Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// Moodle is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * Self enrolment plugin.

 *

 * @package    enrol_self

 * @copyright  2010 Petr Skoda  {@link http://skodak.org}

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

 */

/**

 * Self enrolment plugin implementation.

 * @author Petr Skoda

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

 */

class enrol_self_plugin extends enrol_plugin {

    protected $lasternoller = null;

    protected $lasternollerinstanceid = 0;

    /**

     * Returns optional enrolment information icons.

     *

     * This is used in course list for quick overview of enrolment options.

     *

     * We are not using single instance parameter because sometimes

     * we might want to prevent icon repetition when multiple instances

     * of one type exist. One instance may also produce several icons.

     *

     * @param array $instances all enrol instances of this type in one course

     * @return array of pix_icon

     */

    public function get_info_icons(array $instances) {

        $key = false;

        $nokey = false;

        foreach ($instances as $instance) {

            if ($this->can_self_enrol($instance, false) !== true) {

                // User can not enrol himself.

                // Note that we do not check here if user is already enrolled for performance reasons -

                // such check would execute extra queries for each course in the list of courses and

                // would hide self-enrolment icons from guests.

                continue;

            }

            if ($instance->password or $instance->customint1) {

                $key = true;

            } else {

                $nokey = true;

            }

        }

        $icons = array();

        if ($nokey) {

            $icons[] = new pix_icon('withoutkey', get_string('pluginname', 'enrol_self'), 'enrol_self');

        }

        if ($key) {

            $icons[] = new pix_icon('withkey', get_string('pluginname', 'enrol_self'), 'enrol_self');

        }

        return $icons;

    }

    /**

     * Returns localised name of enrol instance

     *

     * @param stdClass $instance (null is accepted too)

     * @return string

     */

    public function get_instance_name($instance) {

        global $DB;

        if (empty($instance->name)) {

            if (!empty($instance->roleid) and $role = $DB->get_record('role', array('id'=>$instance->roleid))) {

                $role = ' (' . role_get_name($role, context_course::instance($instance->courseid, IGNORE_MISSING)) . ')';

            } else {

                $role = '';

            }

            $enrol = $this->get_name();

            return get_string('pluginname', 'enrol_'.$enrol) . $role;

        } else {

            return format_string($instance->name);

        }

    }

    public function roles_protected() {

        // Users may tweak the roles later.

        return false;

    }

    public function allow_unenrol(stdClass $instance) {

        // Users with unenrol cap may unenrol other users manually manually.

        return true;

    }

    public function allow_manage(stdClass $instance) {

        // Users with manage cap may tweak period and status.

        return true;

    }

    public function show_enrolme_link(stdClass $instance) {

        if (true !== $this->can_self_enrol($instance, false)) {

            return false;

        }

        return true;

    }

    /**

     * Return true if we can add a new instance to this course.

     *

     * @param int $courseid

     * @return boolean

     */

    public function can_add_instance($courseid) {

        $context = context_course::instance($courseid, MUST_EXIST);

        if (!has_capability('moodle/course:enrolconfig', $context) or !has_capability('enrol/self:config', $context)) {

            return false;

        }

        return true;

    }

    /**

     * Self enrol user to course

     *

     * @param stdClass $instance enrolment instance

     * @param stdClass $data data needed for enrolment.

     * @return bool|array true if enroled else eddor code and messege

     */

    public function enrol_self(stdClass $instance, $data = null) {

        global $DB, $USER, $CFG;

        // Don't enrol user if password is not passed when required.

        if ($instance->password && !isset($data->enrolpassword)) {

            return;

        }

        $timestart = time();

        if ($instance->enrolperiod) {

            $timeend = $timestart + $instance->enrolperiod;

        } else {

            $timeend = 0;

        }

        $this->enrol_user($instance, $USER->id, $instance->roleid, $timestart, $timeend);

        \core\notification::success(get_string('youenrolledincourse', 'enrol'));

        // Test whether the password is also used as a group key.

        if ($instance->password && $instance->customint1) {

            $groups = $DB->get_records('groups', array('courseid'=>$instance->courseid), 'id', 'id, enrolmentkey');

            foreach ($groups as $group) {

                if (empty($group->enrolmentkey)) {

                    continue;

                }

                if ($group->enrolmentkey === $data->enrolpassword) {

                    // Add user to group.

                    require_once($CFG->dirroot.'/group/lib.php');

                    groups_add_member($group->id, $USER->id);

                    break;

                }

            }

        }

    }

    /**

     * Creates course enrol form, checks if form submitted

     * and enrols user if necessary. It can also redirect.

     *

     * @param stdClass $instance

     * @return string html text, usually a form in a text box

     */

    public function enrol_page_hook(stdClass $instance) {

        global $CFG, $OUTPUT, $USER;

        require_once("$CFG->dirroot/enrol/self/locallib.php");

        $enrolstatus = $this->can_self_enrol($instance);

        if (true === $enrolstatus) {

            // This user can self enrol using this instance.

            $form = new enrol_self_enrol_form(null, $instance);

            $instanceid = optional_param('instance', 0, PARAM_INT);

            if ($instance->id == $instanceid) {

                if ($data = $form->get_data()) {

                    $this->enrol_self($instance, $data);

                }

            }

        } else {

            // This user can not self enrol using this instance. Using an empty form to keep

            // the UI consistent with other enrolment plugins that returns a form.

            $data = new stdClass();

            $data->header = $this->get_instance_name($instance);

            $data->info = $enrolstatus;

            // The can_self_enrol call returns a button to the login page if the user is a

            // guest, setting the login url to the form if that is the case.

            $url = isguestuser() ? get_login_url() : null;

            $form = new enrol_self_empty_form($url, $data);

        }

        ob_start();

        $form->display();

        $output = ob_get_clean();

        return $OUTPUT->box($output);

    }

    /**

     * Checks if user can self enrol.

     *

     * @param stdClass $instance enrolment instance

     * @param bool $checkuserenrolment if true will check if user enrolment is inactive.

     *             used by navigation to improve performance.

     * @return bool|string true if successful, else error message or false.

     */

    public function can_self_enrol(stdClass $instance, $checkuserenrolment = true) {

        global $DB, $OUTPUT, $USER;

        if ($checkuserenrolment) {

            if (isguestuser()) {

                // Can not enrol guest.

                return get_string('noguestaccess', 'enrol') . $OUTPUT->continue_button(get_login_url());

            }

            // Check if user is already enroled.

            if ($DB->get_record('user_enrolments', array('userid' => $USER->id, 'enrolid' => $instance->id))) {

                return get_string('canntenrol', 'enrol_self');

            }

        }

        // Check if self enrolment is available right now for users.

        $result = $this->is_self_enrol_available($instance);

        if ($result !== true) {

            return $result;

        }

        // Check if user has the capability to enrol in this context.

        if (!has_capability('enrol/self:enrolself', context_course::instance($instance->courseid))) {

            return get_string('canntenrol', 'enrol_self');

        }

        return true;

    }

    /**

     * Does this plugin support some way to self enrol?

     * This function doesn't check user capabilities. Use can_self_enrol to check capabilities.

     *

     * @param stdClass $instance enrolment instance

     * @return bool - true means "Enrol me in this course" link could be available

     */

    public function is_self_enrol_available(stdClass $instance) {

        global $CFG, $DB, $USER;

        if ($instance->status != ENROL_INSTANCE_ENABLED) {

            return get_string('canntenrol', 'enrol_self');

        }

        if ($instance->enrolstartdate != 0 and $instance->enrolstartdate > time()) {

            return get_string('canntenrolearly', 'enrol_self', userdate($instance->enrolstartdate));

        }

        if ($instance->enrolenddate != 0 and $instance->enrolenddate < time()) {

            return get_string('canntenrollate', 'enrol_self', userdate($instance->enrolenddate));

        }

        if (!$instance->customint6) {

            // New enrols not allowed.

            return get_string('canntenrol', 'enrol_self');

        }

        if ($DB->record_exists('user_enrolments', array('userid' => $USER->id, 'enrolid' => $instance->id))) {

            return get_string('canntenrol', 'enrol_self');

        }

        if ($instance->customint3 > 0) {

            // Max enrol limit specified.

            $count = $DB->count_records('user_enrolments', array('enrolid' => $instance->id));

            if ($count >= $instance->customint3) {

                // Bad luck, no more self enrolments here.

                return get_string('maxenrolledreached', 'enrol_self');

            }

        }

        if ($instance->customint5) {

            require_once("$CFG->dirroot/cohort/lib.php");

            if (!cohort_is_member($instance->customint5, $USER->id)) {

                $cohort = $DB->get_record('cohort', array('id' => $instance->customint5));

                if (!$cohort) {

                    return null;

                }

                $a = format_string($cohort->name, true, array('context' => context::instance_by_id($cohort->contextid)));

                return markdown_to_html(get_string('cohortnonmemberinfo', 'enrol_self', $a));

            }

        }

        return true;

    }

    /**

     * Return information for enrolment instance containing list of parameters required

     * for enrolment, name of enrolment plugin etc.

     *

     * @param stdClass $instance enrolment instance

     * @return stdClass instance info.

     */

    public function get_enrol_info(stdClass $instance) {

        $instanceinfo = new stdClass();

        $instanceinfo->id = $instance->id;

        $instanceinfo->courseid = $instance->courseid;

        $instanceinfo->type = $this->get_name();

        $instanceinfo->name = $this->get_instance_name($instance);

        $instanceinfo->status = $this->can_self_enrol($instance);

        if ($instance->password) {

            $instanceinfo->requiredparam = new stdClass();

            $instanceinfo->requiredparam->enrolpassword = get_string('password', 'enrol_self');

        }

        // If enrolment is possible and password is required then return ws function name to get more information.

        if ((true === $instanceinfo->status) && $instance->password) {

            $instanceinfo->wsfunction = 'enrol_self_get_instance_info';

        }

        return $instanceinfo;

    }

    /**

     * Add new instance of enrol plugin with default settings.

     * @param stdClass $course

     * @return int id of new instance

     */

    public function add_default_instance($course) {

        $fields = $this->get_instance_defaults();

        if ($this->get_config('requirepassword')) {

            $fields['password'] = generate_password(20);

        }

        return $this->add_instance($course, $fields);

    }

    /**

     * Returns defaults for new instances.

     * @return array

     */

    public function get_instance_defaults() {

        $expirynotify = $this->get_config('expirynotify');

        if ($expirynotify == 2) {

            $expirynotify = 1;

            $notifyall = 1;

        } else {

            $notifyall = 0;

        }

        $fields = array();

        $fields['status']          = $this->get_config('status');

        $fields['roleid']          = $this->get_config('roleid');

        $fields['enrolperiod']     = $this->get_config('enrolperiod');

        $fields['expirynotify']    = $expirynotify;

        $fields['notifyall']       = $notifyall;

        $fields['expirythreshold'] = $this->get_config('expirythreshold');

        $fields['customint1']      = $this->get_config('groupkey');

        $fields['customint2']      = $this->get_config('longtimenosee');

        $fields['customint3']      = $this->get_config('maxenrolled');

        $fields['customint4']      = $this->get_config('sendcoursewelcomemessage');

        $fields['customint5']      = 0;

        $fields['customint6']      = $this->get_config('newenrols');

        return $fields;

    }

    /**

     * Send welcome email to specified user.

     *

     * @param stdClass $instance

     * @param stdClass $user user record

     * @return void

     * @deprecated since Moodle 4.4

     * @see \enrol_plugin::send_course_welcome_message_to_user()

     * @todo MDL-81185 Final deprecation in Moodle 4.8.

     */

    #[\core\attribute\deprecated('enrol_plugin::send_course_welcome_message_to_user', since: '4.4', mdl: 'MDL-4188')]

    protected function email_welcome_message($instance, $user) {

        \core\deprecation::emit_deprecation_if_present(__FUNCTION__);

        $this->send_course_welcome_message_to_user(

            instance: $instance,

            userid: $user->id,

            sendoption: $instance->customint4,

            message: $instance->customtext1,

        );

    }

    /**

     * Sync all meta course links.

     *

     * @param progress_trace $trace

     * @param int $courseid one course, empty mean all

     * @return int 0 means ok, 1 means error, 2 means plugin disabled

     */

    public function sync(progress_trace $trace, $courseid = null) {

        global $DB;

        if (!enrol_is_enabled('self')) {

            $trace->finished();

            return 2;

        }

        // Unfortunately this may take a long time, execution can be interrupted safely here.

        core_php_time_limit::raise();

        raise_memory_limit(MEMORY_HUGE);

        $trace->output('Verifying self-enrolments...');

        $params = array('now'=>time(), 'useractive'=>ENROL_USER_ACTIVE, 'courselevel'=>CONTEXT_COURSE);

        $coursesql = "";

        if ($courseid) {

            $coursesql = "AND e.courseid = :courseid";

            $params['courseid'] = $courseid;

        }

        // Note: the logic of self enrolment guarantees that user logged in at least once (=== u.lastaccess set)

        //       and that user accessed course at least once too (=== user_lastaccess record exists).

        // First deal with users that did not log in for a really long time - they do not have user_lastaccess records.

        $sql = "SELECT e.*, ue.userid

                  FROM {user_enrolments} ue

                  JOIN {enrol} e ON (e.id = ue.enrolid AND e.enrol = 'self' AND e.customint2 > 0)

                  JOIN {user} u ON u.id = ue.userid

                 WHERE :now - u.lastaccess > e.customint2

                       $coursesql";

        $rs = $DB->get_recordset_sql($sql, $params);

        foreach ($rs as $instance) {

            $userid = $instance->userid;

            unset($instance->userid);

            $this->unenrol_user($instance, $userid);

            $days = $instance->customint2 / DAYSECS;

            $trace->output("unenrolling user $userid from course $instance->courseid " .

                "as they did not log in for at least $days days", 1);

        }

        $rs->close();

        // Now unenrol from course user did not visit for a long time.

        $sql = "SELECT e.*, ue.userid

                  FROM {user_enrolments} ue

                  JOIN {enrol} e ON (e.id = ue.enrolid AND e.enrol = 'self' AND e.customint2 > 0)

                  JOIN {user_lastaccess} ul ON (ul.userid = ue.userid AND ul.courseid = e.courseid)

                 WHERE :now - ul.timeaccess > e.customint2

                       $coursesql";

        $rs = $DB->get_recordset_sql($sql, $params);

        foreach ($rs as $instance) {

            $userid = $instance->userid;

            unset($instance->userid);

            $this->unenrol_user($instance, $userid);

            $days = $instance->customint2 / DAYSECS;

            $trace->output("unenrolling user $userid from course $instance->courseid " .

                "as they did not access the course for at least $days days", 1);

        }

        $rs->close();

        $trace->output('...user self-enrolment updates finished.');

        $trace->finished();

        $this->process_expirations($trace, $courseid);

        return 0;

    }

    /**

     * Notify users about enrolment expiration.

     *

     * Users may be notified by the expiration time of enrollment or unenrollment due to inactivity. The latter is checked in

     * the last condition of the where clause:

     * days of inactivity + number of days in advance to send the notification > days of inactivity allowed before unenrollment

     *

     * @param int $timenow Current time.

     * @param string $name Name of this enrol plugin.

     * @param progress_trace $trace (accepts bool for backwards compatibility only)

     * @return void

     */

    protected function fetch_users_and_notify_expiry(int $timenow, string $name, progress_trace $trace): void {

        global $DB, $CFG;

        $sql = "SELECT ue.*, e.expirynotify, e.notifyall, e.expirythreshold, e.courseid, c.fullname, e.customint2,

                       COALESCE(ul.timeaccess, 0) AS timeaccess, ue.timestart

                  FROM {user_enrolments} ue

                  JOIN {enrol} e ON (e.id = ue.enrolid AND e.enrol = :name AND e.expirynotify > 0  AND e.status = :enabled)

                  JOIN {course} c ON (c.id = e.courseid)

                  JOIN {user} u ON (u.id = ue.userid AND u.deleted = 0 AND u.suspended = 0)

                  LEFT JOIN {user_lastaccess} ul ON (ul.userid = u.id AND ul.courseid = c.id)

                 WHERE ue.status = :active

                       AND ((ue.timeend > 0 AND ue.timeend > :now1 AND ue.timeend < (e.expirythreshold + :now2))

                            OR (e.customint2 > 0 AND (:now3 - COALESCE(ul.timeaccess, 0) + e.expirythreshold > e.customint2)))

              ORDER BY ue.enrolid ASC, u.lastname ASC, u.firstname ASC, u.id ASC";

        $params = [

            'name' => $name,

            'enabled' => ENROL_INSTANCE_ENABLED,

            'active' => ENROL_USER_ACTIVE,

            'now1' => $timenow,

            'now2' => $timenow,

            'now3' => $timenow,

        ];

        $rs = $DB->get_recordset_sql($sql, $params);

        $lastenrollid = 0;

        $users = [];

        foreach ($rs as $ue) {

            $expirycond = ($ue->timeend > 0) && ($ue->timeend > $timenow) && ($ue->timeend < ($ue->expirythreshold + $timenow));

            $inactivitycond = ($ue->customint2 > 0) && (($timenow - $ue->timeaccess + $ue->expirythreshold) > $ue->customint2);

            $user = $DB->get_record('user', ['id' => $ue->userid]);

            if ($expirycond) {

                if ($lastenrollid && $lastenrollid != $ue->enrolid) {

                    $this->notify_expiry_enroller($lastenrollid, $users, $trace);

                    $users = [];

                }

                $lastenrollid = $ue->enrolid;

                $enroller = $this->get_enroller($ue->enrolid);

                $context = context_course::instance($ue->courseid);

                $users[] = [

                    'fullname' => fullname($user, has_capability('moodle/site:viewfullnames', $context, $enroller)),

                    'timeend' => $ue->timeend,

                ];

            }

            // Notifications to inactive users only if inactive time limit is set.

            if ($inactivitycond && $ue->notifyall) {

                $ue->message = 'expiryinactivemessageenrolledbody';

                $lastaccess = $ue->timeaccess;

                if (!$lastaccess) {

                    $lastaccess = $ue->timestart;

                }

                $ue->inactivetime = floor(($timenow - $lastaccess) / DAYSECS);

                $this->notify_expiry_enrolled($user, $ue, $trace);

            }

            if ($expirycond) {

                if (!$ue->notifyall) {

                    continue;

                }

                if ($ue->timeend - $ue->expirythreshold + 86400 < $timenow) {

                    // Notify enrolled users only once at the start of the threshold.

                    $trace->output("user $ue->userid was already notified that enrolment in course $ue->courseid expires on " .

                        userdate($ue->timeend, '', $CFG->timezone), 1);

                    continue;

                }

                $this->notify_expiry_enrolled($user, $ue, $trace);

            }

        }

        $rs->close();

        if ($lastenrollid && $users) {

            $this->notify_expiry_enroller($lastenrollid, $users, $trace);

        }

    }

    /**

     * Returns the user who is responsible for self enrolments in given instance.

     *

     * Usually it is the first editing teacher - the person with "highest authority"

     * as defined by sort_by_roleassignment_authority() having 'enrol/self:manage'

     * capability.

     *

     * @param int $instanceid enrolment instance id

     * @return stdClass user record

     */

    protected function get_enroller($instanceid) {

        global $DB;

        if ($this->lasternollerinstanceid == $instanceid and $this->lasternoller) {

            return $this->lasternoller;

        }

        $instance = $DB->get_record('enrol', array('id'=>$instanceid, 'enrol'=>$this->get_name()), '*', MUST_EXIST);

        $context = context_course::instance($instance->courseid);

        if ($users = get_enrolled_users($context, 'enrol/self:manage')) {

            $users = sort_by_roleassignment_authority($users, $context);

            $this->lasternoller = reset($users);

            unset($users);

        } else {

            $this->lasternoller = parent::get_enroller($instanceid);

        }

        $this->lasternollerinstanceid = $instanceid;

        return $this->lasternoller;

    }

    protected function get_expiry_message_body(stdClass $user, stdClass $ue, string $name,

            stdClass $enroller, context $context): string {

        $a = new stdClass();

        $a->course = format_string($ue->fullname, true, ['context' => $context]);

        $a->user = fullname($user, true);

        // If the enrolment duration is disabled, replace timeend with other data.

        if ($ue->timeend == 0) {

            $timenow = time();

            $lastaccess = $ue->timeaccess > 0 ? $ue->timeaccess : $ue->timestart;

            $ue->timeend = $timenow + ($ue->customint2 - ($timenow - $lastaccess));

        }

        $a->timeend  = userdate($ue->timeend, '', $user->timezone);

        $a->enroller = fullname($enroller, has_capability('moodle/site:viewfullnames', $context, $user));

        if (isset($ue->inactivetime)) {

            $a->inactivetime = $ue->inactivetime;

        }

        $a->url = new moodle_url('/course/view.php', ['id' => $ue->courseid]);

        return get_string($ue->message ?? 'expirymessageenrolledbody', 'enrol_' . $name, $a);

    }

    /**

     * Restore instance and map settings.

     *

     * @param restore_enrolments_structure_step $step

     * @param stdClass $data

     * @param stdClass $course

     * @param int $oldid

     */

    public function restore_instance(restore_enrolments_structure_step $step, stdClass $data, $course, $oldid) {

        global $DB;

        if ($step->get_task()->get_target() == backup::TARGET_NEW_COURSE) {

            $merge = false;

        } else {

            $merge = array(

                'courseid'   => $data->courseid,

                'enrol'      => $this->get_name(),

                'status'     => $data->status,

                'roleid'     => $data->roleid,

            );

        }

        if ($merge and $instances = $DB->get_records('enrol', $merge, 'id')) {

            $instance = reset($instances);

            $instanceid = $instance->id;

        } else {

            if (!empty($data->customint5)) {

                if ($step->get_task()->is_samesite()) {

                    // Keep cohort restriction unchanged - we are on the same site.

                } else {

                    // Use some id that can not exist in order to prevent self enrolment,

                    // because we do not know what cohort it is in this site.

                    $data->customint5 = -1;

                }

            }

            $instanceid = $this->add_instance($course, (array)$data);

        }

        $step->set_mapping('enrol', $oldid, $instanceid);

    }

    /**

     * Restore user enrolment.

     *

     * @param restore_enrolments_structure_step $step

     * @param stdClass $data

     * @param stdClass $instance

     * @param int $oldinstancestatus

     * @param int $userid

     */

    public function restore_user_enrolment(restore_enrolments_structure_step $step, $data, $instance, $userid, $oldinstancestatus) {

        $this->enrol_user($instance, $userid, null, $data->timestart, $data->timeend, $data->status);

    }

    /**

     * Restore role assignment.

     *

     * @param stdClass $instance

     * @param int $roleid

     * @param int $userid

     * @param int $contextid

     */

    public function restore_role_assignment($instance, $roleid, $userid, $contextid) {

        // This is necessary only because we may migrate other types to this instance,

        // we do not use component in manual or self enrol.

        role_assign($roleid, $userid, $contextid, '', 0);

    }

    /**

     * Is it possible to delete enrol instance via standard UI?

     *

     * @param stdClass $instance

     * @return bool

     */

    public function can_delete_instance($instance) {

        $context = context_course::instance($instance->courseid);

        return has_capability('enrol/self:config', $context);

    }

    /**

     * Is it possible to hide/show enrol instance via standard UI?

     *

     * @param stdClass $instance

     * @return bool

     */

    public function can_hide_show_instance($instance) {

        $context = context_course::instance($instance->courseid);

        if (!has_capability('enrol/self:config', $context)) {

            return false;

        }

        // If the instance is currently disabled, before it can be enabled,

        // we must check whether the password meets the password policies.

        if ($instance->status == ENROL_INSTANCE_DISABLED) {

            if ($this->get_config('requirepassword')) {

                if (empty($instance->password)) {

                    return false;

                }

            }

            // Only check the password if it is set.

            if (!empty($instance->password) && $this->get_config('usepasswordpolicy')) {

                if (!check_password_policy($instance->password, $errmsg)) {

                    return false;

                }

            }

        }

        return true;

    }

    /**

     * Return an array of valid options for the status.

     *

     * @return array

     */

    protected function get_status_options() {

        $options = array(ENROL_INSTANCE_ENABLED  => get_string('yes'),

                         ENROL_INSTANCE_DISABLED => get_string('no'));

        return $options;

    }

    /**

     * Return an array of valid options for the newenrols property.

     *

     * @return array

     */

    protected function get_newenrols_options() {

        $options = array(1 => get_string('yes'), 0 => get_string('no'));

        return $options;

    }

    /**

     * Return an array of valid options for the groupkey property.

     *

     * @return array

     */

    protected function get_groupkey_options() {

        $options = array(1 => get_string('yes'), 0 => get_string('no'));

        return $options;

    }

    /**

     * Return an array of valid options for the expirynotify property.

     *

     * @return array

     */

    protected function get_expirynotify_options() {

        $options = array(0 => get_string('no'),

                         1 => get_string('expirynotifyenroller', 'enrol_self'),

                         2 => get_string('expirynotifyall', 'enrol_self'));

        return $options;

    }

    /**

     * Return an array of valid options for the longtimenosee property.

     *

     * @return array

     */

    protected function get_longtimenosee_options() {

        $options = array(0 => get_string('never'),

                         1800 * 3600 * 24 => get_string('numdays', '', 1800),

                         1000 * 3600 * 24 => get_string('numdays', '', 1000),

                         365 * 3600 * 24 => get_string('numdays', '', 365),

                         180 * 3600 * 24 => get_string('numdays', '', 180),

                         150 * 3600 * 24 => get_string('numdays', '', 150),

                         120 * 3600 * 24 => get_string('numdays', '', 120),

                         90 * 3600 * 24 => get_string('numdays', '', 90),

                         60 * 3600 * 24 => get_string('numdays', '', 60),

                         30 * 3600 * 24 => get_string('numdays', '', 30),

                         21 * 3600 * 24 => get_string('numdays', '', 21),

                         14 * 3600 * 24 => get_string('numdays', '', 14),

                         7 * 3600 * 24 => get_string('numdays', '', 7));

        return $options;

    }

    /**

     * The self enrollment plugin has several bulk operations that can be performed.

     * @param course_enrolment_manager $manager

     * @return array

     */

    public function get_bulk_operations(course_enrolment_manager $manager) {

        global $CFG;

        require_once($CFG->dirroot.'/enrol/self/locallib.php');

        $context = $manager->get_context();

        $bulkoperations = array();

        if (has_capability("enrol/self:manage", $context)) {

            $bulkoperations['editselectedusers'] = new enrol_self_editselectedusers_operation($manager, $this);

        }

        if (has_capability("enrol/self:unenrol", $context)) {

            $bulkoperations['deleteselectedusers'] = new enrol_self_deleteselectedusers_operation($manager, $this);

        }

        return $bulkoperations;

    }

    /**

     * Add elements to the edit instance form.

     *

     * @param stdClass $instance

     * @param MoodleQuickForm $mform

     * @param context $context

     * @return bool

     */

    public function edit_instance_form($instance, MoodleQuickForm $mform, $context) {

        global $CFG, $DB;

        // Merge these two settings to one value for the single selection element.

        if ($instance->notifyall and $instance->expirynotify) {

            $instance->expirynotify = 2;

        }

        unset($instance->notifyall);

        $nameattribs = array('size' => '20', 'maxlength' => '255');

        $mform->addElement('text', 'name', get_string('custominstancename', 'enrol'), $nameattribs);

        $mform->setType('name', PARAM_TEXT);

        $mform->addRule('name', get_string('maximumchars', '', 255), 'maxlength', 255, 'server');

        $options = $this->get_status_options();

        $mform->addElement('select', 'status', get_string('status', 'enrol_self'), $options);

        $mform->addHelpButton('status', 'status', 'enrol_self');

        $options = $this->get_newenrols_options();

        $mform->addElement('select', 'customint6', get_string('newenrols', 'enrol_self'), $options);

        $mform->addHelpButton('customint6', 'newenrols', 'enrol_self');

        $mform->disabledIf('customint6', 'status', 'eq', ENROL_INSTANCE_DISABLED);

        $passattribs = array('size' => '20', 'maxlength' => '50');

        $mform->addElement('passwordunmask', 'password', get_string('password', 'enrol_self'), $passattribs);

        $mform->addHelpButton('password', 'password', 'enrol_self');

        if (empty($instance->id) and $this->get_config('requirepassword')) {

            $mform->addRule('password', get_string('required'), 'required', null, 'client');

        }

        $mform->addRule('password', get_string('maximumchars', '', 50), 'maxlength', 50, 'server');

        $options = $this->get_groupkey_options();

        $mform->addElement('select', 'customint1', get_string('groupkey', 'enrol_self'), $options);

        $mform->addHelpButton('customint1', 'groupkey', 'enrol_self');

        $roles = $this->extend_assignable_roles($context, $instance->roleid);

        $mform->addElement('select', 'roleid', get_string('role', 'enrol_self'), $roles);

        $options = array('optional' => true, 'defaultunit' => 86400);

        $mform->addElement('duration', 'enrolperiod', get_string('enrolperiod', 'enrol_self'), $options);

        $mform->addHelpButton('enrolperiod', 'enrolperiod', 'enrol_self');

        $options = $this->get_expirynotify_options();

        $mform->addElement('select', 'expirynotify', get_string('expirynotify', 'core_enrol'), $options);

        $mform->addHelpButton('expirynotify', 'expirynotify', 'core_enrol');

        $options = array('optional' => false, 'defaultunit' => 86400);

        $mform->addElement('duration', 'expirythreshold', get_string('expirythreshold', 'core_enrol'), $options);

        $mform->addHelpButton('expirythreshold', 'expirythreshold', 'core_enrol');

        $mform->disabledIf('expirythreshold', 'expirynotify', 'eq', 0);

        $options = array('optional' => true);

        $mform->addElement('date_time_selector', 'enrolstartdate', get_string('enrolstartdate', 'enrol_self'), $options);

        $mform->setDefault('enrolstartdate', 0);

        $mform->addHelpButton('enrolstartdate', 'enrolstartdate', 'enrol_self');

        $options = array('optional' => true);

        $mform->addElement('date_time_selector', 'enrolenddate', get_string('enrolenddate', 'enrol_self'), $options);

        $mform->setDefault('enrolenddate', 0);

        $mform->addHelpButton('enrolenddate', 'enrolenddate', 'enrol_self');

        $options = $this->get_longtimenosee_options();

        $mform->addElement('select', 'customint2', get_string('longtimenosee', 'enrol_self'), $options);

        $mform->addHelpButton('customint2', 'longtimenosee', 'enrol_self');

        $mform->addElement('text', 'customint3', get_string('maxenrolled', 'enrol_self'));

        $mform->addHelpButton('customint3', 'maxenrolled', 'enrol_self');

        $mform->setType('customint3', PARAM_INT);

        require_once($CFG->dirroot.'/cohort/lib.php');

        $cohorts = array(0 => get_string('no'));

        $allcohorts = cohort_get_available_cohorts($context, 0, 0, 0);

        if ($instance->customint5 && !isset($allcohorts[$instance->customint5])) {

            $c = $DB->get_record('cohort',

                                 array('id' => $instance->customint5),

                                 'id, name, idnumber, contextid, visible',

                                 IGNORE_MISSING);

            if ($c) {

                // Current cohort was not found because current user can not see it. Still keep it.

                $allcohorts[$instance->customint5] = $c;

            }

        }

        foreach ($allcohorts as $c) {

            $cohorts[$c->id] = format_string($c->name, true, array('context' => context::instance_by_id($c->contextid)));

            if ($c->idnumber) {

                $cohorts[$c->id] .= ' ['.s($c->idnumber).']';

            }

        }

        if ($instance->customint5 && !isset($allcohorts[$instance->customint5])) {

            // Somebody deleted a cohort, better keep the wrong value so that random ppl can not enrol.

            $cohorts[$instance->customint5] = get_string('unknowncohort', 'cohort', $instance->customint5);

        }

        if (count($cohorts) > 1) {

            $mform->addElement('select', 'customint5', get_string('cohortonly', 'enrol_self'), $cohorts);

            $mform->addHelpButton('customint5', 'cohortonly', 'enrol_self');

        } else {

            $mform->addElement('hidden', 'customint5');

            $mform->setType('customint5', PARAM_INT);

            $mform->setConstant('customint5', 0);

        }

        $mform->addElement('select', 'customint4', get_string('sendcoursewelcomemessage', 'enrol_self'),

                enrol_send_welcome_email_options());

        $mform->addHelpButton('customint4', 'sendcoursewelcomemessage', 'enrol_self');

        $options = array('cols' => '60', 'rows' => '8');

        $mform->addElement('textarea', 'customtext1', get_string('customwelcomemessage', 'core_enrol'), $options);

        $mform->setDefault('customtext1', get_string('customwelcomemessageplaceholder', 'core_enrol'));

        $mform->hideIf(

            elementname: 'customtext1',

            dependenton: 'customint4',

            condition: 'eq',

            value: ENROL_DO_NOT_SEND_EMAIL,

        );

        // Static form elements cannot be hidden by hideIf() so we need to add a dummy group.

        // See: https://tracker.moodle.org/browse/MDL-66251.

        $group[] = $mform->createElement(

            'static',

            'customwelcomemessage_extra_help',

            null,

            get_string(

                identifier: 'customwelcomemessage_help',

                component: 'core_enrol',

            ),

        );

        $mform->addGroup($group, 'group_customwelcomemessage_extra_help', '', ' ', false);

        $mform->hideIf(

            elementname: 'group_customwelcomemessage_extra_help',

            dependenton: 'customint4',

            condition: 'eq',

            value: ENROL_DO_NOT_SEND_EMAIL,

        );

        if (enrol_accessing_via_instance($instance)) {

            $warntext = get_string('instanceeditselfwarningtext', 'core_enrol');

            $mform->addElement('static', 'selfwarn', get_string('instanceeditselfwarning', 'core_enrol'), $warntext);

        }

    }

    /**

     * We are a good plugin and don't invent our own UI/validation code path.

     *

     * @return boolean

     */

    public function use_standard_editing_ui() {

        return true;

    }

    /**

     * Perform custom validation of the data used to edit the instance.

     *

     * @param array $data array of ("fieldname"=>value) of submitted data

     * @param array $files array of uploaded files "element_name"=>tmp_file_path

     * @param object $instance The instance loaded from the DB

     * @param context $context The context of the instance we are editing

     * @return array of "element_name"=>"error_description" if there are errors,

     *         or an empty array if everything is OK.

     * @return void

     */

    public function edit_instance_validation($data, $files, $instance, $context) {

        global $CFG;

        require_once("{$CFG->dirroot}/enrol/self/locallib.php");

        $errors = array();

        $checkpassword = false;

        if ($instance->id) {

            // Check the password if we are enabling the plugin again.

            if (($instance->status == ENROL_INSTANCE_DISABLED) && ($data['status'] == ENROL_INSTANCE_ENABLED)) {

                $checkpassword = true;

            }

            // Check the password if the instance is enabled and the password has changed.