File Manager

<?php
/*
* 2007-2014 PrestaShop
*
* NOTICE OF LICENSE
*
* This source file is subject to the Open Software License (OSL 3.0)
* that is bundled with this package in the file LICENSE.txt.
* It is also available through the world-wide-web at this URL:
* http://opensource.org/licenses/osl-3.0.php
* If you did not receive a copy of the license and are unable to
* obtain it through the world-wide-web, please send an email
* to license@prestashop.com so we can send you a copy immediately.
*
* DISCLAIMER
*
* Do not edit or add to this file if you wish to upgrade PrestaShop to newer
* versions in the future. If you wish to customize PrestaShop for your
* needs please refer to http://www.prestashop.com for more information.
*
*  @author PrestaShop SA <contact@prestashop.com>
*  @copyright  2007-2014 PrestaShop SA
*  @license    http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
*  International Registered Trademark & Property of PrestaShop SA
*/

/*
 * StockManagerFactory : factory of stock manager
 * @since 1.5.0
 */
class StockManagerFactoryCore
{
	/**
	 * @var $stock_manager : instance of the current StockManager.
	 */
	protected static $stock_manager;

	/**
	 * Returns a StockManager
	 *
	 * @return StockManagerInterface
	 */
	public static function getManager()
	{
		if (!isset(StockManagerFactory::$stock_manager))
		{
			$stock_manager = StockManagerFactory::execHookStockManagerFactory();
			if (!($stock_manager instanceof StockManagerInterface))
				$stock_manager = new StockManager();
			StockManagerFactory::$stock_manager = $stock_manager;
		}
		return StockManagerFactory::$stock_manager;
	}

	/**
	 *  Looks for a StockManager in the modules list.
	 *
	 *  @return StockManagerInterface
	 */
	public static function execHookStockManagerFactory()
	{
		$modules_infos = Hook::getModulesFromHook(Hook::getIdByName('stockManager'));
		$stock_manager = false;

		foreach ($modules_infos as $module_infos)
		{
			$module_instance = Module::getInstanceByName($module_infos['name']);

			if (is_callable(array($module_instance, 'hookStockManager')))
				$stock_manager = $module_instance->hookStockManager();

			if ($stock_manager)
				break;
		}

		return $stock_manager;
	}
}