# Automated Enrollment manager
# $Id: Enrollment.pm,v 1.27 2006/01/12 01:30:44 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 LONCAPA::Enrollment;

use Apache::loncoursedata;
use Apache::lonnet;
use Apache::lonmsg;
use HTML::Entities;
use LONCAPA::Configuration;
use Time::Local;
use lib '/home/httpd/lib/perl';

use strict;

sub update_LC {
    my ($dom,$crs,$adds,$drops,$startdate,$enddate,$authtype,$autharg,$classesref,$groupref,$logmsg,$newusermsg,$context) = @_; 
# Get institutional code and title of this class
    my %courseinfo = ();
    &get_courseinfo($dom,$crs,\%courseinfo);
# Get current LON-CAPA student enrollment for this class
    my $configvars = &LONCAPA::Configuration::read_conf('loncapa.conf');
    my $cid = $dom."_".$crs;
    my $roster = &Apache::loncoursedata::get_classlist($dom,$crs);
    my $cend = &Apache::loncoursedata::CL_END;
    my $cstart = &Apache::loncoursedata::CL_START; 
    my $stuid=&Apache::loncoursedata::CL_ID;
    my $sec=&Apache::loncoursedata::CL_SECTION;
    my $status=&Apache::loncoursedata::CL_STATUS;
    my $type=&Apache::loncoursedata::CL_TYPE;
    my $lockedtype=&Apache::loncoursedata::CL_LOCKEDTYPE;
    my @localstudents = ();
    my @futurestudents = ();
    my @activestudents = ();
    my @excludedstudents = ();
    my $currlist;
    foreach my $uname (keys %{$roster} ) {
        if ($uname =~ m/^(.+):$dom$/) {
            if ($$roster{$uname}[$status] eq "Active") {
                push @activestudents, $1;
                @{$$currlist{$1}} = @{$$roster{$uname}};
                push @localstudents, $1;
            } elsif ( ($$roster{$uname}[$cstart] > time)  && ($$roster{$uname}[$cend] > time || $$roster{$uname}[$cend] == 0 || $$roster{$uname}[$cend] eq '') ) {
                push @futurestudents, $1;
                @{$$currlist{$1}} = @{$$roster{$uname}};
                push @localstudents, $1;
            } elsif ($$roster{$uname}[$lockedtype] == 1) {
                push @excludedstudents, $1;
            }
        }
    }
    my $linefeed = '';
    my $addresult = '';
    my $dropresult = '';
    my $switchresult = '';
    if ($context eq "updatenow") {
        $linefeed = "</li>\n<li>"; 
    } elsif ($context eq "automated") {
        $linefeed = "\n";
    }
    my $enrollcount = 0;
    my $dropcount = 0;
    my $switchcount = 0;

# Get role names
    my %longroles = ();
    open(FILE,"<$$configvars{'lonTabDir'}.'/rolesplain.tab");
    my @rolesplain = <FILE>;
    close(FILE);
    foreach (@rolesplain) {
        if ($_ =~ /^(st|ta|ex|ad|in|cc):([\w\s]+)$/) {
            $longroles{$1} = $2;
        }
    }

    srand( time() ^ ($$ + ($$ << 15))  ); # Seed rand in case initial passwords have to be generated for new users.

# Get mapping of IDs to usernames for current LON-CAPA student enrollment for this class 
    my @LCids = ();
    my %unameFromLCid = ();
    foreach my $uname (sort keys %{$currlist}) {
        my $stuID = $$currlist{$uname}[$stuid];
        if (!grep/^$stuID$/,@LCids) {
            push @LCids, $stuID;
            @{$unameFromLCid{$stuID}} = ();
        }
        push @{$unameFromLCid{$stuID}},$uname;
    }
 
# Get latest institutional enrollment for this class.
    my %allenrolled = ();
    my @reg_students = ();
    my %place = ();
    $place{'autharg'} = &CL_autharg();
    $place{'authtype'} = &CL_authtype();
    $place{'email'} = &CL_email();
    $place{'enddate'} = &CL_enddate();
    $place{'firstname'} = &CL_firstname();
    $place{'generation'} = &CL_generation();
    $place{'groupID'} = &CL_groupID();
    $place{'lastname'} = &CL_lastname();
    $place{'middlename'} = &CL_middlename();
    $place{'startdate'} = &CL_startdate();
    $place{'studentID'} = &CL_studentID();
    my %ucount = ();
    my %enrollinfo = ();
    foreach my $class (@{$classesref}) {
        my %enrolled = ();
        &parse_classlist($$configvars{'lonDaemons'},$dom,$crs,$class,\%place,$$groupref{$class},\%enrolled);
        foreach my $uname (sort keys %enrolled ) {
            if (!grep/^$uname$/,@reg_students) {
                push @reg_students,$uname;
                $ucount{$uname} = 0;
                @{$allenrolled{$uname}} = ();
            }
            @{$allenrolled{$uname}[$ucount{$uname}]} = @{$enrolled{$uname}};
            $ucount{$uname} ++;
        }
    }

# Check for multiple sections for a single student 
    my @okusers = ();
    foreach my $uname (@reg_students)  {
        if (grep/^$uname$/,@excludedstudents) {
            $$logmsg .= "No re-enrollment for $uname - user was previously manually unenrolled and locked.".$linefeed;
        } elsif (@{$allenrolled{$uname}} > 1) {
            my @sections = ();
            my $saved;
            for (my $i=0; $i<@{$allenrolled{$uname}}; $i++) {
                my @stuinfo = @{$allenrolled{$uname}[$i]};
                my $secnum = $stuinfo[ $place{'groupID'} ];
                unless ($secnum eq '') {
                    unless (grep/^$secnum$/,@sections) {
                        $saved = $i; 
                        push @sections,$secnum;
                    }
                }
            }
            if (@sections == 0) {
                @{$enrollinfo{$uname}} = @{$allenrolled{$uname}[0]};
                push @okusers, $uname;
            }
            elsif (@sections == 1) {
                @{$enrollinfo{$uname}} = @{$allenrolled{$uname}[$saved]};
                push @okusers, $uname;
            }
            elsif (@sections > 1) {
                $$logmsg .=  "$uname appears in classlists for more than one section of this course, i.e. in sections: ";
                foreach (@sections) {
                    $$logmsg .= " $_,";
                }
                chop($$logmsg);
                $$logmsg .= ". Because of this ambiguity, no enrollment action was taken for this student.".$linefeed;
            }
        } else {
            @{$enrollinfo{$uname}} = @{$allenrolled{$uname}[0]};
            push @okusers, $uname;
        }
    }
# Get mapping of student IDs to usernames for users in institutional data for this class  
    my @allINids = ();
    my %unameFromINid = ();
    foreach my $uname (@okusers) {
        $enrollinfo{$uname}[ $place{'studentID'} ] =~ tr/A-Z/a-z/;
        my $stuID = $enrollinfo{$uname}[ $place{'studentID'} ];
        if (grep/^$stuID$/,@allINids)  {
            push @{$unameFromINid{$stuID}},$uname;
        } else {
            push @allINids, $stuID;
            @{$unameFromINid{$stuID}} = $uname; 
        }
    }
# Explicitly allow access to creation/modification of students if called as an automated process.
    if ($context eq 'automated') {
        $env{'allowed.cst'}='F';
    }

# Compare IDs with existing LON-CAPA enrollment for this class
    foreach my $uname (@okusers) {
        unless ($uname eq '') {
            my %uidhash=&Apache::lonnet::idrget($dom,$uname);
            my @stuinfo = @{$enrollinfo{$uname}};
            my $access = '';
            if (grep/^$uname$/,@localstudents) {
# Check for studentID changes
                if ( ($uidhash{$uname}) && ($uidhash{$uname} !~ /error\:/) )  {
                    unless ( ($uidhash{$uname}) eq ($stuinfo[ $place{studentID} ]) ) {
                        $$logmsg .= "Change in ID for $uname. StudentID in LON-CAPA system is $uidhash{$uname}; StudentID in institutional data is $stuinfo[ $place{studentID} ]".$linefeed; 
                    }
                }
# Check for switch from manual to auto
                unless (($$currlist{$uname}[$type] eq "auto") || ($$currlist{$uname}[$lockedtype] eq "1") || (!$adds) ) {
# drop manually added student
                    my $drop_reply = &Apache::lonnet::modifystudent($dom,$uname,'','','',undef,undef,undef,undef,$$currlist{$uname}[$sec],time,undef,undef,undef,undef,'auto','',$cid);
# re-enroll as auto student
                    if ($drop_reply !~ /^ok/) {
                            $$logmsg .= "An error occured during the attempt to convert $uname from a manual type to an auto type student - $drop_reply.".$linefeed;
                    } else {
# re-enroll as auto student
                        my ($auth,$authparam,$first,$middle,$last,$gene,$usec,$end,$start,$emailaddr,$pid,$emailenc);
                        &prepare_add($authtype,$autharg,$enddate,$startdate,\@stuinfo,\%place,\$dom,\$uname,\$auth,\$authparam,\$first,\$middle,\$last,\$gene,\$usec,\$end,\$start,\$emailaddr,\$pid,\$emailenc);
                        if ($$currlist{$uname}[$sec] ne $usec) {
                            $switchresult .= "Section for $uname switched from $$currlist{$uname}[$sec] to ".$usec.$linefeed;
                            if ($context eq 'automated') {
                                $$logmsg .= "Section switch for $uname from $$currlist{$uname}[$sec] to ".$usec.$linefeed; ;
                            }
                            $switchcount ++;
                        }
                        &execute_add($context,'switchtype',$uname,$dom,$auth,$authparam,$first,$middle,$last,$gene,$pid,$usec,$end,$start,$emailenc,$cid,\$addresult,\$enrollcount,$linefeed,$logmsg);
                    }
                } 
# Check for section changes
                if ($$currlist{$uname}[$sec] eq $stuinfo[ $place{groupID} ]) {
# Check for access date changes for students with access starting in the future.
                    if ( (grep/^$uname$/,@futurestudents) && ($$currlist{$uname}[$type] eq "auto") && ($adds == 1) ) {
                        my $datechange = &datechange_check($$currlist{$uname}[$cstart],$$currlist{$uname}[$cend],$startdate,$enddate);
                        if ($datechange) {
                            my $modify_access_result = &Apache::lonnet::modify_student_enrollment($dom,$uname,undef,undef,undef,undef,undef,$stuinfo[ $place{groupID} ],$enddate,$startdate,'auto','',$cid);
                            $access = &showaccess($enddate,$startdate);
                            if ($modify_access_result =~ /^ok/) {
                                $$logmsg .= "Change in access dates for $uname.".$access.$linefeed;
                            } else {
                                $$logmsg .= "Error when attempting to change start and/or end access dates for $uname in section: ".$stuinfo[ $place{groupID} ]." -error $modify_access_result".$linefeed;
                            }
                        }
                    }
                } else {
                    if ( ($$currlist{$uname}[$type] eq "auto") && ($adds == 1) ) {
# Delete from roles.db for current section
                        my $expiretime = time;
                        my $uurl='/'.$cid;
                        $uurl=~s/\_/\//g;
                        if ($$currlist{$uname}[$sec]) {
                            $uurl.='/'.$$currlist{$uname}[$sec];
                        }
                        my $expire_role_result = &Apache::lonnet::assignrole($dom,$uname,$uurl,'st',$expiretime);
                        if ($expire_role_result eq 'ok') {
                            my $modify_section_result;
                            if (grep/^$uname$/,@activestudents) {
                                $modify_section_result = &Apache::lonnet::modify_student_enrollment($dom,$uname,undef,undef,undef,undef,undef,$stuinfo[ $place{groupID} ],$$currlist{$uname}[$cend],$$currlist{$uname}[$cstart],'auto','',$cid);
                            } else {
                                $modify_section_result =  &Apache::lonnet::modify_student_enrollment($dom,$uname,undef,undef,undef,undef,undef,$stuinfo[ $place{groupID} ],$enddate,$startdate,'auto','',$cid);
                                $access =  &showaccess($enddate,$startdate);
                            }
                            if ($modify_section_result =~ /^ok/) {
                                $switchresult .= "Section for $uname switched from old section: ".$$currlist{$uname}[$sec] ." to new section: ".$stuinfo[ $place{groupID} ].".".$access.$linefeed;
                                if ($context eq 'automated') {
                                    $$logmsg .= "Section switch for $uname from $$currlist{$uname}[$sec] to $stuinfo[ $place{groupID} ]".$linefeed;
                                }
                                $switchcount ++;
                            } else {
                                $$logmsg .= "Error when attempting section change for $uname from old section ".$$currlist{$uname}[$sec]." to new section: ".$stuinfo[ $place{groupID} ]." -error: $modify_section_result".$linefeed;
                            }
                        } else {
                            $$logmsg .= "Error when attempting to expire role for $uname in old section" .$$currlist{$uname}[$sec]." -error: $expire_role_result".$linefeed;
                        }
                    }
                }
            } else {
# Check for changed usernames by checking studentIDs
                if ( ($stuinfo[ $place{studentID} ] ne '') && (grep/^$stuinfo[ $place{studentID} ]$/,@LCids) ) {
                    foreach my $match ( @{ $unameFromLCid{ $stuinfo[ $place{studentID} ] } }  ) {
                        $$logmsg .= "A possible change in username has been detected for a student enrolled in this course. The existing LON-CAPA classlist contains user: $match and student ID: ".$stuinfo[ $place{studentID} ].". ";
                        if (grep/^$match$/,@okusers) {
                            $$logmsg .= "The username $match remains in the institutional classlist, but the same student ID is used for new user: $uname now found in the institutional classlist. You may need to contact your Domain Coordinator to determine how to reolve this issue and whether to move student data files for user: $match to $uname. ";
                        } else {
                            unless ($drops == 1) {
                                $$logmsg .= "This username - $match - has been dropped from the institutional classlist, but the student ID of this user is also used by $uname who now appears in the institutional classlist. You may need to contact your Domain Coordinator to request a move of the student data files for user: $match to $uname. ";
                            }
                        }
                        $$logmsg .= "Because of this student ID conflict, the new username - $uname - has not been added to the LON-CAPA classlist.".$linefeed;      
                    }
                } elsif ($adds == 1) {
                    my ($auth,$authparam,$first,$middle,$last,$gene,$usec,$end,$start,$emailaddr,$pid,$emailenc);
                    &prepare_add($authtype,$autharg,$enddate,$startdate,\@stuinfo,\%place,\$dom,\$uname,\$auth,\$authparam,\$first,\$middle,\$last,\$gene,\$usec,\$end,\$start,\$emailaddr,\$pid,\$emailenc);
# Check for existing account in this LON-CAPA domain for this username
                    my $uhome=&Apache::lonnet::homeserver($uname,$dom);
                    if ($uhome eq 'no_host') { # User does not exist
                        my $args = {'auth' => $auth,
                                    'authparam' => $authparam,
                                    'emailenc' => $emailenc,
                                    'udom' => $dom,
                                    'uname' => $uname,
                                    'pid' => $pid,
                                    'first' => $first,
                                    'middle' => $middle,
                                    'last' => $last,
                                    'gene' => $gene,
                                    'usec' => $usec,
                                    'end' => $end,
                                    'start' => $start,
                                    'emailaddr' => $emailaddr,
                                    'cid' => $cid,
                                    'crs' => $crs,
                                    'cdom' => $dom,
                                    'context' => $context,
                                    'linefeed' => $linefeed,
                                    'role' => 'st'
                                   };
                        my $outcome = &create_newuser($args,$logmsg,$newusermsg,\$enrollcount,\$addresult,\%longroles,\%courseinfo);
                    } else {
                        &execute_add($context,'newstudent',$uname,$dom,$auth,$authparam,$first,$middle,$last,$gene,$pid,$usec,$end,$start,$emailenc,$cid,\$addresult,\$enrollcount,$linefeed,$logmsg);
                    }
                }
            }
        }
    }
# Do drops
    if ( ($drops == 1) && (@reg_students > 0) ) {
        foreach my $uname (@localstudents) {
            if ($$currlist{$uname}[$type] eq "auto") {
                my @saved = ();
                if (!grep/^$uname$/,@reg_students) {
# Check for changed usernames by checking studentIDs
                    if (grep/^$$currlist{$uname}[ $stuid ]$/,@allINids) {
                        foreach my $match (@{$unameFromINid{$$currlist{$uname}[ $stuid ]}} ) {
                            $$logmsg .= "A possible change in username has been detected for a student enrolled in this course. The existing LON-CAPA classlist contains user: $uname and student ID: $$currlist{$uname}[ $place{studentID} ].  This username has been dropped from the institutional classlist, but the same student ID is used for user: $match who still appears in the institutional classlist. You may need to move the student data files for user: $uname to $match. Because of this, user $uname has not been dropped from the course.".$linefeed;
                            push @saved,$uname;
                        }
                    } elsif (@saved == 0) {
                        my $drop_reply = &Apache::lonnet::modifystudent($dom,$uname,'','','',undef,undef,undef,undef,$$currlist{$uname}[$sec],time,undef,undef,undef,undef,'auto','',$cid);
                        if ($drop_reply !~ /^ok/) {
                            $$logmsg .= "An error occured during the attempt to expire the $uname from the old section $$currlist{$uname}[$sec] - $drop_reply.".$linefeed;
                        } else {
                            $dropcount ++;
                            my %userenv = &Apache::lonnet::get('environment',['firstname','lastname','id'],$dom,$uname);
                            $dropresult .= $userenv{'firstname'}." ".$userenv{'lastname'}." (".$userenv{'id'}.") - ".$uname." dropped from section/group ".$$currlist{$uname}[$sec].$linefeed; 
                            if ($context eq 'automated') {
                                $$logmsg .= "User $uname student role expired from course.".$linefeed;
                            }
                        }
                    }
                }
            }
        }
    }

# Terminated explictly allowed access to student creation/modification
    if ($context eq 'automated') {
        delete($env{'allowed.cst'});
    }
    if ($enrollcount > 0) {
        if ($context eq "updatenow") {
            $addresult = substr($addresult,0,rindex($addresult,"<li>"));
            $addresult = "The following $enrollcount student(s) was/were added to this LON-CAPA course:<br/><ul><li>".$addresult."</ul><br/><br/>";
        } else {
            $addresult = "The following $enrollcount student(s) was/were added to this LON-CAPA course:\n\n".$addresult."\n\n";
        }
    }
    if ($dropcount > 0) {
        if ($context eq "updatenow") {
            $dropresult = substr($dropresult,0,rindex($dropresult,"<li>"));
            $dropresult = "The following $dropcount student(s) was/were expired from this LON-CAPA course:<br/><ul><li>".$dropresult."</ul><br/><br/>";
        } else {
            $dropresult = "The following $dropcount student(s) was/were expired from this LON-CAPA course:\n\n".$dropresult."\n\n";
        }
    }
    if ($switchcount > 0) {
        if ($context eq "updatenow") {
            $switchresult = substr($switchresult,0,rindex($switchresult,"<li>"));
            $switchresult = "The following $switchcount student(s) switched sections in this LON-CAPA course:<br/><ul><li>".$switchresult."</ul><br/><br/>";
        } else {
            $switchresult = "The following $switchcount student(s) switched sections in this LON-CAPA course:\n\n".$switchresult."\n\n";
        }
    }
    if ( ($adds) && ($enrollcount == 0) ) {
        $addresult = "There were no new students to add to the course.";
        if ($context eq "updatenow") {
            $addresult .="<br/><br/>";
        } else {
            $addresult .="\n";
        }
    }
    if ( ($drops) && ($dropcount == 0) ) {
        $dropresult = "There were no students with roles to expire because all active students previously added to the course from institutional classlist(s) are still officially registered.";
        if ($context eq "updatenow") {
            $dropresult .="<br/>";
        } else {
            $dropresult .="\n";
        }
    }
    my $changecount = $enrollcount + $dropcount + $switchcount;
    return ($changecount,$addresult.$dropresult.$switchresult);
}

sub create_newuser {
    my ($args,$logmsg,$newusermsg,$enrollcount,$addresult,$longroles,$courseinfo) = @_;
    my $auth = $args->{'auth'};
    my $authparam = $args->{'authparam'};
    my $emailenc = $args->{'emailenc'};
    my $udom = $args->{'udom'};
    my $uname = $args->{'uname'};
    my $pid = $args->{'pid'};
    my $first = $args->{'first'};
    my $middle = $args->{'middle'};
    my $last = $args->{'last'} ;
    my $gene = $args->{'gene'};
    my $usec = $args->{'usec'};
    my $end = $args->{'end'};
    my $start = $args->{'start'};
    my $emailaddr = $args->{'emailaddr'};
    my $cid = $args->{'cid'};
    my $crs = $args->{'crs'};
    my $cdom = $args->{'cdom'};
    my $context = $args->{'context'};
    my $linefeed = $args->{'linefeed'};
    my $role = $args->{'role'};
    my $create_passwd = 0;
    my $authchk = '';
    my $outcome;
    unless ($authparam eq '') { $authchk = 'ok'; };
# If no account exists and passwords should be generated
    if ($auth eq "internal") {
        if ($authparam eq '') {
            $authparam = &create_password();
            if ($authparam eq '') {
                $authchk = '';
            } else {
                $create_passwd = 1;
                $authchk = 'ok';
            }
        }
    } elsif ($auth eq "localauth") {
        ($authparam,$create_passwd,$authchk) = &Apache::lonnet::auto_create_password($crs,$cdom,$authparam);
    } elsif ($auth =~ m/^krb/) {
        if ($authparam eq '') {
            $$logmsg .= "No Kerberos domain was provided for the new user - $uname, so the new user was not enrolled in the course.".$linefeed;
            $authchk = 'invalid';
        }
    } else {
        $authchk = 'invalid';
        $$logmsg .= "An invalid authentication type was provided for the new user - $uname, so the user was not enrolled in the course.".$linefeed;
    }   
    if ($authchk eq 'ok') {
# Now create user.
        my $type = 'auto';
        my $userurl = '/'.$cdom.'/'.$crs;
        if ($usec ne '') {
            $userurl .= '/'.$usec;
        }
        if ($context eq 'createowner' || $context eq 'createcourse') {
            my $result = &Apache::lonnet::modifyuser($udom,$uname,$pid,$auth,$authparam,$first,$middle,$last,$gene,'1',undef,$emailaddr);
            if ($result eq 'ok' && $context eq 'createcourse') {
                $outcome = &Apache::loncreateuser::commit_standardrole($udom,$uname,$userurl,$role,$start,$end,$cdom,$crs,$usec);
                unless ($outcome =~ /^Error:/) {
                    $outcome = 'ok';
                }
            } else {
                $outcome = $result;
            }
        } else {
            $outcome=&Apache::lonnet::modifystudent($udom,$uname,$pid,$auth,$authparam,$first,$middle,$last,$gene,$usec,$end,$start,'',undef,$emailaddr,'auto','',$cid);
        }
        if ($outcome eq 'ok') {
            my $access = &showaccess($end,$start);
            $$addresult .= "$first $last ($pid) - $uname enrolled in section/group $usec.".$access.$linefeed;
            unless ($context eq 'createowner' || $context eq 'createcourse') {
                $$enrollcount ++;
            }
            if ($context eq 'automated') {
                $$logmsg .= "New $udom user $uname added successfully.";
            }
            unless ($emailenc eq '' || $context eq 'createowner' || $context eq 'createcourse') {
                my %emailHash;
                $emailHash{'critnotification'}  = $emailenc;
                $emailHash{'notification'} = $emailenc;
                $emailHash{'permanentemail'} = $emailenc;
                my $putresult = &Apache::lonnet::put('environment',\%emailHash,$udom,$uname);
            }
            if ($create_passwd) {
# Send e-mail with initial password to new user at $emailaddr.
# If e-mail address is invalid, send password via message to courseowner i
# (if automated call) or to user if roster update.
                if ($emailaddr eq '') {
                    $$newusermsg .= " username: $uname, password: ".$authparam.$linefeed."\n";
                } else {
                    my $subject = "New LON-CAPA account";
                    my $body;
                    if ($context eq 'createowner') {
                        $body = "A user account has been created for you while creating your new course in the LON-CAPA course management and online homework system.\n\nYou should log-in to the system using the following credentials:\nusername: $uname\npassword: $authparam\n\nThe URL you should use to access the LON-CAPA system at your school is: http://".$ENV{'SERVER_NAME'}."\n\n";
                    } elsif ($context eq 'createcourse') {
                        $body = "You have been assigned the role of $$longroles{$role} in a new course: $$courseinfo{'description'} - $$courseinfo{'inst_code'} in the LON-CAPA course management and online homework system.  As you did not have an existing user account in the system, one has been created for you.\n\nYou should log-in to the system using the following credentials:\nusername: $uname\npassword: $authparam\n\nThe URL you should use to access the LON-CAPA system at your school is: http://".$ENV{'SERVER_NAME'}."\n\n"; 
                    } else {
                        my $access_start = 'immediately';
                        if ($start > 0) {
                            $access_start = localtime($start)
                        }
                        $body = "You have been enrolled in the LON-CAPA system at your school, because you are a registered student in a class that is using the LON-CAPA couse management and online homework system.\n\nYou should log-in to the system using the following credentials:\nusername: $uname\npassword: $authparam\n\nThe URL you should use to access the LON-CAPA system at your school is: http://".$ENV{'SERVER_NAME'}."\n\n.When you log-in you will be able to access the LON-CAPA course for $$courseinfo{'description'} - $$courseinfo{'inst_code'} starting $access_start.\n";
                    }
                    &Apache::lonmsg::sendemail($emailaddr,$subject,$body);
                }
                if ($context eq 'automated') {
                    $$logmsg .= " Initial password -  - sent to ".$emailaddr.$linefeed;
                }
            } else {
                if ($context eq 'automated') {
                    $$logmsg .= $linefeed;
                }
            }
        } else {
            $$logmsg .= "An error occurred adding new user $uname - ".$outcome.$linefeed;
        }
    }
    return $outcome;
}

sub prepare_add {
    my ($authtype,$autharg,$enddate,$startdate,$stuinfo,$place,$dom,$uname,$auth,$authparam,$first,$middle,$last,$gene,$usec,$end,$start,$emailaddr,$pid,$emailenc) = @_;
    $$auth = $$stuinfo[ $$place{'authtype'} ];
    $$authparam = $$stuinfo[ $$place{'autharg'} ];
    $$first = $$stuinfo[ $$place{'firstname'} ];
    $$middle = $$stuinfo[ $$place{'middlename'} ];
    $$last = $$stuinfo[ $$place{'lastname'} ];
    $$gene = $$stuinfo[ $$place{'generation'} ];
    $$usec = $$stuinfo[ $$place{'groupID'} ];
    $$end = $$stuinfo[ $$place{'enddate'} ];
    $$start = $$stuinfo[ $$place{'startdate'} ];
    $$emailaddr = $$stuinfo[ $$place{'email'} ];
    $$pid = $$stuinfo[ $$place{'studentID'} ];
                                                                                  
# remove non alphanumeric values from section
    $$usec =~ s/\W//g;
                                                                                  
    unless ($$emailaddr =~/^[^\@]+\@[^\@]+$/) { $$emailaddr =''; }
    $$emailenc = &HTML::Entities::encode($$emailaddr,'<>&"');
                                                                                  
# Use course defaults where entry is absent
    if ( ($$auth eq '') || (!defined($$auth)) ) {
        $$auth =  $authtype;
    }
    if ( ($$authparam eq '')  || (!defined($$authparam)) )  {
        $$authparam = $autharg;
    }
    if ( ($$end eq '') || (!defined($$end)) )  {
        $$end = $enddate;
    }
    if ( ($$start eq '')  || (!defined($$start)) )  {
        $$start = $startdate;
    }
# Clean up whitespace
    foreach ($dom,$uname,$pid,$first,$middle,$last,$gene,$usec) {
        $$_ =~ s/(\s+$|^\s+)//g;
    }
    return;
}

sub execute_add {
    my ($context,$caller,$uname,$dom,$auth,$authparam,$first,$middle,$last,$gene,$pid,$usec,$end,$start,$emailenc,$cid,$addresult,$enrollcount,$linefeed,$logmsg) = @_;
# Get the user's information and authentication
    my %userenv = &Apache::lonnet::get('environment',['firstname','middlename','lastname','generation','id','critnotification','notification','permanentemail'],$dom,$uname);
    my ($tmp) = keys(%userenv);
    if ($tmp =~ /^(con_lost|error)/i) {
        %userenv = ();
    }
# Get the user's e-mail address
    if ($userenv{critnotification} =~ m/%40/) {
        unless ($emailenc eq $userenv{critnotification}) {
            $$logmsg .= "Current critical notification e-mail
- ".$userenv{critnotification}." for $uname is different to e-mail address in institutional classlist - ".$emailenc.$linefeed;
        }
    }
    if ($userenv{notification} =~ m/%40/) {
        unless ($emailenc eq $userenv{notification}) {
            $$logmsg .= "Current standard notification e-mail
- ".$userenv{notification}." for $uname is different to e-mail address in institutional classlist - ".$emailenc.$linefeed;
        }
    }
    if ($userenv{permanentemail} =~ m/%40/) {
        unless ($emailenc eq $userenv{permanentemail}) {
            $$logmsg .= "Current permanent e-mail
- ".$userenv{permanentemail}." for $uname is different to e-mail address in institutional classlist - ".$emailenc.$linefeed;
        }
    }
    my $krbdefdom = '';
    my $currentauth=&Apache::lonnet::queryauthenticate($uname,$dom);
    if ($currentauth=~/^(krb[45]):(.*)/) {
        $currentauth = $1;
        $krbdefdom = $2;
    } elsif ($currentauth=~ /^(unix|internal|localauth):/) {
        $currentauth = $1;
    } else {
        $$logmsg .= "Invalid authentication method $currentauth for $uname.".$linefeed;
    }
# Report if authentication methods are different.
    if ($currentauth ne $auth) {
        $$logmsg .= "Authentication type mismatch for $uname - '$currentauth' in system, '$auth' based on information in classlist or default for this course.".$linefeed;
    } elsif ($auth =~ m/^krb/) {
        if ($krbdefdom ne $authparam) {
            $$logmsg .= "Kerberos domain mismatch for $uname - '$krbdefdom' in system, '$authparam' based on information in classlist or default for this course.".$linefeed;
        }
    }
                                                                                  
# Check user data
    if ($first  ne $userenv{'firstname'}  ||
        $middle ne $userenv{'middlename'} ||
        $last   ne $userenv{'lastname'}   ||
        $gene   ne $userenv{'generation'} ||
        $pid    ne $userenv{'id'} ||
        $emailenc ne $userenv{'permanentemail'} ) {
# Make the change(s)
        my %changeHash;
        $changeHash{'firstname'}  = $first;
        $changeHash{'middlename'} = $middle;
        $changeHash{'lastname'}   = $last;
        $changeHash{'generation'} = $gene;
        $changeHash{'id'} = $pid;
        $changeHash{'permanentemail'} = $emailenc;
        my $putresult = &Apache::lonnet::put('environment',\%changeHash,$dom,$uname);
        if ($putresult eq 'ok') {
            $$logmsg .= "User information updated for user: $uname prior to enrollment.".$linefeed;
        } else {
            $$logmsg .= "There was a problem modifying user data for existing user - $uname -error: $putresult, enrollment will still be attempted.".$linefeed;
        }
    }
                                                                                  
# Assign the role of student in the course.
    my $classlist_reply = &Apache::lonnet::modify_student_enrollment($dom,$uname,$pid,$first,$middle,$last,$gene,$usec,$end,$start,'auto','',$cid);
    if ($classlist_reply eq 'ok') {
        my $access = &showaccess($end,$start);
        if ($caller eq 'switchtype') {
            $$logmsg .= "Existing user $uname detected in institutional classlist - switched from 'manual' to 'auto' enrollment in section/group $usec.".$access.$linefeed;
        } elsif ($caller eq 'newstudent') {
            $$enrollcount ++;
            $$addresult .= "$first $last ($pid) - $uname enrolled in section/group $usec.".$access.$linefeed;
        }
        if ($context eq 'automated') {
            $$logmsg .= "Existing $dom user $uname enrolled successfully.".$linefeed;
        }
    } else {
           $$logmsg .= "There was a problem updating the classlist db file for user $uname to show the new enrollment -error: $classlist_reply, so no enrollment occurred for this user.".$linefeed;
    }
    return;
}

sub datechange_check {
    my ($oldstart,$oldend,$startdate,$enddate) = @_;
    my $datechange = 0;
    unless ($oldstart eq $startdate) {
        $datechange = 1;
    }
    if (!$datechange) {
        if (!$oldend) {
            if ($enddate) {
                $datechange = 1;
            }
        } elsif ($oldend ne $enddate) {
            $datechange = 1;
        }
    }
    return $datechange;
}

sub showaccess {
    my ($end,$start) = @_;
    my $showstart;
    my $showend;
    if ( (!$start) || ($start <= time) ) {
        $showstart = 'immediately';
    } else {
        $showstart = &Apache::lonlocal::locallocaltime($start);
    }
    if (!$end) {
        $showend = 'no end date';
    } else {
        $showend = &Apache::lonlocal::locallocaltime($end);
    }
    my $access_msg = " Access starts: ".$showstart.", ends: ".$showend.".";
    return $access_msg;
}

sub parse_classlist {
    my ($tmpdir,$dom,$crs,$class,$placeref,$groupID,$studentsref) = @_;
    my $xmlfile = $tmpdir."/tmp/".$dom."_".$crs."_".$class."_classlist.xml";
    my $uname = '';
    my @state;
    my @items = ('autharg','authtype','email','firstname','generation','lastname','middlename','studentID');
    my $p = HTML::Parser->new
    (
        xml_mode => 1,
        start_h =>
            [sub {
                 my ($tagname, $attr) = @_;
                 push @state, $tagname;
                 if ("@state" eq "students student") {
                     $uname = $attr->{username};
                 }
            }, "tagname, attr"],
         text_h =>
             [sub {
                 my ($text) = @_;
                 if ("@state" eq "students student groupID") {
                     $$studentsref{$uname}[ $$placeref{'groupID'} ] = $groupID;
                 } elsif ("@state" eq "students student startdate") {
                     my $start = $text;
                     unless ($text eq '') {
                         $start = &process_date($text);
                     }
                     $$studentsref{$uname}[ $$placeref{'startdate'} ] = $start; 
                 } elsif ("@state" eq "students student enddate") {
                     my $end = $text;
                     unless ($text eq '') {
                         $end = &process_date($text);
                     }
                     $$studentsref{$uname}[ $$placeref{'enddate'} ] = $end;
                 } else {
                     foreach my $item (@items) {
                         if ("@state" eq "students student $item") {
                             $$studentsref{$uname}[ $$placeref{$item} ] = $text;
                         }
                     }
                 }
               }, "dtext"],
         end_h =>
               [sub {
                   my ($tagname) = @_;
                   pop @state;
                }, "tagname"],
    );
                                                                                                             
    $p->parse_file($xmlfile);
    $p->eof;
    if (-e "$xmlfile") {
        unlink $xmlfile;
    }
    return;
}

sub process_date {
    my $timestr = shift;
    my $timestamp = '';
    if ($timestr =~ m/^\d{4}:\d{2}:\d{2}/) {
        my @entries = split/:/,$timestr;
        for (my $j=0; $j<@entries; $j++) {
            if ( length($entries[$j]) > 1 ) {
                $entries[$j] =~ s/^0//;
            }
        }
        $entries[1] = $entries[1] - 1;
        $timestamp =  timelocal($entries[5],$entries[4],$entries[3],$entries[2],$entries[1],$entries[0]);
    }
    return $timestamp;
}

sub create_password {
    my $passwd = '';
    my @letts = ("a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z");
    for (my $i=0; $i<8; $i++) {
        my $lettnum = int (rand 2);
        my $item = '';
        if ($lettnum) {
            $item = $letts[int( rand(26) )];
            my $uppercase = int(rand 2);
            if ($uppercase) {
                $item =~ tr/a-z/A-Z/;
            }
        } else {
            $item = int( rand(10) );
        } 
        $passwd .= $item;
    }
    return ($passwd);
}

sub get_courseinfo {
    my ($dom,$crs,$courseinfo) = @_;
    my $owner;
    if (defined($dom) && defined($crs)) {
        my %settings = &Apache::lonnet::get('environment',['internal.coursecode','description'],$dom,$crs);
        if ( defined($settings{'internal.coursecode'}) ) {
            $$courseinfo{'inst_code'} = $settings{'internal.coursecode'};

        }
        if ( defined($settings{'description'}) ) {
            $$courseinfo{'description'} = $settings{'description'};
        }
    }
    return;
}

sub CL_autharg { return 0; }
sub CL_authtype { return 1;}
sub CL_email { return 2;}
sub CL_enddate { return 3;}
sub CL_firstname { return 4;}
sub CL_generation { return 5;}
sub CL_groupID { return 6;}
sub CL_lastname { return 7;}
sub CL_middlename { return 8;}
sub CL_startdate { return 9; }
sub CL_studentID { return 10; }

1;