SameChatMessageFilter.php

<?php
 
namespace Bitrix\Im\V2\Controller\Filter;
 
use Bitrix\Im\V2\Message;
use Bitrix\Im\V2\MessageCollection;
use Bitrix\Main\Engine\ActionFilter\Base;
use Bitrix\Main\Event;
use Bitrix\Main\EventResult;
 
class SameChatMessageFilter extends Base
{
 
    public function onBeforeAction(Event $event)
    {
        foreach ($this->getAction()->getArguments() as $argument)
        {
            if ($argument instanceof MessageCollection)
            {
                $commonChatId = $argument->getCommonChatId();
 
                if ($commonChatId === null)
                {
                    $this->addError(new Message\MessageError(Message\MessageError::DIFFERENT_CHAT_ERROR));
 
                    return new EventResult(EventResult::ERROR, null, null, $this);
                }
 
                $this->filterMessageByChatId($argument, $commonChatId);
            }
        }
 
        return null;
    }
 
    private function filterMessageByChatId(MessageCollection $messages, int $chatId): void
    {
        $keysToUnset = [];
 
        foreach ($messages as $key => $message)
        {
            if ($message->getChatId() !== $chatId)
            {
                $keysToUnset[$key] = $key;
            }
        }
 
        $messages->unsetByKeys($keysToUnset);
    }
 
}