Proyectos de Subversion Moodle

<?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/>.

/**

 * Helper functions for asynchronous backups and restores.

 *

 * @package    core

 * @copyright  2019 Matt Porritt <mattp@catalyst-au.net>

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

defined('MOODLE_INTERNAL') || die();

require_once($CFG->dirroot . '/user/lib.php');

/**

 * Helper functions for asynchronous backups and restores.

 *

 * @package     core

 * @copyright   2019 Matt Porritt <mattp@catalyst-au.net>

 * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

class async_helper  {

    /**

     * @var string $type The type of async operation.

     */

    protected $type = 'backup';

    /**

     * @var string $backupid The id of the backup or restore.

     */

    protected $backupid;

    /**

     * @var object $user The user who created the backup record.

     */

    protected $user;

    /**

     * @var object $backuprec The backup controller record from the database.

     */

    protected $backuprec;

    /**

     * Class constructor.

     *

     * @param string $type The type of async operation.

     * @param string $id The id of the backup or restore.

     */

    public function __construct($type, $id) {

        $this->type = $type;

        $this->backupid = $id;

        $this->backuprec = self::get_backup_record($id);

        $this->user = $this->get_user();

    }

    /**

     * Given a backup id return a the record from the database.

     * We use this method rather than 'load_controller' as the controller may

     * not exist if this backup/restore has completed.

     *

     * @param int $id The backup id to get.

     * @return object $backuprec The backup controller record.

     */

    public static function get_backup_record($id) {

        global $DB;

        $backuprec = $DB->get_record('backup_controllers', array('backupid' => $id), '*', MUST_EXIST);

        return $backuprec;

    }

    /**

     * Given a user id return a user object.

     *

     * @return object $user The limited user record.

     */

    private function get_user() {

        $userid = $this->backuprec->userid;

        $user = core_user::get_user($userid, '*', MUST_EXIST);

        return $user;

    }

    /**

     * Return appropriate description for current async operation {@see async_helper::type}

     *

     * @return string

     */

    private function get_operation_description(): string {

        $operations = [

            'backup' => new lang_string('backup'),

            'copy' => new lang_string('copycourse'),

            'restore' => new lang_string('restore'),

        ];

        return (string) ($operations[$this->type] ?? $this->type);

    }

    /**

     * Callback for preg_replace_callback.

     * Replaces message placeholders with real values.

     *

     * @param array $matches The match array from from preg_replace_callback.

     * @return string $match The replaced string.

     */

    private function lookup_message_variables($matches) {

        $options = array(

                'operation' => $this->get_operation_description(),

                'backupid' => $this->backupid,

                'user_username' => $this->user->username,

                'user_email' => $this->user->email,

                'user_firstname' => $this->user->firstname,

                'user_lastname' => $this->user->lastname,

                'link' => $this->get_resource_link(),

        );

        $match = $options[$matches[1]] ?? $matches[1];

        return $match;

    }

    /**

     * Get the link to the resource that is being backuped or restored.

     *

     * @return moodle_url $url The link to the resource.

     */

    private function get_resource_link() {

        // Get activity context only for backups.

        if ($this->backuprec->type == 'activity' && $this->type == 'backup') {

            $context = context_module::instance($this->backuprec->itemid);

        } else { // Course or Section which have the same context getter.

            $context = context_course::instance($this->backuprec->itemid);

        }

        // Generate link based on operation type.

        if ($this->type == 'backup') {

            // For backups simply generate link to restore file area UI.

            $url = new moodle_url('/backup/restorefile.php', array('contextid' => $context->id));

        } else {

            // For restore generate link to the item itself.

            $url = $context->get_url();

        }

        return $url;

    }

    /**

     * Sends a confirmation message for an aynchronous process.

     *

     * @return int $messageid The id of the sent message.

     */

    public function send_message() {

        global $USER;

        $subjectraw = get_config('backup', 'backup_async_message_subject');

        $subjecttext = preg_replace_callback(

                '/\{([-_A-Za-z0-9]+)\}/u',

                array('async_helper', 'lookup_message_variables'),

                $subjectraw);

        $messageraw = get_config('backup', 'backup_async_message');

        $messagehtml = preg_replace_callback(

                '/\{([-_A-Za-z0-9]+)\}/u',

                array('async_helper', 'lookup_message_variables'),

                $messageraw);

        $messagetext = html_to_text($messagehtml);

        $message = new \core\message\message();

        $message->component = 'moodle';

        $message->name = 'asyncbackupnotification';

        $message->userfrom          = $USER;

        $message->userto            = $this->user;

        $message->subject           = $subjecttext;

        $message->fullmessage       = $messagetext;

        $message->fullmessageformat = FORMAT_HTML;

        $message->fullmessagehtml   = $messagehtml;

        $message->smallmessage      = '';

        $message->notification      = '1';

        $messageid = message_send($message);

        return $messageid;

    }

    /**

     * Check if asynchronous backup and restore mode is

     * enabled at system level.

     *

     * @return bool $async True if async mode enabled false otherwise.

     */

    public static function is_async_enabled() {

        global $CFG;

        $async = false;

        if (!empty($CFG->enableasyncbackup)) {

            $async = true;

        }

        return $async;

    }

    /**

     * Check if there is a pending async operation for given details.

     *

     * @param int $id The item id to check in the backup record.

     * @param string $type The type of operation: course, activity or section.

     * @param string $operation Operation backup or restore.

     * @return boolean $asyncpedning Is there a pending async operation.

     */

    public static function is_async_pending($id, $type, $operation) {

        global $DB, $USER, $CFG;

        $asyncpending = false;

        // Only check for pending async operations if async mode is enabled.

        require_once($CFG->dirroot . '/backup/util/interfaces/checksumable.class.php');

        require_once($CFG->dirroot . '/backup/backup.class.php');

        $select = 'userid = ? AND itemid = ? AND type = ? AND operation = ? AND execution = ? AND status < ? AND status > ?';

        $params = array(

            $USER->id,

            $id,

            $type,

            $operation,

            backup::EXECUTION_DELAYED,

            backup::STATUS_FINISHED_ERR,

            backup::STATUS_NEED_PRECHECK

        );

        $asyncrecord= $DB->get_record_select('backup_controllers', $select, $params);

        if ((self::is_async_enabled() && $asyncrecord) || ($asyncrecord && $asyncrecord->purpose == backup::MODE_COPY)) {

            $asyncpending = true;

        }

        return $asyncpending;

    }

    /**

     * Get the size, url and restore url for a backup file.

     *

     * @param string $filename The name of the file to get info for.

     * @param string $filearea The file area for the file.

     * @param int $contextid The context ID of the file.

     * @return array $results The result array containing the size, url and restore url of the file.

     */

    public static function get_backup_file_info($filename, $filearea, $contextid) {

        $fs = get_file_storage();

        $file = $fs->get_file($contextid, 'backup', $filearea, 0, '/', $filename);

        $filesize = display_size ($file->get_filesize());

        $fileurl = moodle_url::make_pluginfile_url(

            $file->get_contextid(),

            $file->get_component(),

            $file->get_filearea(),

            null,

            $file->get_filepath(),

            $file->get_filename(),

            true

            );

        $params = array();

        $params['action'] = 'choosebackupfile';

        $params['filename'] = $file->get_filename();

        $params['filepath'] = $file->get_filepath();

        $params['component'] = $file->get_component();

        $params['filearea'] = $file->get_filearea();

        $params['filecontextid'] = $file->get_contextid();

        $params['contextid'] = $contextid;

        $params['itemid'] = $file->get_itemid();

        $restoreurl = new moodle_url('/backup/restorefile.php', $params);

        $filesize = display_size ($file->get_filesize());

        $results = array(

            'filesize' => $filesize,

            'fileurl' => $fileurl->out(false),

            'restoreurl' => $restoreurl->out(false));

        return $results;

    }

    /**

     * Get the url of a restored backup item based on the backup ID.

     *

     * @param string $backupid The backup ID to get the restore location url.

     * @return array $urlarray The restored item URL as an array.

     */

    public static function get_restore_url($backupid) {

        global $DB;

        $backupitemid = $DB->get_field('backup_controllers', 'itemid', array('backupid' => $backupid), MUST_EXIST);

        $newcontext = context_course::instance($backupitemid);

        $restoreurl = $newcontext->get_url()->out();

        $urlarray = array('restoreurl' => $restoreurl);

        return $urlarray;

    }

    /**

     * Get markup for in progress async backups,

     * to use in backup table UI.

     *

     * @param string $filearea The filearea to get backup data for.

     * @param integer $instanceid The context id to get backup data for.

     * @return array $tabledata the rows of table data.

     */

    public static function get_async_backups($filearea, $instanceid) {

        global $DB;

        $backups = [];

        $table = 'backup_controllers';

        $select = 'execution = :execution AND status < :status1 AND status > :status2 ' .

            'AND operation = :operation';

        $params = [

            'execution' => backup::EXECUTION_DELAYED,

            'status1' => backup::STATUS_FINISHED_ERR,

            'status2' => backup::STATUS_NEED_PRECHECK,

            'operation' => 'backup',

        ];

        $sort = 'timecreated DESC';

        $fields = 'id, backupid, status, timecreated';

        if ($filearea == 'backup') {

            // Get relevant backup ids based on user id.

            $params['userid'] = $instanceid;

            $select = 'userid = :userid AND ' . $select;

            $records = $DB->get_records_select($table, $select, $params, $sort, $fields);

            foreach ($records as $record) {

                $bc = \backup_controller::load_controller($record->backupid);

                // Get useful info to render async status in correct area.

                list($hasusers, $isannon) = self::get_userdata_backup_settings($bc);

                // Backup has users and is not anonymised -> don't show it in users backup file area.

                if ($hasusers && !$isannon) {

                    continue;

                }

                $record->filename = $bc->get_plan()->get_setting('filename')->get_value();

                $bc->destroy();

                array_push($backups, $record);

            }

        } else {

            if ($filearea == 'course' || $filearea == 'activity') {

                // Get relevant backup ids based on context instance id.

                $params['itemid'] = $instanceid;

                $select = 'itemid = :itemid AND ' . $select;

                $records = $DB->get_records_select($table, $select, $params, $sort, $fields);

                foreach ($records as $record) {

                    $bc = \backup_controller::load_controller($record->backupid);

                    // Get useful info to render async status in correct area.

                    list($hasusers, $isannon) = self::get_userdata_backup_settings($bc);

                    // Backup has no user or is anonymised -> don't show it in course/activity backup file area.

                    if (!$hasusers || $isannon) {

                        continue;

                    }

                    $record->filename = $bc->get_plan()->get_setting('filename')->get_value();

                    $bc->destroy();

                    array_push($backups, $record);

                }

            }

        }

        return $backups;

    }

    /**

     * Get the user data settings for backups.

     *

     * @param \backup_controller $backupcontroller The backup controller object.

     * @return array Array of user data settings.

     */

    public static function get_userdata_backup_settings(\backup_controller $backupcontroller): array {

        $hasusers = (bool)$backupcontroller->get_plan()->get_setting('users')->get_value(); // Backup has users.

        $isannon = (bool)$backupcontroller->get_plan()->get_setting('anonymize')->get_value(); // Backup is anonymised.

        return [$hasusers, $isannon];

    }

    /**

     * Get the course name of the resource being restored.

     *

     * @param \context $context The Moodle context for the restores.

     * @return string $coursename The full name of the course.

     */

    public static function get_restore_name(\context $context) {

        global $DB;

        $instanceid = $context->instanceid;

        if ($context->contextlevel == CONTEXT_MODULE) {

            // For modules get the course name and module name.

            $cm = get_coursemodule_from_id('', $context->instanceid, 0, false, MUST_EXIST);

            $coursename = $DB->get_field('course', 'fullname', array('id' => $cm->course));

            $itemname = $coursename . ' - ' . $cm->name;

        } else {

            $itemname = $DB->get_field('course', 'fullname', array('id' => $context->instanceid));

        }

        return $itemname;

    }

    /**

     * Get all the current in progress async restores for a user.

     *

     * @param int $userid Moodle user id.

     * @return array $restores List of current restores in progress.

     */

    public static function get_async_restores($userid) {

        global $DB;

        $select = 'userid = ? AND execution = ? AND status < ? AND status > ? AND operation = ?';

        $params = array($userid, backup::EXECUTION_DELAYED, backup::STATUS_FINISHED_ERR, backup::STATUS_NEED_PRECHECK, 'restore');

        $restores = $DB->get_records_select(

            'backup_controllers',

            $select,

            $params,

            'timecreated DESC',

            'id, backupid, status, itemid, timecreated');

            return $restores;

    }

}