Sync.php

<?php
 
namespace Bitrix\Im\V2\Controller;
 
use Bitrix\Im\V2\Error;
use Bitrix\Im\V2\Sync\SyncError;
use Bitrix\Im\V2\Sync\SyncService;
use Bitrix\Main\ObjectException;
use Bitrix\Main\Type\DateTime;
use DateTimeInterface;
 
class Sync extends BaseController
{
    public function listAction(array $filter = [], int $limit = 50): ?array
    {
        $syncService = new SyncService();
 
        if (isset($filter['lastDate']))
        {
            try
            {
                $date = new DateTime($filter['lastDate'], DateTimeInterface::RFC3339);
            }
            catch (ObjectException $exception)
            {
                $this->addError(new Error($exception->getCode(), $exception->getMessage()));
 
                return null;
            }
 
            return $syncService->getChangesFromDate($date, $limit);
        }
 
        $lastId = null;
 
        if (isset($filter['lastId']))
        {
            $lastId = (int)$filter['lastId'];
        }
 
        return $syncService->getChangesFromId($lastId, $limit);
    }
}