Secretary::createChatFromMessageAction

public function createChatFromMessageAction(int $messageId): ?int
{
	if (!Loader::includeModule('im'))
	{
		return null;
	}

	global $USER;
	$userId = $USER->GetID();

	if (!$this->canBindEntities($messageId, (int)$userId))
	{
		$this->addError(new Error(Loc::getMessage('MAIL_SECRETARY_ACCESS_DENIED')));
		return null;
	}

	$message = BitrixMailIntegrationIntranetSecretary::getMessage($messageId);
	$messageData = $message->toArray();
	$messageData['USER_IDS'] = [$USER->GetID()];

	if ($chatId = BitrixIntranetSecretary::getChatIdIfExists($messageId, 'MAIL'))
	{
		// get back to chat if user left in past
		if (! BitrixIntranetSecretary::isUserInChat($chatId, $userId))
		{
			BitrixIntranetSecretary::addUserToChat($chatId, $userId, false);
			// // post welcome message again because it was hidden
			// BitrixIntranetSecretary::postMailChatWelcomeMessage($message, $chatId, $userId);
		}
	}
	else
	{
		$lockName = "chat_create_mail_{$messageId}";
		if (!Application::getConnection()->lock($lockName))
		{
			$this->addError(new Error(
					Loc::getMessage('MAIL_SECRETARY_CREATE_CHAT_LOCK_ERROR'), 'lock_error')
			);
			return null;
		}

		$chatId = BitrixIntranetSecretary::createMailChat($messageData, $userId);

		Application::getConnection()->unlock($lockName);
	}

	if (Loader::includeModule('pull'))
	{
		$mailboxId = BitrixMailIntegrationIntranetSecretary::getMailboxIdForMessage($messageId);

		if($mailboxId)
		{
			CPullWatch::addToStack(
				'mail_mailbox_' . $mailboxId,
				[
					'module_id' => 'mail',
					'command' => 'messageBindingCreated',
					'params' => [
						'messageId' => $messageId,
						'mailboxId' => $mailboxId,
						'entityType' => Message::ENTITY_TYPE_IM_CHAT,
						'entityId' => $chatId,
						'bindingEntityLink' =>
						CComponentEngine::makePathFromTemplate(
							'/online/?IM_DIALOG=chat#chat_id#',
							[
								'chat_id' => $chatId,
							]
						),
					],
				]
			);
		}
	}

	return $chatId;
}