Agent::start

static function start($feedType, $exportId, $startPosition = "", $once = false, $execNumber = 1)
{
	if (empty($exportId))
		throw new ArgumentNullException('exportId');
	$exportId = \EscapePHPString($exportId);
	
	if (!in_array($feedType, Vk::getExportTypes()))
		throw new ArgumentOutOfRangeException('feedType');
	
	$result = "";
	$vk = Vk::getInstance();
	$vk->log(
		TradingPlatform\Logger::LOG_LEVEL_DEBUG,
		"VK_AGENT__FEED_STARTED",
		'FEED_' . $feedType,
		"VKontakte export of " . $feedType . " started from agent. Export profile: " . $exportId . ", start position: " . $startPosition
	);
	
	try
	{
//			if we run ALL export - first we must add ALBUMS. After this we create PRODUCTS agent
		if ($feedType == 'ALL')
			$feedTypeCurr = 'ALBUMS';
		else
			$feedTypeCurr = $feedType;
		
		$timelimit = $vk->getTimelimit($exportId);
		$vkFeed = Manager::createFeed($feedTypeCurr, $exportId, $timelimit, $startPosition);
		$vkFeed->processData($exportId);
	}
	
	catch (TimeIsOverException $e)
	{
		$endPosition = $e->getEndPosition();
//			control of slow export
		if ($startPosition == $endPosition)
		{
			$execNumber++;
			if ($execNumber >= 3)
			{
				\CAdminNotify::Add(array(
					'MESSAGE' => Loc::getMessage("SALE_VK__TOO_MUCH_TIMES_NOTIFY"),
					'MODULE_ID' => 'sale',
					'TAG' => 'vk_agent_much_times_notify',
					'NOTIFY_TYPE' => \CAdminNotify::TYPE_ERROR,
				));
			}
		}
		else
		{
			$execNumber = 1;
		}
		$result = self::createAgentNameForAdd($feedType, $exportId, $endPosition, $once, $execNumber);
		$vk->log(
			TradingPlatform\Logger::LOG_LEVEL_DEBUG,
			"VK_AGENT__FEED_TIMELIMIT",
			'FEED_' . $feedType,
			"VKontakte export of " . $feedType . " for profile " . $exportId . " takes too long and was finished at position '" . $startPosition . "'. To continue will be create agent."
		);
	}
	
	catch (ExecuteException $e)
	{
		$msg = $e->getFullMessage() ? $e->getFullMessage() : Loc::getMessage("SALE_VK__UNKNOWN_ERROR");
		$vk->log(TradingPlatform\Logger::LOG_LEVEL_ERROR, "VK_FEED__FEED_ERRORS", 'FEED_' . $feedType, $msg);
	}
	
	catch (\Exception $e)
	{
		$vk->log(
			TradingPlatform\Logger::LOG_LEVEL_ERROR,
			"VK_AGENT__FEED_ERRORS", 'FEED_' . $feedType,
			"VKontakte export of " . $feedType . " for profile " . $exportId . " finished with some errors. " .
			$e->getMessage()
		);
	}

//		if ALL export - we catch end of one cycle and run next type (ALBUMS => PRODUCTS)
//		if ALBUM part end normal (not with timer) - run agent to PRODUCTS export
	if ($feedType == 'ALL' && !isset($endPosition))
	{
//			for ALL export we open PRODUCTS journal after ALBUMS export end. Need for correctly show statistic to user
		$journal = new Journal($exportId, 'PRODUCTS');
		$journal->start();

		$result = self::createAgentNameForAdd('PRODUCTS', $exportId, '', $once);
		$vk->log(
			TradingPlatform\Logger::LOG_LEVEL_DEBUG,
			"VK_FEED__FEED_ALBUM_PART_FINISH",
			'FEED_' . $feedType,
			"VKontakte export of ALBUMS for profile " . $exportId . " was finished successfull. PRODUCTS export will be continue on agent."
		);
	}

//		all OK - create new agent with null start position
	elseif (strlen($result) <= 0 && !$once)
	{
		$result = self::createAgentNameForAdd($feedType, $exportId, "", $once);
	}

	$vk->log(
		TradingPlatform\Logger::LOG_LEVEL_DEBUG,
		"VK_AGENT__FEED_FINISH",
		'FEED_' . $feedType,
		"VKontakte export of " . $feedType . " for profile " . $exportId . " was finished."
	);
	return $result;
}