owncloud/core

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lib/private/PreviewManager.php

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<?php
/**
 * @author Joas Schilling <coding@schilljs.com>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Olivier Paroz <github@oparoz.com>
 * @author Robin Appelman <icewind@owncloud.com>
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 * @author Vincent Petry <pvince81@owncloud.com>
 * @author Lorenzo Perone <lorenzo.perone@yellowspace.net>
 *
 * @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;

use OC\AppFramework\Middleware\Security\Exceptions\NotLoggedInException;
use OCP\Files\IRootFolder;
use OCP\IConfig;
use OCP\IImage;
use OCP\IPreview;
use OCP\IUserSession;
use OCP\Preview\IProvider;
use OCP\Preview\IProvider2;

class PreviewManager implements IPreview {
    /** @var IConfig */
    protected $config;

    /** @var bool */
    protected $providerListDirty = false;

    /** @var bool */
    protected $registeredCoreProviders = false;

    /** @var array */
    protected $providers = [];

    /** @var array mime type => support status */
    protected $mimeTypeSupportMap = [];

    /** @var array */
    protected $defaultProviders;

    /** @var IRootFolder */
    private $rootFolder;

    /** @var IUserSession */
    private $userSession;

    /**
     * Constructor
     *
     * @param IConfig $config
     * @param IRootFolder $rootFolder
     * @param IUserSession $userSession
     */
    public function __construct(IConfig $config, IRootFolder $rootFolder, IUserSession $userSession) {
        $this->config = $config;
        $this->rootFolder = $rootFolder;
        $this->userSession = $userSession;
    }

    /**
     * In order to improve lazy loading a closure can be registered which will be
     * called in case preview providers are actually requested
     *
     * $callable has to return an instance of \OCP\Preview\IProvider
     *
     * @param string $mimeTypeRegex Regex with the mime types that are supported by this provider
     * @param \Closure $callable
     * @return void
     */
    public function registerProvider($mimeTypeRegex, \Closure $callable) {
        if (!$this->config->getSystemValue('enable_previews', true)) {
            return;
        }

        if (!isset($this->providers[$mimeTypeRegex])) {
            $this->providers[$mimeTypeRegex] = [];
        }
        $this->providers[$mimeTypeRegex][] = $callable;
        $this->providerListDirty = true;
    }

    /**
     * Get all providers
     * @return array
     */
    public function getProviders() {
        if (!$this->config->getSystemValue('enable_previews', true)) {
            return [];
        }

        $this->registerCoreProviders();
        if ($this->providerListDirty) {
            $keys = \array_map('strlen', \array_keys($this->providers));
            \array_multisort($keys, SORT_DESC, $this->providers);
            $this->providerListDirty = false;
        }

        return $this->providers;
    }

    /**
     * Does the manager have any providers
     * @return bool
     */
    public function hasProviders() {
        $this->registerCoreProviders();
        return !empty($this->providers);
    }

    /**
     * return a preview of a file
     *
     * @param string $file The path to the file where you want a thumbnail from
     * @param int $maxX The maximum X size of the thumbnail. It can be smaller depending on the shape of the image
     * @param int $maxY The maximum Y size of the thumbnail. It can be smaller depending on the shape of the image
     * @param boolean $scaleUp Scale smaller images up to the thumbnail size or not. Might look ugly
     * @return IImage
     * @throws NotLoggedInException
     * @throws \OCP\Files\NotFoundException
     * @throws \Exception
     */
    public function createPreview($file, $maxX = 100, $maxY = 75, $scaleUp = false) {
        $user = $this->userSession->getUser();
        if ($user === null) {
            throw new NotLoggedInException();
        }
        $file = $this->rootFolder->getUserFolder($user->getUID())->getParent()->get($file);
        $preview = new Preview('', '', $file, $maxX, $maxY, $scaleUp);
        return $preview->getPreview();
    }

    /**
     * returns true if the passed mime type is supported
     *
     * @param string $mimeType
     * @return boolean
     */
    public function isMimeSupported($mimeType = '*') {
        if (!$this->config->getSystemValue('enable_previews', true)) {
            return false;
        }

        if (isset($this->mimeTypeSupportMap[$mimeType])) {
            return $this->mimeTypeSupportMap[$mimeType];
        }

        $this->registerCoreProviders();
        $providerMimeTypes = \array_keys($this->providers);
        foreach ($providerMimeTypes as $supportedMimeType) {
            if (\preg_match($supportedMimeType, $mimeType)) {
                $this->mimeTypeSupportMap[$mimeType] = true;
                return true;
            }
        }
        $this->mimeTypeSupportMap[$mimeType] = false;
        return false;
    }
    
    /**
     * Returns all registered MimeTypes as an array
     *
     * @return string[]
     */
    public function getSupportedMimes() {
        $supportedMimes = [];
        $this->registerCoreProviders();
        $mimeRegexArray = \array_keys($this->providers);
        // Now trim start/stop regexp delimiters
        foreach ($mimeRegexArray as $mimeRegex) {
            $supportedMimes[] = \trim($mimeRegex, '/');
        }
        return $supportedMimes;
    }

    /**
     * Check if a preview can be generated for a file
     *
     * @param \OCP\Files\FileInfo $file
     * @return bool
     */
    public function isAvailable(\OCP\Files\FileInfo $file) {
        if (!$this->config->getSystemValue('enable_previews', true)) {
            return false;
        }

        $this->registerCoreProviders();
        if (!$this->isMimeSupported($file->getMimetype())) {
            return false;
        }

        $mount = $file->getMountPoint();
        if ($mount and !$mount->getOption('previews', true)) {
            return false;
        }

        foreach ($this->providers as $supportedMimeType => $providers) {
            if (\preg_match($supportedMimeType, $file->getMimetype())) {
                foreach ($providers as $closure) {
                    $provider = $closure();
                    if (!($provider instanceof IProvider) && !($provider instanceof IProvider2)) {
                        continue;
                    }

                    /** @var $provider IProvider */
                    if ($provider->isAvailable($file)) {
                        return true;
                    }
                }
            }
        }
        return false;
    }

    /**
     * List of enabled default providers
     *
     * The following providers are enabled by default:
     *  - OC\Preview\PNG
     *  - OC\Preview\JPEG
     *  - OC\Preview\WEBP
     *  - OC\Preview\GIF
     *  - OC\Preview\BMP
     *  - OC\Preview\XBitmap
     *  - OC\Preview\MarkDown
     *  - OC\Preview\MP3
     *  - OC\Preview\TXT
     *
     * The following providers are disabled by default due to performance or privacy concerns:
     *  - OC\Preview\Font
     *  - OC\Preview\Illustrator
     *  - OC\Preview\Movie
     *  - OC\Preview\MSOfficeDoc
     *  - OC\Preview\MSOffice2003
     *  - OC\Preview\MSOffice2007
     *  - OC\Preview\OpenDocument
     *  - OC\Preview\StarOffice
     *  - OC\Preview\PDF
     *  - OC\Preview\Photoshop
     *  - OC\Preview\Postscript
     *  - OC\Preview\SVG
     *  - OC\Preview\TIFF
     *
     * @return array
     */
    protected function getEnabledDefaultProvider() {
        if ($this->defaultProviders !== null) {
            return $this->defaultProviders;
        }

        $imageProviders = [
            'OC\Preview\PNG',
            'OC\Preview\JPEG',
            'OC\Preview\WEBP',
            'OC\Preview\GIF',
            'OC\Preview\BMP',
            'OC\Preview\Heic',
            'OC\Preview\XBitmap',
            'OC\Preview\SGI',
        ];

        $this->defaultProviders = $this->config->getSystemValue('enabledPreviewProviders', \array_merge([
            'OC\Preview\MarkDown',
            'OC\Preview\MP3',
            'OC\Preview\TXT',
        ], $imageProviders));

        if (\in_array('OC\Preview\Image', $this->defaultProviders)) {
            $this->defaultProviders = \array_merge($this->defaultProviders, $imageProviders);
        }
        $this->defaultProviders = \array_unique($this->defaultProviders);
        return $this->defaultProviders;
    }

    /**
     * Register the default providers (if enabled)
     *
     * @param string $class
     * @param string $mimeType
     */
    protected function registerCoreProvider($class, $mimeType, $options = []) {
        if (\in_array(\trim($class, '\\'), $this->getEnabledDefaultProvider())) {
            $this->registerProvider($mimeType, function () use ($class, $options) {
                return new $class($options);
            });
        }
    }

    /**
     * Register the default providers (if enabled)
     */
    protected function registerCoreProviders() {
        if ($this->registeredCoreProviders) {
            return;
        }
        $this->registeredCoreProviders = true;

        $this->registerCoreProvider('OC\Preview\TXT', '/text\/plain/');
        $this->registerCoreProvider('OC\Preview\MarkDown', '/text\/(x-)?markdown/');
        $this->registerCoreProvider('OC\Preview\PNG', '/image\/png/');
        $this->registerCoreProvider('OC\Preview\JPEG', '/image\/jpeg/');
        $this->registerCoreProvider('OC\Preview\WEBP', '/image\/webp/');
        $this->registerCoreProvider('OC\Preview\GIF', '/image\/gif/');
        $this->registerCoreProvider('OC\Preview\BMP', '/image\/bmp/');
        $this->registerCoreProvider('OC\Preview\XBitmap', '/image\/x-xbitmap/');
        $this->registerCoreProvider('OC\Preview\MP3', '/audio\/mpeg/');

        // SVG, Office and Bitmap require imagick
        // Either use the additional library mentioned below when using imagick 6, or use imagick 7
        // which does not need this library. See the installation and preview documentation for more details.
        // Install `libmagickcore-6.q16-3-extra` additional to the imagick library when using SVG.
        // This library adds imagick support for SVG, WMF, OpenEXR, DjVu and Graphviz:
        
        if (\extension_loaded('imagick')) {
            $imagickProviders = [
                'SVG'    => ['mimetype' => '/image\/svg\+xml/', 'class' => '\OC\Preview\SVG'],
                'TIFF'    => ['mimetype' => '/image\/tiff/', 'class' => '\OC\Preview\TIFF'],
                'PDF'    => ['mimetype' => '/application\/pdf/', 'class' => '\OC\Preview\PDF'],
                'AI'    => ['mimetype' => '/application\/illustrator/', 'class' => '\OC\Preview\Illustrator'],
                'PSD'    => ['mimetype' => '/application\/x-photoshop/', 'class' => '\OC\Preview\Photoshop'],
                'EPS'    => ['mimetype' => '/application\/postscript/', 'class' => '\OC\Preview\Postscript'],
                'TTF'    => ['mimetype' => '/application\/(?:font-sfnt|x-font$)/', 'class' => '\OC\Preview\Font'],
                'HEIF'    => ['mimetype' => '/image\/heif/', 'class' => '\OC\Preview\Heic'],
                'HEIC'    => ['mimetype' => '/image\/heic/', 'class' => '\OC\Preview\Heic'],
                'SGI'    => ['mimetype' => '/image\/sgi/', 'class' => '\OC\Preview\SGI'],
            ];

            foreach ($imagickProviders as $queryFormat => $provider) {
                $class = $provider['class'];
                if (!\in_array(\trim($class, '\\'), $this->getEnabledDefaultProvider())) {
                    continue;
                }

                if (\count(\Imagick::queryFormats($queryFormat)) === 1) {
                    $this->registerCoreProvider($class, $provider['mimetype']);
                }
            }

            if (\count(\Imagick::queryFormats('PDF')) === 1) {
                // Office previews are only supported if either LibreOffice or OpenOffice is installed on the server
                if (\OC_Helper::is_function_enabled('shell_exec')) {
                    $officeFound = \is_string($this->config->getSystemValue('preview_libreoffice_path', null));

                    if (!$officeFound) {
                        //let's see if there is libreoffice or openoffice on this machine
                        $whichLibreOffice = \shell_exec('command -v libreoffice');
                        $officeFound = !empty($whichLibreOffice);
                        if (!$officeFound) {
                            $whichOpenOffice = \shell_exec('command -v openoffice');
                            $officeFound = !empty($whichOpenOffice);
                        }
                    }

                    if ($officeFound) {
                        $this->registerCoreProvider('\OC\Preview\MSOfficeDoc', '/application\/msword/');
                        $this->registerCoreProvider('\OC\Preview\MSOffice2003', '/application\/vnd.ms-.*/');
                        $this->registerCoreProvider('\OC\Preview\MSOffice2007', '/application\/vnd.openxmlformats-officedocument.*/');
                        $this->registerCoreProvider('\OC\Preview\OpenDocument', '/application\/vnd.oasis.opendocument.*/');
                        $this->registerCoreProvider('\OC\Preview\StarOffice', '/application\/vnd.sun.xml.*/');
                    }
                }
            }
        }

        // Video requires avconv or ffmpeg to be installed on the server
        if (\in_array('OC\Preview\Movie', $this->getEnabledDefaultProvider())) {
            $avconvBinary = \OC_Helper::findBinaryPath('avconv');
            $ffmpegBinary = ($avconvBinary) ? null : \OC_Helper::findBinaryPath('ffmpeg');
            $atomicParsleyBinary = \OC_Helper::findBinaryPath('AtomicParsley');

            // FIXME // a bit hacky but didn't want to use subclasses
            $registerProvider = false;
            if ($avconvBinary !== null) {
                \OC\Preview\Movie::$avconvBinary = $avconvBinary;
                $registerProvider = true;
            }
            if ($ffmpegBinary !== null) {
                \OC\Preview\Movie::$ffmpegBinary = $ffmpegBinary;
                $registerProvider = true;
            }
            if ($atomicParsleyBinary !== null) {
                \OC\Preview\Movie::$atomicParsleyBinary = $atomicParsleyBinary;
                $registerProvider = true;
            }
            if ($registerProvider === true) {
                $this->registerCoreProvider('\OC\Preview\Movie', '/video\/.*/');
            }
        }
    }
}