# Automated Enrollment manager
# $Id: Enrollment.pm,v 1.20 2004/12/26 21:03:34 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 $roster = &Apache::loncoursedata::get_classlist($cid,$dom,$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 $dropresult = '';
    if ($context eq "updatenow") {
        $linefeed = "</li>\n<li>"; 
    } elsif ($context eq "automated") {
        $linefeed = "\n";
    }
    my $enrollcount = 0;
    my $dropcount = 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 the 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) {
                            $$logmsg .= "Section for $uname switched from $$currlist{$uname}[$sec] to $usec".$linefeed;
                        }
                        &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],$$currlist{$uname}[$cstart],'auto','',$cid);
                            } else {
                                $modify_section_result =  &Apache::lonnet::modify_student_enrollment($dom,$uname,undef,undef,undef,undef,undef,$stuinfo[ $place{groupID} ],$enddate,$startdate,'auto','',$cid);
                                $access =  &showaccess($enddate,$startdate);
                            }
                            if ($modify_section_result =~ /^ok/) {
                                $$logmsg .= "Section for $uname switched from old section: ".$$currlist{$uname}[$sec] ." to new section: ".$stuinfo[ $place{groupID} ].".".$access.$linefeed;
                            } else {
                                $$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" .$$currlist{$uname}[$sec]." -error: $expire_role_result".$linefeed;
                        }
                    }
                }
            } else {
# Check for changed usernames by checking studentIDs
                if ( ($stuinfo[ $place{studentID} ] ne '') && (grep/^$stuinfo[ $place{studentID} ]$/,@LCids) ) {
                    if (grep/^$$currlist{$uname}[ $place{'studentID'} ]$/,@allINids) {
                        foreach my $match ( @{ $unameFromLCid{ $stuinfo[ $place{studentID} ] } }  ) {
                            if (grep/^$match$/,@okusers) {
                                $$logmsg .= "A possible change in username has been detected for a student enrolled in this course. The existing LON-CAPA classlist contains user: $uname and student ID: ".$$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 contact your Domain Coordinator to request a move of the student data files for user: $uname to $match".$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: $$currlist{$uname}[ $place{studentID} ].  This username has been dropped from the institutional classlist, but the same student ID is used for user: $match who still appears in the institutional classlist. You may need to move the student data files for user: $uname to $match.".$linefeed;
                            push @saved,$uname;
                        }
                    } elsif (@saved == 0) {
                        my $drop_reply = &Apache::lonnet::modifystudent($dom,$uname,'','','',undef,undef,undef,undef,$$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."</li></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."</li></ul><br/><br/>";
        } else {
            $dropresult = "The following $dropcount student(s) was/were expired from this LON-CAPA course:\n\n".$dropresult."\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 + $dropcount;
    return ($changecount,$addresult.$dropresult); 
}

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') {
                $outcome = &Apache::loncreateuser::commit_standardrole($userurl,$role,$cdom,$crs,$start,$end);
                unless ($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') {
                $$logmsg .= "New $udom user $uname added successfully.";
            }
            unless ($emailenc eq '' || $context eq 'createowner' || $context eq 'createcourse') {
                my %emailHash;
                $emailHash{'critnotification'}  = $emailenc;
                $emailHash{'notification'} = $emailenc;
                my $putresult = &Apache::lonnet::put('environment',\%emailHash,$udom,$uname);
            }
            if ($create_passwd) {
# Send e-mail with initial password to new user at $emailaddr.
# If e-mail address is invalid, send password via message to courseowner i
# (if automated call) or to user if roster update.
                if ($emailaddr eq '') {
                    $$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'],$dom,$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}) {
            $$logmsg .= "Current critical notification e-mail
- ".$userenv{critnotification}." for $uname is different to e-mail address in institutional classlist - ".$emailenc.$linefeed;
        }
    }
    if ($userenv{notification} =~ m/%40/) {
        unless ($emailenc eq $userenv{critnotification}) {
            $$logmsg .= "Current standard notification e-mail
- ".$userenv{notification}." 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'} ) {
# Make the change(s)
        my %changeHash;
        $changeHash{'firstname'}  = $first;
        $changeHash{'middlename'} = $middle;
        $changeHash{'lastname'}   = $last;
        $changeHash{'generation'} = $gene;
        $changeHash{'id'} = $pid;
        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 check_user_status {
    my ($udom,$uname,$cdom,$crs,$role,$secgrp) = @_;
    my %userinfo = &Apache::lonnet::dump('roles',$udom,$uname);
    my @uroles = keys %userinfo;
    my $srchstr;
    my $active_chk = 'none';
    if (@uroles > 0) {
        if ( ($role eq 'cc') || ($secgrp eq '') || ( !defined($secgrp) ) ) {
            $srchstr = '/'.$cdom.'/'.$crs.'_'.$role;
        } else {
            $srchstr = '/'.$cdom.'/'.$crs.'/'.$secgrp.'_'.$role;
        }
        if (grep/^$srchstr$/,@uroles) {
            my $role_end = 0;
            my $role_start = 0;
            $active_chk = 'ok';
            if ( $userinfo{$srchstr} =~ m/^($role)_(\d+)/ ) {
                $role_end = $2;
                if ( $userinfo{$srchstr} =~ m/^($role)_($role_end)_(\d+)$/ )
                {
                    $role_start = $3;
                }
            }   
            if ($role_start > 0) {
                if (time < $role_start) {
                    $active_chk = 'expired';
                }
            }
            if ($role_end > 0) {
                if (time > $role_end) {
                    $active_chk = 'expired';
                }
            }
        }
    }
    return $active_chk;
}

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;