| <?php | |
| use Symfony\Component\HttpFoundation\Request; | |
| use Symfony\Component\HttpFoundation\Response; | |
| 
 | |
| use XRay\Formats; | |
| 
 | |
| class Parse { | |
| 
 | |
|   public $http; | |
|   public $mc; | |
|   private $_cacheTime = 120; | |
|   private $_pretty = false; | |
| 
 | |
|   public function __construct() { | |
|     $this->http = new p3k\HTTP(); | |
|     if(Config::$cache && class_exists('Memcache')) { | |
|       $this->mc = new Memcache(); | |
|       $this->mc->addServer('127.0.0.1'); | |
|     } | |
|   } | |
| 
 | |
|   public static function debug($msg, $header='X-Parse-Debug') { | |
|     syslog(LOG_INFO, $msg); | |
|     if(array_key_exists('REMOTE_ADDR', $_SERVER)) | |
|       header($header . ": " . $msg); | |
|   } | |
| 
 | |
|   private function respond(Response $response, $code, $params, $headers=[]) { | |
|     $response->setStatusCode($code); | |
|     foreach($headers as $k=>$v) { | |
|       $response->headers->set($k, $v); | |
|     } | |
|     $response->headers->set('Content-Type', 'application/json'); | |
|     $opts = JSON_UNESCAPED_SLASHES; | |
|     if($this->_pretty) $opts += JSON_PRETTY_PRINT; | |
|     $response->setContent(json_encode($params, $opts)."\n"); | |
|     return $response; | |
|   } | |
| 
 | |
|   private static function toHtmlEntities($input) { | |
|     return mb_convert_encoding($input, 'HTML-ENTITIES', mb_detect_encoding($input)); | |
|   } | |
| 
 | |
|   public function parse(Request $request, Response $response) { | |
| 
 | |
|     if($request->get('timeout')) { | |
|       // We might make 2 HTTP requests, so each request gets half the desired timeout | |
|       $this->http->timeout = $request->get('timeout') / 2; | |
|     } | |
| 
 | |
|     if($request->get('max_redirects')) { | |
|       $this->http->max_redirects = (int)$request->get('max_redirects'); | |
|     } | |
| 
 | |
|     if($request->get('pretty')) { | |
|       $this->_pretty = true; | |
|     } | |
| 
 | |
|     $url = $request->get('url'); | |
|     $html = $request->get('html'); | |
| 
 | |
|     if(!$url && !$html) { | |
|       return $this->respond($response, 400, [ | |
|         'error' => 'missing_url', | |
|         'error_description' => 'Provide a URL or HTML to fetch' | |
|       ]); | |
|     } | |
| 
 | |
|     if($html) { | |
|       // If HTML is provided in the request, parse that, and use the URL provided as the base URL for mf2 resolving | |
|       $result['body'] = $html; | |
|       $result['url'] = $url; | |
|     } else { | |
|       // Attempt some basic URL validation | |
|       $scheme = parse_url($url, PHP_URL_SCHEME); | |
|       if(!in_array($scheme, ['http','https'])) { | |
|         return $this->respond($response, 400, [ | |
|           'error' => 'invalid_url', | |
|           'error_description' => 'Only http and https URLs are supported' | |
|         ]); | |
|       } | |
| 
 | |
|       $host = parse_url($url, PHP_URL_HOST); | |
|       if(!$host) { | |
|         return $this->respond($response, 400, [ | |
|           'error' => 'invalid_url', | |
|           'error_description' => 'The URL provided was not valid' | |
|         ]); | |
|       } | |
| 
 | |
|       $url = \normalize_url($url); | |
| 
 | |
|       // Check if this is a Twitter URL and if they've provided API credentials, use the API | |
|       if(preg_match('/https?:\/\/(?:mobile\.twitter\.com|twitter\.com|twtr\.io)\/(?:[a-z0-9_\/!#]+statuse?s?\/([0-9]+)|([a-zA-Z0-9_]+))/i', $url, $match)) { | |
|         return $this->parseTwitterURL($request, $response, $url, $match); | |
|       } | |
| 
 | |
|       // Now fetch the URL and check for any curl errors | |
|       // Don't cache the response if a token is used to fetch it | |
|       if($this->mc && !$request->get('token')) { | |
|         $cacheKey = 'xray-'.md5($url); | |
|         if($cached=$this->mc->get($cacheKey)) { | |
|           $result = json_decode($cached, true); | |
|           self::debug('using HTML from cache', 'X-Cache-Debug'); | |
|         } else { | |
|           $result = $this->http->get($url); | |
|           $cacheData = json_encode($result); | |
|           // App Engine limits the size of cached items, so don't cache ones larger than that | |
|           if(strlen($cacheData) < 1000000)  | |
|             $this->mc->set($cacheKey, $cacheData, MEMCACHE_COMPRESSED, $this->_cacheTime); | |
|         } | |
|       } else { | |
|         $headers = []; | |
|         if($request->get('token')) { | |
|           $headers[] = 'Authorization: Bearer ' . $request->get('token'); | |
|         } | |
| 
 | |
|         $result = $this->http->get($url, $headers); | |
|       } | |
| 
 | |
|       if($result['error']) { | |
|         return $this->respond($response, 200, [ | |
|           'error' => $result['error'], | |
|           'error_description' => $result['error_description'], | |
|           'url' => $result['url'], | |
|           'code' => $result['code'] | |
|         ]); | |
|       } | |
| 
 | |
|       if(trim($result['body']) == '') { | |
|         if($result['code'] == 410) { | |
|           // 410 Gone responses are valid and should not return an error | |
|           return $this->respond($response, 200, [ | |
|             'data' => [ | |
|               'type' => 'unknown' | |
|             ], | |
|             'url' => $result['url'], | |
|             'code' => $result['code'] | |
|           ]); | |
|         } | |
| 
 | |
|         return $this->respond($response, 200, [ | |
|           'error' => 'no_content', | |
|           'error_description' => 'We did not get a response body when fetching the URL', | |
|           'url' => $result['url'], | |
|           'code' => $result['code'] | |
|         ]); | |
|       } | |
| 
 | |
|       // Check for HTTP 401/403 | |
|       if($result['code'] == 401) { | |
|         return $this->respond($response, 200, [ | |
|           'error' => 'unauthorized', | |
|           'error_description' => 'The URL returned "HTTP 401 Unauthorized"', | |
|           'url' => $result['url'], | |
|           'code' => 401 | |
|         ]); | |
|       } | |
|       if($result['code'] == 403) { | |
|         return $this->respond($response, 200, [ | |
|           'error' => 'forbidden', | |
|           'error_description' => 'The URL returned "HTTP 403 Forbidden"', | |
|           'url' => $result['url'], | |
|           'code' => 403 | |
|         ]); | |
|       } | |
| 
 | |
|     } | |
| 
 | |
|     // Check for known services | |
|     $host = parse_url($result['url'], PHP_URL_HOST); | |
| 
 | |
|     if(in_array($host, ['www.instagram.com','instagram.com'])) { | |
|       list($data, $parsed) = Formats\Instagram::parse($result['body'], $result['url'], $this->http); | |
|       if($request->get('include_original')) | |
|         $data['original'] = $parsed; | |
|       $data['url'] = $result['url']; | |
|       $data['code'] = $result['code']; | |
|       return $this->respond($response, 200, $data); | |
|     } | |
| 
 | |
|     // attempt to parse the page as HTML | |
|     $doc = new DOMDocument(); | |
|     @$doc->loadHTML(self::toHtmlEntities($result['body'])); | |
| 
 | |
|     if(!$doc) { | |
|       return $this->respond($response, 200, [ | |
|         'error' => 'invalid_content', | |
|         'error_description' => 'The document could not be parsed as HTML' | |
|       ]); | |
|     } | |
| 
 | |
|     $xpath = new DOMXPath($doc); | |
| 
 | |
|     // Check for meta http equiv and replace the status code if present | |
|     foreach($xpath->query('//meta[translate(@http-equiv,\'STATUS\',\'status\')=\'status\']') as $el) { | |
|       $equivStatus = ''.$el->getAttribute('content'); | |
|       if($equivStatus && is_string($equivStatus)) { | |
|         if(preg_match('/^(\d+)/', $equivStatus, $match)) { | |
|           $result['code'] = (int)$match[1]; | |
|         } | |
|       } | |
|     } | |
| 
 | |
|     // If a target parameter was provided, make sure a link to it exists on the page | |
|     if($target=$request->get('target')) { | |
|       $found = []; | |
|       if($target) { | |
|         self::xPathFindNodeWithAttribute($xpath, 'a', 'href', function($u) use($target, &$found){ | |
|           if($u == $target) { | |
|             $found[$u] = null; | |
|           } | |
|         }); | |
|         self::xPathFindNodeWithAttribute($xpath, 'img', 'src', function($u) use($target, &$found){ | |
|           if($u == $target) { | |
|             $found[$u] = null; | |
|           } | |
|         }); | |
|         self::xPathFindNodeWithAttribute($xpath, 'video', 'src', function($u) use($target, &$found){ | |
|           if($u == $target) { | |
|             $found[$u] = null; | |
|           } | |
|         }); | |
|         self::xPathFindNodeWithAttribute($xpath, 'audio', 'src', function($u) use($target, &$found){ | |
|           if($u == $target) { | |
|             $found[$u] = null; | |
|           } | |
|         }); | |
|       } | |
| 
 | |
|       if(!$found) { | |
|         return $this->respond($response, 200, [ | |
|           'error' => 'no_link_found', | |
|           'error_description' => 'The source document does not have a link to the target URL', | |
|           'url' => $result['url'], | |
|           'code' => $result['code'], | |
|         ]); | |
|       } | |
|     } | |
| 
 | |
|     // If the URL has a fragment ID, find the DOM starting at that node and parse it instead | |
|     $html = $result['body']; | |
| 
 | |
|     $fragment = parse_url($url, PHP_URL_FRAGMENT); | |
|     if($fragment) { | |
|       $fragElement = self::xPathGetElementById($xpath, $fragment); | |
|       if($fragElement) { | |
|         $html = $doc->saveHTML($fragElement); | |
|         $foundFragment = true; | |
|       } else { | |
|         $foundFragment = false; | |
|       } | |
|     } | |
| 
 | |
|     // Now start pulling in the data from the page. Start by looking for microformats2 | |
|     $mf2 = mf2\Parse($html, $result['url']); | |
| 
 | |
|     if($mf2 && count($mf2['items']) > 0) { | |
|       $data = Formats\Mf2::parse($mf2, $result['url'], $this->http); | |
|       if($data) { | |
|         if($fragment) { | |
|           $data['info'] = [ | |
|             'found_fragment' => $foundFragment | |
|           ]; | |
|         } | |
|         if($request->get('include_original')) | |
|           $data['original'] = $html; | |
|         $data['url'] = $result['url']; // this will be the effective URL after following redirects | |
|         $data['code'] = $result['code']; | |
|         return $this->respond($response, 200, $data); | |
|       } | |
|     } | |
| 
 | |
|     // TODO: look for other content like OEmbed or other known services later | |
|  | |
|     return $this->respond($response, 200, [ | |
|       'data' => [ | |
|         'type' => 'unknown', | |
|       ], | |
|       'url' => $result['url'], | |
|       'code' => $result['code'] | |
|     ]); | |
|   } | |
| 
 | |
|   private static function xPathFindNodeWithAttribute($xpath, $node, $attr, $callback) { | |
|     foreach($xpath->query('//'.$node.'[@'.$attr.']') as $el) { | |
|       $v = $el->getAttribute($attr); | |
|       $callback($v); | |
|     } | |
|   } | |
| 
 | |
|   private static function xPathGetElementById($xpath, $id) { | |
|     $element = null; | |
|     foreach($xpath->query("//*[@id='$id']") as $el) { | |
|       $element = $el; | |
|     } | |
|     return $element; | |
|   } | |
| 
 | |
|   private function parseTwitterURL(&$request, &$response, $url, $match) { | |
|     $fields = ['twitter_api_key','twitter_api_secret','twitter_access_token','twitter_access_token_secret']; | |
|     $creds = []; | |
|     foreach($fields as $f) { | |
|       if($v=$request->get($f)) | |
|         $creds[$f] = $v; | |
|     } | |
|     $data = false; | |
|     if(count($creds) == 4) { | |
|       list($data, $parsed) = Formats\Twitter::parse($url, $match[1], $creds); | |
|     } elseif(count($creds) > 0) { | |
|       // If only some Twitter credentials were present, return an error   | |
|       return $this->respond($response, 400, [ | |
|         'error' => 'missing_parameters', | |
|         'error_description' => 'All 4 Twitter credentials must be included in the request' | |
|       ]); | |
|     } else { | |
|       // Accept Tweet JSON and parse that if provided | |
|       $json = $request->get('json'); | |
|       if($json) { | |
|         list($data, $parsed) = Formats\Twitter::parse($url, $match[1], null, $json); | |
|       } | |
|       // Skip parsing from the Twitter API if they didn't include credentials | |
|     } | |
| 
 | |
|     if($data) { | |
|       if($request->get('include_original')) | |
|         $data['original'] = $parsed; | |
|       $data['url'] = $url; | |
|       $data['code'] = 200; | |
|       return $this->respond($response, 200, $data); | |
|     } else { | |
|       return $this->respond($response, 200, [ | |
|         'data' => [ | |
|           'type' => 'unknown' | |
|         ], | |
|         'url' => $url, | |
|         'code' => 0 | |
|       ]); | |
|     } | |
| 
 | |
|   } | |
| 
 | |
| }
 |