private function convertActivityToArray(array $activity)
    {
        $activityArray = array();

        $previousGroupNumber = null;
        /** @var Activity $activityItem */
        foreach ($activity as $activityItem) {
            $type = $activityItem->getType();
            $groupNumber = $activityItem->getGroupNumber();
            $user = $activityItem->getUser();
            $name = $user->getName();
            $avatar = $this->request->getScheme() .'://' . $this->request->getHttpHost() . $this->request->getBasePath() . '/uploads/avatar/' . $user->getAvatar();
            $data = $activityItem->getData();
            $created = $activityItem->getCreatedAt();

            $activityArray[$groupNumber]['type'] = $type;
            $activityArray[$groupNumber]['created'] = $created;

            if ($type == ActivityType::Like) {
                if ($groupNumber != $previousGroupNumber) {
                    $data['documentaryThumbnail'] = $this->request->getScheme() .'://' . $this->request->getHttpHost() . $this->request->getBasePath() . '/uploads/posters/' . $data['documentaryThumbnail'];
                    $activityArray[$groupNumber]['parent']['data'] = $data;
                    $activityArray[$groupNumber]['parent']['user']['name'] = $name;
                    $activityArray[$groupNumber]['parent']['user']['avatar'] = $avatar;
                } else {
                    $data['documentaryThumbnail'] = $this->request->getScheme() .'://' . $this->request->getHttpHost() . $this->request->getBasePath() . '/uploads/posters/' . $data['documentaryThumbnail'];
                    $child['data'] = $data;
                    $child['user']['name'] = $name;
                    $child['user']['avatar'] = $avatar;
                    $activityArray[$groupNumber]['child'][] = $child;
                }
            } else if ($type == ActivityType::Comment) {
                $activityArray[$groupNumber]['parent']['user']['name'] = $name;
                $activityArray[$groupNumber]['parent']['user']['avatar'] = $avatar;
                $activityArray[$groupNumber]['parent']['data'] = $data;
            } else if ($type == ActivityType::Joined) {
                if ($groupNumber != $previousGroupNumber) {
                    $activityArray[$groupNumber]['parent']['user']['name'] = $name;
                    $activityArray[$groupNumber]['parent']['user']['avatar'] = $avatar;
                } else {
                    $child['user']['name'] = $name;
                    $child['user']['avatar'] = $avatar;#
                    $activityArray[$groupNumber]['child'][] = $child;
                }
            } else if ($type == ActivityType::Added) {
                if ($groupNumber != $previousGroupNumber) {
                    $activityArray[$groupNumber]['parent']['data'] = $data;
                    $activityArray[$groupNumber]['parent']['user']['name'] = $name;
                    $activityArray[$groupNumber]['parent']['user']['avatar'] = $avatar;
                } else {
                    $child['data'] = $data;
                    $child['user']['name'] = $name;
                    $child['user']['avatar'] = $avatar;
                    $activityArray[$groupNumber]['child'][] = $child;
                }
            }

            $previousGroupNumber = $groupNumber;
        }

        return $activityArray;
    }