaryFile();

					// set the gearman running type
					if ($fInfo->getMimetype() === $this::MIMETYPE_PDF) {
						$ftype = 'mypdf';
					} else {
						$ftype = 'tess';
					}

					// Create status object
					$status = new OcrStatus('PENDING', $fInfo->getId(), $newName, $tempFile, $ftype, $this->userId);

					// Init Gearman client and send task / job
					// Feed the gearman worker
					$this->sendGearmanJob($ftype, $this->config->getSystemValue('datadirectory'), $fInfo->getPath(), $tempFile, $language, $status, \OC::$SERVERROOT);
				}
				return 'PROCESSING';
			} else {
				throw new NotFoundException($this->l10n->t('Empty passed parameters.'));
			}
		} catch (Exception $e) {
			$this->handleException($e);
		}
	}

	/**
	 * A function which returns the JSONResponse for all required status checks and tasks.
	 * It will check for already processed, pending and failed ocr tasks and return them as needed.
	 *
	 * @return string
	 */
	public function status() {
		try {
			// TODO: release lock
			$processed = $this->handleProcessed();

			$failed = count($this->handleFailed());

			$pending = count($this->statusMapper->findAllPending($this->userId));

			return ['processed' => $processed, 'failed' => $failed, 'pending' => $pending];
		} catch (Exception $e) {
			$this->handleException($e);
		}
	}

	/**
	 * The command ocr:complete for occ will call this function in order to set the status.
	 * the gearman worker should call it automatically after each processing step.
	 *
	 * @param $statusId
	 * @param boolean $failed
	 */
	public function complete($statusId, $failed) {
		try {
			$status = $this->statusMapper->find($statusId);
			if (!$failed) {
				$status->setStatus('PROCESSED');
				$this->statusMapper->update($status);
			} else {
				$status->setStatus('FAILED');
				$this->statusMapper->update($status);
			}
		} catch (Exception $e) {
			$this->handleException($e);
		}
	}

	/**
	 * Finishes all Processed files by copying them to the right path and deleteing the temp files.
	 * Returns the number of processed files.
	 *
	 * @return int
	 */
	private function handleProcessed() {
		try {
			$this->logger->debug('Find processed ocr files and put them to the right dirs.', ['app' => 'ocr']);
			$processed = $this->statusMapper->findAllProcessed($this->userId);
			foreach ($processed as $status) {
				if ($status->getType() === 'tess' && file_exists($status->getTempFile() . '.txt')) {
					//Save the tmp file with newname
					$this->view->file_put_contents($status->getNewName(), file_get_contents($status->getTempFile() . '.txt')); // need .txt because tesseract saves it like this
					// Cleaning temp files
					$this->statusMapper->delete($status);
					exec('rm ' . $status->getTempFile() . '.txt');
				} elseif ($status->getType() === 'mypdf' && file_exists($status->getTempFile())) {
					//Save the tmp file with newname
					$this->view->file_put_contents($status->getNewName(), file_get_contents($status->getTempFile())); // don't need to extend with .pdf / it uses the tmp file to save
					$this->statusMapper->delete($status);
					exec('rm ' . $status->getTempFile());
				} else {
					throw new NotFoundException($this->l10n->t('Temp file does not exist.'));
				}
			}
			return count($processed);
		} catch (Exception $e) {
			$this->handleException($e);
		}
	}

	/**
	 * Handles all failed orders of ocr processing queue and returns the status objects.
	 *
	 * @return array
	 */
	private function handleFailed() {
		try {
			$failed = $this->statusMapper->findAllFailed($this->userId);
			foreach ($failed as $status) {
				// clean the tempfile
				exec('rm ' . $status->getTempFile());
				// clean from db
				$this->statusMapper->delete($status);
			}
			$this->logger->debug('Following status objects failed: ' . json_encode($failed), ['app' => 'ocr']);
			return $failed;
		} catch (Exception $e) {
			$this->handleException($e);
		}
	}


	/**
	 * Returns a not existing file name for pdf or image processing
	 *
	 * @param FileInfo $fileInfo
	 * @return string
	 */
	private function buildNewName(FileInfo $fileInfo) {
		// get rid of the .png or .pdf and so on
		$fileName = substr($fileInfo->getName(), 0, -4);
		// eliminate the file name from the path
		$filePath = str_replace($fileInfo->getName(), '', $fileInfo->getPath());
		// and get the path on top of the user/files/ dir
		$filePath = str_replace('/' . $this->userId . '/files', '', $filePath);
		if ($fileInfo->getMimetype() === $this::MIMETYPE_PDF) {
			// PDFs:
			return Files::buildNotExistingFileName($filePath, $fileName . '_OCR.pdf');
		} else {
			// IMAGES:
			return Files::buildNotExistingFileName($filePath, $fileName . '_OCR.txt');
		}
	}

	/**
	 * Returns the fileInfo for each file in files and checks
	 * if it has a allowed mimetype and some other conditions.
	 *
	 * @param array $files
	 * @return array of Files\FileInfo
	 * @throws NotFoundException
	 */
	private function buildFileInfo(array $files) {
		try {
			$fileArray = array();
			foreach ($files as $file) {
				// Check if anything is missing and file type is correct
				if ((!empty($file['path']) || !empty($file['directory'])) && $file['type'] === 'file') {
					// get correct path
					$path = $this->getCorrectPath($file);
					$fileInfo = $this->view->getFileInfo($path);
					$this->checkMimeType($fileInfo);
					array_push($fileArray, $fileInfo);
				} else {
					throw new NotFoundException($this->l10n->t('Wrong path parameter.'));
				}
			}
			return $fileArray;
		} catch (Exception $e) {
			$this->handleException($e);
		}
	}

	/**
	 * Checks a Mimetype for a specific given FileInfo.
	 * @param Files\FileInfo $fileInfo
	 */
	private function checkMimeType(FileInfo $fileInfo) {
		try {
			if (!$fileInfo || !in_array($fileInfo->getMimetype(), $this::ALLOWED_MIMETYPES)) {
				$this->logger->debug('Getting FileInfo did not work or not included in the ALLOWED_MIMETYPES array.', ['app' => 'ocr']);
				throw new NotFoundException($this->l10n->t('Wrong parameters or wrong mimetype.'));
			}
		} catch (Exception $e) {
			$this->handleException($e);
		}
	}

	/**
	 * Returns the correct path based on delivered file variable
	 * @param $file
	 * @return string
	 */
	private function getCorrectPath($file) {
		if (empty($file['path'])) {
			//Because new updated files have the property directory instead of path
			$file['path'] = $file['directory'];
		}
		if ($file['path'] === '/') {
			$path = '' . '/' . $file['name'];
		} else {
			$path = $file['path'] . '/' . $file['name'];
		}
		return $path;
	}

	/**
	 * Inits the Gearman client and sends the task to the background worker (async)
	 * @param string $type
	 * @param $datadirectory
	 * @param $path
	 * @param $tempFile
	 * @param string $language
	 * @param OcrStatus $status
	 * @param string $occDir
	 */
	private function sendGearmanJob($type, $datadirectory, $path, $tempFile, $language, $status, $occDir) {
		try {
			if ($this->workerService->workerExists() === false) {
				throw new NotFoundException($this->l10n->t('No gearman worker exists.'));
			}
			$this->statusMapper->insert($status);
			// Gearman thing
			$client = new \GearmanClient();
			$client->addServer('127.0.0.1', 4730);
			$result = $client->doBackground("ocr", json_encode(array(
				'type' => $type,
				'datadirectory' => $datadirectory,
				'path' => $path,
				'tempfile' => $tempFile,
				'language' => $language,
				'statusid' => $status->getId(),
				'occdir' => $occDir
			)));
			$this->logger->debug('Gearman Client output: ' . json_encode($result), ['app' => 'ocr']);
		} catch (Exception $e) {
			$this->handleException($e);
		}
	}

	/**
	 * Handle the possible thrown Exceptions from all methods of this class.
	 *
	 * @param Exception $e
	 * @throws Exception
	 * @throws NotFoundException
	 */
	private function handleException($e) {
		$this->logger->logException($e, ['app' => 'ocr', 'message' => 'Exception during ocr service function processing']);
		if ($e instanceof NotFoundException) {
			throw new NotFoundException($e->getMessage());
		} else {
			throw $e;
		}
	}
}