CounterService::getCountUnreadMessagesByChatId

protected function getCountUnreadMessagesByChatId(int $chatId): int
{
	return MessageUnreadTable::query()
		->setSelect(['COUNT'])
		->where('CHAT_ID', $chatId)
		->where('USER_ID', $this->getContext()->getUserId())
		->registerRuntimeField('COUNT', new ExpressionField('COUNT', 'COUNT(*)'))
		->fetch()['COUNT'] ?? 0
	;
}