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/>.

/**

 * Data provider.

 *

 * @package    mod_chat

 * @copyright  2018 Frédéric Massart

 * @author     Frédéric Massart <fred@branchup.tech>

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

 */

namespace mod_chat\privacy;

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

use context;

use context_helper;

use context_module;

use moodle_recordset;

use stdClass;

use core_privacy\local\metadata\collection;

use core_privacy\local\request\approved_contextlist;

use core_privacy\local\request\approved_userlist;

use core_privacy\local\request\contextlist;

use core_privacy\local\request\helper;

use core_privacy\local\request\transform;

use core_privacy\local\request\userlist;

use core_privacy\local\request\writer;

/**

 * Data provider class.

 *

 * @package    mod_chat

 * @copyright  2018 Frédéric Massart

 * @author     Frédéric Massart <fred@branchup.tech>

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

 */

class provider implements

    \core_privacy\local\metadata\provider,

    \core_privacy\local\request\core_userlist_provider,

    \core_privacy\local\request\plugin\provider {

    /**

     * Returns metadata.

     *

     * @param collection $collection The initialised collection to add items to.

     * @return collection A listing of user data stored through this system.

     */

    public static function get_metadata(collection $collection): collection {

        $collection->add_database_table('chat_messages', [

            'userid' => 'privacy:metadata:messages:userid',

            'message' => 'privacy:metadata:messages:message',

            'issystem' => 'privacy:metadata:messages:issystem',

            'timestamp' => 'privacy:metadata:messages:timestamp',

        ], 'privacy:metadata:messages');

        // The tables chat_messages_current and chat_users are not exported/deleted

        // because they are considered as short-lived data and are deleted on a

        // regular basis by cron, or during normal requests. TODO MDL-62006.

        $collection->add_database_table('chat_messages_current', [

            'userid' => 'privacy:metadata:messages:userid',

            'message' => 'privacy:metadata:messages:message',

            'issystem' => 'privacy:metadata:messages:issystem',

            'timestamp' => 'privacy:metadata:messages:timestamp'

        ], 'privacy:metadata:chat_messages_current');

        $collection->add_database_table('chat_users', [

            'userid' => 'privacy:metadata:chat_users:userid',

            'version' => 'privacy:metadata:chat_users:version',

            'ip' => 'privacy:metadata:chat_users:ip',

            'firstping' => 'privacy:metadata:chat_users:firstping',

            'lastping' => 'privacy:metadata:chat_users:lastping',

            'lastmessageping' => 'privacy:metadata:chat_users:lastmessageping',

            'lang' => 'privacy:metadata:chat_users:lang'

        ], 'privacy:metadata:chat_users');

        return $collection;

    }

    /**

     * Get the list of contexts that contain user information for the specified user.

     *

     * @param int $userid The user to search.

     * @return contextlist $contextlist The contextlist containing the list of contexts used in this plugin.

     */

    public static function get_contexts_for_userid(int $userid): \core_privacy\local\request\contextlist {

        $contextlist = new \core_privacy\local\request\contextlist();

        $sql = "

            SELECT DISTINCT ctx.id

              FROM {chat} c

              JOIN {modules} m

                ON m.name = :chat

              JOIN {course_modules} cm

                ON cm.instance = c.id

               AND cm.module = m.id

              JOIN {context} ctx

                ON ctx.instanceid = cm.id

               AND ctx.contextlevel = :modulelevel

              JOIN {chat_messages} chm

                ON chm.chatid = c.id

             WHERE chm.userid = :userid";

        $params = [

            'chat' => 'chat',

            'modulelevel' => CONTEXT_MODULE,

            'userid' => $userid,

        ];

        $contextlist->add_from_sql($sql, $params);

        return $contextlist;

    }

    /**

     * Get the list of users who have data within a context.

     *

     * @param   userlist    $userlist   The userlist containing the list of users who have data in this context/plugin combination.

     */

    public static function get_users_in_context(userlist $userlist) {

        $context = $userlist->get_context();

        if (!is_a($context, \context_module::class)) {

            return;

        }

        $params = [

            'instanceid'    => $context->instanceid,

            'modulename'    => 'chat',

        ];

        $sql = "SELECT chm.userid

                  FROM {course_modules} cm

                  JOIN {modules} m ON m.id = cm.module AND m.name = :modulename

                  JOIN {chat} c ON c.id = cm.instance

                  JOIN {chat_messages} chm ON chm.chatid = c.id

                 WHERE cm.id = :instanceid";

        $userlist->add_from_sql('userid', $sql, $params);

    }

    /**

     * Export all user data for the specified user, in the specified contexts.

     *

     * @param approved_contextlist $contextlist The approved contexts to export information for.

     */

    public static function export_user_data(approved_contextlist $contextlist) {

        global $DB;

        $user = $contextlist->get_user();

        $userid = $user->id;

        $cmids = array_reduce($contextlist->get_contexts(), function($carry, $context) {

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

                $carry[] = $context->instanceid;

            }

            return $carry;

        }, []);

        if (empty($cmids)) {

            return;

        }

        $chatidstocmids = static::get_chat_ids_to_cmids_from_cmids($cmids);

        $chatids = array_keys($chatidstocmids);

        // Export the messages.

        list($insql, $inparams) = $DB->get_in_or_equal($chatids, SQL_PARAMS_NAMED);

        $params = array_merge($inparams, ['userid' => $userid]);

        $recordset = $DB->get_recordset_select('chat_messages', "chatid $insql AND userid = :userid", $params, 'timestamp, id');

        static::recordset_loop_and_export($recordset, 'chatid', [], function($carry, $record) use ($user, $chatidstocmids) {

            $message = $record->message;

            if ($record->issystem) {

                $message = get_string('message' . $record->message, 'mod_chat', fullname($user));

            }

            $carry[] = [

                'message' => $message,

                'sent_at' => transform::datetime($record->timestamp),

                'is_system_generated' => transform::yesno($record->issystem),

            ];

            return $carry;

        }, function($chatid, $data) use ($user, $chatidstocmids) {

            $context = context_module::instance($chatidstocmids[$chatid]);

            $contextdata = helper::get_context_data($context, $user);

            $finaldata = (object) array_merge((array) $contextdata, ['messages' => $data]);

            helper::export_context_files($context, $user);

            writer::with_context($context)->export_data([], $finaldata);

        });

    }

    /**

     * Delete all data for all users in the specified context.

     *

     * @param context $context The specific context to delete data for.

     */

    public static function delete_data_for_all_users_in_context(context $context) {

        global $DB;

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

            return;

        }

        $cm = get_coursemodule_from_id('chat', $context->instanceid);

        if (!$cm) {

            return;

        }

        $chatid = $cm->instance;

        $DB->delete_records_select('chat_messages', 'chatid = :chatid', ['chatid' => $chatid]);

        $DB->delete_records_select('chat_messages_current', 'chatid = :chatid', ['chatid' => $chatid]);

        $DB->delete_records_select('chat_users', 'chatid = :chatid', ['chatid' => $chatid]);

    }

    /**

     * Delete all user data for the specified user, in the specified contexts.

     *

     * @param approved_contextlist $contextlist The approved contexts and user information to delete information for.

     */

    public static function delete_data_for_user(approved_contextlist $contextlist) {

        global $DB;

        $userid = $contextlist->get_user()->id;

        $cmids = array_reduce($contextlist->get_contexts(), function($carry, $context) {

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

                $carry[] = $context->instanceid;

            }

            return $carry;

        }, []);

        if (empty($cmids)) {

            return;

        }

        $chatidstocmids = static::get_chat_ids_to_cmids_from_cmids($cmids);

        $chatids = array_keys($chatidstocmids);

        list($insql, $inparams) = $DB->get_in_or_equal($chatids, SQL_PARAMS_NAMED);

        $sql = "chatid $insql AND userid = :userid";

        $params = array_merge($inparams, ['userid' => $userid]);

        $DB->delete_records_select('chat_messages', $sql, $params);

        $DB->delete_records_select('chat_messages_current', $sql, $params);

        $DB->delete_records_select('chat_users', $sql, $params);

    }

    /**

     * Delete multiple users within a single context.

     *

     * @param   approved_userlist       $userlist The approved context and user information to delete information for.

     */

    public static function delete_data_for_users(approved_userlist $userlist) {

        global $DB;

        $context = $userlist->get_context();

        $cm = $DB->get_record('course_modules', ['id' => $context->instanceid]);

        $chat = $DB->get_record('chat', ['id' => $cm->instance]);

        list($userinsql, $userinparams) = $DB->get_in_or_equal($userlist->get_userids(), SQL_PARAMS_NAMED);

        $params = array_merge(['chatid' => $chat->id], $userinparams);

        $sql = "chatid = :chatid AND userid {$userinsql}";

        $DB->delete_records_select('chat_messages', $sql, $params);

        $DB->delete_records_select('chat_messages_current', $sql, $params);

        $DB->delete_records_select('chat_users', $sql, $params);

    }

    /**

     * Return a dict of chat IDs mapped to their course module ID.

     *

     * @param array $cmids The course module IDs.

     * @return array In the form of [$chatid => $cmid].

     */

    protected static function get_chat_ids_to_cmids_from_cmids(array $cmids) {

        global $DB;

        list($insql, $inparams) = $DB->get_in_or_equal($cmids, SQL_PARAMS_NAMED);

        $sql = "

            SELECT c.id, cm.id AS cmid

              FROM {chat} c

              JOIN {modules} m

                ON m.name = :chat

              JOIN {course_modules} cm

                ON cm.instance = c.id

               AND cm.module = m.id

             WHERE cm.id $insql";

        $params = array_merge($inparams, ['chat' => 'chat']);

        return $DB->get_records_sql_menu($sql, $params);

    }

    /**

     * Loop and export from a recordset.

     *

     * @param moodle_recordset $recordset The recordset.

     * @param string $splitkey The record key to determine when to export.

     * @param mixed $initial The initial data to reduce from.

     * @param callable $reducer The function to return the dataset, receives current dataset, and the current record.

     * @param callable $export The function to export the dataset, receives the last value from $splitkey and the dataset.

     * @return void

     */

    protected static function recordset_loop_and_export(moodle_recordset $recordset, $splitkey, $initial,

            callable $reducer, callable $export) {

        $data = $initial;

        $lastid = null;

        foreach ($recordset as $record) {

            if ($lastid && $record->{$splitkey} != $lastid) {

                $export($lastid, $data);

                $data = $initial;

            }

            $data = $reducer($data, $record);

            $lastid = $record->{$splitkey};

        }

        $recordset->close();

        if (!empty($lastid)) {

            $export($lastid, $data);

        }

    }

}