public function convertKeysForSession(CourseSession $session, $content, $withEventsList = true, User $user = null)
 {
     $course = $session->getCourse();
     $events = $session->getEvents();
     $eventsList = '';
     $sessionTrainers = $this->getUsersBySessionAndType($session, CourseSessionUser::TEACHER);
     $sessionTrainersHtml = '';
     if (count($sessionTrainers) > 0) {
         $sessionTrainersHtml = '<ul>';
         foreach ($sessionTrainers as $trainer) {
             $sessionTrainersHtml .= '<li>' . $trainer->getFirstName() . ' ' . $trainer->getLastName() . '</li>';
         }
         $sessionTrainersHtml .= '</ul>';
     }
     if ($withEventsList && count($events) > 0) {
         $eventsList = '<ul>';
         foreach ($events as $event) {
             $eventsList .= '<li>' . $event->getName() . ' [' . $event->getStartDate()->format('d/m/Y H:i') . ' -> ' . $event->getEndDate()->format('d/m/Y H:i') . ']';
             $location = $event->getLocation();
             if (!is_null($location)) {
                 $locationHtml = '<br>' . $location->getStreet() . ', ' . $location->getStreetNumber();
                 $locationHtml .= $location->getBoxNumber() ? ' / ' . $location->getBoxNumber() : '';
                 $locationHtml .= '<br>' . $location->getPc() . ' ' . $location->getTown() . '<br>' . $location->getCountry();
                 $locationHtml .= $location->getPhone() ? '<br>' . $location->getPhone() : '';
                 $eventsList .= $locationHtml;
             }
             $eventsList .= $event->getLocationExtra();
         }
         $eventsList .= '</ul>';
     }
     $now = new \DateTime();
     $keys = ['%date%', '%course_title%', '%course_code%', '%course_description%', '%session_name%', '%session_description%', '%session_start%', '%session_end%', '%session_trainers%'];
     $values = [$now->format('d/m/Y'), $course->getTitle(), $course->getCode(), $course->getDescription(), $session->getName(), $session->getDescription(), $session->getStartDate()->format('d/m/Y'), $session->getEndDate()->format('d/m/Y'), $sessionTrainersHtml];
     if ($withEventsList) {
         $keys[] = '%events_list%';
         $values[] = $eventsList;
     }
     if (!is_null($user)) {
         $keys[] = '%first_name%';
         $keys[] = '%last_name%';
         $values[] = $user->getFirstName();
         $values[] = $user->getLastName();
     }
     return str_replace($keys, $values, $content);
 }