<?php   /// $Id: enrol.php,v 1.25.2.6 2008/04/26 11:07:15 dongsheng Exp $
///////////////////////////////////////////////////////////////////////////
//                                                                       //
// NOTICE OF COPYRIGHT                                                   //
//                                                                       //
// Moodle - Modular Object-Oriented Dynamic Learning Environment         //
//          http://moodle.org                                            //
//                                                                       //
// Copyright (C) 2004  Martin Dougiamas  http://moodle.com               //
//                                                                       //
// This program 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 2 of the License, or     //
// (at your option) any later version.                                   //
//                                                                       //
// This program 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:                          //
//                                                                       //
//          http://www.gnu.org/copyleft/gpl.html                         //
//                                                                       //
///////////////////////////////////////////////////////////////////////////

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

/**
* enrolment_plugin_manual is the default enrolment plugin
*
* This class provides all the functionality for an enrolment plugin
* In fact it includes all the code for the default, "manual" method
* so that other plugins can override these as necessary.
*/

class enrolment_plugin_manual {

var $errormsg;

/**
* Prints the entry form/page for this enrolment
*
* This is only called from course/enrol.php
* Most plugins will probably override this to print payment
* forms etc, or even just a notice to say that manual enrolment
* is disabled
*
* @param    course  current course object
*/
function print_entry($course) {
    global $CFG, $USER, $SESSION, $THEME;

    $strloginto = get_string('loginto', '', $course->shortname);
    $strcourses = get_string('courses');

/// Automatically enrol into courses without password

    $context = get_context_instance(CONTEXT_SYSTEM);

    $navlinks = array();
    $navlinks[] = array('name' => $strcourses, 'link' => ".", 'type' => 'misc');
    $navlinks[] = array('name' => $strloginto, 'link' => null, 'type' => 'misc');
    $navigation = build_navigation($navlinks);

    if ($course->password == '') {   // no password, so enrol

        if (has_capability('moodle/legacy:guest', $context, $USER->id, false)) {
            add_to_log($course->id, 'course', 'guest', 'view.php?id='.$course->id, getremoteaddr());

        } else if (empty($_GET['confirm']) && empty($_GET['cancel'])) {

            print_header($strloginto, $course->fullname, $navigation);
            echo '<br />';
            notice_yesno(get_string('enrolmentconfirmation'), "enrol.php?id=$course->id&amp;confirm=1",
                                                              "enrol.php?id=$course->id&amp;cancel=1");
            print_footer();
            exit;

        } else if (!empty($_GET['confirm'])) {

            if (!enrol_into_course($course, $USER, 'manual')) {
                print_error('couldnotassignrole');
            }
            // force a refresh of mycourses
            unset($USER->mycourses);

            if (!empty($SESSION->wantsurl)) {
                $destination = $SESSION->wantsurl;
                unset($SESSION->wantsurl);
            } else {
                $destination = "$CFG->wwwroot/course/view.php?id=$course->id";
            }

            redirect($destination);

        } else if (!empty($_GET['cancel'])) {
            unset($SESSION->wantsurl);
            if (!empty($SESSION->enrolcancel)) {
                $destination = $SESSION->enrolcancel;
                unset($SESSION->enrolcancel);
            } else {
                $destination = $CFG->wwwroot;
            }
            redirect($destination);
        }
    }

    // if we get here we are going to display the form asking for the enrolment key
    // and (hopefully) provide information about who to ask for it.
    if (!isset($password)) {
        $password = '';
    }

    print_header($strloginto, $course->fullname, $navigation, "form.password");

    print_course($course, "80%");

    include("$CFG->dirroot/enrol/manual/enrol.html");

    print_footer();

}



/**
* The other half to print_entry, this checks the form data
*
* This function checks that the user has completed the task on the
* enrolment entry page and then enrolls them.
*
* @param    form    the form data submitted, as an object
* @param    course  the current course, as an object
*/
function check_entry($form, $course) {
    global $CFG, $USER, $SESSION, $THEME;

    if (empty($form->password)) {
        $form->password = '';
    }

    if (empty($course->password)) {
        // do not allow entry when no course password set
        // automatic login when manual primary, no login when secondary at all!!
        error('illegal enrolment attempted');
    }

    $groupid = $this->check_group_entry($course->id, $form->password);

    if ((stripslashes($form->password) == $course->password) or ($groupid !== false) ) {

        if (isguestuser()) { // only real user guest, do not use this for users with guest role
            $USER->enrolkey[$course->id] = true;
            add_to_log($course->id, 'course', 'guest', 'view.php?id='.$course->id, getremoteaddr());

        } else {  /// Update or add new enrolment
            if (enrol_into_course($course, $USER, 'manual')) {
                // force a refresh of mycourses
                unset($USER->mycourses);
                if ($groupid !== false) {
                    if (!groups_add_member($groupid, $USER->id)) {
                        print_error('couldnotassigngroup');
                    }
                }
            } else {
                print_error('couldnotassignrole');
            }
        }

        if ($SESSION->wantsurl) {
            $destination = $SESSION->wantsurl;
            unset($SESSION->wantsurl);
        } else {
            $destination = "$CFG->wwwroot/course/view.php?id=$course->id";
        }

        redirect($destination);

    } else {
        $this->errormsg = get_string('enrolmentkeyhint', '', substr($course->password,0,1));
    }
}


/**
* Check if the given enrolment key matches a group enrolment key for the given course
*
* @param    courseid  the current course id
* @param    password  the submitted enrolment key
*/
function check_group_entry ($courseid, $password) {

    if ($groups = groups_get_all_groups($courseid)) {
        foreach ($groups as $group) {
            if ( !empty($group->enrolmentkey) and (stripslashes($password) == $group->enrolmentkey) ) {
                return $group->id;
            }
        }
    }

    return false;
}


/**
* Prints a form for configuring the current enrolment plugin
*
* This function is called from admin/enrol.php, and outputs a
* full page with a form for defining the current enrolment plugin.
*
* @param    frm  an object containing all the data for this page
*/
function config_form($frm) {
    global $CFG;

    if (!isset( $frm->enrol_manual_keyholderrole )) {
        $frm->enrol_manual_keyholderrole = '';
    }

    include ("$CFG->dirroot/enrol/manual/config.html");
}


/**
* Processes and stored configuration data for the enrolment plugin
*
* @param    config  all the configuration data as entered by the admin
*/
function process_config($config) {

    $return = true;

    foreach ($config as $name => $value) {
        if (!set_config($name, $value)) {
            $return = false;
        }
    }

    return $return;
}


/**
* Notify users about enrolments that are going to expire soon!
* This function is run by admin/cron.php
* @return void
*/
function cron() {
    global $CFG, $USER, $SITE;

    if (!isset($CFG->lastexpirynotify)) {
        set_config('lastexpirynotify', 0);
    }

    // notify once a day only - TODO: add some tz handling here, maybe use timestamps
    if ($CFG->lastexpirynotify == date('Ymd')) {
        return;
    }

    if ($rs = get_recordset_select('course', 'enrolperiod > 0 AND expirynotify > 0 AND expirythreshold > 0')) {

        $cronuser = clone($USER);

        $admin = get_admin();

        while($course = rs_fetch_next_record($rs)) {
            $a = new object();
            $a->coursename = $course->shortname .'/'. $course->fullname; // must be processed by format_string later
            $a->threshold  = $course->expirythreshold / 86400;
            $a->extendurl  = $CFG->wwwroot . '/user/index.php?id=' . $course->id;
            $a->current    = array();
            $a->past       = array();

            $expiry = time() + $course->expirythreshold;
            $cname  = $course->fullname;

            /// Get all the manual role assignments for this course that have expired.

            if (!$context = get_context_instance(CONTEXT_COURSE, $course->id)) {
                continue;
            }

            if ($oldenrolments = get_records_sql("
                      SELECT u.*, ra.timeend
                        FROM {$CFG->prefix}user u
                             JOIN {$CFG->prefix}role_assignments ra ON (ra.userid = u.id)
                        WHERE ra.contextid = $context->id
                              AND ra.timeend > 0 AND ra.timeend <= $expiry
                              AND ra.enrol = 'manual'")) {

                // inform user who can assign roles or admin
                if ($teachers = get_users_by_capability($context, 'moodle/role:assign', '', '', '', '', '', '', false)) {
                    $teachers = sort_by_roleassignment_authority($teachers, $context);
                    $teacher  = reset($teachers);
                } else {
                    $teachers = array($admin);
                    $teacher  = $admin;
                }

                $a->teacherstr = fullname($teacher, true);

                foreach ($oldenrolments as $user) {       /// Email all users about to expire
                    $a->studentstr = fullname($user, true);
                    if ($user->timeend < ($expiry - 86400)) {
                        $a->past[] = fullname($user) . " <$user->email>";
                    } else {
                        $a->current[] = fullname($user) . " <$user->email>";
                        if ($course->notifystudents) {     // Send this guy notice
                            // setup global $COURSE properly - needed for languages
                            $USER = $user;
                            course_setup($course);
                            $a->coursename = format_string($cname);
                            $a->course     = $a->coursename;
                            $strexpirynotifystudentsemail = get_string('expirynotifystudentsemail', '', $a);
                            $strexpirynotify              = get_string('expirynotify');

                            email_to_user($user, $teacher, format_string($SITE->fullname) .' '. $strexpirynotify,
                                          $strexpirynotifystudentsemail);
                        }
                    }
                }

                $a->current = implode("\n", $a->current);
                $a->past    = implode("\n", $a->past);

                if ($a->current || $a->past) {
                    foreach ($teachers as $teacher) {
                        // setup global $COURSE properly - needed for languages
                        $USER = $teacher;
                        course_setup($course);
                        $a->coursename = format_string($cname);
                        $strexpirynotifyemail = get_string('expirynotifyemail', '', $a);
                        $strexpirynotify      = get_string('expirynotify');

                        email_to_user($teacher, $admin, $a->coursename .' '. $strexpirynotify, $strexpirynotifyemail);
                    }
                }
            }
        }
        $USER = $cronuser;
        course_setup($course);   // More environment
    }

    set_config('lastexpirynotify', date('Ymd'));
}


/**
* Returns the relevant icons for a course
*
* @param    course  the current course, as an object
*/
function get_access_icons($course) {
    global $CFG;

    global $strallowguests;
    global $strrequireskey;

    if (empty($strallowguests)) {
        $strallowguests = get_string('allowguests');
        $strrequireskey = get_string('requireskey');
    }

    $str = '';

    if (!empty($course->guest)) {
        $str .= '<a title="'.$strallowguests.'" href="'.$CFG->wwwroot.'/course/view.php?id='.$course->id.'">';
        $str .= '<img class="accessicon" alt="'.$strallowguests.'" src="'.$CFG->pixpath.'/i/guest.gif" /></a>&nbsp;&nbsp;';
    }
    if (!empty($course->password)) {
        $str .= '<a title="'.$strrequireskey.'" href="'.$CFG->wwwroot.'/course/view.php?id='.$course->id.'">';
        $str .= '<img class="accessicon" alt="'.$strrequireskey.'" src="'.$CFG->pixpath.'/i/key.gif" /></a>';
    }

    return $str;
}

/**
 * Prints the message telling you were to get the enrolment key
 * appropriate for the prevailing circumstances
 * A bit clunky because I didn't want to change the standard strings
 */
function print_enrolmentkeyfrom($course) {
    global $CFG;
    global $USER;

    $context = get_context_instance(CONTEXT_SYSTEM);
    $guest = has_capability('moodle/legacy:guest', $context, $USER->id, false);

    // if a keyholder role is defined we list teachers in that role (if any exist)
    $contactslisted = false;
    $canseehidden = has_capability('moodle/role:viewhiddenassigns', $context);
    if (!empty($CFG->enrol_manual_keyholderrole)) {
        if ($contacts = get_role_users($CFG->enrol_manual_keyholderrole, get_context_instance(CONTEXT_COURSE, $course->id),$canseehidden  )) {
            // guest user has a slightly different message
            if ($guest) {
                print_string('enrolmentkeyfromguest', '', ':<br />' );
            }
            else {
                print_string('enrolmentkeyfrom', '', ':<br />');
            }
            foreach ($contacts as $contact) {
                $contactname = "<a href=\"../user/view.php?id=$contact->id&course=".SITEID."\">".fullname($contact)."</a>.";
                echo "$contactname<br />";
            }
            $contactslisted = true;
        }
    }

    // if no keyholder role is defined OR nobody is in that role we do this the 'old' way
    // (show the first person with update rights)
    if (!$contactslisted) {
        if ($teachers = get_users_by_capability(get_context_instance(CONTEXT_COURSE, $course->id), 'moodle/course:update',
            'u.*', 'u.id ASC', 0, 1, '', '', false, true)) {
            $teacher = array_shift($teachers);
        }
        if (!empty($teacher)) {
            $teachername = "<a href=\"../user/view.php?id=$teacher->id&course=".SITEID."\">".fullname($teacher)."</a>.";
        } else {
            $teachername = strtolower( get_string('defaultcourseteacher') ); //get_string('yourteacher', '', $course->teacher);
        }

        // guest user has a slightly different message
        if ($guest) {
            print_string('enrolmentkeyfromguest', '', $teachername );
        }
        else {
            print_string('enrolmentkeyfrom', '', $teachername);
        }
    }
}

} /// end of class

?>
