owncloud/core

<?php
/**
 * @author Joas Schilling <coding@schilljs.com>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Olivier Paroz <github@oparoz.com>
 * @author Robin McCorkell <robin@mccorkell.me.uk>
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 *
 * @copyright Copyright (c) 2018, ownCloud GmbH
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */
namespace OC\Preview;

use OCP\Files\File;
use OCP\Files\FileInfo;
use OCP\Preview\IProvider2;

abstract class Office implements IProvider2 {
    private $cmd;

    /**
     * {@inheritDoc}
     */
    public function getThumbnail(File $file, $maxX, $maxY, $scalingUp) {
        $this->initCmd();
        if ($this->cmd === null) {
            return false;
        }

        $useFileDirectly = (!$file->isEncrypted() && !$file->isMounted());
        if ($useFileDirectly) {
            $absPath = $file->getStorage()->getLocalFile($file->getInternalPath());
        } else {
            $absPath = \OC::$server->getTempManager()->getTemporaryFile();

            $handle = $file->fopen('rb');
            \file_put_contents($absPath, $handle);
            \fclose($handle);
        }

        $tmpDir = \OC::$server->getTempManager()->getTempBaseDir();

        $defaultParameters = ' -env:UserInstallation=file://' . \escapeshellarg($tmpDir . '/owncloud-' . \OC_Util::getInstanceId() . '/') . ' --headless --nologo --nofirststartwizard --invisible --norestore --convert-to pdf --outdir ';
        $clParameters = \OC::$server->getConfig()->getSystemValue('preview_office_cl_parameters', $defaultParameters);

        $exec = $this->cmd . $clParameters . \escapeshellarg($tmpDir) . ' ' . \escapeshellarg($absPath);

        \shell_exec($exec);

        //create imagick object from pdf
        $pdfPreview = null;
        try {
            $pathInfo = \pathinfo($absPath);
            $pdfPreview = $tmpDir . '/' . $pathInfo['filename'] . '.pdf';

            $pdf = new \Imagick($pdfPreview . '[0]');
            $pdf->setImageFormat('jpg');
        } catch (\Exception $e) {
            @\unlink($pdfPreview);
            \OCP\Util::writeLog('core', $e->getmessage(), \OCP\Util::ERROR);
            return false;
        }

        $image = new \OC_Image();
        $image->loadFromData($pdf);

        \unlink($pdfPreview);

        if ($image->valid()) {
            $image->scaleDownToFit($maxX, $maxY);

            return $image;
        }
        return false;
    }

    /**
     * @inheritdoc
     */
    public function isAvailable(FileInfo $file) {
        return true;
    }

    private function initCmd() {
        $cmd = '';

        $libreOfficePath = \OC::$server->getConfig()->getSystemValue('preview_libreoffice_path', null);
        if (\is_string($libreOfficePath)) {
            $cmd = $libreOfficePath;
        }

        $whichLibreOffice = \shell_exec('command -v libreoffice');
        if ($cmd === '' && !empty($whichLibreOffice)) {
            $cmd = 'libreoffice';
        }

        $whichOpenOffice = \shell_exec('command -v openoffice');
        if ($cmd === '' && !empty($whichOpenOffice)) {
            $cmd = 'openoffice';
        }

        if ($cmd === '') {
            $cmd = null;
        }

        $this->cmd = $cmd;
    }
}