<?php
/*
 * Gallery - a web based photo album viewer and editor
 * Copyright (C) 2000-2007 Bharat Mediratta
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA  02110-1301, USA.
 */

/**
 * Utility functions useful in managing Permalinks.
 * @package Permalinks
 * @subpackage Classes
 * @author Pierre-Luc Paour <gallery@paour.com>
 * @version $Revision: 15513 $
 * @static
 */
class PermalinksMapHelper {

    /**
     * Return the aliases defined for a given item
     *
     * @param int $itemId (optional) item id or null for all aliases
     * @return array object GalleryStatus a status code
     *         array of aliase names
     */
    function fetchAliasesForItem($itemId=null) {
	$match = isset($itemId) ? array('destId' => (int)$itemId) : array();
	list ($ret, $searchResults) = GalleryCoreApi::getMapEntry('PermalinksMap',
	    array('aliasName'), $match);
	if ($ret) {
	    return array($ret, null);
	}

	$aliases = array();
	while ($result = $searchResults->nextResult()) {
	    $aliases[] = $result[0];
	}
	return array(null, $aliases);
    }

    /**
     * Return the item id the alias name refers to, if any
     *
     * @param string $aliasName
     * @return array object GalleryStatus a status code
     *               int item id
     */
    function fetchItemIdForAlias($aliasName) {
	list ($ret, $searchResults) = GalleryCoreApi::getMapEntry('PermalinksMap',
	    array('destId'), array('aliasName' => $aliasName));
	if ($ret) {
	    return array($ret, null);
	}

	if ($result = $searchResults->nextResult()) {
	    $destId = (int)$result[0];
	} else {
	    $destId = null;
	}
	return array(null, $destId);
    }

    /**
     * Create an alias
     *
     * @param string $aliasName
     * @param int $itemId
     * @return object GalleryStatus a status code
     */
    function createAlias($aliasName, $itemId) {
	/* first, check for collision */
	list ($ret, $collisionId) = PermalinksMapHelper::fetchItemIdForAlias($aliasName);
	if ($ret) {
	    return $ret;
	}
	if (isset($collisionId)) {
	    /* we expected null, this means we have a collision. Throw it */
	    return GalleryCoreApi::error(ERROR_COLLISION);
	}

	/* Add a new alias */
	$ret = GalleryCoreApi::addMapEntry('PermalinksMap',
					   array('aliasName' => $aliasName, 'destId' => $itemId));
	if ($ret) {
	    return $ret;
	}

	return null;
    }

    /**
     * Delete an alias
     *
     * @param int $aliasName
     * @return object GalleryStatus a status code
     */
    function deleteAlias($aliasName) {
	/* Remove this alias from our groups table. */
	$ret = GalleryCoreApi::removeMapEntry('PermalinksMap', array('aliasName' => $aliasName));
	if ($ret) {
	    return $ret;
	}

	return null;
    }
}
?>