src/Wallabag/CoreBundle/Helper/DownloadImages.php

   1 <?php
   2
   3 namespace Wallabag\CoreBundle\Helper;
   4
   5 use GuzzleHttp\Psr7\Uri;
   6 use GuzzleHttp\Psr7\UriResolver;
   7 use Http\Client\Common\HttpMethodsClient;
   8 use Http\Client\Common\Plugin\ErrorPlugin;
   9 use Http\Client\Common\PluginClient;
  10 use Http\Client\HttpClient;
  11 use Http\Discovery\MessageFactoryDiscovery;
  12 use Http\Message\MessageFactory;
  13 use Psr\Http\Message\ResponseInterface;
  14 use Psr\Log\LoggerInterface;
  15 use Symfony\Component\DomCrawler\Crawler;
  16 use Symfony\Component\Finder\Finder;
  17 use Symfony\Component\HttpFoundation\File\MimeType\MimeTypeExtensionGuesser;
  18
  19 class DownloadImages
  20 {
  21     const REGENERATE_PICTURES_QUALITY = 80;
  22
  23     private $client;
  24     private $baseFolder;
  25     private $logger;
  26     private $mimeGuesser;
  27     private $wallabagUrl;
  28
  29     public function __construct(HttpClient $client, $baseFolder, $wallabagUrl, LoggerInterface $logger, MessageFactory $messageFactory = null)
  30     {
  31         $this->client = new HttpMethodsClient(new PluginClient($client, [new ErrorPlugin()]), $messageFactory ?: MessageFactoryDiscovery::find());
  32         $this->baseFolder = $baseFolder;
  33         $this->wallabagUrl = rtrim($wallabagUrl, '/');
  34         $this->logger = $logger;
  35         $this->mimeGuesser = new MimeTypeExtensionGuesser();
  36
  37         $this->setFolder();
  38     }
  39
  40     /**
  41      * Process the html and extract images URLs from it.
  42      *
  43      * @param string $html
  44      *
  45      * @return string[]
  46      */
  47     public static function extractImagesUrlsFromHtml($html)
  48     {
  49         $crawler = new Crawler($html);
  50         $imagesCrawler = $crawler->filterXpath('//img');
  51         $imagesUrls = $imagesCrawler->extract(['src']);
  52         $imagesSrcsetUrls = self::getSrcsetUrls($imagesCrawler);
  53
  54         return array_unique(array_merge($imagesUrls, $imagesSrcsetUrls));
  55     }
  56
  57     /**
  58      * Process the html and extract image from it, save them to local and return the updated html.
  59      *
  60      * @param int    $entryId ID of the entry
  61      * @param string $html
  62      * @param string $url     Used as a base path for relative image and folder
  63      *
  64      * @return string
  65      */
  66     public function processHtml($entryId, $html, $url)
  67     {
  68         $imagesUrls = self::extractImagesUrlsFromHtml($html);
  69
  70         $relativePath = $this->getRelativePath($entryId);
  71
  72         // download and save the image to the folder
  73         foreach ($imagesUrls as $image) {
  74             $imagePath = $this->processSingleImage($entryId, $image, $url, $relativePath);
  75
  76             if (false === $imagePath) {
  77                 continue;
  78             }
  79
  80             // if image contains "&" and we can't find it in the html it might be because it's encoded as &amp;
  81             if (false !== stripos($image, '&') && false === stripos($html, $image)) {
  82                 $image = str_replace('&', '&amp;', $image);
  83             }
  84
  85             $html = str_replace($image, $imagePath, $html);
  86         }
  87
  88         return $html;
  89     }
  90
  91     /**
  92      * Process a single image:
  93      *     - retrieve it
  94      *     - re-saved it (for security reason)
  95      *     - return the new local path.
  96      *
  97      * @param int    $entryId      ID of the entry
  98      * @param string $imagePath    Path to the image to retrieve
  99      * @param string $url          Url from where the image were found
 100      * @param string $relativePath Relative local path to saved the image
 101      *
 102      * @return string Relative url to access the image from the web
 103      */
 104     public function processSingleImage($entryId, $imagePath, $url, $relativePath = null)
 105     {
 106         if (null === $imagePath) {
 107             return false;
 108         }
 109
 110         if (null === $relativePath) {
 111             $relativePath = $this->getRelativePath($entryId);
 112         }
 113
 114         $this->logger->debug('DownloadImages: working on image: ' . $imagePath);
 115
 116         $folderPath = $this->baseFolder . '/' . $relativePath;
 117
 118         // build image path
 119         $absolutePath = $this->getAbsoluteLink($url, $imagePath);
 120         if (false === $absolutePath) {
 121             $this->logger->error('DownloadImages: Can not determine the absolute path for that image, skipping.');
 122
 123             return false;
 124         }
 125
 126         try {
 127             $res = $this->client->get($absolutePath);
 128         } catch (\Exception $e) {
 129             $this->logger->error('DownloadImages: Can not retrieve image, skipping.', ['exception' => $e]);
 130
 131             return false;
 132         }
 133
 134         $ext = $this->getExtensionFromResponse($res, $imagePath);
 135         if (false === $res) {
 136             return false;
 137         }
 138
 139         $hashImage = hash('crc32', $absolutePath);
 140         $localPath = $folderPath . '/' . $hashImage . '.' . $ext;
 141
 142         try {
 143             $im = imagecreatefromstring((string) $res->getBody());
 144         } catch (\Exception $e) {
 145             $im = false;
 146         }
 147
 148         if (false === $im) {
 149             $this->logger->error('DownloadImages: Error while regenerating image', ['path' => $localPath]);
 150
 151             return false;
 152         }
 153
 154         switch ($ext) {
 155             case 'gif':
 156                 // use Imagick if available to keep GIF animation
 157                 if (class_exists('\\Imagick')) {
 158                     try {
 159                         $imagick = new \Imagick();
 160                         $imagick->readImageBlob($res->getBody());
 161                         $imagick->setImageFormat('gif');
 162                         $imagick->writeImages($localPath, true);
 163                     } catch (\Exception $e) {
 164                         // if Imagick fail, fallback to the default solution
 165                         imagegif($im, $localPath);
 166                     }
 167                 } else {
 168                     imagegif($im, $localPath);
 169                 }
 170
 171                 $this->logger->debug('DownloadImages: Re-creating gif');
 172                 break;
 173             case 'jpeg':
 174             case 'jpg':
 175                 imagejpeg($im, $localPath, self::REGENERATE_PICTURES_QUALITY);
 176                 $this->logger->debug('DownloadImages: Re-creating jpg');
 177                 break;
 178             case 'png':
 179                 imagealphablending($im, false);
 180                 imagesavealpha($im, true);
 181                 imagepng($im, $localPath, ceil(self::REGENERATE_PICTURES_QUALITY / 100 * 9));
 182                 $this->logger->debug('DownloadImages: Re-creating png');
 183         }
 184
 185         imagedestroy($im);
 186
 187         return $this->wallabagUrl . '/assets/images/' . $relativePath . '/' . $hashImage . '.' . $ext;
 188     }
 189
 190     /**
 191      * Remove all images for the given entry id.
 192      *
 193      * @param int $entryId ID of the entry
 194      */
 195     public function removeImages($entryId)
 196     {
 197         $relativePath = $this->getRelativePath($entryId);
 198         $folderPath = $this->baseFolder . '/' . $relativePath;
 199
 200         $finder = new Finder();
 201         $finder
 202             ->files()
 203             ->ignoreDotFiles(true)
 204             ->in($folderPath);
 205
 206         foreach ($finder as $file) {
 207             @unlink($file->getRealPath());
 208         }
 209
 210         @rmdir($folderPath);
 211     }
 212
 213     /**
 214      * Get images urls from the srcset image attribute.
 215      *
 216      * @return array An array of urls
 217      */
 218     private static function getSrcsetUrls(Crawler $imagesCrawler)
 219     {
 220         $urls = [];
 221         $iterator = $imagesCrawler->getIterator();
 222
 223         while ($iterator->valid()) {
 224             $srcsetAttribute = $iterator->current()->getAttribute('srcset');
 225
 226             if ('' !== $srcsetAttribute) {
 227                 // Couldn't start with " OR ' OR a white space
 228                 // Could be one or more white space
 229                 // Must be one or more digits followed by w OR x
 230                 $pattern = "/(?:[^\"'\s]+\s*(?:\d+[wx])+)/";
 231                 preg_match_all($pattern, $srcsetAttribute, $matches);
 232
 233                 $srcset = \call_user_func_array('array_merge', $matches);
 234                 $srcsetUrls = array_map(function ($src) {
 235                     return trim(explode(' ', $src, 2)[0]);
 236                 }, $srcset);
 237                 $urls = array_merge($srcsetUrls, $urls);
 238             }
 239
 240             $iterator->next();
 241         }
 242
 243         return $urls;
 244     }
 245
 246     /**
 247      * Setup base folder where all images are going to be saved.
 248      */
 249     private function setFolder()
 250     {
 251         // if folder doesn't exist, attempt to create one and store the folder name in property $folder
 252         if (!file_exists($this->baseFolder)) {
 253             mkdir($this->baseFolder, 0755, true);
 254         }
 255     }
 256
 257     /**
 258      * Generate the folder where we are going to save images based on the entry url.
 259      *
 260      * @param int $entryId ID of the entry
 261      *
 262      * @return string
 263      */
 264     private function getRelativePath($entryId)
 265     {
 266         $hashId = hash('crc32', $entryId);
 267         $relativePath = $hashId[0] . '/' . $hashId[1] . '/' . $hashId;
 268         $folderPath = $this->baseFolder . '/' . $relativePath;
 269
 270         if (!file_exists($folderPath)) {
 271             mkdir($folderPath, 0777, true);
 272         }
 273
 274         $this->logger->debug('DownloadImages: Folder used for that Entry id', ['folder' => $folderPath, 'entryId' => $entryId]);
 275
 276         return $relativePath;
 277     }
 278
 279     /**
 280      * Make an $url absolute based on the $base.
 281      *
 282      * @see Graby->makeAbsoluteStr
 283      *
 284      * @param string $base Base url
 285      * @param string $url  Url to make it absolute
 286      *
 287      * @return false|string
 288      */
 289     private function getAbsoluteLink($base, $url)
 290     {
 291         if (preg_match('!^https?://!i', $url)) {
 292             // already absolute
 293             return $url;
 294         }
 295
 296         $base = new Uri($base);
 297
 298         // in case the url has no scheme & host
 299         if ('' === $base->getAuthority() || '' === $base->getScheme()) {
 300             $this->logger->error('DownloadImages: Can not make an absolute link', ['base' => $base, 'url' => $url]);
 301
 302             return false;
 303         }
 304
 305         return (string) UriResolver::resolve($base, new Uri($url));
 306     }
 307
 308     /**
 309      * Retrieve and validate the extension from the response of the url of the image.
 310      *
 311      * @param ResponseInterface $res       Http Response
 312      * @param string            $imagePath Path from the src image from the content (used for log only)
 313      *
 314      * @return string|false Extension name or false if validation failed
 315      */
 316     private function getExtensionFromResponse(ResponseInterface $res, $imagePath)
 317     {
 318         $ext = $this->mimeGuesser->guess(current($res->getHeader('content-type')));
 319         $this->logger->debug('DownloadImages: Checking extension', ['ext' => $ext, 'header' => $res->getHeader('content-type')]);
 320
 321         // ok header doesn't have the extension, try a different way
 322         if (empty($ext)) {
 323             $types = [
 324                 'jpeg' => "\xFF\xD8\xFF",
 325                 'gif' => 'GIF',
 326                 'png' => "\x89\x50\x4e\x47\x0d\x0a",
 327             ];
 328             $bytes = substr((string) $res->getBody(), 0, 8);
 329
 330             foreach ($types as $type => $header) {
 331                 if (0 === strpos($bytes, $header)) {
 332                     $ext = $type;
 333                     break;
 334                 }
 335             }
 336
 337             $this->logger->debug('DownloadImages: Checking extension (alternative)', ['ext' => $ext]);
 338         }
 339
 340         if (!\in_array($ext, ['jpeg', 'jpg', 'gif', 'png'], true)) {
 341             $this->logger->error('DownloadImages: Processed image with not allowed extension. Skipping: ' . $imagePath);
 342
 343             return false;
 344         }
 345
 346         return $ext;
 347     }
 348 }