enable passing a session cookie in instagram requests

lib/XRay.php

@@ -5,7 +5,7 @@ class XRay {
   public $http;
 
   public function __construct() {
-    $this->http = new HTTP();
+    $this->http = new HTTP('Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36 p3k/XRay');
   }
 
   public function rels($url, $opts=[]) {
@@ -40,6 +40,7 @@ class XRay {
       'url' => $url,
       'code' => $code,
     ], $opts);
+
     if(!isset($opts['include_original']) || !$opts['include_original'])
       unset($result['original']);
     if(!isset($result['url'])) $result['url'] = $url;

lib/XRay/Fetcher.php

@@ -58,6 +58,11 @@ class Fetcher {
       return Formats\Hackernews::fetch($this->http, $url, $opts);
     }
 
+    // Check if this is an Instagram URL and enable passing a session cookie
+    if(Formats\Instagram::matches($url)) {
+      return Formats\Instagram::fetch($this->http, $url, $opts);
+    }
+
     // All other URLs are fetched normally
 
     // Special-case appspot.com URLs to not follow redirects.

lib/XRay/Formats/Instagram.php

@@ -15,6 +15,42 @@ class Instagram extends Format {
     return self::matches_host($url);
   }
 
+  public static function fetch($http, $url, $opts=[]) {
+    if(!self::matches($url))
+      return false;
+
+    $headers = [];
+
+    if(isset($opts['instagram_session']) && $opts['instagram_session'])
+      $headers[] = 'Cookie: sessionid='.$opts['instagram_session'];
+
+    $result = $http->get($url, $headers);
+
+    // Check for errors such as getting redirected to the login page or getting rate limiited
+    /*
+    // TODO
+    if(false) {
+      return [
+        'error' => 'rate_limited',
+        'error_description' => 'Instagram has rate limited this client. Please try again later.',
+        'url' => $result['url'],
+        'code' => $result['code'],
+      ];
+    }
+
+    if(false) {
+      return [
+        'error' => 'unauthorized',
+        'error_description' => 'Instagram redirected to the login page. Either this user is private, or the client has been rate limited.',
+        'url' => $result['url'],
+        'code' => $result['code'],
+      ];
+    }
+    */
+
+    return $result;
+  }
+
   public static function parse($http, $http_response, $opts=[]) {
     $html = $http_response['body'];
     $url = $http_response['url'];