<?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
*/

/**
 * @since 1.5
 */
class PrestaShopAutoload
{
	/**
	 * File where classes index is stored
	 */
	const INDEX_FILE = 'cache/class_index.php';

	/**
	 * @var Autoload
	 */
	protected static $instance;

	/**
	 * @var string Root directory
	 */
	protected $root_dir;

	/**
	 *  @var array array('classname' => 'path/to/override', 'classnamecore' => 'path/to/class/core')
	 */
	public $index = array();

	public $_include_override_path = true;
	
	protected static $class_aliases = array(
		'Collection' => 'PrestaShopCollection',
		'Autoload' => 'PrestaShopAutoload',
		'Backup' => 'PrestaShopBackup',
		'Logger' => 'PrestaShopLogger'
	);

	protected function __construct()
	{
		$this->root_dir = _PS_CORE_DIR_.'/';
		$file = _PS_ROOT_DIR_.PrestaShopAutoload::INDEX_FILE;
		if (@filemtime($file) && is_readable($file))
			$this->index = include($file);
		else
			$this->generateIndex();
	}

	/**
	 * Get instance of autoload (singleton)
	 *
	 * @return Autoload
	 */
	public static function getInstance()
	{
		if (!PrestaShopAutoload::$instance)
			PrestaShopAutoload::$instance = new PrestaShopAutoload();

		return PrestaShopAutoload::$instance;
	}

	/**
	 * Retrieve informations about a class in classes index and load it
	 *
	 * @param string $classname
	 */
	public function load($classname)
	{
		// Retrocompatibility 
		if (isset(PrestaShopAutoload::$class_aliases[$classname]) && !interface_exists($classname, false) && !class_exists($classname, false))
			return eval('class '.$classname.' extends '.PrestaShopAutoload::$class_aliases[$classname].' {}');

		// regenerate the class index if the requested file doesn't exists
		if ((isset($this->index[$classname]) && $this->index[$classname]['path'] && !is_file($this->root_dir.$this->index[$classname]['path']))
			|| (isset($this->index[$classname.'Core']) && $this->index[$classname.'Core']['path'] && !is_file($this->root_dir.$this->index[$classname.'Core']['path'])))
			$this->generateIndex();

		// If $classname has not core suffix (E.g. Shop, Product)
		if (substr($classname, -4) != 'Core')
		{
			// If requested class does not exist, load associated core class
			if (isset($this->index[$classname]) && !$this->index[$classname]['path'])
			{
				require($this->root_dir.$this->index[$classname.'Core']['path']);

				if ($this->index[$classname.'Core']['type'] != 'interface')
					eval($this->index[$classname.'Core']['type'].' '.$classname.' extends '.$classname.'Core {}');
			}
			else
			{
				// request a non Core Class load the associated Core class if exists
				if (isset($this->index[$classname.'Core']))
					require_once($this->root_dir.$this->index[$classname.'Core']['path']);

				$class_dir = (isset($this->index[$classname]['override'])
					&& $this->index[$classname]['override'] === true) ? _PS_ROOT_DIR_ : $this->root_dir;

				if (isset($this->index[$classname]))
					require_once($class_dir.$this->index[$classname]['path']);
			}
		}
		// Call directly ProductCore, ShopCore class
		elseif (isset($this->index[$classname]['path']) && $this->index[$classname]['path'])
			require($this->root_dir.$this->index[$classname]['path']);
	}

	/**
	 * Generate classes index
	 */
	public function generateIndex()
	{
		$classes = array_merge(
			$this->getClassesFromDir('classes/'),
			$this->getClassesFromDir('controllers/')
		);

		if ($this->_include_override_path)
			$classes = array_merge(
				$classes,
				$this->getClassesFromDir('override/classes/', defined('_PS_HOST_MODE_')),
				$this->getClassesFromDir('override/controllers/', defined('_PS_HOST_MODE_'))
			);

		ksort($classes);
		$content = '<?php return '.var_export($classes, true).'; ?>';

		// Write classes index on disc to cache it
		$filename = _PS_ROOT_DIR_.PrestaShopAutoload::INDEX_FILE;
		$filename_tmp = tempnam(dirname($filename), basename($filename.'.'));
		if ($filename_tmp !== false && file_put_contents($filename_tmp, $content) !== false)
		{
			if (!@rename($filename_tmp, $filename))
				unlink($filename_tmp);
			else
				@chmod($filename, 0666);
		}
		// $filename_tmp couldn't be written. $filename should be there anyway (even if outdated), no need to die.
		else
			error_log('Cannot write temporary file '.$filename_tmp);
		$this->index = $classes;
	}

	/**
	 * Retrieve recursively all classes in a directory and its subdirectories
	 *
	 * @param string $path Relativ path from root to the directory
	 * @return array
	 */
	protected function getClassesFromDir($path, $host_mode = false)
	{
		$classes = array();
		$root_dir = $host_mode ? _PS_ROOT_DIR_ : $this->root_dir;

		foreach (scandir($root_dir.$path) as $file)
		{
			if ($file[0] != '.')
			{
				if (is_dir($root_dir.$path.$file))
					$classes = array_merge($classes, $this->getClassesFromDir($path.$file.'/', $host_mode));
				else if (substr($file, -4) == '.php')
				{
					$content = file_get_contents($root_dir.$path.$file);
			 		$pattern = '#\W((abstract\s+)?class|interface)\s+(?P<classname>'.basename($file, '.php').'(?:Core)?)'
			 					.'(?:\s+extends\s+[a-z][a-z0-9_]*)?(?:\s+implements\s+[a-z][a-z0-9_]*(?:\s*,\s*[a-z][a-z0-9_]*)*)?\s*\{#i';
			 		if (preg_match($pattern, $content, $m))
			 		{
			 			$classes[$m['classname']] = array(
			 				'path' => $path.$file,
			 				'type' => trim($m[1]),
			 				'override' => $host_mode
			 			);

						if (substr($m['classname'], -4) == 'Core')
							$classes[substr($m['classname'], 0, -4)] = array(
								'path' => '',
								'type' => $classes[$m['classname']]['type'],
								'override' => $host_mode
							);
			 		}
				}
			}
		}

		return $classes;
	}

	public function getClassPath($classname)
	{
		return (isset($this->index[$classname]) && isset($this->index[$classname]['path'])) ? $this->index[$classname]['path'] : null;
	}
}