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<?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);
}
}
}