<?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 core_xapi\privacy;
/**
> 
 * Privacy Subsystem implementation for core xAPI Library.
> use core_privacy\local\metadata\collection;
 *
> use core_privacy\local\request\approved_contextlist;
 * @package    core_xapi
> use core_privacy\local\request\transform;
 * @copyright  2020 Ferran Recio
> 



<  * Privacy Subsystem implementation for core xAPI Library.



>  * Privacy implementation for core xAPI Library.


 */

>  * @category   privacy




> class provider implements
namespace core_xapi\privacy;
>     \core_privacy\local\metadata\provider,

>     \core_privacy\local\request\subsystem\plugin_provider,
defined('MOODLE_INTERNAL') || die();
>     \core_privacy\local\request\shared_userlist_provider {



< namespace core_xapi\privacy;



>     /**
>      * Return the fields which contain personal data.
>      *
>      * @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('xapi_states', [
>                 'component' => 'privacy:metadata:component',
>                 'userid' => 'privacy:metadata:userid',
>                 'itemid' => 'privacy:metadata:itemid',
>                 'stateid' => 'privacy:metadata:stateid',
>                 'statedata' => 'privacy:metadata:statedata',
>                 'registration' => 'privacy:metadata:registration',
>                 'timecreated' => 'privacy:metadata:timecreated',
>                 'timemodified' => 'privacy:metadata:timemodified',
>             ], 'privacy:metadata:xapi_states');



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



>         return $collection;
>     }



<  * Privacy Subsystem for core_xapi implementing null_provider.



>      * Provide a list of contexts which have xAPI for the user, in the respective area (component/itemtype combination).


 *

<  * @copyright  2020 Ferran Recio
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later



>      * This method is to be called by consumers of the xAPI subsystem (plugins), in their get_contexts_for_userid() method,
>      * to add the contexts for items which may have xAPI data, but would normally not be reported as having user data by the
>      * plugin responsible for them.
>      *
>      * @param \core_privacy\local\request\contextlist $contextlist
>      * @param int $userid The id of the user in scope.
>      * @param string $component the frankenstyle component name.
>      */
>     public static function add_contexts_for_userid(
>             \core_privacy\local\request\contextlist $contextlist,
>             int $userid,
>             string $component) {
>         $sql = "SELECT ctx.id
>                   FROM {xapi_states} xs
>                   JOIN {context} ctx
>                     ON ctx.id = xs.itemid
>                  WHERE xs.userid = :userid
>                    AND xs.component = :component";
> 
>         $params = ['userid' => $userid, 'component' => $component];
> 
>         $contextlist->add_from_sql($sql, $params);
>     }
> 
>     /**
>      * Add users to a userlist who have xAPI within the specified context.
>      *
>      * @param \core_privacy\local\request\userlist $userlist The userlist to add the users to.
>      * @return void
>      */
>     public static function add_userids_for_context(\core_privacy\local\request\userlist $userlist) {
>         if (empty($userlist)) {
>             return;
>         }
> 
>         $params = [
>             'contextid' => $userlist->get_context()->id,
>             'component' => $userlist->get_component()
>         ];
> 
>         $sql = "SELECT xs.userid
>                   FROM {xapi_states} xs
>                   JOIN {context} ctx
>                     ON ctx.id = xs.itemid
>                  WHERE ctx.id = :contextid
>                    AND xs.component = :component";
> 
>         $userlist->add_from_sql('userid', $sql, $params);
>     }
> 
>     /**
>      * Get xAPI states data for the specified user in the specified component and item ID.
>      *
>      * @param int $userid The id of the user in scope.
>      * @param string $component The component name.
>      * @param int $itemid The item ID.
>      * @return array|null
>      */
>     public static function get_xapi_states_for_user(int $userid, string $component, int $itemid) {
>         global $DB;
> 
>         $params = [
>             'userid' => $userid,
>             'component' => $component,
>             'itemid' => $itemid,
>         ];
> 
>         if (!$states = $DB->get_records('xapi_states', $params)) {
>             return;
>         }
> 
>         $result = [];
>         foreach ($states as $state) {
>             $result[] = [
>                 'statedata' => $state->statedata,
>                 'timecreated' => transform::datetime($state->timecreated),
>                 'timemodified' => transform::datetime($state->timemodified)
>             ];
>         }
> 
>         return $result;
>     }
> 
>     /**
>      * Delete all xAPI states for all users in the specified contexts, and component area.
>      *
>      * @param \context $context The context to which deletion is scoped.
>      * @param string $component The component name.
>      * @throws \dml_exception if any errors are encountered during deletion.


 */

< class provider implements \core_privacy\local\metadata\null_provider {



>     public static function delete_states_for_all_users(\context $context, string $component) {
>         global $DB;
> 
>         $params = [
>             'component' => $component,
>         ];
> 
>         $select = "component = :component";
> 
>         if (!empty($context)) {
>             $select .= " AND itemid = :itemid";
>             $params['itemid'] = $context->id;
>         }
>         $DB->delete_records_select('xapi_states', $select, $params);
>     }



    /**

<      * Get the language string identifier with the component's language
<      * file to explain why this plugin stores no data.



>      * Delete all xAPI states for the specified users in the specified context, component area and item type.


     *

<      * @return  string



>      * @param \core_privacy\local\request\approved_userlist $userlist The approved contexts and user information
>      * to delete information for.
>      * @param int $itemid Optional itemid associated with component.
>      * @throws \dml_exception if any errors are encountered during deletion.


     */

<     public static function get_reason(): string {
<         return 'privacy:metadata';



>     public static function delete_states_for_userlist(\core_privacy\local\request\approved_userlist $userlist, int $itemid = 0) {
>         global $DB;
> 
>         $userids = $userlist->get_userids();
> 
>         if (empty($userids)) {
>             return;
>         }
> 
>         list($usersql, $userparams) = $DB->get_in_or_equal($userids, SQL_PARAMS_NAMED);
> 
>         $params = [
>             'component' => $userlist->get_component(),
>         ];
> 
>         $params += $userparams;
>         $select = "component = :component AND userid $usersql";
> 
>         if (!empty($itemid)) {
>             $select .= " AND itemid = :itemid";
>             $params['itemid'] = $itemid;
>         }
> 
>         $DB->delete_records_select('xapi_states', $select, $params);
>     }
> 
>     /**
>      * Delete all xAPI states for the specified user, in the specified contexts.
>      *
>      * @param approved_contextlist $contextlist The approved contexts and user information to delete information for.
>      * @param string $component The component name.
>      * @param int $itemid Optional itemid associated with component.
>      * @throws \coding_exception
>      * @throws \dml_exception
>      */
>     public static function delete_states_for_user(approved_contextlist $contextlist, string $component, int $itemid = 0) {
>         global $DB;
> 
>         $userid = $contextlist->get_user()->id;
> 
>         $params = [
>             'userid' => $userid,
>             'component' => $component,
>         ];
> 
>         $select = "userid = :userid AND component = :component";
> 
>         if (!empty($itemid)) {
>             $select .= " AND itemid = :itemid";
>             $params['itemid'] = $itemid;
>         }
> 
>         $DB->delete_records_select('xapi_states', $select, $params);


    }
}