# Automated Enrollment manager
# $Id: Enrollment.pm,v 1.36 2007/08/03 22:02:01 albertel 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::loncommon();
use Apache::lonmsg;
use Apache::lonlocal;
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,$context,$phototypes) = @_; 
# 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 = '';
    my $photoresult = '';
    if ($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) {
            $$logmsg .= &mt('No re-enrollment for [_1] - user was previously manually unenrolled and locked.',$uname).$linefeed;
        } elsif (@{$allenrolled{$uname}} > 1) {
            my @sections = ();
            my $saved;
            for (my $i=0; $i<@{$allenrolled{$uname}}; $i++) {
                my @stuinfo = @{$allenrolled{$uname}[$i]};
                my $secnum = $stuinfo[ $place{'groupID'} ];
                unless ($secnum eq '') {
                    unless (grep/^$secnum$/,@sections) {
                        $saved = $i; 
                        push @sections,$secnum;
                    }
                }
            }
            if (@sections == 0) {
                @{$enrollinfo{$uname}} = @{$allenrolled{$uname}[0]};
                push @okusers, $uname;
            }
            elsif (@sections == 1) {
                @{$enrollinfo{$uname}} = @{$allenrolled{$uname}[$saved]};
                push @okusers, $uname;
            }
            elsif (@sections > 1) {
                $$logmsg .=  &mt('[_1] appears in classlists for more than one section of this course, i.e. in sections: ',$uname);
                foreach (@sections) {
                    $$logmsg .= " $_,";
                }
                chop($$logmsg);
                $$logmsg .= '. '.&mt('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} ]) ) {
                        $$logmsg .= &mt('Change in ID for [_1]. StudentID in LON-CAPA system is [_2]; StudentID in institutional data is [_3].',$uname,$uidhash{$uname},$stuinfo[ $place{studentID} ]).$linefeed; 
                    }
                }
# Check for switch from manual to auto
                unless (($$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/) {
                            $$logmsg .= &mt('An error occured during the attempt to convert [_1] from a manual type to an auto type student - [_2].',$uname,$drop_reply).$linefeed;
                    } else {
# re-enroll as auto student
                        my ($auth,$authparam,$first,$middle,$last,$gene,$usec,$end,$start,$emailaddr,$pid,$emailenc);
                        &prepare_add($authtype,$autharg,$enddate,$startdate,\@stuinfo,\%place,\$dom,\$uname,\$auth,\$authparam,\$first,\$middle,\$last,\$gene,\$usec,\$end,\$start,\$emailaddr,\$pid,\$emailenc);
                        if ($$currlist{$uname}[$sec] ne $usec) {
                            my $showoldsec = $$currlist{$uname}[$sec];
                            if ($$currlist{$uname}[$sec] eq '') {
                                $showoldsec = &mt('none');
                            }
                            my $showsec = $usec;
                            if ($usec eq '') {
                                $showsec = &mt('none');
                            }
                            $switchresult .= &mt("Section for [_1] switched from '[_2]' to '[_3]'.",$uname,$showoldsec,$showsec).$linefeed;
                            if ($context eq 'automated') {
                                $$logmsg .= &mt("Section switch for [_1] from '[_2]' to '[_3]'.",$uname,$showoldsec,$usec).$linefeed;
                            }
                            $switchcount ++;
                        }
                        &execute_add($context,'switchtype',$uname,$dom,$auth,$authparam,$first,$middle,$last,$gene,$pid,$usec,$end,$start,$emailenc,$cid,\$addresult,\$enrollcount,$linefeed,$logmsg);
                    }
                } 
# Check for section changes
                if ($$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 .= &mt('Change in access dates for [_1].',$uname).$access.$linefeed;
                            } else {
                                $$logmsg .= &mt('Error when attempting to change start and/or end access dates for [_1] in section: [_2] -error [_3].',$uname,$stuinfo[$place{groupID}],$modify_access_result).$linefeed;
                            }
                        }
                    }
                } else {
                    if ( ($$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/) {
                                $switchresult .= &mt("Section for [_1] switched from old section: '[_2]' to new section: '[_3]'.",$uname,$$currlist{$uname}[$sec],$stuinfo[ $place{groupID} ]).$access.$linefeed;
                                if ($context eq 'automated') {
                                    $$logmsg .= &mt('Section switch for [_1] from [_2] to [_3]',$uname,$$currlist{$uname}[$sec],$stuinfo[ $place{groupID} ]).$linefeed;
                                }
                                $switchcount ++;
                            } else {
                                $$logmsg .= &mt("Error when attempting section change for [_1], from old section: '[_2]' to new section: '[_3]' -error: [_4]",$uname,$$currlist{$uname}[$sec],$stuinfo[ $place{groupID} ],$modify_section_result).$linefeed;
                            }
                        } else {
                            $$logmsg .= &mt("Error when attempting to expire role for [_1] in old section: '[_2]' -error: '[_3]'.",$uname,$$currlist{$uname}[$sec],$expire_role_result).$linefeed;
                        }
                    }
                }
            } else {
# Check for changed usernames by checking studentIDs
                if ( ($stuinfo[ $place{studentID} ] ne '') && (grep/^$stuinfo[ $place{studentID} ]$/,@LCids) ) {
                    foreach my $match ( @{ $unameFromLCid{ $stuinfo[ $place{studentID} ] } }  ) {
                        $$logmsg .= &mt('A possible change in username has been detected for a student enrolled in this course.').' '.&mt('The existing LON-CAPA classlist contains user: [_1] and student ID: [_2].',$match,$stuinfo[ $place{studentID} ]);
                        if (grep/^$match$/,@okusers) {
                            $$logmsg .= &mt('The username [_1] remains in the institutional classlist, but the same student ID is used for new user: [_2] now found in the institutional classlist.',$match,$uname).' '.&mt('You may need to contact your Domain Coordinator to determine how to resolve this issue and whether to move student data files for user: [_1] to [_2].',$match,$uname).' ';
                        } else {
                            unless ($drops == 1) {
                                $$logmsg .= &mt('This username - [_1] - has been dropped from the institutional classlist, but the student ID of this user is also used by [_2] who now appears in the institutional classlist.',$match,$uname).' '.&mt('You may need to contact your Domain Coordinator to request a move of the student data files for user: [_1] to [_2].',$match,$uname).' ';
                            }
                        }
                        $$logmsg .= &mt('Because of this student ID conflict, the new username - [_1] - has not been added to the LON-CAPA classlist',$uname).$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);
                    }
                    if ($courseinfo{'showphoto'}) {
                        my ($result,$resulttype) = 
                           &Apache::lonnet::auto_checkphotos($uname,$dom,$pid);
                        if ($resulttype) {
                            push(@{$$phototypes{$resulttype}},$uname);
                        }
                    }
                }
            }
        }
    }
    if ($courseinfo{'showphoto'}) {
        if (keys(%{$phototypes})>0) {
            my %lt = &photo_response_types();
            foreach my $type (sort(keys(%{$phototypes}))) {
                my $numphoto = @{$$phototypes{$type}};
                if ($numphoto > 0) {
                    if ($context eq 'updatenow') {
                        $photoresult .=  '<br /><b>'.
			    &mt('For [_1] students, photos ',$numphoto).
			    $lt{$type}.'</b><ul><li>';
                    } else {
                        $photoresult .=  "\n".&mt("For [quant,_1,student], photos ",$numphoto).
			    $lt{$type}."\n";
                    }
                    foreach my $user (@{$$phototypes{$type}}) { 
                        $photoresult .= $user.$linefeed;
                    }
                    if ($context eq 'updatenow') {
                        $photoresult = substr($photoresult,0,
					      rindex($photoresult,"<li>"));
                        $photoresult .= '</ul><br />';
                    } else {
                        $photoresult .= "\n";
                    }
                }
            }
        }
    }

# 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 .= &mt('A possible change in username has been detected for a student enrolled in this course.').' '.&mt('The existing LON-CAPA classlist contains user: [_1] and student ID: [_2].',$uname,$$currlist{$uname}[ $place{studentID} ]).' '.&mt('This username has been dropped from the institutional classlist, but the same student ID is used for user: [_1] who still appears in the institutional classlist.',$match).' '.&mt('You may need to move the student data files for user: [_1] to [_2]',$uname,$match).' '.&mt('Because of this, user [_1] has not been dropped from the course.',$uname).$linefeed;
                            push @saved,$uname;
                        }
                    } elsif (@saved == 0) {
                        my $drop_reply = &Apache::lonnet::modifystudent($dom,$uname,'','','',undef,undef,undef,undef,$$currlist{$uname}[$sec],time,undef,undef,undef,undef,'auto','',$cid);
                        if ($drop_reply !~ /^ok/) {
                            $$logmsg .= &mt('An error occured during the attempt to expire the [_1] from the old section [_2] - [_3].',$uname,$$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.' '.&mt("dropped from section/group: '[_1]'.",$$currlist{$uname}[$sec]).$linefeed; 
                            if ($context eq 'automated') {
                                $$logmsg .= &mt('User [_1] student role expired from course.',$uname).$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>"));
            $addresult = &mt("The following [quant,_1,student was,students were] added to this LON-CAPA course:",$enrollcount).'<br/><ul><li>'.$addresult.'</ul><br/><br/>';
        } else {
            $addresult = &mt("The following [quant,_1,student was,students were] added to this LON-CAPA course:",$enrollcount)."\n\n".$addresult."\n\n";
        }
    }
    if ($dropcount > 0) {
        if ($context eq "updatenow") {
            $dropresult = substr($dropresult,0,rindex($dropresult,"<li>"));
            $dropresult = &mt("The following [quant,_1,student was,students were] expired from this LON-CAPA course:",$dropcount).'<br/><ul><li>'.$dropresult.'</ul><br/><br/>';
        } else {
            $dropresult = &mt("The following [quant,_1,student was,students were] expired from this LON-CAPA course:",$dropcount)."\n\n".$dropresult."\n\n";
        }
    }
    if ($switchcount > 0) {
        if ($context eq "updatenow") {
            $switchresult = substr($switchresult,0,rindex($switchresult,"<li>"));
            $switchresult = &mt("The following [quant,_1,student] switched sections in this LON-CAPA course:",$switchcount).'<br/><ul><li>'.$switchresult.'</ul><br/><br/>';
        } else {
            $switchresult = &mt("The following [quant,_1,student] switched sections in this LON-CAPA course:",$switchcount)."\n\n".$switchresult."\n\n";
        }
    }
    if ( ($adds) && ($enrollcount == 0) ) {
        $addresult = &mt('There were no new students to add to the course.');
        if ($context eq "updatenow") {
            $addresult .="<br/><br/>";
        } else {
            $addresult .="\n";
        }
    }
    if ( ($drops) && ($dropcount == 0) ) {
        $dropresult = &mt('There were no students with roles to expire because all active students previously added to the course from institutional classlist(s) are still officially registered.');
        if ($context eq "updatenow") {
            $dropresult .="<br/>";
        } else {
            $dropresult .="\n";
        }
    }
    my $changecount = $enrollcount + $dropcount + $switchcount;
    return ($changecount,$addresult.$photoresult.$dropresult.$switchresult);
}

sub create_newuser {
    my ($args,$logmsg,$newusermsg,$enrollcount,$addresult,$longroles,
	$courseinfo,$called_context) = @_;
    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,$udom);
    } elsif ($auth =~ m/^krb/) {
        if ($authparam eq '') {
            $$logmsg .= &mt('No Kerberos domain was provided for the new user - [_1], so the new user was not enrolled in the course',$uname).$linefeed;
            $authchk = 'invalid';
        }
    } else {
        $authchk = 'invalid';
        $$logmsg .= &mt('An invalid authentication type was provided for the new user - [_1], so the user was not enrolled in the course.',$uname).$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') {
                $outcome = &Apache::loncommon::commit_standardrole($udom,$uname,$userurl,$role,$start,$end,$cdom,$crs,$usec,$called_context);
                unless ($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);
            my $showsec = $usec;
            if ($usec eq '') {
                $showsec = &mt('none');
            }
            $$addresult .= "$first $last ($pid) - $uname ".&mt("enrolled in section/group: '[_1]'.",$showsec).$access.$linefeed;
            unless ($context eq 'createowner' || $context eq 'createcourse') {
                $$enrollcount ++;
            }
            if ($called_context eq 'automated') {
                $$logmsg .= &mt('New [_1] user [_2] added successfully.',$udom,$uname);
            }
            unless ($emailenc eq '' || $context eq 'createowner' || $context eq 'createcourse') {
                my %emailHash;
                $emailHash{'critnotification'}  = $emailenc;
                $emailHash{'notification'} = $emailenc;
                $emailHash{'permanentemail'} = $emailenc;
                my $putresult = &Apache::lonnet::put('environment',\%emailHash,$udom,$uname);
            }
            if ($create_passwd) {
# Send e-mail with initial password to new user at $emailaddr.
# If e-mail address is invalid, send password via message to courseowner i
# (if automated call) or to user if roster update.
                if ($emailaddr eq '') {
                    $$newusermsg .= &mt(' username: [_1], password: [_2]',$uname,$authparam).$linefeed."\n";
                } else {
                    my $subject = &mt('New LON-CAPA account');
                    my $body;
                    if ($context eq 'createowner') {
                        $body = &mt('A user account has been created for you while creating your new course in the LON-CAPA course management and online homework system.')."\n\n".&mt('You should log-in to the system using the following credentials:')."\n".&mt('username: ').$uname."\n".&mt('password: ').$authparam."\n\n".&mt('The URL you should use to access the LON-CAPA system at your school is: ').'http://'.$ENV{'SERVER_NAME'}."\n\n";
                    } elsif ($context eq 'createcourse') {
                        $body = &mt('You have been assigned the role of [_1] in a new course: [_2] - [_3] in the LON-CAPA course management and online homework system.',$$longroles{$role},$$courseinfo{'description'},$$courseinfo{'inst_code'}).' '.&mt('As you did not have an existing user account in the system, one has been created for you.')."\n\n".&mt("You should log-in to the system using the following credentials:\nusername: [_1]\npassword: [_2]",$uname,$authparam)."\n\n".&mt('The URL you should use to access the LON-CAPA system at your school is: '),'http://'.$ENV{'SERVER_NAME'}."\n\n"; 
                    } else {
                        my $access_start = 'immediately';
                        if ($start > 0) {
                            $access_start = localtime($start)
                        }
                        $body = &mt('You have been enrolled in the LON-CAPA system at your school, because you are a registered student in a class that is using the LON-CAPA couse management and online homework system.')."\n\n".&mt("You should log-in to the system using the following credentials:\nusername: [_1]\npassword: [_2]",$uname,$authparam)."\n\n".&mt('The URL you should use to access the LON-CAPA system at your school is: ').'http://'.$ENV{'SERVER_NAME'}."\n\n".&mt('When you log-in you will be able to access the LON-CAPA course for [_1] - [_2] starting [_3].',$$courseinfo{'description'},$$courseinfo{'inst_code'},$access_start)."\n";
                    }
                    &Apache::lonmsg::sendemail($emailaddr,$subject,$body);
                }
                if ($called_context eq 'automated') {
                    $$logmsg .= &mt(' Initial password - sent to ').$emailaddr.$linefeed;
                }
            } else {
                if ($called_context eq 'automated') {
                    $$logmsg .= $linefeed;
                }
            }
        } else {
            $$logmsg .= &mt('An error occurred adding new user [_1] - [_2].',$uname,$outcome).$linefeed;
        }
    } else {
        $$logmsg .= &mt('An error occurred adding the new user [_1] because the authcheck failed for authtype [_2] and parameter [_3].',$uname,$auth,$authparam).' '.&mt('The authcheck response was [_1].',$authchk).$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}) {
            $$logmsg .= &mt('Current critical notification e-mail
- [_1] for [_2] is different to e-mail address in institutional classlist - [_3].',$userenv{critnotification},$uname,$emailenc).$linefeed;
        }
    }
    if ($userenv{notification} =~ m/%40/) {
        unless ($emailenc eq $userenv{notification}) {
            $$logmsg .= &mt('Current standard notification e-mail
- [_1] for [_2] is different to e-mail address in institutional classlist - [_3]',$userenv{notification},$uname,$emailenc).$linefeed;
        }
    }
    if ($userenv{permanentemail} =~ m/%40/) {
        unless ($emailenc eq $userenv{permanentemail}) {
            $$logmsg .= &mt('Current permanent e-mail
- [_1] for [_2] is different to e-mail address in institutional classlist - [_3]',$userenv{permanentemail},$uname,$emailenc).$linefeed;
        }
    }
    my $krbdefdom = '';
    my $currentauth=&Apache::lonnet::queryauthenticate($uname,$dom);
    if ($currentauth=~/^(krb[45]):(.*)/) {
        $currentauth = $1;
        $krbdefdom = $2;
    } elsif ($currentauth=~ /^(unix|internal|localauth):/) {
        $currentauth = $1;
    } else {
        $$logmsg .= &mt('Invalid authentication method [_1] for [_2].',$currentauth,$uname).$linefeed;
    }
# Report if authentication methods are different.
    if ($currentauth ne $auth) {
        $$logmsg .= &mt("Authentication type mismatch for [_1] - '[_2]' in system, '[_3]' based on information in classlist or default for this course.",$uname,$currentauth,$auth).$linefeed;
    } elsif ($auth =~ m/^krb/) {
        if ($krbdefdom ne $authparam) {
            $$logmsg .= &mt("Kerberos domain mismatch for [_1] - '[_2]' in system, '[_3]' based on information in classlist or default for this course.",$uname,$krbdefdom,$authparam).$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') {
            $$logmsg .= &mt('User information updated for user: [_1]$uname prior to enrollment.',$uname).$linefeed;
        } else {
            $$logmsg .= &mt('There was a problem modifying user data for existing user - [_1] -error: [_2], enrollment will still be attempted.',$uname,$putresult).$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);
        my $showsec = $usec;
        if ($usec eq '') {
            $showsec = &mt('none');
        }
        if ($caller eq 'switchtype') {
            $$logmsg .= &mt("Existing user [_1] detected in institutional classlist - switched from 'manual' to 'auto' enrollment in section/group [_2].",$uname,$showsec).$access.$linefeed;
        } elsif ($caller eq 'newstudent') {
            $$enrollcount ++;
            $$addresult .= "$first $last ($pid) - $uname ".&mt("enrolled in section/group '[_1]'.",$showsec).$access.$linefeed;
        }
        if ($context eq 'automated') {
            $$logmsg .= &mt('Existing [_1] user [_2] enrolled successfully.',$dom,$uname).$linefeed;
        }
    } else {
           $$logmsg .= &mt('There was a problem updating the classlist db file for user [_1] to show the new enrollment -error: [_2], so no enrollment occurred for this user.',$uname,$classlist_reply).$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 $access_msg = ' '.&mt('Access starts: [_1], ends: [_2].',$showstart,$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($crs)) {
        my %settings = &Apache::lonnet::get('environment',['internal.coursecode','internal.showphoto','description'],$dom,$crs);
        if ( defined($settings{'internal.coursecode'}) ) {
            $$courseinfo{'inst_code'} = $settings{'internal.coursecode'};
        }
        if ( defined($settings{'description'}) ) {
            $$courseinfo{'description'} = $settings{'description'};
        }
        if ( defined($settings{'internal.showphoto'}) ) {
            $$courseinfo{'showphoto'} = $settings{'internal.showphoto'};
        }
    }
    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; }

sub photo_response_types {
    my %lt = &Apache::lonlocal::texthash(
                      'same' => 'remained unchanged',
                      'update' => 'were updated',
                      'new' => 'were added',
                      'missing' => 'were missing',
                      'error' => 'were not imported because an error occurred',
                      'nouser' => 'were for users without accounts',
                      'noid' => 'were for users without student IDs',
					 );
    return %lt;
}


1;