# The LearningOnline Network
# Allow users to self-enroll in a course
#
# $Id: selfenroll.pm,v 1.13 2008/07/17 20:08:17 raeburn Exp $
#
# Copyright Michigan State University Board of Trustees
#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
#
# LON-CAPA 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.
#
# LON-CAPA 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 LON-CAPA; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# /home/httpd/html/adm/gpl.txt
#
# http://www.lon-capa.org/
#
#
package Apache::selfenroll;

use strict;
use Apache::Constants qw(:common);
use Apache::lonnet;
use Apache::loncommon;
use Apache::lonlocal;
use Apache::createaccount;
use LONCAPA qw(:DEFAULT :match);

sub handler {
    my $r = shift;
    &Apache::loncommon::content_type($r,'text/html');
    $r->send_http_header;
    if ($r->header_only) {
        return OK;
    }
    my $handle = &Apache::lonnet::check_for_valid_session($r);
    my $lonidsdir=$r->dir_config('lonIDsDir');
    my $lonhost = $r->dir_config('lonHostID');
    if ($handle ne '') {
        &Apache::lonnet::transfer_profile_to_env($lonidsdir,$handle);
    }
    &Apache::lonacc::get_posted_cgi($r);
    &Apache::lonlocal::get_language_handle($r);
    &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},['courseid']);
    my $js = &Apache::createaccount::catreturn_js();
    my $desc;
    my ($coursechk,$courseid) = &validate_course_id($env{'form.courseid'});
    if ($coursechk ne 'ok') {
        &page_header($r,$courseid,$js);
        $r->print('<h3>'.&mt('Self-enrollment error').'</h3>'.
                  '<span class="LC_error">'.
                  &mt('Invalid domain or course number').'</span>');
        &page_footer($r);
        return OK;
    }
    my $now = time;
    if ($env{'form.phase'} eq 'login') {
        $js .= "\n".&Apache::createaccount::javascript_setforms($now);
    }
    my %coursehash = &Apache::lonnet::coursedescription($courseid);
    my $cdom = $coursehash{'domain'};
    my $cnum = $coursehash{'num'};
    my $desc = $coursehash{'description'};
    &page_header($r,$courseid,$js,$desc);
    my $include = $r->dir_config('lonIncludes');
    if ($env{'form.phase'} eq 'login') {
        my $jsh=Apache::File->new($include."/londes.js");
        $r->print(<$jsh>);
    }
    my ($canenroll,$selfenroll_types,$selfenroll_registered,@cancreate,
        $knownuser,$selfenroll_access_start,$selfenroll_access_end,
        $selfenroll_section,$selfenroll_future,%curr_role,$cdomdesc);
    $selfenroll_types = $coursehash{'internal.selfenroll_types'};
    $selfenroll_registered =  $coursehash{'internal.selfenroll_registered'};
    $selfenroll_section = $coursehash{'internal.selfenroll_section'};
    $selfenroll_access_start =  $coursehash{'internal.selfenroll_start_access'};
    $selfenroll_access_end =  $coursehash{'internal.selfenroll_end_access'};
    if ($selfenroll_types ne '') {
        my $start = $coursehash{'internal.selfenroll_start_date'};
        my $end = $coursehash{'internal.selfenroll_end_date'};
        if (($start > 0 && $start < $now) && (($end == 0) || ($end > 0 && $end > $now))) {
            $canenroll = 1;
        } elsif (($end == 0) || ($end > 0 && $end > $now)) {
            if ($start > $now) {
                $selfenroll_future = &Apache::lonlocal::locallocaltime($start);
            }
        }
    }
    $knownuser = &user_is_known();
    if (!$canenroll) {
        $r->print('<h3>'.&mt('Self-enrollment unavailable').'</h3><span class="LC_warning">'.
                  &mt('Self-enrollment is not currently available for this course.').
                  '</span><br /><br />');
        if ($selfenroll_types ne '') {
            if ($selfenroll_future ne '') {
                if ($selfenroll_types eq '*') {
                    $r->print(&mt('Self-enrollment will become available starting [_1], and will be available to all LON-CAPA users.',$selfenroll_future).'<br />');
                } else {
                    my ($enrolltypes,$longtypes,$alldoms);
                    if ($knownuser) {
                        &get_selfenroll_filters($selfenroll_types,$env{'user.domain'});
                        my $domdesc = &Apache::lonnet::domain($env{'user.domain'},'description');
                        if (ref($enrolltypes) eq 'HASH') {
                            if (ref($enrolltypes->{$env{'user.domain'}}) eq 'ARRAY') {
                                if (grep(/^any$/,@{$enrolltypes->{$env{'user.domain'}}})) {
                                    $r->print(&mt('Self-enrollment will become available starting [_1], and will be available to all LON-CAPA users at your institution ([_2]).',
                                              $selfenroll_future,$domdesc).'<br />');

                                } else {
                                    if (&user_can_selfenroll($env{'user.domain'},
                                                        $env{'user.name'},
                                                        $enrolltypes->{$env{'user.domain'}})) {
                                        $r->print(&mt('Self-enrollment will become available starting [_1]; please enroll at that time.',$selfenroll_future)); 
                                    } else {
                                        $r->print(&mt('Although self-enrollment will become available starting [_1], you are ineligible for enrollment.',$selfenroll_future).'<br />');
                                        $r->print(&print_selfenroll_types($longtypes,$env{'user.domain'}));
                                    }
                                }
                            }
                        } 
                    } else {
                        $r->print(&mt('Self-enrollment will become available starting [_1].',
                                      $selfenroll_future).'<br />');
                        $r->print(&print_selfenroll_types($longtypes));
                    }
                }
            } 
        }
    }
    if ($knownuser) {
        foreach my $key (keys(%env)) {
            if ($key =~ m-^user\.role\.st\./$cdom/$cnum/?(\w*)$-) {
                my $sec = $1;
                my ($start,$end) = split(/\./,$env{$key});
                my $status = 'active';
                if (($end) && ($end<=$now)) {
                    $status = 'previous';
                }
                if (($start) && ($now<$start)) {
                    $status = 'future';
                }
                if ($status eq 'active' || $status eq 'future') {
                     $curr_role{'status'} = $status;
                     $curr_role{'section'} = $sec;
                     if ($curr_role{'section'} eq '') {
                         $curr_role{'section'} = &mt('none'); 
                     }
                     $curr_role{'start'} = &Apache::lonlocal::locallocaltime($start);
                     $curr_role{'role'} = 'st./'.$cdom.'/'.$cnum;
                     if ($sec ne '') {
                         $curr_role{'role'} .= '/'.$sec; 
                     }
                }
            }
        }
    }
    if (!$canenroll) {
        if (keys(%curr_role)) {
            $r->print(&has_role(%curr_role));
        }
        &page_footer($r);
        return OK;
    }
    @cancreate = &can_create($cdom);
    my ($form,$login_path,$firsturl,$create_path,$sso_url,$missing_formitem);
    $form = 'logmein';
    $login_path = '/adm/login';
    $firsturl= '/adm/selfenroll?courseid='.$courseid;
    $create_path = '/adm/createaccount';
    $sso_url = $r->dir_config('lonSSOReloginServer');
    if ($sso_url eq '') {
        $sso_url = $login_path;
    }
    $missing_formitem = &mt('The link to the requested page could not be followed.')."\\n".&mt('The placeholder for the courseID is absent.');
    if ($knownuser) {
        if (keys(%curr_role)) {
            $r->print('<h3>'.&mt('Self-enrollment unavailable').'</h3>'.
                      '<span class="LC_warning">'.&has_role(%curr_role).'</span>');
            &page_footer($r);
            return OK;
        }
        &process_self_enroll($r,$cdom,$cnum,$selfenroll_types,$selfenroll_registered,
                             $selfenroll_access_start,$selfenroll_access_end,
                             $selfenroll_section,$now);
    } elsif ($env{'form.phase'} eq 'login') {
        my $submit_text = &mt('Log in');
        $r->print('<h3>'.&mt('Log-in to LON-CAPA').'</h3>');
        my $udom = &Apache::lonnet::default_login_domain();
        $r->print(&Apache::createaccount::login_box($now,$lonhost,$courseid,
                                           $submit_text,$udom,'selfenroll'));
        $r->print(&mt('You will be able to self-enroll in the course you selected ([_1]) after you have successfully logged in.','<b>'.$desc.'</b>'));
        &page_footer($r);
        return OK;
    } elsif (@cancreate > 0) {
        $r->print(<<END);
<script type="text/javascript">
function setPath(formname,formaction,item,arg) {
    var formidx = getFormByName(formname);
    if (formidx > -1) {
        if (formaction != '') {
            document.forms[formidx].action = formaction;
        }
        var itemid = getIndexByName(formidx,'setting');
        if (itemid > -1) {
            document.forms[formidx].elements[itemid].name = item;
            document.forms[formidx].elements[itemid].value = arg;
            document.forms[formidx].submit();
        } else {
            alert("$missing_formitem");
        }
    }
    return;
}

</script>
END
        $r->print('<h3>'.&mt('LON-CAPA account required').'</h3>'.
                  &mt('You need to be logged into LON-CAPA to self-enroll in a course.').'<ul><li>'.&mt('If you have an account in LON-CAPA, [_1]log-in[_2].','<a href="javascript:setPath('."'$form','','phase','login'".')">','</a>').'</li>');
        if (@cancreate > 1) {
            $r->print('<li>'.&mt('Otherwise:').'<br />');
            my $count = 0;
            foreach my $type ('sso','login','email') { 
                if (($count > 0) && ($count <@cancreate)) {
                    $r->print('&nbsp;, '.&mt('or').'<br />');
                }
                if (grep(/^$type$/,@cancreate)) {
                    if ($type eq 'sso') {
                        $r->print('&nbsp;&nbsp;'.&mt("if you have an institutional log-in, use your institution's [_1]single sign on page[_2] to log-in, then create an account",'<a href="javascript:setPath('."'$form','$sso_url','firsturl','$firsturl'".')">','</a>'));
                    } elsif ($type eq 'login') {
                        $r->print('&nbsp;&nbsp;'.&mt('if you have an institutional login, [_1]create an account[_2]','<a href="javascript:setPath('."'$form','$create_path','context','selfenroll_create'".')">','</a>'));
                    } elsif ($type eq 'email') {
                        $r->print('&nbsp;&nbsp;'.&mt('you can use an e-mail address to [_1]create an account[_2]','<a href="javascript:setPath('."'$form','$create_path','context','selfenroll_create'".')">','</a>'));
                    }
                    $count ++;
                }
            }
            $r->print('.<br />');
        } else {
            if ($cancreate[0] eq 'login') {
                $r->print('<li>'.&mt('Otherwise, if you have an institutional login, [_1]create an account[_2].','<a href="javascript:setPath('."'$form','$create_path','context','selfenroll_create'".')">','</a>'));
            } elsif ($cancreate[0] eq 'email') {
                $r->print('<li>'.&mt('Otherwise, you will use an e-mail address to [_1]create an account[_2].','<a href="javascript:setPath('."'$form','$create_path','context','selfenroll_create'".')">','</a>'));
            } elsif ($cancreate[0] eq 'sso') {
                $r->print('<li>'.&mt("Otherwise, use your institution's [_1]single sign on page[_2] to log-in, then create an account.",'<a href="javascript:setPath('."'$form','$sso_url','firsturl','$firsturl'".')">','</a>'));
            }
        }
        if ($selfenroll_types eq '*') {
            $r->print('<br />'.&mt('You will be able to self enroll in this course once the account has been created.').'</li></ul>');
        } else {
            $r->print('</li></ul>');
            my ($enrolltypes,$longtypes,$alldoms) = 
                &get_selfenroll_filters($selfenroll_types);
            $r->print(&print_selfenroll_types($longtypes));
        }
    } else {
        my $cdomdesc = &Apache::lonnet::domain($cdom,'description');
        $r->print('<h3>'.&mt('LON-CAPA account required').'</h3>');
        $r->print(&mt('You must [_1]log-in[_2] to LON-CAPA with an existing account to be able to enroll in this course, as account creation at this institution ([_3]) is not permitted when self-enrolling.','<a href="'.$login_path.'">','</a>',$cdomdesc));
        if ($selfenroll_types ne '*') {
            my ($enrolltypes,$longtypes,$alldoms) =
                &get_selfenroll_filters($selfenroll_types);
            $r->print('<br />'.&print_selfenroll_types($longtypes));
        }
        my $displayurl = &escape($firsturl);
        $r->print(&mt('Submit a request to the LON-CAPA [_1]helpdesk[_2] for [_3] if you require assistance.','<a href="/adm/helpdesk?origurl='.$displayurl.'">','</a>',$cdomdesc));
    }
    $r->print("\n".'<form name="'.$form.'" method="post" action="">'."\n".
              '<input type="hidden" name="courseid" value="'.$courseid.'" />'."\n".
              '<input type="hidden" name="setting" value=""/>'."\n".
              &Apache::lonhtmlcommon::echo_form_input(['backto','courseid','context','phase'])."\n".
              '</form>'."\n");
              &page_footer($r);
    return OK;
}

sub page_header {
    my ($r,$courseid,$js,$desc) = @_;
    my $start_page =
        &Apache::loncommon::start_page('Self-enroll in a LON-CAPA course',$js,
                                       {'no_inline_link'   => 1,});
    $r->print($start_page);
    &Apache::lonhtmlcommon::clear_breadcrumbs();
    &Apache::createaccount::selfenroll_crumbs($r,$courseid,$desc);
    $r->print(&Apache::lonhtmlcommon::breadcrumbs('Self-enroll in course'));
    return;
}

sub page_footer {
    my ($r) = @_;
    $r->print('<form name="backupcrumbs" method="post" action="/adm/coursecatalog">'."\n".
              &Apache::lonhtmlcommon::echo_form_input(['backto','courseid','phase','context']).
              '</form>'.&Apache::loncommon::end_page());
    return;
}

sub validate_course_id {
    my ($courseid) = @_;
    my ($cdom,$cnum) = ($env{'form.courseid'} =~ /^($match_domain)_($match_courseid)$/);
    if ($cdom ne '' && $cnum ne '') {
        if (&Apache::lonnet::is_course($cdom,$cnum)) {
            return ('ok',$courseid);
        }
    } 
    return;
}

sub user_is_known {
    my $known = 0;
    if ($env{'user.name'} ne '' && $env{'user.name'} ne 'public'
        && $env{'user.domain'} ne '' && $env{'user.domain'} ne 'public') {
        $known = 1;
    }
    return $known;
}

sub can_create {
    my ($cdom) = @_;
    my @cancreate;
    my %domconfig = &Apache::lonnet::get_dom('configuration',['usercreation'],$cdom);
    if (ref($domconfig{'usercreation'}) eq 'HASH') {
        if (ref($domconfig{'usercreation'}{'cancreate'}) eq 'HASH') {
            if ($domconfig{'usercreation'}{'cancreate'}{'selfcreate'} ne 'none') {
                if (ref($domconfig{'usercreation'}{'cancreate'}{'selfcreate'}) eq 'ARRAY') {
                    @cancreate = @{$domconfig{'usercreation'}{'cancreate'}{'selfcreate'}};
                } else {
                    if (($domconfig{'usercreation'}{'cancreate'}{'selfcreate'} ne 'none') && 
                        ($domconfig{'usercreation'}{'cancreate'}{'selfcreate'} ne '')) {
                        @cancreate = ($domconfig{'usercreation'}{'cancreate'}{'selfcreate'});
                    }
                }
            }
        }
    }
    return @cancreate;
}

sub has_role {
    my (%curr_role) = @_;
    my $output;
    if ($curr_role{'status'} eq 'active') {
          my $rolelink = &jump_to_role($curr_role{'role'});
          $output = &mt('You already have an active student role (section: "[_1]") in this course.',$curr_role{'section'}).'<br>'.$rolelink;
    } elsif ($curr_role{'status'} eq 'future') {
        $output = &mt('You have a student role (section: "[_1]") in this course which will become active [_2].',$curr_role{'section'},$curr_role{'start'});
    }
    return $output;
}

sub process_self_enroll {
    my ($r,$cdom,$cnum,$selfenroll_types,$selfenroll_registered,
        $selfenroll_access_start,$selfenroll_access_end,$selfenroll_section,$now) = @_;
    my $udom = $env{'user.domain'};
    my $uname = $env{'user.name'};
    my $selfenroll = 0;
    my ($enrolltypes,$longtypes,$alldoms);
    if ($selfenroll_types eq '*') {
        $selfenroll = 1;
    } else {
        ($enrolltypes,$longtypes,$alldoms) =
            &get_selfenroll_filters($selfenroll_types,$udom);
        if ($alldoms) {
            $selfenroll = 1;
        } elsif (ref($enrolltypes) eq 'HASH') {
            if (ref($enrolltypes->{$udom}) eq 'ARRAY') {
                if (grep(/^any$/,@{$enrolltypes->{$udom}})) {
                    $selfenroll = 1;
                } else {
                    $selfenroll = &user_can_selfenroll($udom,$uname,$enrolltypes->{$udom});
                }
            }
        }
    }
    if ($selfenroll) {
        my $usec = $selfenroll_section;
        if ($selfenroll_section eq 'none') {
            $usec = '';
        }
        if ($selfenroll_registered) {
            my ($registered,$instsec,$message) = &check_registered($cdom,$cnum);
            $usec = $instsec;
            if (!$registered) {
                $r->print('<h3>'.&mt('Self-enrollment unavailable').'</h3>'.&mt('Self-enrollment is restricted to students officially registered for this course.').'<br />');
                if ($message) {
                    $r->print($message);
                } else {
                    $r->print(&mt('As you are not currently registered for this course, self-enrollment is unavailable.'));
                }
                return; 
            } 
        }
        my $enrollresult = 
            &Apache::lonnet::modify_student_enrollment($udom,$uname,undef,undef,undef,
                    undef,undef,$usec,$selfenroll_access_end,$selfenroll_access_start,
                   'manual',undef,$cdom.'_'.$cnum,$selfenroll);
        if ($enrollresult eq 'ok') {
            my (%userroles,%newrole,%newgroups);
            my $role = 'st';
            my $area = '/'.$cdom.'/'.$cnum;
            my $spec = $role.'.'.$area;
            if ($usec ne '') {
                $spec .= '/'.$usec;
                $area .= '/'.$usec;
            }
            &Apache::lonnet::standard_roleprivs(\%newrole,$role,$cdom,$spec,$cnum,
                                                $area);
            &Apache::lonnet::set_userprivs(\%userroles,\%newrole,%newgroups);
            $userroles{'user.role.'.$spec} = $selfenroll_access_start.'.'.$selfenroll_access_end;
            &Apache::lonnet::appenv(\%userroles,[$role,'cm']);
            $r->print('<h3>'.&mt('Enrollment process complete').'</h3>');
            if ($selfenroll_access_end && $selfenroll_access_end <= $now) {
                $r->print(&mt('The end date for access to this course for users who self-enroll has passed.').'<br />'.&mt('Consequently, although a new role was created for you in the course, it is an inactive role which does not provide access to the course.'));
            } else {
                $r->print(&mt('Self-enrollment in this course was successful.').'<br />');
                my $showstart = &Apache::lonlocal::locallocaltime($selfenroll_access_start);
                my $showend = &Apache::lonlocal::locallocaltime($selfenroll_access_end);
                if ($selfenroll_access_start && $selfenroll_access_start >$now) {
                    $r->print(&mt('The start date for access to this course for users who self-enroll has yet to be reached.').'<br />'.&mt('Consequently, although a new role was created for you in the course, you will not be able to select this role until [_1].',$showstart));
                } else {
                    my $newrole = 'st./'.$cdom.'/'.$cnum;
                    if ($usec ne '') {
                        $newrole .= '/'.$usec;
                    }
                    my $rolelink = &jump_to_role($newrole);
                    $r->print(&mt('Your new role is available immediately, and will provide access to the course until [_1].',$showend).'<br /><br />'."\n".
                             $rolelink); 
                }
            }
        } else {
            $r->print('<h3>'.&mt('Enrollment incomplete').'</h3>'.
                      &mt('Self-enrollment in this course failed.'));
            if ($enrollresult ne '') {
                $r->print('<span class="LC_error">'.$enrollresult.'</span>');
            }
        }
    } else {
        $r->print('<h3>'.&mt('Self-enrollment unavailable').'</h3>'.
                  &mt('You are not permitted to enroll yourself in this course.').'<br />');
        $r->print(&print_selfenroll_types($longtypes));
    }
    return;
}

sub user_can_selfenroll {
    my ($udom,$uname,$domenrolltypes) = @_;
    my $selfenroll = 0;
    my %userhash = &Apache::lonnet::userenvironment($udom,$uname,'inststatus');
    my @inststatuses;
    if ($userhash{'inststatus'} eq '') {
        push(@inststatuses,'other');
    } else {
        @inststatuses = split(':',$userhash{'inststatus'});
    }
    foreach my $type (@inststatuses) {
        if (ref($domenrolltypes) eq 'ARRAY') {
            if (grep(/^\Q$type\E$/,@{$domenrolltypes})) {
                $selfenroll = 1;
                last;
            }
        }
    }
    return $selfenroll;
}

sub jump_to_role {
    my ($role) = @_;
    my $output = <<"END";
<script type="text/javascript">
function SelectRole() {
    document.rolechoice.selectrole.value = '1';
    document.rolechoice.submit();
}
</script>
END
    $output .= '<a href="javascript:SelectRole()">'."\n". 
               &mt('Enter course now').'</a>'."\n".
               '<form name="rolechoice" action="/adm/roles" method="post">'."\n".
               '<input type="hidden" name="selectrole" value="" />'."\n".
               '<input type="hidden" name="'.$role.'" value="1" />'."\n".
               '</form>';
    return $output;
}

sub get_selfenroll_filters {
    my ($selfenroll_types,$domain) = @_;
    my (%enrolltypes,%longtypes,$alldoms);
    my @selfenrolldoms = split(/;/,$selfenroll_types);
    foreach my $item (@selfenrolldoms) {
        my ($selfdom,$type_str) = split(/:/,$item);
        if ($selfdom eq '*') {
            $alldoms = 1;
            last;
        }
        if ($domain ne '') {
            next if ($selfdom ne $domain);
        }
        if ($selfdom =~ /^$match_domain$/) {
            if (&Apache::lonnet::domain($selfdom) ne '') {
                my @types = split(/,/,$type_str);
                my @unesc_types = map { &unescape($_); } @types;
                my ($othertitle,$usertypes,$types) =
                    &Apache::loncommon::sorted_inst_types($selfdom);
                if (ref($usertypes) eq 'HASH') {
                    my $anytype = 1;
                    foreach my $key (keys(%{$usertypes})) {
                        if (!grep(/^\Q$key\E$/,@unesc_types)) {
                            $anytype = 0;
                            last;
                        }
                    }
                    if ($anytype) {
                        if (!(grep(/^other$/,@types))) {
                            $anytype = 0;
                        }
                    }
                    $usertypes->{'any'} = &mt('Any users');
                    $usertypes->{'other'} = &mt('Others');
                    my @showtypes;
                    if ($anytype) {
                        @{$enrolltypes{$selfdom}} = ('any');
                        @showtypes =  ('any');
                    } else {
                        @{$enrolltypes{$selfdom}} = @types;
                        @showtypes = @unesc_types;
                    }
                    @{$longtypes{$selfdom}} = 
                        map {$usertypes->{$_}} @showtypes;
                }
            }
        }
    }
    return (\%enrolltypes,\%longtypes,$alldoms);
}

sub print_selfenroll_types {
    my ($longtypes,$domain) = @_;
    my $output;
    if (ref($longtypes) eq 'HASH') {
        if ($domain ne '') {
            my $domdesc = &Apache::lonnet::domain($domain,'description');
            if (ref($longtypes->{$domain}) eq 'ARRAY') {
                if (grep(/^any$/,@{$longtypes->{$domain}})) {
                    $output = &mt('Self-enrollment in this course is available to any user affiliated with [_1].',$domdesc);
                } else {
                    my $status_str = join(', ',@{$longtypes->{$domain}});
                    $output = &mt('Self-enrollment in this course is only available to users affiliated with [_1] who have the following status: "[_2]".',$domdesc,$status_str);
                }
            } else {
                $output = &mt('Self-enrollment is not currently available for this course for users affiliated with [_1].',$domdesc);
            }
        } elsif (keys(%{$longtypes}) > 0) {
            $output = &mt('Self-enrollment in this course is only available to users affiliated with the following institutions, and who have the required status:').' <ul>'."\n";
            foreach my $selfdom (sort(keys(%{$longtypes}))) {
                my $selfdomdesc = &Apache::lonnet::domain($selfdom,'description');
                if (ref($longtypes->{$selfdom}) eq 'ARRAY') {
                    $output .= '<li>'.$selfdomdesc.': '.join(', ',@{$longtypes->{$selfdom}}).'</li>'."\n";
                }
            }
            $output .= '</ul>'."\n";
        } else {
            $output = &mt('Self-enrollment is not currently available for this course.');
        }
    }
    return $output;
}

sub check_registered {
    my ($cdom,$cnum) = @_;
    my ($registered,$instsec,$message);
    my %settings = &Apache::lonnet::get('environment',['internal.coursecode',
                                        'internal.sectionnums',
                                        'internal.crosslistings'],$cdom,$cnum);
    my (@allcourses,%LC_code,%affiliates,%reply);
    &Apache::loncommon::get_institutional_codes(\%settings,\@allcourses,\%LC_code);
    if (@allcourses > 0) {
        @{$affiliates{$cnum}} = @allcourses;
        my $outcome = &Apache::lonnet::fetch_enrollment_query('updatenow',\%affiliates,\%reply,$cdom,$cnum);
        if ($outcome eq 'ok') {
            if ($reply{$cnum} > 0) {
                foreach my $class (@allcourses) {
                    my %enrolled;
                    my $dir = $Apache::lonnet::perlvar{'lonDaemons'};
                    my %place = &LONCAPA::Enrollment::place_hash();
                    &LONCAPA::Enrollment::parse_classlist($dir,$cdom,$cnum,$class,
                             \%place,$LC_code{$class},\%enrolled);
                    if (defined($enrolled{$env{'user.name'}})) {
                        $registered = 1;
                        $instsec = $LC_code{$class};
                        last;
                    }
                }
            } else {
                $message = &mt('Your registration status could not be verified.');
            }
        } else {
             $message = &mt('Your registration status could not determined, because a problem occurred retrieving data.');
        }
    } else {
        $message = &mt('As no institutional course sections are currently associated with this course, your registration status is undetermined.'); 
    }
    return ($registered,$instsec,$message);
}

1;