<?php
/*
 * Gallery - a web based photo album viewer and editor
 * Copyright (C) 2000-2008 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.
 */

/**
 * Helper class for GalleryEntities
 * @package GalleryCore
 * @subpackage Helpers
 * @author Bharat Mediratta <bharat@menalto.com>
 * @version $Revision: 17580 $
 * @static
 */
class GalleryEntityHelper_simple {

    /**
     * @see GalleryCoreApi::loadEntitiesById
     */
    function loadEntitiesById($ids, $requiredEntityType=null) {
	global $gallery;
	$gallery->guaranteeTimeLimit(5);

	if (empty($ids)) {
	    return array(GalleryCoreApi::error(ERROR_BAD_PARAMETER), null);
	}

	if (is_array($ids)) {
	    $returnArray = true;
	} else {
	    $returnArray = false;
	    $ids = array($ids);
	}

	/* Grab what we can from the cache and make up a list of what's missing */
	$cached = $missing = $onLoad = array();
	foreach ($ids as $id) {
	    $cacheKey = "GalleryEntityHelper::loadEntitiesById($id)";
	    if (GalleryDataCache::containsKey($cacheKey)) {
		$cached[$id] = GalleryDataCache::get($cacheKey);
	    } else {
		$data =& GalleryDataCache::getFromDisk(array('type' => 'entity', 'itemId' => $id));
		if (isset($data)) {
		    $cached[$id] =& $data;
		} else {
		    $missing[] = $id;
		}
		$onLoad[] = $id;
	    }
	}

	if (!empty($missing)) {
	    /* Get our storage object */
	    $storage =& $gallery->getStorage();

	    /* Load the entities from our persistent store */
	    list ($ret, $missing) = $storage->loadEntities($missing);
	    if ($ret) {
		return array($ret, null);
	    }
	}

	/* Move the new entities into the cache */
	foreach ($missing as $entity) {
	    $id = $entity->getId();
	    list ($ret, $classFile) = $entity->getClassFile();
	    if ($ret) {
		return array($ret, null);
	    }
	    GalleryDataCache::putToDisk(array('type' => 'entity', 'itemId' => $id),
					$entity, array($classFile));
	    $cached[$id] = $entity;
	}

	/* Let each entity do its post-load procedure */
	foreach ($onLoad as $id) {
	    $ret = $cached[$id]->onLoad();
	    if ($ret) {
		return array($ret, null);
	    }
	    GalleryDataCache::put("GalleryEntityHelper::loadEntitiesById($id)", $cached[$id]);
	}

	/* Build up the results from the cache */
	$results = array();
	foreach ($ids as $id) {
	    $results[] = $cached[$id];
	}

	/* Assert the entity-type if requested */
	if ($requiredEntityType && $requiredEntityType != 'GalleryEntity') {
	    if (!is_array($requiredEntityType)) {
		$requiredEntityType = array($requiredEntityType);
	    }

	    /*
	     * Assume entityType and class-names correspond 1:1 and use isA rather than
	     * describeEntity since we'd need to build a class-hierarchy tree from entityInfo which
	     * we get for free with isA.
	     */
	    foreach ($results as $entity) {
		$match = false;
		foreach ($requiredEntityType as $requiredType) {
		    if (GalleryUtilities::isA($entity, $requiredType)) {
			$match = true;
			break;
		    }
		}
		if (!$match) {
		    $errorMessage =
			sprintf('Entity with id [%d] is a [%s] and does not extend the required '
				. 'entity type [%s].', $entity->getId(), $entity->getEntityType(),
				implode(', ', $requiredEntityType));
		    return array(GalleryCoreApi::error(ERROR_MISSING_OBJECT, __FILE__, __LINE__,
						       $errorMessage),
				 null);
		}
	    }
	}

	if (!$returnArray) {
	    $results = $results[0];
	}

	return array(null, $results);
    }

    /**
     * @see GalleryCoreApi::loadEntityByExternalId
     */
    function loadEntityByExternalId($externalId, $entityType) {
	global $gallery;

	list ($ret, $results) = GalleryCoreApi::getMapEntry('ExternalIdMap',
	    array('entityId'), array('externalId' => $externalId, 'entityType' => $entityType));
	if ($ret) {
	    return array($ret, null);
	}
	if (!($result = $results->nextResult())) {
	    return array(GalleryCoreApi::error(ERROR_MISSING_OBJECT, __FILE__, __LINE__,
					      "$externalId $entityType"), null);
	}

	list ($ret, $entity) =
	    GalleryEntityHelper_simple::loadEntitiesById($result[0], $entityType);
	if ($ret) {
	    return array($ret, null);
	}

	return array(null, $entity);
    }
}
?>