confirmed with date and block multiple times confirm action

src/Confide/EloquentRepository.php

@@ -118,16 +118,18 @@ public function getUserByEmailOrUsername($emailOrUsername)
      *
      * @param string $code
      *
-     * @return bool Success
+     * @return bool Success or Null for nothing affected
      */
     public function confirmByCode($code)
     {
         $identity = ['confirmation_code' => $code];
 
         $user = $this->getUserByIdentity($identity);
 
-        if ($user) {
+        if ($user->confirmed == null) {
             return $this->confirmUser($user);
+        } else if ($user) {
+            return null;
         } else {
             return false;
         }
@@ -143,7 +145,10 @@ public function confirmByCode($code)
      */
     protected function confirmUser($user)
     {
-        $user->confirmed = true;
+        $date = new \DateTime();
+        $date->setTimezone(new \DateTimeZone('UTC'));
+
+        $user->confirmed = $date->format('Y-m-d H:i:s');
 
         return $user->save();
     }