SupportBox::checkTypingRestriction

static function checkTypingRestriction(array $messageFields): bool
{
	return
		// Allow only one-to-one conversation
		(
			empty($messageFields['CHAT']) && empty($messageFields['RELATION'])
		)
		||
		// allow conversation in specialized questioning chat
		(
			$messageFields['CHAT']['TYPE'] === IM_MESSAGE_CHAT
			&& $messageFields['CHAT']['ENTITY_TYPE'] === self::CHAT_ENTITY_TYPE
		);
}