<?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.
 */

/**
 * A collection of useful maintenance related methods
 * @package GalleryCore
 * @subpackage Helpers
 * @author Bharat Mediratta <bharat@menalto.com>
 * @version $Revision: 17580 $
 * @static
 */
class MaintenanceHelper_simple {

    /**
     * Fetch all the available maintenance tasks
     * @return array GalleryStatus a status code
     *               array(taskId => MaintenanceTask, ...)
     */
    function fetchTasks() {
	/* Get all the option plugins */
	list ($ret, $allTaskIds) =
	    GalleryCoreApi::getAllFactoryImplementationIds('MaintenanceTask');
	if ($ret) {
	    return array($ret, null);
	}

	$taskInstances = array();
	foreach (array_keys($allTaskIds) as $taskId) {
	    list ($ret, $task) = GalleryCoreApi::newFactoryInstanceById('MaintenanceTask', $taskId);
	    if ($ret) {
		return array($ret, null);
	    }

	    $taskInstances[$taskId] = $task;
	}

	return array(null, $taskInstances);
    }

    /**
     * Return information about the last run of this task.
     *
     * @param string $taskId
     * @return array GalleryStatus a status code
     *               array(runId => int,
     *                     timestamp => int,
     *                     success => bool,
     *                     details => string)
     */
    function fetchLastRun($taskId) {
	list ($ret, $searchResults) = GalleryCoreApi::getMapEntry('GalleryMaintenanceMap',
	    array('runId', 'timestamp', 'success', 'details'), array('taskId' => $taskId),
	    array('orderBy' => array('timestamp' => ORDER_DESCENDING),
		  'limit' => array('count' => 1)));
	if ($ret) {
	    return array($ret, null);
	}
	$result = $searchResults->nextResult();
	$info = null;
	if ($searchResults->resultCount() == 1) {
	    $info = array('runId' => $result[0],
			  'timestamp' => (int)$result[1],
			  'success' => (bool)$result[2],
			  'details' => unserialize($result[3]));
	}

	return array(null, $info);
    }

    /**
     * Add a new task run to the maintenance map.
     *
     * @param string $taskId
     * @param int $timestamp when the run happened
     * @param bool $success task success/failure
     * @param array $details string task details
     * @return GalleryStatus a status code
     */
    function addRun($taskId, $timestamp, $success, $details) {
	global $gallery;

	$storage =& $gallery->getStorage();
	list ($ret, $runId) = $storage->getUniqueId();
	if ($ret) {
	    return $ret;
	}

	$ret = GalleryCoreApi::addMapEntry(
	    'GalleryMaintenanceMap',
	    array('runId' => $runId,
		  'taskId' => $taskId,
		  'timestamp' => $timestamp,
		  'success' => (int)$success,
		  'details' => serialize($details)));
	if ($ret) {
	    return $ret;
	}

	return null;
    }

    /**
     * @see GalleryCoreApi::setMaintenanceMode
     */
    function setMaintenanceMode($mode) {
	global $gallery;

	$currentMode = $gallery->getConfig('mode.maintenance');

	/* If already in the requested mode, don't have to do anything. */
	if ($currentMode !== $mode) {
	    $platform =& $gallery->getPlatform();
	    $versionFile = $gallery->getConfig('data.gallery.version');

	    list ($ret, $module) = GalleryCoreApi::loadPlugin('module', 'core');
	    if ($ret) {
		return $ret;
	    }

	    $versions = $module->getInstalledVersions();
	    $versionsData = array($versions['core'], $versions['gallery']);
	    if (!empty($mode)) {
		$modeText = 'maintenance-mode';

		/* If $mode is a string then treat as a url of the custom maintenance page. */
		if (is_string($mode)) {
		    $modeText .= ":$mode";
		}
		$versionsData[] = $modeText;
	    }

	    $gallery->debug('Update versions file with maintenance mode');

	    $data = implode("\n", $versionsData);
	    if (!$platform->atomicWrite($versionFile, $data)) {
		$gallery->debug('Error: Can\'t write to versions file');
		return GalleryCoreApi::error(ERROR_PLATFORM_FAILURE, __FILE__, __LINE__,
							       'Can\'t write to the versions file');
	    }

	    $gallery->setConfig('mode.maintenance', $mode);
	}

	return null;
    }
}
?>