<?php
/**
 * Akeeba Engine
 * The modular PHP5 site backup engine
 * @copyright Copyright (c)2009-2011 Nicholas K. Dionysopoulos
 * @license GNU GPL version 3 or, at your option, any later version
 * @package akeebaengine
 * @version $Id: incremental.php 410 2011-01-24 11:29:01Z nikosdion $
 */

// Protection against direct access
defined('AKEEBAENGINE') or die('Restricted access');

/**
 * Incremental file filter
 * 
 * It will only backup files which are newer than the last backup taken with this profile
 */
class AEFilterIncremental extends AEAbstractFilter
{
	function __construct()
	{
		$this->object	= 'file';
		$this->subtype	= 'all';
		$this->method	= 'api';
	}

	protected function is_excluded_by_api($test, $root)
	{
		static $filter_switch;
		static $last_backup;

		if(is_null($filter_switch))
		{
			$config =& AEFactory::getConfiguration();
			$filter_switch = AEUtilScripting::getScriptingParameter('filter.incremental',0);
			$filter_switch = ($filter_switch == 1);

			$last_backup = $config->get('volatile.filter.last_backup', null);
			if(is_null($last_backup) && $filter_switch)
			{
				// Get a list of backups on this profile
				$backups = AEPlatform::get_statistics_list(0, 0, AEPlatform::get_active_profile() );

				// Find this backup's ID
				$model =& AEFactory::getStatistics();
				$id = $model->getId();
				if(is_null($id)) $id = -1;

				// Initialise
				jimport('joomla.utilities.date');
				$last_backup = time();
				$now = $last_backup;

				// Find the last time a successful backup with this profile was made
				if(count($backups)) foreach($backups as $backup)
				{
					// Skip the current backup
					if($backup['id'] == $id) continue;

					// Skip non-complete backups
					if($backup['status'] != 'complete') continue;

					$jdate = new JDate($backup['backupstart']);
					$backuptime = $jdate->toUnix();

					$last_backup = $backuptime;
					break;
				}

				if($last_backup == $now) {
					// No suitable backup found; disable this filter
					$config->set('volatile.scripting.incfile.filter.incremental',0);
					$filter_switch = false;
				} else {
					// Cache the last backup timestamp
					$config->set('volatile.filter.last_backup',$last_backup);
				}
			}
		}

		if(!$filter_switch) return false;

		// Get the filesystem path for $root
		$config =& AEFactory::getConfiguration();
		$fsroot = $config->get('volatile.filesystem.current_root','');
		$ds = ($fsroot == '') || ($fsroot == '/') ? '' : DS;
		$filename = $fsroot.$ds.$test;

		// Get the timestamp of the file
		$timestamp = @filemtime($filename);

		// If we could not get this information, include the file in the archive
		if($timestamp === false) return false;

		// Compare it with the last backup timestamp and exclude if it's older than the last backup
		if($timestamp <= $last_backup) {
			//AEUtilLogger::WriteLog(_AE_LOG_DEBUG, "Excluding $filename due to incremental backup restrictions");
			return true;
		}

		// No match? Just include the file!
		return false;
	}

}