first draft (from v1)

src/Wallabag/CoreBundle/Helper/ContentProxy.php

@@ -151,4 +151,172 @@ class ContentProxy
     {
         return isset($content['title']) && isset($content['html']) && isset($content['url']) && isset($content['language']) && isset($content['content_type']);
     }
+
+    /**
+     * Changing pictures URL in article content.
+     */
+    public static function filterPicture($content, $url, $id)
+    {
+        $matches = array();
+        $processing_pictures = array(); // list of processing image to avoid processing the same pictures twice
+        preg_match_all('#<\s*(img)[^>]+src="([^"]*)"[^>]*>#Si', $content, $matches, PREG_SET_ORDER);
+        foreach ($matches as $i => $link) {
+            $link[1] = trim($link[1]);
+            if (!preg_match('#^(([a-z]+://)|(\#))#', $link[1])) {
+                $absolute_path = self::_getAbsoluteLink($link[2], $url);
+                $filename = basename(parse_url($absolute_path, PHP_URL_PATH));
+                $directory = self::_createAssetsDirectory($id);
+                $fullpath = $directory.'/'.$filename;
+
+                if (in_array($absolute_path, $processing_pictures) === true) {
+                    // replace picture's URL only if processing is OK : already processing -> go to next picture
+                  continue;
+                }
+
+                if (self::_downloadPictures($absolute_path, $fullpath) === true) {
+                    $content = str_replace($matches[$i][2], Tools::getPocheUrl().$fullpath, $content);
+                }
+
+                $processing_pictures[] = $absolute_path;
+            }
+        }
+
+        return $content;
+    }
+
+    /**
+     * Get absolute URL.
+     */
+    private static function _getAbsoluteLink($relativeLink, $url)
+    {
+        /* return if already absolute URL */
+        if (parse_url($relativeLink, PHP_URL_SCHEME) != '') {
+            return $relativeLink;
+        }
+
+        /* queries and anchors */
+        if ($relativeLink[0] == '#' || $relativeLink[0] == '?') {
+            return $url.$relativeLink;
+        }
+
+        /* parse base URL and convert to local variables:
+           $scheme, $host, $path */
+        extract(parse_url($url));
+
+        /* remove non-directory element from path */
+        $path = preg_replace('#/[^/]*$#', '', $path);
+
+        /* destroy path if relative url points to root */
+        if ($relativeLink[0] == '/') {
+            $path = '';
+        }
+
+        /* dirty absolute URL */
+        $abs = $host.$path.'/'.$relativeLink;
+
+        /* replace '//' or '/./' or '/foo/../' with '/' */
+        $re = array('#(/\.?/)#', '#/(?!\.\.)[^/]+/\.\./#');
+        for ($n = 1; $n > 0; $abs = preg_replace($re, '/', $abs, -1, $n)) {
+        }
+
+        /* absolute URL is ready! */
+        return $scheme.'://'.$abs;
+    }
+
+    /**
+     * Downloading pictures.
+     *
+     * @return bool true if the download and processing is OK, false else
+     */
+    private static function _downloadPictures($absolute_path, $fullpath)
+    {
+        $rawdata = Tools::getFile($absolute_path);
+        $fullpath = urldecode($fullpath);
+
+        if (file_exists($fullpath)) {
+            unlink($fullpath);
+        }
+
+        // check extension
+        $file_ext = strrchr($fullpath, '.');
+        $whitelist = array('.jpg', '.jpeg', '.gif', '.png');
+        if (!(in_array($file_ext, $whitelist))) {
+            Tools::logm('processed image with not allowed extension. Skipping '.$fullpath);
+
+            return false;
+        }
+
+        // check headers
+        $imageinfo = getimagesize($absolute_path);
+        if ($imageinfo['mime'] != 'image/gif' && $imageinfo['mime'] != 'image/jpeg' && $imageinfo['mime'] != 'image/jpg' && $imageinfo['mime'] != 'image/png') {
+            Tools::logm('processed image with bad header. Skipping '.$fullpath);
+
+            return false;
+        }
+
+        // regenerate image
+        $im = imagecreatefromstring($rawdata);
+        if ($im === false) {
+            Tools::logm('error while regenerating image '.$fullpath);
+
+            return false;
+        }
+
+        switch ($imageinfo['mime']) {
+            case 'image/gif':
+                $result = imagegif($im, $fullpath);
+                break;
+            case 'image/jpeg':
+            case 'image/jpg':
+                $result = imagejpeg($im, $fullpath, REGENERATE_PICTURES_QUALITY);
+                break;
+            case 'image/png':
+                $result = imagepng($im, $fullpath, ceil(REGENERATE_PICTURES_QUALITY / 100 * 9));
+                break;
+        }
+        imagedestroy($im);
+
+        return $result;
+    }
+
+    /**
+     * Create a directory for an article.
+     *
+     * @param $id ID of the article
+     *
+     * @return string
+     */
+    private static function _createAssetsDirectory($id)
+    {
+        $assets_path = ABS_PATH;
+        if (!is_dir($assets_path)) {
+            mkdir($assets_path, 0715);
+        }
+
+        $article_directory = $assets_path.$id;
+        if (!is_dir($article_directory)) {
+            mkdir($article_directory, 0715);
+        }
+
+        return $article_directory;
+    }
+
+    /**
+     * Remove the directory.
+     *
+     * @param $directory
+     *
+     * @return bool
+     */
+    public static function removeDirectory($directory)
+    {
+        if (is_dir($directory)) {
+            $files = array_diff(scandir($directory), array('.', '..'));
+            foreach ($files as $file) {
+                (is_dir("$directory/$file")) ? self::removeDirectory("$directory/$file") : unlink("$directory/$file");
+            }
+
+            return rmdir($directory);
+        }
+    }
 }