<?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/>.


< 


/**
 * Support for external API
 *
 * @package    core_webservice
 * @copyright  2009 Petr Skodak
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */


< defined('MOODLE_INTERNAL') || die();
< 
< /**
<  * Exception indicating user is not allowed to use external function in the current context.
<  *
<  * @package    core_webservice
<  * @copyright  2009 Petr Skodak
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since Moodle 2.0
<  */
< class restricted_context_exception extends moodle_exception {
<     /**
<      * Constructor
<      *
<      * @since Moodle 2.0
<      */
<     function __construct() {
<         parent::__construct('restrictedcontextexception', 'error');
<     }
< }
< 
< /**
<  * Base class for external api methods.
<  *
<  * @package    core_webservice
<  * @copyright  2009 Petr Skodak
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since Moodle 2.0
<  */
< class external_api {
< 
<     /** @var stdClass context where the function calls will be restricted */
<     private static $contextrestriction;
< 
<     /**
<      * Returns detailed function information
<      *
<      * @param string|object $function name of external function or record from external_function
<      * @param int $strictness IGNORE_MISSING means compatible mode, false returned if record not found, debug message if more found;
<      *                        MUST_EXIST means throw exception if no record or multiple records found
<      * @return stdClass description or false if not found or exception thrown
<      * @since Moodle 2.0
<      */
<     public static function external_function_info($function, $strictness=MUST_EXIST) {
<         global $DB, $CFG;
< 
<         if (!is_object($function)) {
<             if (!$function = $DB->get_record('external_functions', array('name' => $function), '*', $strictness)) {
<                 return false;
<             }
<         }
< 
<         // First try class autoloading.
<         if (!class_exists($function->classname)) {
<             // Fallback to explicit include of externallib.php.
<             if (empty($function->classpath)) {
<                 $function->classpath = core_component::get_component_directory($function->component).'/externallib.php';
<             } else {
<                 $function->classpath = $CFG->dirroot.'/'.$function->classpath;
<             }
<             if (!file_exists($function->classpath)) {
<                 throw new coding_exception('Cannot find file ' . $function->classpath .
<                         ' with external function implementation');
<             }
<             require_once($function->classpath);
<             if (!class_exists($function->classname)) {
<                 throw new coding_exception('Cannot find external class ' . $function->classname);
<             }
<         }
< 
<         $function->ajax_method = $function->methodname.'_is_allowed_from_ajax';
<         $function->parameters_method = $function->methodname.'_parameters';
<         $function->returns_method    = $function->methodname.'_returns';
<         $function->deprecated_method = $function->methodname.'_is_deprecated';
< 
<         // Make sure the implementaion class is ok.
<         if (!method_exists($function->classname, $function->methodname)) {
<             throw new coding_exception('Missing implementation method ' .
<                     $function->classname . '::' . $function->methodname);
<         }
<         if (!method_exists($function->classname, $function->parameters_method)) {
<             throw new coding_exception('Missing parameters description method ' .
<                     $function->classname . '::' . $function->parameters_method);
<         }
<         if (!method_exists($function->classname, $function->returns_method)) {
<             throw new coding_exception('Missing returned values description method ' .
<                     $function->classname . '::' . $function->returns_method);
<         }
<         if (method_exists($function->classname, $function->deprecated_method)) {
<             if (call_user_func(array($function->classname, $function->deprecated_method)) === true) {
<                 $function->deprecated = true;
<             }
<         }
<         $function->allowed_from_ajax = false;
< 
<         // Fetch the parameters description.
<         $function->parameters_desc = call_user_func(array($function->classname, $function->parameters_method));
<         if (!($function->parameters_desc instanceof external_function_parameters)) {
<             throw new coding_exception($function->classname . '::' . $function->parameters_method .
<                     ' did not return a valid external_function_parameters object.');
<         }
< 
<         // Fetch the return values description.
<         $function->returns_desc = call_user_func(array($function->classname, $function->returns_method));
<         // Null means void result or result is ignored.
<         if (!is_null($function->returns_desc) and !($function->returns_desc instanceof external_description)) {
<             throw new coding_exception($function->classname . '::' . $function->returns_method .
<                     ' did not return a valid external_description object');
<         }
< 
<         // Now get the function description.
< 
<         // TODO MDL-31115 use localised lang pack descriptions, it would be nice to have
<         // easy to understand descriptions in admin UI,
<         // on the other hand this is still a bit in a flux and we need to find some new naming
<         // conventions for these descriptions in lang packs.
<         $function->description = null;
<         $servicesfile = core_component::get_component_directory($function->component).'/db/services.php';
<         if (file_exists($servicesfile)) {
<             $functions = null;
<             include($servicesfile);
<             if (isset($functions[$function->name]['description'])) {
<                 $function->description = $functions[$function->name]['description'];
<             }
<             if (isset($functions[$function->name]['testclientpath'])) {
<                 $function->testclientpath = $functions[$function->name]['testclientpath'];
<             }
<             if (isset($functions[$function->name]['type'])) {
<                 $function->type = $functions[$function->name]['type'];
<             }
<             if (isset($functions[$function->name]['ajax'])) {
<                 $function->allowed_from_ajax = $functions[$function->name]['ajax'];
<             } else if (method_exists($function->classname, $function->ajax_method)) {
<                 if (call_user_func(array($function->classname, $function->ajax_method)) === true) {
<                     debugging('External function ' . $function->ajax_method . '() function is deprecated.' .
<                               'Set ajax=>true in db/service.php instead.', DEBUG_DEVELOPER);
<                     $function->allowed_from_ajax = true;
<                 }
<             }
<             if (isset($functions[$function->name]['loginrequired'])) {
<                 $function->loginrequired = $functions[$function->name]['loginrequired'];
<             } else {
<                 $function->loginrequired = true;
<             }
<             if (isset($functions[$function->name]['readonlysession'])) {
<                 $function->readonlysession = $functions[$function->name]['readonlysession'];
<             } else {
<                 $function->readonlysession = false;
<             }
<         }
< 
<         return $function;
<     }
< 
<     /**
<      * Call an external function validating all params/returns correctly.
<      *
<      * Note that an external function may modify the state of the current page, so this wrapper
<      * saves and restores tha PAGE and COURSE global variables before/after calling the external function.
<      *
<      * @param string $function A webservice function name.
<      * @param array $args Params array (named params)
<      * @param boolean $ajaxonly If true, an extra check will be peformed to see if ajax is required.
<      * @return array containing keys for error (bool), exception and data.
<      */
<     public static function call_external_function($function, $args, $ajaxonly=false) {
<         global $PAGE, $COURSE, $CFG, $SITE;
< 
<         require_once($CFG->libdir . "/pagelib.php");
< 
<         $externalfunctioninfo = static::external_function_info($function);
< 
<         // Eventually this should shift into the various handlers and not be handled via config.
<         $readonlysession = $externalfunctioninfo->readonlysession ?? false;
<         if (!$readonlysession || empty($CFG->enable_read_only_sessions)) {
<             \core\session\manager::restart_with_write_lock();
<         }
< 
<         $currentpage = $PAGE;
<         $currentcourse = $COURSE;
<         $response = array();
< 
<         try {
<             // Taken straight from from setup.php.
<             if (!empty($CFG->moodlepageclass)) {
<                 if (!empty($CFG->moodlepageclassfile)) {
<                     require_once($CFG->moodlepageclassfile);
<                 }
<                 $classname = $CFG->moodlepageclass;
<             } else {
<                 $classname = 'moodle_page';
<             }
<             $PAGE = new $classname();
<             $COURSE = clone($SITE);
< 
<             if ($ajaxonly && !$externalfunctioninfo->allowed_from_ajax) {
<                 throw new moodle_exception('servicenotavailable', 'webservice');
<             }
< 
<             // Do not allow access to write or delete webservices as a public user.
<             if ($externalfunctioninfo->loginrequired && !WS_SERVER) {
<                 if (defined('NO_MOODLE_COOKIES') && NO_MOODLE_COOKIES && !PHPUNIT_TEST) {
<                     throw new moodle_exception('servicerequireslogin', 'webservice');
<                 }
<                 if (!isloggedin()) {
<                     throw new moodle_exception('servicerequireslogin', 'webservice');
<                 } else {
<                     require_sesskey();
<                 }
<             }
<             // Validate params, this also sorts the params properly, we need the correct order in the next part.
<             $callable = array($externalfunctioninfo->classname, 'validate_parameters');
<             $params = call_user_func($callable,
<                                      $externalfunctioninfo->parameters_desc,
<                                      $args);
<             $params = array_values($params);
< 
<             // Allow any Moodle plugin a chance to override this call. This is a convenient spot to
<             // make arbitrary behaviour customisations. The overriding plugin could call the 'real'
<             // function first and then modify the results, or it could do a completely separate
<             // thing.
<             $callbacks = get_plugins_with_function('override_webservice_execution');
<             $result = false;
<             foreach ($callbacks as $plugintype => $plugins) {
<                 foreach ($plugins as $plugin => $callback) {
<                     $result = $callback($externalfunctioninfo, $params);
<                     if ($result !== false) {
<                         break 2;
<                     }
<                 }
<             }
< 
<             // If the function was not overridden, call the real one.
<             if ($result === false) {
<                 $callable = array($externalfunctioninfo->classname, $externalfunctioninfo->methodname);
<                 $result = call_user_func_array($callable, $params);
<             }
< 
<             // Validate the return parameters.
<             if ($externalfunctioninfo->returns_desc !== null) {
<                 $callable = array($externalfunctioninfo->classname, 'clean_returnvalue');
<                 $result = call_user_func($callable, $externalfunctioninfo->returns_desc, $result);
<             }
< 
<             $response['error'] = false;
<             $response['data'] = $result;
<         } catch (Throwable $e) {
<             $exception = get_exception_info($e);
<             unset($exception->a);
<             $exception->backtrace = format_backtrace($exception->backtrace, true);
<             if (!debugging('', DEBUG_DEVELOPER)) {
<                 unset($exception->debuginfo);
<                 unset($exception->backtrace);
<             }
<             $response['error'] = true;
<             $response['exception'] = $exception;
<             // Do not process the remaining requests.
<         }
< 
<         $PAGE = $currentpage;
<         $COURSE = $currentcourse;
< 
<         return $response;
<     }
< 
<     /**
<      * Set context restriction for all following subsequent function calls.
<      *
<      * @param stdClass $context the context restriction
<      * @since Moodle 2.0
<      */
<     public static function set_context_restriction($context) {
<         self::$contextrestriction = $context;
<     }
< 
<     /**
<      * This method has to be called before every operation
<      * that takes a longer time to finish!
<      *
<      * @param int $seconds max expected time the next operation needs
<      * @since Moodle 2.0
<      */
<     public static function set_timeout($seconds=360) {
<         $seconds = ($seconds < 300) ? 300 : $seconds;
<         core_php_time_limit::raise($seconds);
<     }
< 
<     /**
<      * Validates submitted function parameters, if anything is incorrect
<      * invalid_parameter_exception is thrown.
<      * This is a simple recursive method which is intended to be called from
<      * each implementation method of external API.
<      *
<      * @param external_description $description description of parameters
<      * @param mixed $params the actual parameters
<      * @return mixed params with added defaults for optional items, invalid_parameters_exception thrown if any problem found
<      * @since Moodle 2.0
<      */
<     public static function validate_parameters(external_description $description, $params) {
<         if ($description instanceof external_value) {
<             if (is_array($params) or is_object($params)) {
<                 throw new invalid_parameter_exception('Scalar type expected, array or object received.');
<             }
< 
<             if ($description->type == PARAM_BOOL) {
<                 // special case for PARAM_BOOL - we want true/false instead of the usual 1/0 - we can not be too strict here ;-)
<                 if (is_bool($params) or $params === 0 or $params === 1 or $params === '0' or $params === '1') {
<                     return (bool)$params;
<                 }
<             }
<             $debuginfo = 'Invalid external api parameter: the value is "' . $params .
<                     '", the server was expecting "' . $description->type . '" type';
<             return validate_param($params, $description->type, $description->allownull, $debuginfo);
< 
<         } else if ($description instanceof external_single_structure) {
<             if (!is_array($params)) {
<                 throw new invalid_parameter_exception('Only arrays accepted. The bad value is: \''
<                         . print_r($params, true) . '\'');
<             }
<             $result = array();
<             foreach ($description->keys as $key=>$subdesc) {
<                 if (!array_key_exists($key, $params)) {
<                     if ($subdesc->required == VALUE_REQUIRED) {
<                         throw new invalid_parameter_exception('Missing required key in single structure: '. $key);
<                     }
<                     if ($subdesc->required == VALUE_DEFAULT) {
<                         try {
<                             $result[$key] = static::validate_parameters($subdesc, $subdesc->default);
<                         } catch (invalid_parameter_exception $e) {
<                             //we are only interested by exceptions returned by validate_param() and validate_parameters()
<                             //(in order to build the path to the faulty attribut)
<                             throw new invalid_parameter_exception($key." => ".$e->getMessage() . ': ' .$e->debuginfo);
<                         }
<                     }
<                 } else {
<                     try {
<                         $result[$key] = static::validate_parameters($subdesc, $params[$key]);
<                     } catch (invalid_parameter_exception $e) {
<                         //we are only interested by exceptions returned by validate_param() and validate_parameters()
<                         //(in order to build the path to the faulty attribut)
<                         throw new invalid_parameter_exception($key." => ".$e->getMessage() . ': ' .$e->debuginfo);
<                     }
<                 }
<                 unset($params[$key]);
<             }
<             if (!empty($params)) {
<                 throw new invalid_parameter_exception('Unexpected keys (' . implode(', ', array_keys($params)) . ') detected in parameter array.');
<             }
<             return $result;
< 
<         } else if ($description instanceof external_multiple_structure) {
<             if (!is_array($params)) {
<                 throw new invalid_parameter_exception('Only arrays accepted. The bad value is: \''
<                         . print_r($params, true) . '\'');
<             }
<             $result = array();
<             foreach ($params as $param) {
<                 $result[] = static::validate_parameters($description->content, $param);
<             }
<             return $result;
< 
<         } else {
<             throw new invalid_parameter_exception('Invalid external api description');
<         }
<     }
< 
<     /**
<      * Clean response
<      * If a response attribute is unknown from the description, we just ignore the attribute.
<      * If a response attribute is incorrect, invalid_response_exception is thrown.
<      * Note: this function is similar to validate parameters, however it is distinct because
<      * parameters validation must be distinct from cleaning return values.
<      *
<      * @param external_description $description description of the return values
<      * @param mixed $response the actual response
<      * @return mixed response with added defaults for optional items, invalid_response_exception thrown if any problem found
<      * @author 2010 Jerome Mouneyrac
<      * @since Moodle 2.0
<      */
<     public static function clean_returnvalue(external_description $description, $response) {
<         if ($description instanceof external_value) {
<             if (is_array($response) or is_object($response)) {
<                 throw new invalid_response_exception('Scalar type expected, array or object received.');
<             }
< 
<             if ($description->type == PARAM_BOOL) {
<                 // special case for PARAM_BOOL - we want true/false instead of the usual 1/0 - we can not be too strict here ;-)
<                 if (is_bool($response) or $response === 0 or $response === 1 or $response === '0' or $response === '1') {
<                     return (bool)$response;
<                 }
<             }
<             $responsetype = gettype($response);
<             $debuginfo = 'Invalid external api response: the value is "' . $response .
<                     '" of PHP type "' . $responsetype . '", the server was expecting "' . $description->type . '" type';
<             try {
<                 return validate_param($response, $description->type, $description->allownull, $debuginfo);
<             } catch (invalid_parameter_exception $e) {
<                 //proper exception name, to be recursively catched to build the path to the faulty attribut
<                 throw new invalid_response_exception($e->debuginfo);
<             }
< 
<         } else if ($description instanceof external_single_structure) {
<             if (!is_array($response) && !is_object($response)) {
<                 throw new invalid_response_exception('Only arrays/objects accepted. The bad value is: \'' .
<                         print_r($response, true) . '\'');
<             }
< 
<             // Cast objects into arrays.
<             if (is_object($response)) {
<                 $response = (array) $response;
<             }
< 
<             $result = array();
<             foreach ($description->keys as $key=>$subdesc) {
<                 if (!array_key_exists($key, $response)) {
<                     if ($subdesc->required == VALUE_REQUIRED) {
<                         throw new invalid_response_exception('Error in response - Missing following required key in a single structure: ' . $key);
<                     }
<                     if ($subdesc instanceof external_value) {
<                         if ($subdesc->required == VALUE_DEFAULT) {
<                             try {
<                                     $result[$key] = static::clean_returnvalue($subdesc, $subdesc->default);
<                             } catch (invalid_response_exception $e) {
<                                 //build the path to the faulty attribut
<                                 throw new invalid_response_exception($key." => ".$e->getMessage() . ': ' . $e->debuginfo);
<                             }
<                         }
<                     }
<                 } else {
<                     try {
<                         $result[$key] = static::clean_returnvalue($subdesc, $response[$key]);
<                     } catch (invalid_response_exception $e) {
<                         //build the path to the faulty attribut
<                         throw new invalid_response_exception($key." => ".$e->getMessage() . ': ' . $e->debuginfo);
<                     }
<                 }
<                 unset($response[$key]);
<             }
< 
<             return $result;
< 
<         } else if ($description instanceof external_multiple_structure) {
<             if (!is_array($response)) {
<                 throw new invalid_response_exception('Only arrays accepted. The bad value is: \'' .
<                         print_r($response, true) . '\'');
<             }
<             $result = array();
<             foreach ($response as $param) {
<                 $result[] = static::clean_returnvalue($description->content, $param);
<             }
<             return $result;
< 
<         } else {
<             throw new invalid_response_exception('Invalid external api response description');
<         }
<     }
< 
<     /**
<      * Makes sure user may execute functions in this context.
<      *
<      * @param stdClass $context
<      * @since Moodle 2.0
<      */
<     public static function validate_context($context) {
<         global $CFG, $PAGE;
< 
<         if (empty($context)) {
<             throw new invalid_parameter_exception('Context does not exist');
<         }
<         if (empty(self::$contextrestriction)) {
<             self::$contextrestriction = context_system::instance();
<         }
<         $rcontext = self::$contextrestriction;
< 
<         if ($rcontext->contextlevel == $context->contextlevel) {
<             if ($rcontext->id != $context->id) {
<                 throw new restricted_context_exception();
<             }
<         } else if ($rcontext->contextlevel > $context->contextlevel) {
<             throw new restricted_context_exception();
<         } else {
<             $parents = $context->get_parent_context_ids();
<             if (!in_array($rcontext->id, $parents)) {
<                 throw new restricted_context_exception();
<             }
<         }
< 
<         $PAGE->reset_theme_and_output();
<         list($unused, $course, $cm) = get_context_info_array($context->id);
<         require_login($course, false, $cm, false, true);
<         $PAGE->set_context($context);
<     }
< 
<     /**
<      * Get context from passed parameters.
<      * The passed array must either contain a contextid or a combination of context level and instance id to fetch the context.
<      * For example, the context level can be "course" and instanceid can be courseid.
<      *
<      * See context_helper::get_all_levels() for a list of valid context levels.
<      *
<      * @param array $param
<      * @since Moodle 2.6
<      * @throws invalid_parameter_exception
<      * @return context
<      */
<     protected static function get_context_from_params($param) {
<         $levels = context_helper::get_all_levels();
<         if (!empty($param['contextid'])) {
<             return context::instance_by_id($param['contextid'], IGNORE_MISSING);
<         } else if (!empty($param['contextlevel']) && isset($param['instanceid'])) {
<             $contextlevel = "context_".$param['contextlevel'];
<             if (!array_search($contextlevel, $levels)) {
<                 throw new invalid_parameter_exception('Invalid context level = '.$param['contextlevel']);
<             }
<            return $contextlevel::instance($param['instanceid'], IGNORE_MISSING);
<         } else {
<             // No valid context info was found.
<             throw new invalid_parameter_exception('Missing parameters, please provide either context level with instance id or contextid');
<         }
<     }
< 
<     /**
<      * Returns a prepared structure to use a context parameters.
<      * @return external_single_structure
<      */
<     protected static function get_context_parameters() {
<         $id = new external_value(
<             PARAM_INT,
<             'Context ID. Either use this value, or level and instanceid.',
<             VALUE_DEFAULT,
<             0
<         );
<         $level = new external_value(
<             PARAM_ALPHA,
<             'Context level. To be used with instanceid.',
<             VALUE_DEFAULT,
<             ''
<         );
<         $instanceid = new external_value(
<             PARAM_INT,
<             'Context instance ID. To be used with level',
<             VALUE_DEFAULT,
<             0
<         );
<         return new external_single_structure(array(
<             'contextid' => $id,
<             'contextlevel' => $level,
<             'instanceid' => $instanceid,
<         ));
<     }
< 
< }
< 
< /**
<  * Common ancestor of all parameter description classes
<  *
<  * @package    core_webservice
<  * @copyright  2009 Petr Skodak
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since Moodle 2.0
<  */
< abstract class external_description {
<     /** @var string Description of element */
<     public $desc;
< 
<     /** @var bool Element value required, null not allowed */
<     public $required;
< 
<     /** @var mixed Default value */
<     public $default;
< 
<     /**
<      * Contructor
<      *
<      * @param string $desc
<      * @param bool $required
<      * @param mixed $default
<      * @since Moodle 2.0
<      */
<     public function __construct($desc, $required, $default) {
<         $this->desc = $desc;
<         $this->required = $required;
<         $this->default = $default;
<     }
< }
< 
< /**
<  * Scalar value description class
<  *
<  * @package    core_webservice
<  * @copyright  2009 Petr Skodak
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since Moodle 2.0
<  */
< class external_value extends external_description {
< 
<     /** @var mixed Value type PARAM_XX */
<     public $type;



> use core_external\util;




<     /** @var bool Allow null values */
<     public $allownull;



> defined('MOODLE_INTERNAL') || die;




<     /**
<      * Constructor
<      *
<      * @param mixed $type
<      * @param string $desc
<      * @param bool $required
<      * @param mixed $default
<      * @param bool $allownull
<      * @since Moodle 2.0
<      */
<     public function __construct($type, $desc='', $required=VALUE_REQUIRED,
<             $default=null, $allownull=NULL_ALLOWED) {
<         parent::__construct($desc, $required, $default);
<         $this->type      = $type;
<         $this->allownull = $allownull;
<     }
< }
< 
< /**
<  * Associative array description class
<  *
<  * @package    core_webservice
<  * @copyright  2009 Petr Skodak
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since Moodle 2.0
<  */
< class external_single_structure extends external_description {
< 
<      /** @var array Description of array keys key=>external_description */
<     public $keys;
< 
<     /**
<      * Constructor
<      *
<      * @param array $keys
<      * @param string $desc
<      * @param bool $required
<      * @param array $default
<      * @since Moodle 2.0
<      */
<     public function __construct(array $keys, $desc='',
<             $required=VALUE_REQUIRED, $default=null) {
<         parent::__construct($desc, $required, $default);
<         $this->keys = $keys;
<     }
< }
< 
< /**
<  * Bulk array description class.
<  *
<  * @package    core_webservice
<  * @copyright  2009 Petr Skodak
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since Moodle 2.0
<  */
< class external_multiple_structure extends external_description {
< 
<      /** @var external_description content */
<     public $content;
< 
<     /**
<      * Constructor
<      *
<      * @param external_description $content
<      * @param string $desc
<      * @param bool $required
<      * @param array $default
<      * @since Moodle 2.0
<      */
<     public function __construct(external_description $content, $desc='',
<             $required=VALUE_REQUIRED, $default=null) {
<         parent::__construct($desc, $required, $default);
<         $this->content = $content;
<     }
< }
< 
< /**
<  * Description of top level - PHP function parameters.
<  *
<  * @package    core_webservice
<  * @copyright  2009 Petr Skodak
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since Moodle 2.0
<  */
< class external_function_parameters extends external_single_structure {
< 
<     /**
<      * Constructor - does extra checking to prevent top level optional parameters.
<      *
<      * @param array $keys
<      * @param string $desc
<      * @param bool $required
<      * @param array $default
<      */
<     public function __construct(array $keys, $desc='', $required=VALUE_REQUIRED, $default=null) {
<         global $CFG;
< 
<         if ($CFG->debugdeveloper) {
<             foreach ($keys as $key => $value) {
<                 if ($value instanceof external_value) {
<                     if ($value->required == VALUE_OPTIONAL) {
<                         debugging('External function parameters: invalid OPTIONAL value specified.', DEBUG_DEVELOPER);
<                         break;
<                     }
<                 }
<             }
<         }
<         parent::__construct($keys, $desc, $required, $default);
<     }
< }



> // Please note that this file and all of the classes and functions listed below will be deprecated from Moodle 4.6.
> // This deprecation is delayed to aid plugin developers when maintaining plugins for multiple Moodle versions.
> // See MDL-76583 for further information.
> 
> // If including this file for unit testing, it _must_ be run in an isolated process to prevent
> // any side effect upon other tests.
> require_phpunit_isolation();
> 
> class_alias(\core_external\external_api::class, 'external_api');
> class_alias(\core_external\restricted_context_exception::class, 'restricted_context_exception');
> class_alias(\core_external\external_description::class, 'external_description');
> class_alias(\core_external\external_value::class, 'external_value');
> class_alias(\core_external\external_format_value::class, 'external_format_value');
> class_alias(\core_external\external_single_structure::class, 'external_single_structure');
> class_alias(\core_external\external_multiple_structure::class, 'external_multiple_structure');
> class_alias(\core_external\external_function_parameters::class, 'external_function_parameters');
> class_alias(\core_external\util::class, 'external_util');
> class_alias(\core_external\external_files::class, 'external_files');
> class_alias(\core_external\external_warnings::class, 'external_warnings');
> class_alias(\core_external\external_settings::class, 'external_settings');



/**
 * Generate a token
 *
 * @param string $tokentype EXTERNAL_TOKEN_EMBEDDED|EXTERNAL_TOKEN_PERMANENT
 * @param stdClass|int $serviceorid service linked to the token
 * @param int $userid user linked to the token
 * @param stdClass|int $contextorid
 * @param int $validuntil date when the token expired
 * @param string $iprestriction allowed ip - if 0 or empty then all ips are allowed
 * @return string generated token

<  * @author  2010 Jamie Pratt


 * @since Moodle 2.0
 */
function external_generate_token($tokentype, $serviceorid, $userid, $contextorid, $validuntil=0, $iprestriction=''){

<     global $DB, $USER;
<     // make sure the token doesn't exist (even if it should be almost impossible with the random generation)
<     $numtries = 0;
<     do {
<         $numtries ++;
<         $generatedtoken = md5(uniqid(rand(),1));
<         if ($numtries > 5){
<             throw new moodle_exception('tokengenerationfailed');
<         }
<     } while ($DB->record_exists('external_tokens', array('token'=>$generatedtoken)));
<     $newtoken = new stdClass();
<     $newtoken->token = $generatedtoken;
<     if (!is_object($serviceorid)){
<         $service = $DB->get_record('external_services', array('id' => $serviceorid));



>     if (is_numeric($serviceorid)) {
>         $service = util::get_service_by_id($serviceorid);
>     } else if (is_string($serviceorid)) {
>         $service = util::get_service_by_name($serviceorid);


    } else {
        $service = $serviceorid;
    }

> 


    if (!is_object($contextorid)){
        $context = context::instance_by_id($contextorid, MUST_EXIST);
    } else {
        $context = $contextorid;
    }

<     if (empty($service->requiredcapability) || has_capability($service->requiredcapability, $context, $userid)) {
<         $newtoken->externalserviceid = $service->id;
<     } else {
<         throw new moodle_exception('nocapabilitytousethisservice');
<     }
<     $newtoken->tokentype = $tokentype;
<     $newtoken->userid = $userid;
<     if ($tokentype == EXTERNAL_TOKEN_EMBEDDED){
<         $newtoken->sid = session_id();
<     }




<     $newtoken->contextid = $context->id;
<     $newtoken->creatorid = $USER->id;
<     $newtoken->timecreated = time();
<     $newtoken->validuntil = $validuntil;
<     if (!empty($iprestriction)) {
<         $newtoken->iprestriction = $iprestriction;
<     }
<     // Generate the private token, it must be transmitted only via https.
<     $newtoken->privatetoken = random_string(64);
<     $DB->insert_record('external_tokens', $newtoken);
<     return $newtoken->token;



>     return util::generate_token(
>         $tokentype,
>         $service,
>         $userid,
>         $context,
>         $validuntil,
>         $iprestriction
>     );


}

/**
 * Create and return a session linked token. Token to be used for html embedded client apps that want to communicate
 * with the Moodle server through web services. The token is linked to the current session for the current page request.
 * It is expected this will be called in the script generating the html page that is embedding the client app and that the
 * returned token will be somehow passed into the client app being embedded in the page.
 *
 * @param string $servicename name of the web service. Service name as defined in db/services.php
 * @param int $context context within which the web service can operate.
 * @return int returns token id.
 * @since Moodle 2.0
 */

< function external_create_service_token($servicename, $context){
<     global $USER, $DB;
<     $service = $DB->get_record('external_services', array('name'=>$servicename), '*', MUST_EXIST);
<     return external_generate_token(EXTERNAL_TOKEN_EMBEDDED, $service, $USER->id, $context, 0);



> function external_create_service_token($servicename, $contextid) {
>     global $USER;
> 
>     return util::generate_token(
>         EXTERNAL_TOKEN_EMBEDDED,
>         util::get_service_by_name($servicename),
>         $USER->id,
>         \context::instance_by_id($contextid)
>     );


}

/**
 * Delete all pre-built services (+ related tokens) and external functions information defined in the specified component.
 *

<  * @param string $component name of component (moodle, mod_assignment, etc.)



>  * @param string $component name of component (moodle, etc.)


 */
function external_delete_descriptions($component) {

<     global $DB;
< 
<     $params = array($component);
< 
<     $DB->delete_records_select('external_tokens',
<             "externalserviceid IN (SELECT id FROM {external_services} WHERE component = ?)", $params);
<     $DB->delete_records_select('external_services_users',
<             "externalserviceid IN (SELECT id FROM {external_services} WHERE component = ?)", $params);
<     $DB->delete_records_select('external_services_functions',
<             "functionname IN (SELECT name FROM {external_functions} WHERE component = ?)", $params);
<     $DB->delete_records('external_services', array('component'=>$component));
<     $DB->delete_records('external_functions', array('component'=>$component));
< }
< 
< /**
<  * Standard Moodle web service warnings
<  *
<  * @package    core_webservice
<  * @copyright  2012 Jerome Mouneyrac
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since Moodle 2.3
<  */
< class external_warnings extends external_multiple_structure {
< 
<     /**
<      * Constructor
<      *
<      * @since Moodle 2.3
<      */
<     public function __construct($itemdesc = 'item', $itemiddesc = 'item id',
<         $warningcodedesc = 'the warning code can be used by the client app to implement specific behaviour') {
< 
<         parent::__construct(
<             new external_single_structure(
<                 array(
<                     'item' => new external_value(PARAM_TEXT, $itemdesc, VALUE_OPTIONAL),
<                     'itemid' => new external_value(PARAM_INT, $itemiddesc, VALUE_OPTIONAL),
<                     'warningcode' => new external_value(PARAM_ALPHANUM, $warningcodedesc),
<                     'message' => new external_value(PARAM_TEXT,
<                             'untranslated english message to explain the warning')
<                 ), 'warning'),
<             'list of warnings', VALUE_OPTIONAL);
<     }
< }
< 
< /**
<  * A pre-filled external_value class for text format.
<  *
<  * Default is FORMAT_HTML
<  * This should be used all the time in external xxx_params()/xxx_returns functions
<  * as it is the standard way to implement text format param/return values.
<  *
<  * @package    core_webservice
<  * @copyright  2012 Jerome Mouneyrac
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since Moodle 2.3
<  */
< class external_format_value extends external_value {
< 
<     /**
<      * Constructor
<      *
<      * @param string $textfieldname Name of the text field
<      * @param int $required if VALUE_REQUIRED then set standard default FORMAT_HTML
<      * @param int $default Default value.
<      * @since Moodle 2.3
<      */
<     public function __construct($textfieldname, $required = VALUE_REQUIRED, $default = null) {
< 
<         if ($default == null && $required == VALUE_DEFAULT) {
<             $default = FORMAT_HTML;
<         }
< 
<         $desc = $textfieldname . ' format (' . FORMAT_HTML . ' = HTML, '
<                 . FORMAT_MOODLE . ' = MOODLE, '
<                 . FORMAT_PLAIN . ' = PLAIN or '
<                 . FORMAT_MARKDOWN . ' = MARKDOWN)';
< 
<         parent::__construct(PARAM_INT, $desc, $required, $default);
<     }



>     util::delete_service_descriptions($component);


}

/**
 * Validate text field format against known FORMAT_XXX
 *
 * @param array $format the format to validate
 * @return the validated format
 * @throws coding_exception
 * @since Moodle 2.3
 */
function external_validate_format($format) {

<     $allowedformats = array(FORMAT_HTML, FORMAT_MOODLE, FORMAT_PLAIN, FORMAT_MARKDOWN);
<     if (!in_array($format, $allowedformats)) {
<         throw new moodle_exception('formatnotsupported', 'webservice', '' , null,
<                 'The format with value=' . $format . ' is not supported by this Moodle site');
<     }
<     return $format;



>     return util::validate_format($format);


}

/**
 * Format the string to be returned properly as requested by the either the web service server,
 * either by an internally call.
 * The caller can change the format (raw) with the external_settings singleton
 * All web service servers must set this singleton when parsing the $_GET and $_POST.
 *
 * <pre>
 * Options are the same that in {@link format_string()} with some changes:
 *      filter      : Can be set to false to force filters off, else observes {@link external_settings}.
 * </pre>
 *
 * @param string $str The string to be filtered. Should be plain text, expect
 * possibly for multilang tags.
 * @param boolean $striplinks To strip any link in the result text. Moodle 1.8 default changed from false to true! MDL-8713
 * @param context|int $contextorid The id of the context for the string or the context (affects filters).
 * @param array $options options array/object or courseid
 * @return string text
 * @since Moodle 3.0
 */

< function external_format_string($str, $contextorid, $striplinks = true, $options = array()) {
< 
<     // Get settings (singleton).
<     $settings = external_settings::get_instance();
<     if (empty($contextorid)) {
<         throw new coding_exception('contextid is required');



> function external_format_string($str, $context, $striplinks = true, $options = []) {
>     if (!$context instanceof context) {
>         $context = context::instance_by_id($context);


    }


<     if (!$settings->get_raw()) {
<         if (is_object($contextorid) && is_a($contextorid, 'context')) {
<             $context = $contextorid;
<         } else {
<             $context = context::instance_by_id($contextorid);
<         }
<         $options['context'] = $context;
<         $options['filter'] = isset($options['filter']) && !$options['filter'] ? false : $settings->get_filter();
<         $str = format_string($str, $striplinks, $options);
<     }
< 
<     return $str;



>     return util::format_string($str, $context, $striplinks, $options);


}

/**
 * Format the text to be returned properly as requested by the either the web service server,
 * either by an internally call.
 * The caller can change the format (raw, filter, file, fileurl) with the external_settings singleton
 * All web service servers must set this singleton when parsing the $_GET and $_POST.
 *
 * <pre>
 * Options are the same that in {@link format_text()} with some changes in defaults to provide backwards compatibility:
 *      trusted     :   If true the string won't be cleaned. Default false.
 *      noclean     :   If true the string won't be cleaned only if trusted is also true. Default false.
 *      nocache     :   If true the string will not be cached and will be formatted every call. Default false.
 *      filter      :   Can be set to false to force filters off, else observes {@link external_settings}.
 *      para        :   If true then the returned string will be wrapped in div tags. Default (different from format_text) false.
 *                      Default changed because div tags are not commonly needed.
 *      newlines    :   If true then lines newline breaks will be converted to HTML newline breaks. Default true.
 *      context     :   Not used! Using contextid parameter instead.
 *      overflowdiv :   If set to true the formatted text will be encased in a div with the class no-overflow before being
 *                      returned. Default false.
 *      allowid     :   If true then id attributes will not be removed, even when using htmlpurifier. Default (different from
 *                      format_text) true. Default changed id attributes are commonly needed.
 *      blanktarget :   If true all <a> tags will have target="_blank" added unless target is explicitly specified.
 * </pre>
 *
 * @param string $text The content that may contain ULRs in need of rewriting.
 * @param int $textformat The text format.

<  * @param context|int $contextorid This parameter and the next two identify the file area to use.



>  * @param context|int $context This parameter and the next two identify the file area to use.


 * @param string $component
 * @param string $filearea helps identify the file area.
 * @param int $itemid helps identify the file area.
 * @param object/array $options text formatting options
 * @return array text + textformat
 * @since Moodle 2.3
 * @since Moodle 3.2 component, filearea and itemid are optional parameters
 */

< function external_format_text($text, $textformat, $contextorid, $component = null, $filearea = null, $itemid = null,
<                                 $options = null) {
<     global $CFG;
< 
<     // Get settings (singleton).
<     $settings = external_settings::get_instance();
< 
<     if (is_object($contextorid) && is_a($contextorid, 'context')) {
<         $context = $contextorid;
<         $contextid = $context->id;
<     } else {
<         $context = null;
<         $contextid = $contextorid;
<     }
< 
<     if ($component and $filearea and $settings->get_fileurl()) {
<         require_once($CFG->libdir . "/filelib.php");
<         $text = file_rewrite_pluginfile_urls($text, $settings->get_file(), $contextid, $component, $filearea, $itemid);



> function external_format_text($text, $textformat, $context, $component = null, $filearea = null, $itemid = null, $options = null) {
>     if (!$context instanceof context) {
>         $context = context::instance_by_id($context);


    }


<     // Note that $CFG->forceclean does not apply here if the client requests for the raw database content.
<     // This is consistent with web clients that are still able to load non-cleaned text into editors, too.
< 
<     if (!$settings->get_raw()) {
<         $options = (array)$options;
< 
<         // If context is passed in options, check that is the same to show a debug message.
<         if (isset($options['context'])) {
<             if ((is_object($options['context']) && $options['context']->id != $contextid)
<                     || (!is_object($options['context']) && $options['context'] != $contextid)) {
<                 debugging('Different contexts found in external_format_text parameters. $options[\'context\'] not allowed.
<                     Using $contextid parameter...', DEBUG_DEVELOPER);
<             }
<         }
< 
<         $options['filter'] = isset($options['filter']) && !$options['filter'] ? false : $settings->get_filter();
<         $options['para'] = isset($options['para']) ? $options['para'] : false;
<         $options['context'] = !is_null($context) ? $context : context::instance_by_id($contextid);
<         $options['allowid'] = isset($options['allowid']) ? $options['allowid'] : true;
< 
<         $text = format_text($text, $textformat, $options);
<         $textformat = FORMAT_HTML; // Once converted to html (from markdown, plain... lets inform consumer this is already HTML).
<     }
< 
<     return array($text, $textformat);



>     return util::format_text($text, $textformat, $context, $component, $filearea, $itemid, $options);


}

/**
 * Generate or return an existing token for the current authenticated user.
 * This function is used for creating a valid token for users authenticathing via login/token.php or admin/tool/mobile/launch.php.
 *
 * @param stdClass $service external service object
 * @return stdClass token object
 * @since Moodle 3.2

<  * @throws moodle_exception


 */
function external_generate_token_for_current_user($service) {

<     global $DB, $USER, $CFG;
< 
<     core_user::require_active_user($USER, true, true);
< 
<     // Check if there is any required system capability.
<     if ($service->requiredcapability and !has_capability($service->requiredcapability, context_system::instance())) {
<         throw new moodle_exception('missingrequiredcapability', 'webservice', '', $service->requiredcapability);
<     }
< 
<     // Specific checks related to user restricted service.
<     if ($service->restrictedusers) {
<         $authoriseduser = $DB->get_record('external_services_users',
<             array('externalserviceid' => $service->id, 'userid' => $USER->id));
< 
<         if (empty($authoriseduser)) {
<             throw new moodle_exception('usernotallowed', 'webservice', '', $service->shortname);
<         }
< 
<         if (!empty($authoriseduser->validuntil) and $authoriseduser->validuntil < time()) {
<             throw new moodle_exception('invalidtimedtoken', 'webservice');
<         }
< 
<         if (!empty($authoriseduser->iprestriction) and !address_in_subnet(getremoteaddr(), $authoriseduser->iprestriction)) {
<             throw new moodle_exception('invalidiptoken', 'webservice');
<         }
<     }
< 
<     // Check if a token has already been created for this user and this service.
<     $conditions = array(
<         'userid' => $USER->id,
<         'externalserviceid' => $service->id,
<         'tokentype' => EXTERNAL_TOKEN_PERMANENT
<     );
<     $tokens = $DB->get_records('external_tokens', $conditions, 'timecreated ASC');
< 
<     // A bit of sanity checks.
<     foreach ($tokens as $key => $token) {
< 
<         // Checks related to a specific token. (script execution continue).
<         $unsettoken = false;
<         // If sid is set then there must be a valid associated session no matter the token type.
<         if (!empty($token->sid)) {
<             if (!\core\session\manager::session_exists($token->sid)) {
<                 // This token will never be valid anymore, delete it.
<                 $DB->delete_records('external_tokens', array('sid' => $token->sid));
<                 $unsettoken = true;
<             }
<         }
< 
<         // Remove token is not valid anymore.
<         if (!empty($token->validuntil) and $token->validuntil < time()) {
<             $DB->delete_records('external_tokens', array('token' => $token->token, 'tokentype' => EXTERNAL_TOKEN_PERMANENT));
<             $unsettoken = true;
<         }
< 
<         // Remove token if its IP is restricted.
<         if (isset($token->iprestriction) and !address_in_subnet(getremoteaddr(), $token->iprestriction)) {
<             $unsettoken = true;
<         }
< 
<         if ($unsettoken) {
<             unset($tokens[$key]);
<         }
<     }
< 
<     // If some valid tokens exist then use the most recent.
<     if (count($tokens) > 0) {
<         $token = array_pop($tokens);
<     } else {
<         $context = context_system::instance();
<         $isofficialservice = $service->shortname == MOODLE_OFFICIAL_MOBILE_SERVICE;
< 
<         if (($isofficialservice and has_capability('moodle/webservice:createmobiletoken', $context)) or
<                 (!is_siteadmin($USER) && has_capability('moodle/webservice:createtoken', $context))) {
< 
<             // Create a new token.
<             $token = new stdClass;
<             $token->token = md5(uniqid(rand(), 1));
<             $token->userid = $USER->id;
<             $token->tokentype = EXTERNAL_TOKEN_PERMANENT;
<             $token->contextid = context_system::instance()->id;
<             $token->creatorid = $USER->id;
<             $token->timecreated = time();
<             $token->externalserviceid = $service->id;
<             // By default tokens are valid for 12 weeks.
<             $token->validuntil = $token->timecreated + $CFG->tokenduration;
<             $token->iprestriction = null;
<             $token->sid = null;
<             $token->lastaccess = null;
<             // Generate the private token, it must be transmitted only via https.
<             $token->privatetoken = random_string(64);
<             $token->id = $DB->insert_record('external_tokens', $token);
< 
<             $eventtoken = clone $token;
<             $eventtoken->privatetoken = null;
<             $params = array(
<                 'objectid' => $eventtoken->id,
<                 'relateduserid' => $USER->id,
<                 'other' => array(
<                     'auto' => true
<                 )
<             );
<             $event = \core\event\webservice_token_created::create($params);
<             $event->add_record_snapshot('external_tokens', $eventtoken);
<             $event->trigger();
<         } else {
<             throw new moodle_exception('cannotcreatetoken', 'webservice', '', $service->shortname);
<         }
<     }
<     return $token;



>     return util::generate_token_for_current_user($service);


}

/**
 * Set the last time a token was sent and trigger the \core\event\webservice_token_sent event.
 *
 * This function is used when a token is generated by the user via login/token.php or admin/tool/mobile/launch.php.
 * In order to protect the privatetoken, we remove it from the event params.
 *
 * @param  stdClass $token token object
 * @since  Moodle 3.2
 */

< function external_log_token_request($token) {
<     global $DB;
< 
<     $token->privatetoken = null;
< 
<     // Log token access.
<     $DB->set_field('external_tokens', 'lastaccess', time(), array('id' => $token->id));
< 
<     $params = array(
<         'objectid' => $token->id,
<     );
<     $event = \core\event\webservice_token_sent::create($params);
<     $event->add_record_snapshot('external_tokens', $token);
<     $event->trigger();
< }
< 
< /**
<  * Singleton to handle the external settings.
<  *
<  * We use singleton to encapsulate the "logic"
<  *
<  * @package    core_webservice
<  * @copyright  2012 Jerome Mouneyrac
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since Moodle 2.3
<  */
< class external_settings {
< 
<     /** @var object the singleton instance */
<     public static $instance = null;
< 
<     /** @var boolean Should the external function return raw text or formatted */
<     private $raw = false;
< 
<     /** @var boolean Should the external function filter the text */
<     private $filter = false;
< 
<     /** @var boolean Should the external function rewrite plugin file url */
<     private $fileurl = true;
< 
<     /** @var string In which file should the urls be rewritten */
<     private $file = 'webservice/pluginfile.php';
< 
<     /** @var string The session lang */
<     private $lang = '';
< 
<     /** @var string The timezone to use during this WS request */
<     private $timezone = '';
< 
<     /**
<      * Constructor - protected - can not be instanciated
<      */
<     protected function __construct() {
<         if ((AJAX_SCRIPT == false) && (CLI_SCRIPT == false) && (WS_SERVER == false)) {
<             // For normal pages, the default should match the default for format_text.
<             $this->filter = true;
<             // Use pluginfile.php for web requests.
<             $this->file = 'pluginfile.php';
<         }
<     }
< 
<     /**
<      * Clone - private - can not be cloned
<      */
<     private final function __clone() {
<     }
< 
<     /**
<      * Return only one instance
<      *
<      * @return \external_settings
<      */
<     public static function get_instance() {
<         if (self::$instance === null) {
<             self::$instance = new external_settings;
<         }
< 
<         return self::$instance;
<     }
< 
<     /**
<      * Set raw
<      *
<      * @param boolean $raw
<      */
<     public function set_raw($raw) {
<         $this->raw = $raw;
<     }
< 
<     /**
<      * Get raw
<      *
<      * @return boolean
<      */
<     public function get_raw() {
<         return $this->raw;
<     }
< 
<     /**
<      * Set filter
<      *
<      * @param boolean $filter
<      */
<     public function set_filter($filter) {
<         $this->filter = $filter;
<     }
< 
<     /**
<      * Get filter
<      *
<      * @return boolean
<      */
<     public function get_filter() {
<         return $this->filter;
<     }
< 
<     /**
<      * Set fileurl
<      *
<      * @param boolean $fileurl
<      */
<     public function set_fileurl($fileurl) {
<         $this->fileurl = $fileurl;
<     }
< 
<     /**
<      * Get fileurl
<      *
<      * @return boolean
<      */
<     public function get_fileurl() {
<         return $this->fileurl;
<     }
< 
<     /**
<      * Set file
<      *
<      * @param string $file
<      */
<     public function set_file($file) {
<         $this->file = $file;
<     }
< 
<     /**
<      * Get file
<      *
<      * @return string
<      */
<     public function get_file() {
<         return $this->file;
<     }
< 
<     /**
<      * Set lang
<      *
<      * @param string $lang
<      */
<     public function set_lang($lang) {
<         $this->lang = $lang;
<     }
< 
<     /**
<      * Get lang
<      *
<      * @return string
<      */
<     public function get_lang() {
<         return $this->lang;
<     }
< 
<     /**
<      * Set timezone
<      *
<      * @param string $timezone
<      */
<     public function set_timezone($timezone) {
<         $this->timezone = $timezone;
<     }
< 
<     /**
<      * Get timezone
<      *
<      * @return string
<      */
<     public function get_timezone() {
<         return $this->timezone;
<     }
< }
< 
< /**
<  * Utility functions for the external API.
<  *
<  * @package    core_webservice
<  * @copyright  2015 Juan Leyva
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since Moodle 3.0
<  */
< class external_util {
< 
<     /**
<      * Validate a list of courses, returning the complete course objects for valid courses.
<      *
<      * Each course has an additional 'contextvalidated' field, this will be set to true unless
<      * you set $keepfails, in which case it will be false if validation fails for a course.
<      *
<      * @param  array $courseids A list of course ids
<      * @param  array $courses   An array of courses already pre-fetched, indexed by course id.
<      * @param  bool $addcontext True if the returned course object should include the full context object.
<      * @param  bool $keepfails  True to keep all the course objects even if validation fails
<      * @return array            An array of courses and the validation warnings
<      */
<     public static function validate_courses($courseids, $courses = array(), $addcontext = false,
<             $keepfails = false) {
<         global $DB;
< 
<         // Delete duplicates.
<         $courseids = array_unique($courseids);
<         $warnings = array();
< 
<         // Remove courses which are not even requested.
<         $courses = array_intersect_key($courses, array_flip($courseids));
< 
<         // For any courses NOT loaded already, get them in a single query (and preload contexts)
<         // for performance. Preserve ordering because some tests depend on it.
<         $newcourseids = [];
<         foreach ($courseids as $cid) {
<             if (!array_key_exists($cid, $courses)) {
<                 $newcourseids[] = $cid;
<             }
<         }
<         if ($newcourseids) {
<             list ($listsql, $listparams) = $DB->get_in_or_equal($newcourseids);
< 
<             // Load list of courses, and preload associated contexts.
<             $contextselect = context_helper::get_preload_record_columns_sql('x');
<             $newcourses = $DB->get_records_sql("
<                             SELECT c.*, $contextselect
<                               FROM {course} c
<                               JOIN {context} x ON x.instanceid = c.id
<                              WHERE x.contextlevel = ? AND c.id $listsql",
<                     array_merge([CONTEXT_COURSE], $listparams));
<             foreach ($newcourseids as $cid) {
<                 if (array_key_exists($cid, $newcourses)) {
<                     $course = $newcourses[$cid];
<                     context_helper::preload_from_record($course);
<                     $courses[$course->id] = $course;
<                 }
<             }
<         }
< 
<         foreach ($courseids as $cid) {
<             // Check the user can function in this context.
<             try {
<                 $context = context_course::instance($cid);
<                 external_api::validate_context($context);
< 
<                 if ($addcontext) {
<                     $courses[$cid]->context = $context;
<                 }
<                 $courses[$cid]->contextvalidated = true;
<             } catch (Exception $e) {
<                 if ($keepfails) {
<                     $courses[$cid]->contextvalidated = false;
<                 } else {
<                     unset($courses[$cid]);
<                 }
<                 $warnings[] = array(
<                     'item' => 'course',
<                     'itemid' => $cid,
<                     'warningcode' => '1',
<                     'message' => 'No access rights in course context'
<                 );
<             }
<         }
< 
<         return array($courses, $warnings);
<     }
< 
<     /**
<      * Returns all area files (optionally limited by itemid).
<      *
<      * @param int $contextid context ID
<      * @param string $component component
<      * @param string $filearea file area
<      * @param int $itemid item ID or all files if not specified
<      * @param bool $useitemidinurl wether to use the item id in the file URL (modules intro don't use it)
<      * @return array of files, compatible with the external_files structure.
<      * @since Moodle 3.2
<      */
<     public static function get_area_files($contextid, $component, $filearea, $itemid = false, $useitemidinurl = true) {
<         $files = array();
<         $fs = get_file_storage();
< 
<         if ($areafiles = $fs->get_area_files($contextid, $component, $filearea, $itemid, 'itemid, filepath, filename', false)) {
<             foreach ($areafiles as $areafile) {
<                 $file = array();
<                 $file['filename'] = $areafile->get_filename();
<                 $file['filepath'] = $areafile->get_filepath();
<                 $file['mimetype'] = $areafile->get_mimetype();
<                 $file['filesize'] = $areafile->get_filesize();
<                 $file['timemodified'] = $areafile->get_timemodified();
<                 $file['isexternalfile'] = $areafile->is_external_file();
<                 if ($file['isexternalfile']) {
<                     $file['repositorytype'] = $areafile->get_repository_type();
<                 }
<                 $fileitemid = $useitemidinurl ? $areafile->get_itemid() : null;
<                 $file['fileurl'] = moodle_url::make_webservice_pluginfile_url($contextid, $component, $filearea,
<                                     $fileitemid, $areafile->get_filepath(), $areafile->get_filename())->out(false);
<                 $files[] = $file;
<             }
<         }
<         return $files;
<     }
< }
< 
< /**
<  * External structure representing a set of files.
<  *
<  * @package    core_webservice
<  * @copyright  2016 Juan Leyva
<  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
<  * @since      Moodle 3.2
<  */
< class external_files extends external_multiple_structure {
< 
<     /**
<      * Constructor
<      * @param string $desc Description for the multiple structure.
<      * @param int $required The type of value (VALUE_REQUIRED OR VALUE_OPTIONAL).
<      */
<     public function __construct($desc = 'List of files.', $required = VALUE_REQUIRED) {
< 
<         parent::__construct(
<             new external_single_structure(
<                 array(
<                     'filename' => new external_value(PARAM_FILE, 'File name.', VALUE_OPTIONAL),
<                     'filepath' => new external_value(PARAM_PATH, 'File path.', VALUE_OPTIONAL),
<                     'filesize' => new external_value(PARAM_INT, 'File size.', VALUE_OPTIONAL),
<                     'fileurl' => new external_value(PARAM_URL, 'Downloadable file url.', VALUE_OPTIONAL),
<                     'timemodified' => new external_value(PARAM_INT, 'Time modified.', VALUE_OPTIONAL),
<                     'mimetype' => new external_value(PARAM_RAW, 'File mime type.', VALUE_OPTIONAL),
<                     'isexternalfile' => new external_value(PARAM_BOOL, 'Whether is an external file.', VALUE_OPTIONAL),
<                     'repositorytype' => new external_value(PARAM_PLUGIN, 'The repository type for external files.', VALUE_OPTIONAL),
<                 ),
<                 'File.'
<             ),
<             $desc,
<             $required
<         );
<     }
< 
<     /**
<      * Return the properties ready to be used by an exporter.
<      *
<      * @return array properties
<      * @since  Moodle 3.3
<      */
<     public static function get_properties_for_exporter() {
<         return [
<             'filename' => array(
<                 'type' => PARAM_FILE,
<                 'description' => 'File name.',
<                 'optional' => true,
<                 'null' => NULL_NOT_ALLOWED,
<             ),
<             'filepath' => array(
<                 'type' => PARAM_PATH,
<                 'description' => 'File path.',
<                 'optional' => true,
<                 'null' => NULL_NOT_ALLOWED,
<             ),
<             'filesize' => array(
<                 'type' => PARAM_INT,
<                 'description' => 'File size.',
<                 'optional' => true,
<                 'null' => NULL_NOT_ALLOWED,
<             ),
<             'fileurl' => array(
<                 'type' => PARAM_URL,
<                 'description' => 'Downloadable file url.',
<                 'optional' => true,
<                 'null' => NULL_NOT_ALLOWED,
<             ),
<             'timemodified' => array(
<                 'type' => PARAM_INT,
<                 'description' => 'Time modified.',
<                 'optional' => true,
<                 'null' => NULL_NOT_ALLOWED,
<             ),
<             'mimetype' => array(
<                 'type' => PARAM_RAW,
<                 'description' => 'File mime type.',
<                 'optional' => true,
<                 'null' => NULL_NOT_ALLOWED,
<             ),
<             'isexternalfile' => array(
<                 'type' => PARAM_BOOL,
<                 'description' => 'Whether is an external file.',
<                 'optional' => true,
<                 'null' => NULL_NOT_ALLOWED,
<             ),
<             'repositorytype' => array(
<                 'type' => PARAM_PLUGIN,
<                 'description' => 'The repository type for the external files.',
<                 'optional' => true,
<                 'null' => NULL_ALLOWED,
<             ),
<         ];
<     }



> function external_log_token_request($token): void {
>     util::log_token_request($token);


}