Bot::getDefaultLanguage

static function getDefaultLanguage()
{
	$cache = BitrixMainDataCache::createInstance();
	if($cache->initCache(self::CACHE_TTL, 'language_v2', '/bx/im/'))
	{
		$languageId = $cache->getVars();
	}
	else
	{
		$languageId = '';

		$siteIterator = BitrixMainSiteTable::getList(array(
			'select' => array('LANGUAGE_ID'),
			'filter' => array('=DEF' => 'Y', '=ACTIVE' => 'Y')
		));
		if ($site = $siteIterator->fetch())
			$languageId = (string)$site['LANGUAGE_ID'];

		if ($languageId == '')
		{
			if (BitrixMainLoader::includeModule('bitrix24'))
			{
				$languageId = CBitrix24::getLicensePrefix();
			}
			else
			{
				$languageId = LANGUAGE_ID;
			}
		}
		if ($languageId == '')
		{
			$languageId = 'en';
		}

		$languageId = mb_strtolower($languageId);

		$cache->startDataCache();
		$cache->endDataCache($languageId);
	}

	return $languageId;
}