LastMessages.php

См. документацию.

<?php
 
namespace Bitrix\Im\V2\Message;
 
use Bitrix\Im\Model\LastMessageTable;
use Bitrix\Im\V2\Message;
 
class LastMessages
{
    protected const COUNT_OF_LAST_USERS = 3;
    protected const LIMIT_DELETE_BATCH = 20;
 
    private array $chatIds;
    private ?array $lastMessages = null;
 
    public function __construct(array $chatIds)
    {
        $this->chatIds = $chatIds;
    }
 
    public static function insert(Message $message): void
    {
        if ($message->getAuthorId() === 0)
        {
            return;
        }
 
        LastMessageTable::merge(
            [
                'USER_ID' => $message->getAuthorId(),
                'CHAT_ID' => $message->getChatId(),
                'MESSAGE_ID' => $message->getId(),
                'DATE_CREATE' => $message->getDateCreate(),
            ],
            [
                'MESSAGE_ID' => $message->getId(),
                'DATE_CREATE' => $message->getDateCreate(),
            ],
            ['CHAT_ID', 'USER_ID']
        );
 
        static::deleteExtra($message->getChatId());
    }
 
    public function getUsersByChatId(int $chatId): array
    {
        $this->fill();
 
        return $this->lastMessages[$chatId]['USERS'] ?? [];
    }
 
    protected function fill(): void
    {
        if (isset($this->lastMessages))
        {
            return;
        }
 
        $this->lastMessages = [];
 
        if (empty($this->chatIds))
        {
            return;
        }
 
        $raw = LastMessageTable::query()
            ->setSelect(['USER_ID', 'CHAT_ID', 'MESSAGE_ID', 'DATE_CREATE'])
            ->whereIn('CHAT_ID', $this->chatIds)
            ->setOrder(['DATE_CREATE' => 'DESC'])
            ->fetchAll()
        ;
 
        foreach ($raw as $row)
        {
            $chatId = (int)$row['CHAT_ID'];
            if (count($this->lastMessages[$chatId]['USERS'] ?? []) < self::COUNT_OF_LAST_USERS)
            {
                $this->lastMessages[$chatId]['USERS'][] = (int)$row['USER_ID'];
            }
        }
    }
 
    protected static function deleteExtra(int $chatId): void
    {
        $extraIds = LastMessageTable::query()
            ->setSelect(['ID'])
            ->where('CHAT_ID', $chatId)
            ->setOrder(['DATE_CREATE' => 'DESC'])
            ->setLimit(self::LIMIT_DELETE_BATCH)
            ->setOffset(self::COUNT_OF_LAST_USERS)
            ->fetchCollection()
            ->getIdList()
        ;
 
        if (empty($extraIds))
        {
            return;
        }
 
        LastMessageTable::deleteByFilter(['=ID' => $extraIds]);
    }
}