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/>.

namespace tiny_autosave;

use stdClass;

/**

 * Autosave Manager.

 *

 * @package   tiny_autosave

 * @copyright 2022 Andrew Lyons <andrew@nicols.co.uk>

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

 */

class autosave_manager {

    /** @var int The contextid */

    protected $contextid;

    /** @var string The page hash reference */

    protected $pagehash;

    /** @var string The page instance reference */

    protected $pageinstance;

    /** @var string The elementid for this editor */

    protected $elementid;

    /** @var stdClass The user record */

    protected $user;

    /**

     * Constructor for the autosave manager.

     *

     * @param int $contextid The contextid of the session

     * @param string $pagehash The page hash

     * @param string $pageinstance The page instance

     * @param string $elementid The element id

     * @param null|stdClass $user The user object for the owner of the autosave

     */

    public function __construct(

        int $contextid,

        string $pagehash,

        string $pageinstance,

        string $elementid,

        ?stdClass $user = null

    ) {

        global $USER;

        $this->contextid = $contextid;

        $this->pagehash = $pagehash;

        $this->pageinstance = $pageinstance;

        $this->elementid = $elementid;

        $this->user = $user ?? $USER;

    }

    /**

     * Get the autosave record for this session.

     *

     * @return stdClass|null

     */

    public function get_autosave_record(): ?stdClass {

        global $DB;

        $record = $DB->get_record('tiny_autosave', [

            'contextid' => $this->contextid,

            'userid' => $this->user->id,

            'pagehash' => $this->pagehash,

            'elementid' => $this->elementid,

        ]);

        if (empty($record)) {

            return null;

        }

        return $record;

    }

    /**

     * Create an autosave record for the session.

     *

     * @param string $drafttext The draft text to save

     * @param null|int $draftid The draft file area if one is used

     * @return stdClass The autosave record

     */

    public function create_autosave_record(string $drafttext, ?int $draftid = null): stdClass {

        global $DB;

        $record = (object) [

            'userid' => $this->user->id,

            'contextid' => $this->contextid,

            'pagehash' => $this->pagehash,

            'pageinstance' => $this->pageinstance,

            'elementid' => $this->elementid,

            'drafttext' => $drafttext,

            'timemodified' => time(),

        ];

        if ($draftid) {

            $record->draftid = $draftid;

        }

        $record->id = $DB->insert_record('tiny_autosave', $record);

        return $record;

    }

    /**

     * Update the text of the autosave session.

     *

     * @param string $drafttext The text to save

     * @return stdClass The updated record

     */

    public function update_autosave_record(string $drafttext): stdClass {

        global $DB;

        $record = $this->get_autosave_record();

        if ($record) {

            $record->drafttext = $drafttext;

            $record->timemodified = time();

            $DB->update_record('tiny_autosave', $record);

            return $record;

        } else {

            return $this->create_autosave_record($drafttext);

        }

    }

    /**

     * Resume an autosave session, updating the draft file area if relevant.

     *

     * @param null|int $draftid The draft file area to update

     * @return stdClass The updated autosave record

     */

    public function resume_autosave_session(?int $draftid = null): stdClass {

        $record = $this->get_autosave_record();

        if (!$record) {

            return $this->create_autosave_record('', $draftid);

        }

        if ($this->is_autosave_stale($record)) {

            // If the autosave record it stale, remove it and create a new, blank, record.

            $this->remove_autosave_record();

            return $this->create_autosave_record('', $draftid);

        }

        if (empty($draftid)) {

            // There is no file area to handle, so just return the record without any further changes.

            return $record;

        }

        // This autosave is not stale, so update the draftid and move any files over to the new draft file area.

        return $this->update_draftid_for_record($record, $draftid);

    }

    /**

     * Check whether the autosave data is stale.

     *

     * Records are considered stale if either of the following conditions are true:

     * - The record is older than the stale period

     * - Any of the files in the draft area are newer than the autosave data itself

     *

     * @param stdClass $record The autosave record

     * @return bool Whether the record is stale

     */

    protected function is_autosave_stale(stdClass $record): bool {

        $timemodified = $record->timemodified;

        // TODO Create the UI for the stale period.

        $staleperiod = get_config('tiny_autosave', 'staleperiod');

        if (empty($staleperiod)) {

            $staleperiod = (4 * DAYSECS);

        }

        $stale = $timemodified < (time() - $staleperiod);

        if (empty($record->draftid)) {

            return $stale;

        }

        $fs = get_file_storage();

        $files = $fs->get_directory_files($record->contextid, 'user', 'draft', $record->draftid, '/', true, true);

        $lastfilemodified = 0;

        foreach ($files as $file) {

            if ($record->timemodified < $file->get_timemodified()) {

                $stale = true;

                break;

            }

        }

        return $stale;

    }

    /**

     * Move the files relating to the autosave session to a new draft file area.

     *

     * @param stdClass $record The autosave record

     * @param int $newdraftid The new draftid to move files to

     * @return stdClass The updated autosave record

     */

    protected function update_draftid_for_record(stdClass $record, int $newdraftid): stdClass {

        global $CFG, $DB;

        require_once("{$CFG->libdir}/filelib.php");

        // Copy all draft files from the old draft area.

        $usercontext = \context_user::instance($this->user->id);

        // This function copies all the files in one draft area, to another area (in this case it's

        // another draft area). It also rewrites the text to @@PLUGINFILE@@ links.

        $record->drafttext = file_save_draft_area_files(

            $record->draftid,

            $usercontext->id,

            'user',

            'draft',

            $newdraftid,

            [],

            $record->drafttext

        );

        // Final rewrite to the new draft area (convert the @@PLUGINFILES@@ again).

        $record->drafttext = file_rewrite_pluginfile_urls(

            $record->drafttext,

            'draftfile.php',

            $usercontext->id,

            'user',

            'draft',

            $newdraftid

        );

        $record->draftid = $newdraftid;

        $record->pageinstance = $this->pageinstance;

        $record->timemodified = time();

        $DB->update_record('tiny_autosave', $record);

        return $record;

    }

    /**

     * Remove the autosave record.

     */

    public function remove_autosave_record(): void {

        global $DB;

        $DB->delete_records('tiny_autosave', [

            'contextid' => $this->contextid,

            'userid' => $this->user->id,

            'pagehash' => $this->pagehash,

            'elementid' => $this->elementid,

        ]);

    }

}