<?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/>.

/**
 * Class for loading/storing oauth2 endpoints from the DB.
 *
 * @package    core
 * @copyright  2017 Damyon Wiese
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
namespace core\oauth2;

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

require_once($CFG->libdir . '/filelib.php');


< use context_system;
< use curl;


use stdClass;

< use moodle_exception;


use moodle_url;

< 



> use context_system;
> use moodle_exception;



/**
 * Static list of api methods for system oauth2 configuration.
 *
 * @copyright  2017 Damyon Wiese
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class api {

    /**

<      * Build a google ready OAuth 2 service.
<      * @return \core\oauth2\issuer
<      */
<     private static function init_google() {
<         $record = (object) [
<             'name' => 'Google',
<             'image' => 'https://accounts.google.com/favicon.ico',
<             'baseurl' => 'https://accounts.google.com/',
<             'loginparamsoffline' => 'access_type=offline&prompt=consent',
<             'showonloginpage' => true
<         ];
< 
<         $issuer = new issuer(0, $record);
<         return $issuer;
<     }
< 
<     /**
<      * Create endpoints for google issuers.
<      * @param issuer $issuer issuer the endpoints should be created for.
<      * @return mixed
<      * @throws \coding_exception
<      * @throws \core\invalid_persistent_exception
<      */
<     private static function create_endpoints_for_google($issuer) {
< 
<         $record = (object) [
<             'issuerid' => $issuer->get('id'),
<             'name' => 'discovery_endpoint',
<             'url' => 'https://accounts.google.com/.well-known/openid-configuration'
<         ];
<         $endpoint = new endpoint(0, $record);
<         $endpoint->create();
<         return $issuer;
<     }
< 
<     /**
<      * Build a facebook ready OAuth 2 service.
<      * @return \core\oauth2\issuer
<      */
<     private static function init_facebook() {
<         // Facebook is a custom setup.
<         $record = (object) [
<             'name' => 'Facebook',
<             'image' => 'https://facebookbrand.com/wp-content/uploads/2016/05/flogo_rgb_hex-brc-site-250.png',
<             'baseurl' => '',
<             'loginscopes' => 'public_profile email',
<             'loginscopesoffline' => 'public_profile email',
<             'showonloginpage' => true
<         ];
< 
<         $issuer = new issuer(0, $record);
<         return $issuer;
<     }
< 
<     /**
<      * Create endpoints for facebook issuers.
<      * @param issuer $issuer issuer the endpoints should be created for.
<      * @return mixed
<      * @throws \coding_exception
<      * @throws \core\invalid_persistent_exception
<      */
<     private static function create_endpoints_for_facebook($issuer) {
<         // The Facebook API version.
<         $apiversion = '2.12';
<         // The Graph API URL.
<         $graphurl = 'https://graph.facebook.com/v' . $apiversion;
<         // User information fields that we want to fetch.
<         $infofields = [
<             'id',
<             'first_name',
<             'last_name',
<             'link',
<             'picture.type(large)',
<             'name',
<             'email',
<         ];
<         $endpoints = [
<             'authorization_endpoint' => sprintf('https://www.facebook.com/v%s/dialog/oauth', $apiversion),
<             'token_endpoint' => $graphurl . '/oauth/access_token',
<             'userinfo_endpoint' => $graphurl . '/me?fields=' . implode(',', $infofields)
<         ];
< 
<         foreach ($endpoints as $name => $url) {
<             $record = (object) [
<                 'issuerid' => $issuer->get('id'),
<                 'name' => $name,
<                 'url' => $url
<             ];
<             $endpoint = new endpoint(0, $record);
<             $endpoint->create();
<         }
< 
<         // Create the field mappings.
<         $mapping = [
<             'name' => 'alternatename',
<             'last_name' => 'lastname',
<             'email' => 'email',
<             'first_name' => 'firstname',
<             'picture-data-url' => 'picture',
<             'link' => 'url',
<         ];
<         foreach ($mapping as $external => $internal) {
<             $record = (object) [
<                 'issuerid' => $issuer->get('id'),
<                 'externalfield' => $external,
<                 'internalfield' => $internal
<             ];
<             $userfieldmapping = new user_field_mapping(0, $record);
<             $userfieldmapping->create();
<         }
<         return $issuer;
<     }
< 
<     /**
<      * Build a microsoft ready OAuth 2 service.
<      * @return \core\oauth2\issuer
<      */
<     private static function init_microsoft() {
<         // Microsoft is a custom setup.
<         $record = (object) [
<             'name' => 'Microsoft',
<             'image' => 'https://www.microsoft.com/favicon.ico',
<             'baseurl' => '',
<             'loginscopes' => 'openid profile email user.read',
<             'loginscopesoffline' => 'openid profile email user.read offline_access',
<             'showonloginpage' => true
<         ];
< 
<         $issuer = new issuer(0, $record);
<         return $issuer;
<     }
< 
<     /**
<      * Create endpoints for microsoft issuers.
<      * @param issuer $issuer issuer the endpoints should be created for.
<      * @return mixed
<      * @throws \coding_exception
<      * @throws \core\invalid_persistent_exception
<      */
<     private static function create_endpoints_for_microsoft($issuer) {
< 
<         $endpoints = [
<             'authorization_endpoint' => 'https://login.microsoftonline.com/common/oauth2/v2.0/authorize',
<             'token_endpoint' => 'https://login.microsoftonline.com/common/oauth2/v2.0/token',
<             'userinfo_endpoint' => 'https://graph.microsoft.com/v1.0/me/',
<             'userpicture_endpoint' => 'https://graph.microsoft.com/v1.0/me/photo/$value',
<         ];
< 
<         foreach ($endpoints as $name => $url) {
<             $record = (object) [
<                 'issuerid' => $issuer->get('id'),
<                 'name' => $name,
<                 'url' => $url
<             ];
<             $endpoint = new endpoint(0, $record);
<             $endpoint->create();
<         }
< 
<         // Create the field mappings.
<         $mapping = [
<             'givenName' => 'firstname',
<             'surname' => 'lastname',
<             'userPrincipalName' => 'email',
<             'displayName' => 'alternatename',
<             'officeLocation' => 'address',
<             'mobilePhone' => 'phone1',
<             'preferredLanguage' => 'lang'
<         ];
<         foreach ($mapping as $external => $internal) {
<             $record = (object) [
<                 'issuerid' => $issuer->get('id'),
<                 'externalfield' => $external,
<                 'internalfield' => $internal
<             ];
<             $userfieldmapping = new user_field_mapping(0, $record);
<             $userfieldmapping->create();
<         }
<         return $issuer;
<     }
< 
<     /**
<      * Build a nextcloud ready OAuth 2 service.
<      * @return \core\oauth2\issuer
<      */
<     private static function init_nextcloud() {
<         // Nextcloud has a custom baseurl. Thus, the creation of endpoints has to be done later.
<         $record = (object) [
<             'name' => 'Nextcloud',
<             'image' => 'https://nextcloud.com/wp-content/themes/next/assets/img/common/favicon.png?x16328',
<             'basicauth' => 1,
<         ];
< 
<         $issuer = new issuer(0, $record);
< 
<         return $issuer;
<     }
< 
<     /**
<      * Create endpoints for nextcloud issuers.
<      * @param issuer $issuer issuer the endpoints should be created for.
<      * @return mixed
<      * @throws \coding_exception
<      * @throws \core\invalid_persistent_exception
<      */
<     private static function create_endpoints_for_nextcloud($issuer) {
<         $baseurl = $issuer->get('baseurl');
<         // Add trailing slash to baseurl, if needed.
<         if (substr($baseurl, -1) !== '/') {
<             $baseurl .= '/';
<         }
< 
<         $endpoints = [
<             // Baseurl will be prepended later.
<             'authorization_endpoint' => 'index.php/apps/oauth2/authorize',
<             'token_endpoint' => 'index.php/apps/oauth2/api/v1/token',
<             'userinfo_endpoint' => 'ocs/v2.php/cloud/user?format=json',
<             'webdav_endpoint' => 'remote.php/webdav/',
<             'ocs_endpoint' => 'ocs/v1.php/apps/files_sharing/api/v1/shares',
<         ];
< 
<         foreach ($endpoints as $name => $url) {
<             $record = (object) [
<                 'issuerid' => $issuer->get('id'),
<                 'name' => $name,
<                 'url' => $baseurl . $url,
<             ];
<             $endpoint = new \core\oauth2\endpoint(0, $record);
<             $endpoint->create();
<         }
< 
<         // Create the field mappings.
<         $mapping = [
<             'ocs-data-email' => 'email',
<             'ocs-data-id' => 'username',
<         ];
<         foreach ($mapping as $external => $internal) {
<             $record = (object) [
<                 'issuerid' => $issuer->get('id'),
<                 'externalfield' => $external,
<                 'internalfield' => $internal
<             ];
<             $userfieldmapping = new \core\oauth2\user_field_mapping(0, $record);
<             $userfieldmapping->create();
<         }
<     }
< 
<     /**


     * Initializes a record for one of the standard issuers to be displayed in the settings.
     * The issuer is not yet created in the database.

<      * @param string $type One of google, facebook, microsoft, nextcloud



>      * @param string $type One of google, facebook, microsoft, nextcloud, imsobv2p1


     * @return \core\oauth2\issuer
     */
    public static function init_standard_issuer($type) {
        require_capability('moodle/site:config', context_system::instance());

<         if ($type == 'google') {
<             return self::init_google();
<         } else if ($type == 'microsoft') {
<             return self::init_microsoft();
<         } else if ($type == 'facebook') {
<             return self::init_facebook();
<         } else if ($type == 'nextcloud') {
<             return self::init_nextcloud();
<         } else {
<             throw new moodle_exception('OAuth 2 service type not recognised: ' . $type);



> 
>         $classname = self::get_service_classname($type);
>         if (class_exists($classname)) {
>             return $classname::init();


        }

>         throw new moodle_exception('OAuth 2 service type not recognised: ' . $type);


    }

    /**
     * Create endpoints for standard issuers, based on the issuer created from submitted data.

<      * @param string $type One of google, facebook, microsoft, nextcloud



>      * @param string $type One of google, facebook, microsoft, nextcloud, imsobv2p1


     * @param issuer $issuer issuer the endpoints should be created for.
     * @return \core\oauth2\issuer
     */
    public static function create_endpoints_for_standard_issuer($type, $issuer) {
        require_capability('moodle/site:config', context_system::instance());

<         if ($type == 'google') {
<             $issuer = self::create_endpoints_for_google($issuer);
<             self::discover_endpoints($issuer);



> 
>         $classname = self::get_service_classname($type);
>         if (class_exists($classname)) {
>             $classname::create_endpoints($issuer);


            return $issuer;

<         } else if ($type == 'microsoft') {
<             return self::create_endpoints_for_microsoft($issuer);
<         } else if ($type == 'facebook') {
<             return self::create_endpoints_for_facebook($issuer);
<         } else if ($type == 'nextcloud') {
<             return self::create_endpoints_for_nextcloud($issuer);
<         } else {
<             throw new moodle_exception('OAuth 2 service type not recognised: ' . $type);


        }

>         throw new moodle_exception('OAuth 2 service type not recognised: ' . $type);


    }

    /**
     * Create one of the standard issuers.

<      * @param string $type One of google, facebook, microsoft, or nextcloud
<      * @param string|false $baseurl Baseurl (only required for nextcloud)



>      *
>      * @param string $type One of google, facebook, microsoft, MoodleNet, nextcloud or imsobv2p1
>      * @param string|false $baseurl Baseurl (only required for nextcloud, imsobv2p1 and moodlenet)


     * @return \core\oauth2\issuer
     */
    public static function create_standard_issuer($type, $baseurl = false) {
        require_capability('moodle/site:config', context_system::instance());

<         if ($type == 'google') {
<             $issuer = self::init_google();
<             $issuer->create();
<             return self::create_endpoints_for_google($issuer);
<         } else if ($type == 'microsoft') {
<             $issuer = self::init_microsoft();
<             $issuer->create();
<             return self::create_endpoints_for_microsoft($issuer);
<         } else if ($type == 'facebook') {
<             $issuer = self::init_facebook();
<             $issuer->create();
<             return self::create_endpoints_for_facebook($issuer);
<         } else if ($type == 'nextcloud') {



> 
>         switch ($type) {
>             case 'imsobv2p1':
>                 if (!$baseurl) {
>                     throw new moodle_exception('IMS OBv2.1 service type requires the baseurl parameter.');
>                 }
>             case 'nextcloud':


            if (!$baseurl) {
                throw new moodle_exception('Nextcloud service type requires the baseurl parameter.');
            }

<             $issuer = self::init_nextcloud();



>             case 'moodlenet':
>                 if (!$baseurl) {
>                     throw new moodle_exception('MoodleNet service type requires the baseurl parameter.');
>                 }
>             case 'google':
>             case 'facebook':
>             case 'microsoft':
>                 $classname = self::get_service_classname($type);
>                 $issuer = $classname::init();
>                 if ($baseurl) {


            $issuer->set('baseurl', $baseurl);

>                 }


            $issuer->create();

<             return self::create_endpoints_for_nextcloud($issuer);
<         } else {
<             throw new moodle_exception('OAuth 2 service type not recognised: ' . $type);



>                 return self::create_endpoints_for_standard_issuer($type, $issuer);


        }

> 
    }
>         throw new moodle_exception('OAuth 2 service type not recognised: ' . $type);




    /**
     * List all the issuers, ordered by the sortorder field

>      *
     * @return \core\oauth2\issuer[]
>      * @param bool $includeloginonly also include issuers that are configured to be shown only on login page,
     */
>      *     By default false, in this case the method returns all issuers that can be used in services



<     public static function get_all_issuers() {



>     public static function get_all_issuers(bool $includeloginonly = false) {
>         if ($includeloginonly) {


        return issuer::get_records([], 'sortorder');

>         } else {
    }
>             return array_values(issuer::get_records_select('showonloginpage<>?', [issuer::LOGINONLY], 'sortorder'));

>         }


    /**
     * Get a single issuer by id.
     *
     * @param int $id
     * @return \core\oauth2\issuer
     */
    public static function get_issuer($id) {
        return new issuer($id);
    }

    /**
     * Get a single endpoint by id.
     *
     * @param int $id
     * @return \core\oauth2\endpoint
     */
    public static function get_endpoint($id) {
        return new endpoint($id);
    }

    /**
     * Get a single user field mapping by id.
     *
     * @param int $id
     * @return \core\oauth2\user_field_mapping
     */
    public static function get_user_field_mapping($id) {
        return new user_field_mapping($id);
    }

    /**
     * Get the system account for an installed OAuth service.
     * Never ever ever expose this to a webservice because it contains the refresh token which grants API access.
     *
     * @param \core\oauth2\issuer $issuer
     * @return system_account|false
     */
    public static function get_system_account(issuer $issuer) {
        return system_account::get_record(['issuerid' => $issuer->get('id')]);
    }

    /**
     * Get the full list of system scopes required by an oauth issuer.
     * This includes the list required for login as well as any scopes injected by the oauth2_system_scopes callback in plugins.
     *
     * @param \core\oauth2\issuer $issuer
     * @return string
     */
    public static function get_system_scopes_for_issuer($issuer) {
        $scopes = $issuer->get('loginscopesoffline');

        $pluginsfunction = get_plugins_with_function('oauth2_system_scopes', 'lib.php');
        foreach ($pluginsfunction as $plugintype => $plugins) {
            foreach ($plugins as $pluginfunction) {
                // Get additional scopes from the plugin.
                $pluginscopes = $pluginfunction($issuer);
                if (empty($pluginscopes)) {
                    continue;
                }

                // Merge the additional scopes with the existing ones.
                $additionalscopes = explode(' ', $pluginscopes);

                foreach ($additionalscopes as $scope) {
                    if (!empty($scope)) {
                        if (strpos(' ' . $scopes . ' ', ' ' . $scope . ' ') === false) {
                            $scopes .= ' ' . $scope;
                        }
                    }
                }
            }
        }

        return $scopes;
    }

    /**
     * Get an authenticated oauth2 client using the system account.
     * This call uses the refresh token to get an access token.
     *
     * @param \core\oauth2\issuer $issuer
     * @return \core\oauth2\client|false An authenticated client (or false if the token could not be upgraded)
     * @throws moodle_exception Request for token upgrade failed for technical reasons
     */
    public static function get_system_oauth_client(issuer $issuer) {
        $systemaccount = self::get_system_account($issuer);
        if (empty($systemaccount)) {
            return false;
        }
        // Get all the scopes!
        $scopes = self::get_system_scopes_for_issuer($issuer);

< 
<         $client = new \core\oauth2\client($issuer, null, $scopes, true);



>         $class = self::get_client_classname($issuer->get('servicetype'));
>         $client = new $class($issuer, null, $scopes, true);



        if (!$client->is_logged_in()) {
            if (!$client->upgrade_refresh_token($systemaccount)) {
                return false;
            }
        }
        return $client;
    }

    /**
     * Get an authenticated oauth2 client using the current user account.
     * This call does the redirect dance back to the current page after authentication.
     *
     * @param \core\oauth2\issuer $issuer The desired OAuth issuer
     * @param moodle_url $currenturl The url to the current page.
     * @param string $additionalscopes The additional scopes required for authorization.

>      * @param bool $autorefresh Should the client support the use of refresh tokens to persist access across sessions.


     * @return \core\oauth2\client
     */

<     public static function get_user_oauth_client(issuer $issuer, moodle_url $currenturl, $additionalscopes = '') {
<         $client = new \core\oauth2\client($issuer, $currenturl, $additionalscopes);



>     public static function get_user_oauth_client(issuer $issuer, moodle_url $currenturl, $additionalscopes = '',
>             $autorefresh = false) {
>         $class = self::get_client_classname($issuer->get('servicetype'));
>         $client = new $class($issuer, $currenturl, $additionalscopes, false, $autorefresh);



        return $client;
    }

    /**

>      * Get the client classname for an issuer.
     * Get the list of defined endpoints for this OAuth issuer
>      *
     *
>      * @param string $type The OAuth issuer type (google, facebook...).
     * @param \core\oauth2\issuer $issuer The desired OAuth issuer
>      * @return string The classname for the custom client or core client class if the class for the defined type
     * @return \core\oauth2\endpoint[]
>      *                 doesn't exist or null type is defined.
     */
>      */
    public static function get_endpoints(issuer $issuer) {
>     protected static function get_client_classname(?string $type): string {
        return endpoint::get_records(['issuerid' => $issuer->get('id')]);
>         // Default core client class.
    }
>         $classname = 'core\\oauth2\\client';

> 
    /**
>         if (!empty($type)) {
     * Get the list of defined mapping from OAuth user fields to moodle user fields.
>             $typeclassname = 'core\\oauth2\\client\\' . $type;
     *
>             if (class_exists($typeclassname)) {
     * @param \core\oauth2\issuer $issuer The desired OAuth issuer
>                 $classname = $typeclassname;
     * @return \core\oauth2\user_field_mapping[]
>             }
     */
>         }
    public static function get_user_field_mappings(issuer $issuer) {
> 
        return user_field_mapping::get_records(['issuerid' => $issuer->get('id')]);
>         return $classname;
    }
>     }

> 
    /**
>     /**


     * Guess an image from the discovery URL.
     *
     * @param \core\oauth2\issuer $issuer The desired OAuth issuer
     */
    protected static function guess_image($issuer) {
        if (empty($issuer->get('image')) && !empty($issuer->get('baseurl'))) {
            $baseurl = parse_url($issuer->get('baseurl'));
            $imageurl = $baseurl['scheme'] . '://' . $baseurl['host'] . '/favicon.ico';
            $issuer->set('image', $imageurl);
            $issuer->update();
        }
    }

    /**

<      * If the discovery endpoint exists for this issuer, try and determine the list of valid endpoints.
<      *
<      * @param issuer $issuer
<      * @return int The number of discovered services.
<      */
<     protected static function discover_endpoints($issuer) {
<         $curl = new curl();
< 
<         if (empty($issuer->get('baseurl'))) {
<             return 0;
<         }
< 
<         $url = $issuer->get_endpoint_url('discovery');
<         if (!$url) {
<             $url = $issuer->get('baseurl') . '/.well-known/openid-configuration';
<         }
< 
<         if (!$json = $curl->get($url)) {
<             $msg = 'Could not discover end points for identity issuer' . $issuer->get('name');
<             throw new moodle_exception($msg);
<         }
< 
<         if ($msg = $curl->error) {
<             throw new moodle_exception('Could not discover service endpoints: ' . $msg);
<         }
< 
<         $info = json_decode($json);
<         if (empty($info)) {
<             $msg = 'Could not discover end points for identity issuer' . $issuer->get('name');
<             throw new moodle_exception($msg);
<         }
< 
<         foreach (endpoint::get_records(['issuerid' => $issuer->get('id')]) as $endpoint) {
<             if ($endpoint->get('name') != 'discovery_endpoint') {
<                 $endpoint->delete();
<             }
<         }
< 
<         foreach ($info as $key => $value) {
<             if (substr_compare($key, '_endpoint', - strlen('_endpoint')) === 0) {
<                 $record = new stdClass();
<                 $record->issuerid = $issuer->get('id');
<                 $record->name = $key;
<                 $record->url = $value;
< 
<                 $endpoint = new endpoint(0, $record);
<                 $endpoint->create();
<             }
< 
<             if ($key == 'scopes_supported') {
<                 $issuer->set('scopessupported', implode(' ', $value));
<                 $issuer->update();
<             }
<         }
< 
<         // We got to here - must be a decent OpenID connect service. Add the default user field mapping list.
<         foreach (user_field_mapping::get_records(['issuerid' => $issuer->get('id')]) as $userfieldmapping) {
<             $userfieldmapping->delete();
<         }
< 
<         // Create the field mappings.
<         $mapping = [
<             'given_name' => 'firstname',
<             'middle_name' => 'middlename',
<             'family_name' => 'lastname',
<             'email' => 'email',
<             'website' => 'url',
<             'nickname' => 'alternatename',
<             'picture' => 'picture',
<             'address' => 'address',
<             'phone' => 'phone1',
<             'locale' => 'lang'
<         ];
<         foreach ($mapping as $external => $internal) {
<             $record = (object) [
<                 'issuerid' => $issuer->get('id'),
<                 'externalfield' => $external,
<                 'internalfield' => $internal
<             ];
<             $userfieldmapping = new user_field_mapping(0, $record);
<             $userfieldmapping->create();
<         }
< 
<         return endpoint::count_records(['issuerid' => $issuer->get('id')]);
<     }
< 
<     /**


     * Take the data from the mform and update the issuer.
     *
     * @param stdClass $data
     * @return \core\oauth2\issuer
     */
    public static function update_issuer($data) {

<         require_capability('moodle/site:config', context_system::instance());
<         $issuer = new issuer(0, $data);
< 
<         // Will throw exceptions on validation failures.
<         $issuer->update();
< 
<         // Perform service discovery.
<         self::discover_endpoints($issuer);
<         self::guess_image($issuer);
<         return $issuer;



>         return self::create_or_update_issuer($data, false);


    }

    /**
     * Take the data from the mform and create the issuer.
     *
     * @param stdClass $data
     * @return \core\oauth2\issuer
     */
    public static function create_issuer($data) {

>         return self::create_or_update_issuer($data, true);
        require_capability('moodle/site:config', context_system::instance());
>     }
        $issuer = new issuer(0, $data);
> 

>     /**
        // Will throw exceptions on validation failures.
>      * Take the data from the mform and create or update the issuer.
        $issuer->create();
>      *

>      * @param stdClass $data Form data for them issuer to be created/updated.
        // Perform service discovery.
>      * @param bool $create If true, the issuer will be created; otherwise, it will be updated.
        self::discover_endpoints($issuer);
>      * @return issuer The created/updated issuer.
        self::guess_image($issuer);
>      */
        return $issuer;
>     protected static function create_or_update_issuer($data, bool $create): issuer {



<         $issuer = new issuer(0, $data);



>         $issuer = new issuer($data->id ?? 0, $data);




>         if ($create) {



<         self::discover_endpoints($issuer);



>             $classname = self::get_service_classname($issuer->get('servicetype'));
>             $classname::discover_endpoints($issuer);


     * Take the data from the mform and update the endpoint.

>         } else {
     *
>             $issuer->update();
     * @param stdClass $data
>         }
     * @return \core\oauth2\endpoint
> 


     */

>      * Get the service classname for an issuer.
    public static function update_endpoint($data) {
>      *
        require_capability('moodle/site:config', context_system::instance());
>      * @param string $type The OAuth issuer type (google, facebook...).
        $endpoint = new endpoint(0, $data);
>      *

>      * @return string The classname for this issuer or "Custom" service class if the class for the defined type doesn't exist
        // Will throw exceptions on validation failures.
>      *                 or null type is defined.
        $endpoint->update();
>      */

>     protected static function get_service_classname(?string $type): string {
        return $endpoint;
>         // Default custom service class.
    }
>         $classname = 'core\\oauth2\\service\\custom';

> 
    /**
>         if (!empty($type)) {
     * Take the data from the mform and create the endpoint.
>             $typeclassname = 'core\\oauth2\\service\\' . $type;
     *
>             if (class_exists($typeclassname)) {
     * @param stdClass $data
>                 $classname = $typeclassname;
     * @return \core\oauth2\endpoint
>             }
     */
>         }
    public static function create_endpoint($data) {
> 
        require_capability('moodle/site:config', context_system::instance());
>         return $classname;
        $endpoint = new endpoint(0, $data);
>     }

> 
        // Will throw exceptions on validation failures.
>     /**


        $endpoint->create();
        return $endpoint;
    }

    /**
     * Take the data from the mform and update the user field mapping.
     *
     * @param stdClass $data
     * @return \core\oauth2\user_field_mapping
     */
    public static function update_user_field_mapping($data) {
        require_capability('moodle/site:config', context_system::instance());
        $userfieldmapping = new user_field_mapping(0, $data);

        // Will throw exceptions on validation failures.
        $userfieldmapping->update();

        return $userfieldmapping;
    }

    /**
     * Take the data from the mform and create the user field mapping.
     *
     * @param stdClass $data
     * @return \core\oauth2\user_field_mapping
     */
    public static function create_user_field_mapping($data) {
        require_capability('moodle/site:config', context_system::instance());
        $userfieldmapping = new user_field_mapping(0, $data);

        // Will throw exceptions on validation failures.
        $userfieldmapping->create();
        return $userfieldmapping;
    }

    /**
     * Reorder this identity issuer.
     *
     * Requires moodle/site:config capability at the system context.
     *
     * @param int $id The id of the identity issuer to move.
     * @return boolean
     */
    public static function move_up_issuer($id) {
        require_capability('moodle/site:config', context_system::instance());
        $current = new issuer($id);

        $sortorder = $current->get('sortorder');
        if ($sortorder == 0) {
            return false;
        }

        $sortorder = $sortorder - 1;
        $current->set('sortorder', $sortorder);

        $filters = array('sortorder' => $sortorder);
        $children = issuer::get_records($filters, 'id');
        foreach ($children as $needtoswap) {
            $needtoswap->set('sortorder', $sortorder + 1);
            $needtoswap->update();
        }

        // OK - all set.
        $result = $current->update();

        return $result;
    }

    /**
     * Reorder this identity issuer.
     *
     * Requires moodle/site:config capability at the system context.
     *
     * @param int $id The id of the identity issuer to move.
     * @return boolean
     */
    public static function move_down_issuer($id) {
        require_capability('moodle/site:config', context_system::instance());
        $current = new issuer($id);

        $max = issuer::count_records();
        if ($max > 0) {
            $max--;
        }

        $sortorder = $current->get('sortorder');
        if ($sortorder >= $max) {
            return false;
        }
        $sortorder = $sortorder + 1;
        $current->set('sortorder', $sortorder);

        $filters = array('sortorder' => $sortorder);
        $children = issuer::get_records($filters);
        foreach ($children as $needtoswap) {
            $needtoswap->set('sortorder', $sortorder - 1);
            $needtoswap->update();
        }

        // OK - all set.
        $result = $current->update();

        return $result;
    }

    /**
     * Disable an identity issuer.
     *
     * Requires moodle/site:config capability at the system context.
     *
     * @param int $id The id of the identity issuer to disable.
     * @return boolean
     */
    public static function disable_issuer($id) {
        require_capability('moodle/site:config', context_system::instance());
        $issuer = new issuer($id);

        $issuer->set('enabled', 0);
        return $issuer->update();
    }


    /**
     * Enable an identity issuer.
     *
     * Requires moodle/site:config capability at the system context.
     *
     * @param int $id The id of the identity issuer to enable.
     * @return boolean
     */
    public static function enable_issuer($id) {
        require_capability('moodle/site:config', context_system::instance());
        $issuer = new issuer($id);

        $issuer->set('enabled', 1);
        return $issuer->update();
    }

    /**
     * Delete an identity issuer.
     *
     * Requires moodle/site:config capability at the system context.
     *
     * @param int $id The id of the identity issuer to delete.
     * @return boolean
     */
    public static function delete_issuer($id) {
        require_capability('moodle/site:config', context_system::instance());
        $issuer = new issuer($id);

        $systemaccount = self::get_system_account($issuer);
        if ($systemaccount) {
            $systemaccount->delete();
        }
        $endpoints = self::get_endpoints($issuer);
        if ($endpoints) {
            foreach ($endpoints as $endpoint) {
                $endpoint->delete();
            }
        }

        // Will throw exceptions on validation failures.
        return $issuer->delete();
    }

    /**
     * Delete an endpoint.
     *
     * Requires moodle/site:config capability at the system context.
     *
     * @param int $id The id of the endpoint to delete.
     * @return boolean
     */
    public static function delete_endpoint($id) {
        require_capability('moodle/site:config', context_system::instance());
        $endpoint = new endpoint($id);

        // Will throw exceptions on validation failures.
        return $endpoint->delete();
    }

    /**
     * Delete a user_field_mapping.
     *
     * Requires moodle/site:config capability at the system context.
     *
     * @param int $id The id of the user_field_mapping to delete.
     * @return boolean
     */
    public static function delete_user_field_mapping($id) {
        require_capability('moodle/site:config', context_system::instance());
        $userfieldmapping = new user_field_mapping($id);

        // Will throw exceptions on validation failures.
        return $userfieldmapping->delete();
    }

    /**
     * Perform the OAuth dance and get a refresh token.
     *
     * Requires moodle/site:config capability at the system context.
     *
     * @param \core\oauth2\issuer $issuer
     * @param moodle_url $returnurl The url to the current page (we will be redirected back here after authentication).
     * @return boolean
     */
    public static function connect_system_account($issuer, $returnurl) {
        require_capability('moodle/site:config', context_system::instance());

        // We need to authenticate with an oauth 2 client AS a system user and get a refresh token for offline access.
        $scopes = self::get_system_scopes_for_issuer($issuer);

        // Allow callbacks to inject non-standard scopes to the auth request.

< 
<         $client = new client($issuer, $returnurl, $scopes, true);



>         $class = self::get_client_classname($issuer->get('servicetype'));
>         $client = new $class($issuer, $returnurl, $scopes, true);



        if (!optional_param('response', false, PARAM_BOOL)) {
            $client->log_out();
        }

        if (optional_param('error', '', PARAM_RAW)) {
            return false;
        }

        if (!$client->is_logged_in()) {
            redirect($client->get_login_url());
        }

        $refreshtoken = $client->get_refresh_token();
        if (!$refreshtoken) {
            return false;
        }

        $systemaccount = self::get_system_account($issuer);
        if ($systemaccount) {
            $systemaccount->delete();
        }

        $userinfo = $client->get_userinfo();

        $record = new stdClass();
        $record->issuerid = $issuer->get('id');
        $record->refreshtoken = $refreshtoken;
        $record->grantedscopes = $scopes;
        $record->email = isset($userinfo['email']) ? $userinfo['email'] : '';
        $record->username = $userinfo['username'];

        $systemaccount = new system_account(0, $record);

        $systemaccount->create();

        $client->log_out();
        return true;
    }
}