1<?php
2
3// This file is part of Moodle - http://moodle.org/
4//
5// Moodle is free software: you can redistribute it and/or modify
6// it under the terms of the GNU General Public License as published by
7// the Free Software Foundation, either version 3 of the License, or
8// (at your option) any later version.
9//
10// Moodle is distributed in the hope that it will be useful,
11// but WITHOUT ANY WARRANTY; without even the implied warranty of
12// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13// GNU General Public License for more details.
14//
15// You should have received a copy of the GNU General Public License
16// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
17
18/**
19 * @package    moodlecore
20 * @subpackage backup-helper
21 * @copyright  2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
22 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
23 */
24
25/**
26 * Non instantiable helper class providing support for restore prechecks
27 *
28 * This class contains various prechecks to be performed before executing
29 * the restore plan. Its entry point is execute_prechecks() that will
30 * call various stuff. At the end, it will return one array(), if empty
31 * all the prechecks have passed ok. If not empty, you'll find 1/2 elements
32 * in the array, warnings and errors, each one containing one description
33 * of the problem. Warnings aren't stoppers so the restore execution can
34 * continue after displaying them. In the other side, if errors are returned
35 * then restore execution cannot continue
36 *
37 * TODO: Finish phpdocs
38 */
39abstract class restore_prechecks_helper {
40
41    /**
42     * Entry point for all the prechecks to be performed before restore
43     *
44     * Returns empty array or warnings/errors array
45     */
46    public static function execute_prechecks(restore_controller $controller, $droptemptablesafter = false) {
47        global $CFG;
48
49        $errors = array();
50        $warnings = array();
51
52        // Some handy vars to be used along the prechecks
53        $samesite = $controller->is_samesite();
54        $restoreusers = $controller->get_plan()->get_setting('users')->get_value();
55        $hasmnetusers = (int)$controller->get_info()->mnet_remoteusers;
56        $restoreid = $controller->get_restoreid();
57        $courseid = $controller->get_courseid();
58        $userid = $controller->get_userid();
59        $rolemappings = $controller->get_info()->role_mappings;
60        $progress = $controller->get_progress();
61
62        // Start tracking progress. There are currently 8 major steps, corresponding
63        // to $majorstep++ lines in this code; we keep track of the total so as to
64        // verify that it's still correct. If you add a major step, you need to change
65        // the total here.
66        $majorstep = 1;
67        $majorsteps = 8;
68        $progress->start_progress('Carrying out pre-restore checks', $majorsteps);
69
70        // Load all the included tasks to look for inforef.xml files
71        $inforeffiles = array();
72        $tasks = restore_dbops::get_included_tasks($restoreid);
73        $progress->start_progress('Listing inforef files', count($tasks));
74        $minorstep = 1;
75        foreach ($tasks as $task) {
76            // Add the inforef.xml file if exists
77            $inforefpath = $task->get_taskbasepath() . '/inforef.xml';
78            if (file_exists($inforefpath)) {
79                $inforeffiles[] = $inforefpath;
80            }
81            $progress->progress($minorstep++);
82        }
83        $progress->end_progress();
84        $progress->progress($majorstep++);
85
86        // Create temp tables
87        restore_controller_dbops::create_restore_temp_tables($controller->get_restoreid());
88
89        // Check we are restoring one backup >= $min20version (very first ok ever)
90        $min20version = 2010072300;
91        if ($controller->get_info()->backup_version < $min20version) {
92            $message = new stdclass();
93            $message->backup = $controller->get_info()->backup_version;
94            $message->min    = $min20version;
95            $errors[] = get_string('errorminbackup20version', 'backup', $message);
96        }
97
98        // Compare Moodle's versions
99        if ($CFG->version < $controller->get_info()->moodle_version) {
100            $message = new stdclass();
101            $message->serverversion = $CFG->version;
102            $message->serverrelease = $CFG->release;
103            $message->backupversion = $controller->get_info()->moodle_version;
104            $message->backuprelease = $controller->get_info()->moodle_release;
105            $warnings[] = get_string('noticenewerbackup','',$message);
106        }
107
108        // The original_course_format var was introduced in Moodle 2.9.
109        $originalcourseformat = null;
110        if (!empty($controller->get_info()->original_course_format)) {
111            $originalcourseformat = $controller->get_info()->original_course_format;
112        }
113
114        // We can't restore other course's backups on the front page.
115        if ($controller->get_courseid() == SITEID &&
116                $originalcourseformat != 'site' &&
117                $controller->get_type() == backup::TYPE_1COURSE) {
118            $errors[] = get_string('errorrestorefrontpagebackup', 'backup');
119        }
120
121        // We can't restore front pages over other courses.
122        if ($controller->get_courseid() != SITEID &&
123                $originalcourseformat == 'site' &&
124                $controller->get_type() == backup::TYPE_1COURSE) {
125            $errors[] = get_string('errorrestorefrontpagebackup', 'backup');
126        }
127
128        // If restoring to different site and restoring users and backup has mnet users warn/error
129        if (!$samesite && $restoreusers && $hasmnetusers) {
130            // User is admin (can create users at sysctx), warn
131            if (has_capability('moodle/user:create', context_system::instance(), $controller->get_userid())) {
132                $warnings[] = get_string('mnetrestore_extusers_admin', 'admin');
133            // User not admin
134            } else {
135                $errors[] = get_string('mnetrestore_extusers_noadmin', 'admin');
136            }
137        }
138
139        // Load all the inforef files, we are going to need them
140        $progress->start_progress('Loading temporary IDs', count($inforeffiles));
141        $minorstep = 1;
142        foreach ($inforeffiles as $inforeffile) {
143            // Load each inforef file to temp_ids.
144            restore_dbops::load_inforef_to_tempids($restoreid, $inforeffile, $progress);
145            $progress->progress($minorstep++);
146        }
147        $progress->end_progress();
148        $progress->progress($majorstep++);
149
150        // If restoring users, check we are able to create all them
151        if ($restoreusers) {
152            $file = $controller->get_plan()->get_basepath() . '/users.xml';
153             // Load needed users to temp_ids.
154            restore_dbops::load_users_to_tempids($restoreid, $file, $progress);
155            $progress->progress($majorstep++);
156            if ($problems = restore_dbops::precheck_included_users($restoreid, $courseid, $userid, $samesite, $progress)) {
157                $errors = array_merge($errors, $problems);
158            }
159        } else {
160            // To ensure consistent number of steps in progress tracking,
161            // mark progress even though we didn't do anything.
162            $progress->progress($majorstep++);
163        }
164        $progress->progress($majorstep++);
165
166        // Note: restore won't create roles at all. Only mapping/skip!
167        $file = $controller->get_plan()->get_basepath() . '/roles.xml';
168        restore_dbops::load_roles_to_tempids($restoreid, $file); // Load needed roles to temp_ids
169        if ($problems = restore_dbops::precheck_included_roles($restoreid, $courseid, $userid, $samesite, $rolemappings)) {
170            $errors = array_key_exists('errors', $problems) ? array_merge($errors, $problems['errors']) : $errors;
171            $warnings = array_key_exists('warnings', $problems) ? array_merge($warnings, $problems['warnings']) : $warnings;
172        }
173        $progress->progress($majorstep++);
174
175        // Check we are able to restore and the categories and questions
176        $file = $controller->get_plan()->get_basepath() . '/questions.xml';
177        restore_dbops::load_categories_and_questions_to_tempids($restoreid, $file);
178        if ($problems = restore_dbops::precheck_categories_and_questions($restoreid, $courseid, $userid, $samesite)) {
179            $errors = array_key_exists('errors', $problems) ? array_merge($errors, $problems['errors']) : $errors;
180            $warnings = array_key_exists('warnings', $problems) ? array_merge($warnings, $problems['warnings']) : $warnings;
181        }
182        $progress->progress($majorstep++);
183
184        // Prepare results.
185        $results = array();
186        if (!empty($errors)) {
187            $results['errors'] = $errors;
188        }
189        if (!empty($warnings)) {
190            $results['warnings'] = $warnings;
191        }
192        // Warnings/errors detected or want to do so explicitly, drop temp tables
193        if (!empty($results) || $droptemptablesafter) {
194            restore_controller_dbops::drop_restore_temp_tables($controller->get_restoreid());
195        }
196
197        // Finish progress and check we got the initial number of steps right.
198        $progress->progress($majorstep++);
199        if ($majorstep != $majorsteps) {
200            throw new coding_exception('Progress step count wrong: ' . $majorstep);
201        }
202        $progress->end_progress();
203
204        return $results;
205    }
206}
207
208/*
209 * Exception class used by all the @restore_prechecks_helper stuff
210 */
211class restore_prechecks_helper_exception extends backup_exception {
212
213    public function __construct($errorcode, $a=NULL, $debuginfo=null) {
214        parent::__construct($errorcode, $a, $debuginfo);
215    }
216}
217