MDL-21432 restore - spreading restore plan with block tasks

[moodle.git] / backup / util / helper / backup_general_helper.class.php

<?php

// This file is part of Moodle - http://moodle.org/
//
// Moodle 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 3 of the License, or
// (at your option) any later version.
//
// Moodle 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 Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**
 * @package    moodlecore
 * @subpackage backup-helper
 * @copyright  2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

/**
 * Non instantiable helper class providing general helper methods for backup/restore
 *
 * This class contains various general helper static methods available for backup/restore
 *
 * TODO: Finish phpdocs
 */
abstract class backup_general_helper extends backup_helper {

    /**
     * Calculate one checksum for any array/object. Works recursively
     */
    public static function array_checksum_recursive($arr) {

        $checksum = ''; // Init checksum

        // Check we are going to process one array always, objects must be cast before
        if (!is_array($arr)) {
            throw new backup_helper_exception('array_expected');
        }
        foreach ($arr as $key => $value) {
            if ($value instanceof checksumable) {
                $checksum = md5($checksum . '-' . $key . '-' . $value->calculate_checksum());
            } else if (is_object($value)) {
                $checksum = md5($checksum . '-' . $key . '-' . self::array_checksum_recursive((array)$value));
            } else if (is_array($value)) {
                $checksum = md5($checksum . '-' . $key . '-' . self::array_checksum_recursive($value));
            } else {
                $checksum = md5($checksum . '-' . $key . '-' . $value);
            }
        }
        return $checksum;
    }

    /**
     * Load and format all the needed information from moodle_backup.xml
     *
     * This function loads and process all the moodle_backup.xml
     * information, composing a big information structure that will
     * be the used by the plan builder in order to generate the
     * appropiate tasks / steps / settings
     */
    public static function get_backup_information($tempdir) {
        global $CFG;

        $info = new stdclass(); // Final information goes here

        $moodlefile = $CFG->dataroot . '/temp/backup/' . $tempdir . '/moodle_backup.xml';
        if (!file_exists($moodlefile)) { // Shouldn't happen ever, but...
            throw new backup_helper_exception('missing_moodle_backup_xml_file');
        }
        // Load the entire file to in-memory array
        $xmlparser = new progressive_parser();
        $xmlparser->set_file($moodlefile);
        $xmlprocessor = new restore_moodlexml_parser_processor();
        $xmlparser->set_processor($xmlprocessor);
        $xmlparser->process();
        $infoarr = $xmlprocessor->get_all_chunks();
        if (count($infoarr) !== 1) { // Shouldn't happen ever, but...
            throw new backup_helper_exception('problem_parsing_moodle_backup_xml_file');
        }
        $infoarr = $infoarr[0]['tags']; // for commodity

        // Let's build info
        $info->moodle_version = $infoarr['moodle_version'];
        $info->moodle_release = $infoarr['moodle_release'];
        $info->backup_version = $infoarr['backup_version'];
        $info->backup_release = $infoarr['backup_release'];
        $info->backup_date    = $infoarr['backup_date'];
        $info->original_wwwroot         = $infoarr['original_wwwroot'];
        $info->original_site_identifier = $infoarr['original_site_identifier'];
        $info->original_course_id       = $infoarr['original_course_id'];
        $info->type   =  $infoarr['details']['detail'][0]['type'];
        $info->format =  $infoarr['details']['detail'][0]['format'];
        $info->mode   =  $infoarr['details']['detail'][0]['mode'];

        // Now the contents
        $contentsarr = $infoarr['contents'];
        if (isset($contentsarr['course']) && isset($contentsarr['course'][0])) {
            $info->course = new stdclass();
            $info->course = (object)$contentsarr['course'][0];
            $info->course->settings = array();
        }
        if (isset($contentsarr['sections']) && isset($contentsarr['sections']['section'])) {
            $sectionarr = $contentsarr['sections']['section'];
            $sections = array();
            foreach ($sectionarr as $section) {
                $section = (object)$section;
                $section->settings = array();
                $sections[basename($section->directory)] = $section;
            }
            $info->sections = $sections;
        }
        if (isset($contentsarr['activities']) && isset($contentsarr['activities']['activity'])) {
            $activityarr = $contentsarr['activities']['activity'];
            $activities = array();
            foreach ($activityarr as $activity) {
                $activity = (object)$activity;
                $activity->settings = array();
                $activities[basename($activity->directory)] = $activity;
            }
            $info->activities = $activities;
        }
        $info->root_settings = array(); // For root settings

        // Now the settings, putting each one under its owner
        $settingsarr = $infoarr['settings']['setting'];
        foreach($settingsarr as $setting) {
            switch ($setting['level']) {
                case 'root':
                    $info->root_settings[$setting['name']] = $setting['value'];
                    break;
                case 'course':
                    $info->course->settings[$setting['name']] = $setting['value'];
                    break;
                case 'section':
                    $info->sections[$setting['section']]->settings[$setting['name']] = $setting['value'];
                    break;
                case 'activity':
                    $info->activities[$setting['activity']]->settings[$setting['name']] = $setting['value'];
                    break;
                default: // Shouldn't happen
                    throw new backup_helper_exception('wrong_setting_level_moodle_backup_xml_file', $setting['level']);
            }
        }

        return $info;
    }

    /**
     * Given one temp/backup/xxx dir, detect its format
     *
     * TODO: Move harcoded detection here to delegated classes under backup/format (moodle1, imscc..)
     *       conversion code will be there too.
     */
    public static function detect_backup_format($tempdir) {
        global $CFG;

        // First look for MOODLE (moodle2) format
        $filepath = $CFG->dataroot . '/temp/backup/' . $tempdir . '/moodle_backup.xml';
        if (file_exists($filepath)) { // Looks promising, lets load some information
            $handle = fopen ($filepath, "r");
            $first_chars = fread($handle,200);
            $status = fclose ($handle);
            // Check if it has the required strings
            if (strpos($first_chars,'<?xml version="1.0" encoding="UTF-8"?>') !== false &&
                strpos($first_chars,'<moodle_backup>') !== false &&
                strpos($first_chars,'<information>') !== false) {
                    return backup::FORMAT_MOODLE;
            }
        }

        // Then look for MOODLE1 (moodle1) format
        $filepath = $CFG->dataroot . '/temp/backup/' . $tempdir . '/moodle.xml';
        if (file_exists($filepath)) { // Looks promising, lets load some information
            $handle = fopen ($filepath, "r");
            $first_chars = fread($handle,200);
            $status = fclose ($handle);
            // Check if it has the required strings
            if (strpos($first_chars,'<?xml version="1.0" encoding="UTF-8"?>') !== false &&
                strpos($first_chars,'<MOODLE_BACKUP>') !== false &&
                strpos($first_chars,'<INFO>') !== false) {
                    return backup::FORMAT_MOODLE1;
            }
        }

        // Other formats

        // Arrived here, unknown format
        return backup::FORMAT_UNKNOWN;
    }
}