# The LearningOnline Network with CAPA
# (Publication Handler
#
# $Id: lonchart.pm,v 1.49 2002/07/01 21:12:06 stredwic 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/
#
# Homework Performance Chart
#
# (Navigate Maps Handler
#
# (Page Handler
#
# (TeX Content Handler
# YEAR=2000
# 05/29/00,05/30 Gerd Kortemeyer)
# 08/30,08/31,09/06,09/14,09/15,09/16,09/19,09/20,09/21,09/23,
# 10/02,10/10,10/14,10/16,10/18,10/19,10/31,11/6,11/14,11/16 Gerd Kortemeyer)
# YEAR=2001
# 3/1/1,6/1,17/1,29/1,30/1,31/1 Gerd Kortemeyer)
# 7/10/01 Behrouz Minaei
# 9/8 Gerd Kortemeyer
# 10/1, 10/19, 11/17, 11/22, 11/24, 11/28 12/18 Behrouz Minaei
# YEAR=2002
# 2/1, 2/6, 2/19, 2/28 Behrouz Minaei
#
###

package Apache::lonchart;

use strict;
use Apache::Constants qw(:common :http);
use Apache::lonnet();
use Apache::loncommon();
use HTML::TokeParser;
use GDBM_File;

my $jr; 
# ----- FORMAT PRINT DATA ----------------------------------------------

sub FormatStudentInformation {
    my ($cache,$name,$studentInformation,$reselected,$spacePadding)=@_;
    my $Str='<pre>';

    for(my $index=0; $index<(scalar @$studentInformation); $index++) {
        if(!&ShouldShowColumn($reselected, 'heading', $index)) {
            next;
        }
	my $data=$cache->{$name.':'.$studentInformation->[$index]};
	$Str .= $data;

	my @dataLength=split(//,$data);
	my $length=scalar @dataLength;
	$Str .= (' 'x($cache->{$studentInformation->[$index].'Length'}-
                      $length));
	$Str .= $spacePadding;
    }

    return $Str;
}

sub FormatStudentData {
    my ($reselected,$name,$coid,$studentInformation,$spacePadding,$ChartDB)=@_;
    my ($sname,$sdom) = split(/\:/,$name);
    my $Str;
    my %CacheData;

    unless(tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_READER,0640)) {
        return '';
    }
    # Handle Student information ------------------------------------------
    # Handle user data
    $Str=&FormatStudentInformation(\%CacheData, $name, $studentInformation, 
                                   $reselected, $spacePadding);

    # Handle errors
    if($CacheData{$name.':error'} =~ /environment/) {
        untie(%CacheData);
        $Str .= '</pre>';
        return $Str;
#	my $errorMessage = $CacheData{$name.':error'};
#	return '<td>'.$sname.'</td><td>'.$sdom.
#	    '</td><td><font color="#000088">'.$errorMessage.'</font></td>';
    }

    if($CacheData{$name.':error'} =~ /course/) {
        untie(%CacheData);
        $Str .= '</pre>';
	return $Str;
#	my $errorMessage = 'May have no course data or '.
#	                   $CacheData{$name.':error'};
#	return '<td>'.$sname.'</td><td>'.$sdom.
#	    '</td><td><font color="#000088">'.$errorMessage.'</font></td>';
    }

    # Handle problem data ------------------------------------------------
    my $Version;
    my $problemsCorrect = 0;
    my $totalProblems   = 0;
    my $problemsSolved  = 0;
    my $numberOfParts   = 0;
    foreach my $sequence (split(/\:/,$CacheData{'orderedSequences'})) {
        if(!&ShouldShowColumn($reselected, 'sequence', $sequence)) {
            next;
        }

	my $characterCount=0;
	foreach my $problemID (split(/\:/,$CacheData{$sequence.':problems'})) {
	    my $problem = $CacheData{$problemID.':problem'};
	    my $LatestVersion = $CacheData{$name.":version:$problem"};

            if(!$LatestVersion) {
                foreach my $part (split(/\:/,$CacheData{$sequence.':'.
                                                        $problemID.
                                                        ':parts'})) {
                    $Str .= ' ';
                    $totalProblems++;
                    $characterCount++;
                }
                next;
            }

            my %partData=undef;
            #initialize data, displays skips correctly
            foreach my $part (split(/\:/,$CacheData{$sequence.':'.
                                                    $problemID.
                                                    ':parts'})) {
                $partData{$part.':tries'}=0;
                $partData{$part.':code'}=' ';
            }
	    for(my $Version=1; $Version<=$LatestVersion; $Version++) {
                foreach my $part (split(/\:/,$CacheData{$sequence.':'.
                                                        $problemID.
                                                        ':parts'})) {

                    if(!defined($CacheData{$name.":$Version:$problem".
                                               ":resource.$part.solved"})) {
                        next;
                    }

                    my $tries=0;
                    my $code=' ';

                    $tries = $CacheData{$name.":$Version:$problem".
                                        ":resource.$part.tries"};
                    $partData{$part.':tries'}=($tries) ? $tries : 0;

                    my $val = $CacheData{$name.":$Version:$problem".
                                         ":resource.$part.solved"};
                    if    ($val eq 'correct_by_student')   {$code = '*';} 
                    elsif ($val eq 'correct_by_override')  {$code = '+';}
                    elsif ($val eq 'incorrect_attempted')  {$code = '.';} 
                    elsif ($val eq 'incorrect_by_override'){$code = '-';}
                    elsif ($val eq 'excused')              {$code = 'x';}
                    elsif ($val eq 'ungraded_attempted')   {$code = '#';}
                    else                                   {$code = ' ';}
                    $partData{$part.':code'}=$code;
                }
            }

            $Str.='<a href="/adm/grades?symb='.
                &Apache::lonnet::escape($problem).
                '&student='.$sname.'&domain='.$sdom.'&command=submission">'; 
            foreach(split(/\:/,$CacheData{$sequence.':'.$problemID.
                                          ':parts'})) {
                if($partData{$_.':code'} eq '*') {
                    $problemsCorrect++;
                    if (($partData{$_.':tries'}<10) &&
                        ($partData{$_.':tries'} ne '')) {
                        $partData{$_.':code'}=$partData{$_.':tries'};
                    }
                } elsif($partData{$_.':code'} eq '+') {
                    $problemsCorrect++;
                }

                $Str .= $partData{$_.':code'};
                $characterCount++;

                if($partData{$_.':code'} ne 'x') {
                    $totalProblems++;
                }
            }
            $Str.='</a>';
        }

        my $spacesNeeded=$CacheData{$sequence.':columnWidth'}-$characterCount;
        $spacesNeeded -= 3;
        $Str .= (' 'x$spacesNeeded);

	my $outputProblemsCorrect = sprintf( "%3d", $problemsCorrect );
	$Str .= '<font color="#007700">'.$outputProblemsCorrect.'</font>';
	$problemsSolved += $problemsCorrect;
	$problemsCorrect=0;

        $Str .= $spacePadding;
    }

    $Str .= '<font color="#000088">'.$problemsSolved.
	    ' / '.$totalProblems.'</font></pre>';

    untie(%CacheData);
    return $Str;
}

sub CreateTableHeadings {
    my ($CacheData,$studentInformation,$headings,$reselected,$spacePadding)=@_;
    my $Str='<pre>';

    for(my $index=0; $index<(scalar @$headings); $index++) {
        if(!&ShouldShowColumn($reselected, 'heading', $index)) {
            next;
        }

	my $data=$$headings[$index];
	$Str .= $data;

	my @dataLength=split(//,$data);
	my $length=scalar @dataLength;
	$Str .= (' 'x($CacheData->{$$studentInformation[$index].'Length'}-
                      $length));
	$Str .= $spacePadding;
    }

    foreach my $sequence (split(/\:/,$CacheData->{'orderedSequences'})) {
        if(!&ShouldShowColumn($reselected, 'sequence', $sequence)) {
            next;
        }

        my $name = $CacheData->{$sequence.':title'};
	$Str .= $name;
	my @titleLength=split(//,$CacheData->{$sequence.':title'});
	my $leftover=$CacheData->{$sequence.':columnWidth'}-
                     (scalar @titleLength);
	$Str .= (' 'x$leftover);
	$Str .= $spacePadding;
    }

    $Str .= 'Total Solved/Total Problems';
    $Str .= '</pre>';

    return $Str;
}

sub CreateColumnSelectionBox {
    my ($CacheData,$studentInformation,$headings,$reselected,$spacePadding)=@_;

    my $missing=0;
    my $notThere='<br><br><b>Select column to view:</b><br><br>';
    my $name;
    $notThere .= '&nbsp;&nbsp;&nbsp';
    $notThere .= '<select name="reselect" size="4" multiple="true">'."\n";

    for(my $index=0; $index<(scalar @$headings); $index++) {
        if(&ShouldShowColumn($reselected, 'heading', $index)) {
            next;
        }
        $name = $headings->[$index];
        $notThere .= '<option value="heading'.$index.'">';
        $notThere .= $name.'</option>'."\n";
        $missing++;
    }

    foreach my $sequence (split(/\:/,$CacheData->{'orderedSequences'})) {
        if(&ShouldShowColumn($reselected, 'sequence', $sequence)) {
            next;
        }
        $name = $CacheData->{$sequence.':title'};
        $notThere .= '<option value="sequence'.$sequence.'">';
        $notThere .= $name.'</option>'."\n";
        $missing++;
    }

    if($missing) {
        $notThere .= '</select><br><br>';
    } else {
        $notThere='';
    }

    return $notThere;
}

sub CreateColumnSelectors {
    my ($CacheData,$studentInformation,$headings,$reselected,$spacePadding)=@_;

    my $found=0;
    my ($name, $length, $position);
    my $present='<pre>';
    for(my $index=0; $index<(scalar @$headings); $index++) {
        if(!&ShouldShowColumn($reselected, 'heading', $index)) {
            next;
        }
        $name = $headings->[$index];
        $length=$CacheData->{$$studentInformation[$index].'Length'};
        $position=int($length/2);
	$present .= (' 'x($position));
        $present .= '<input type="checkbox" checked="on" ';
        $present .= 'name="heading'.$index.'">';
        $position+=2;
	$present .= (' 'x($length-$position));
	$present .= $spacePadding;
        $found++;
    }

    foreach my $sequence (split(/\:/,$CacheData->{'orderedSequences'})) {
        if(!&ShouldShowColumn($reselected, 'sequence', $sequence)) {
            next;
        }
        $name = $CacheData->{$sequence.':title'};
        $length=$CacheData->{$sequence.':columnWidth'};
        $position=int($length/2);
	$present .= (' 'x($position));
        $present .= '<input type="checkbox" checked="on" ';
        $present .= 'name="sequence'.$sequence.'">';
        $position+=2;
	$present .= (' 'x($length-$position));
	$present .= $spacePadding;
        $found++;
    }

    if($found) {
        $present .= '</pre>';
        $present  = $present;
    } else {
        $present = '';
    }

    return $present.'</form>'."\n";;
}

sub CreateForm {
    my $OpSel1='';
    my $OpSel2='';
    my $OpSel3='';
    my $Status = $ENV{'form.status'};
    if ( $Status eq 'Any' ) { $OpSel3='selected'; }
    elsif ($Status eq 'Expired' ) { $OpSel2 = 'selected'; }
    else { $OpSel1 = 'selected'; }

    my $Ptr = '<form name="stat" method="post" action="/adm/chart" >'."\n";
    $Ptr .= '<input type="submit" name="sort" value="Recalculate Chart"/>';
    $Ptr .= "\n";
    $Ptr .= '&nbsp;&nbsp;&nbsp;';
    $Ptr .= '<input type="submit" name="refresh" value="Refresh Chart"/>';
    $Ptr .= "\n";
    $Ptr .= '<br><br>';
    $Ptr .= '<b> Sort by: &nbsp; </b>'."\n";
    $Ptr .= '&nbsp;&nbsp;&nbsp;';
    $Ptr .= '<input type="submit" name="sort" value="User Name" />'."\n";
    $Ptr .= '&nbsp;&nbsp;&nbsp;';
    $Ptr .= '<input type="submit" name="sort" value="Last Name" />'."\n";
    $Ptr .= '&nbsp;&nbsp;&nbsp;';
    $Ptr .= '<input type="submit" name="sort" value="Section"/>'."\n";
    $Ptr .= '<br><br>';
    $Ptr .= '<b> Student Status: &nbsp; </b>'."\n".
            '&nbsp;&nbsp;&nbsp;'.
            '<select name="status">'. 
            '<option '.$OpSel1.' >Active</option>'."\n".
            '<option '.$OpSel2.' >Expired</option>'."\n".
	    '<option '.$OpSel3.' >Any</option> </select> '."\n";

    return $Ptr;
}

sub CreateLegend {
    my $Str = '<h1>'.$ENV{'course.'.$ENV{'request.course.id'}.'.description'}.
              '</h1><h3>'.localtime().
              "</h3><p><pre>1..9: correct by student in 1..9 tries\n".
              "   *: correct by student in more than 9 tries\n".
	      "   +: correct by override\n".
              "   -: incorrect by override\n".
	      "   .: incorrect attempted\n".
	      "   #: ungraded attempted\n".
              "    : not attempted\n".
	      "   x: excused</pre><p>"; 
    return $Str;
}

sub StartDocument {
    my $Str = '';
    $Str .= '<html>';
    $Str .= '<head><title>';
    $Str .= 'LON-CAPA Assessment Chart</title></head>';
    $Str .= '<body bgcolor="#FFFFFF">';
    $Str .= '<script>window.focus();</script>';
    $Str .= '<img align=right src=/adm/lonIcons/lonlogos.gif>';
    $Str .= '<h1>Assessment Chart</h1>';

    return $Str;
}

# ----- END FORMAT PRINT DATA ------------------------------------------

# ----- DOWNLOAD INFORMATION -------------------------------------------

sub DownloadPrerequisiteData {
    my ($courseID, $c)=@_;
    my ($courseDomain,$courseNumber)=split(/\_/,$courseID);

    my %classlist=&Apache::lonnet::dump('classlist',$courseDomain,
                                        $courseNumber);
    my ($checkForError)=keys (%classlist);
    if($checkForError =~ /^(con_lost|error|no_such_host)/i) {
        return \%classlist;
    }

    foreach my $name (keys(%classlist)) {
        if($c->aborted()) {
            $classlist{'error'}='aborted';
            return \%classlist;
        }

        my ($studentName,$studentDomain) = split(/\:/,$name);
        # Download student environment data, specifically the full name and id.
        my %studentInformation=&Apache::lonnet::get('environment',
                                                    ['lastname','generation',
                                                     'firstname','middlename',
                                                     'id'],
                                                    $studentDomain,
                                                    $studentName);
        $classlist{$name.':studentInformation'}=\%studentInformation;

        if($c->aborted()) {
            $classlist{'error'}='aborted';
            return \%classlist;
        }

        #Section
        my %section=&Apache::lonnet::dump('roles',$studentDomain,$studentName);
        $classlist{$name.':section'}=\%section;
    }

    return \%classlist;
}

sub DownloadStudentCourseInformation {
    my ($name,$courseID)=@_;
    my ($studentName,$studentDomain) = split(/\:/,$name);

    # Download student course data
    my %courseData=&Apache::lonnet::dump($courseID,$studentDomain,
					 $studentName);
    return \%courseData;
}

# ----- END DOWNLOAD INFORMATION ---------------------------------------

# ----- END PROCESSING FUNCTIONS ---------------------------------------

sub ProcessTopResourceMap {
    my ($ChartDB,$c)=@_;
    my %hash;
    my $fn=$ENV{'request.course.fn'};
    if(-e "$fn.db") {
	my $tieTries=0;
	while($tieTries < 3) {
	    if(tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER,0640)) {
		last;
	    }
	    $tieTries++;
	    sleep 1;
	}
	if($tieTries >= 3) {
            return 'Coursemap undefined.';
        }
    } else {
        return 'Can not open Coursemap.';
    }

    my %CacheData;
    unless(tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_WRCREAT,0640)) {
        untie(%hash);
	return 'Could not tie cache hash.';
    }

    my (@sequences, @currentResource, @finishResource);
    my ($currentSequence, $currentResourceID, $lastResourceID);

    $currentResourceID=$hash{'ids_/res/'.$ENV{'request.course.uri'}};
    push(@currentResource, $currentResourceID);
    $lastResourceID=-1;
    $currentSequence=-1;
    my $topLevelSequenceNumber = $currentSequence;

    while(1) {
        if($c->aborted()) {
            last;
        }
	# HANDLE NEW SEQUENCE!
	#if page || sequence
	if(defined($hash{'map_pc_'.$hash{'src_'.$currentResourceID}})) {
	    push(@sequences, $currentSequence);
	    push(@currentResource, $currentResourceID);
	    push(@finishResource, $lastResourceID);

	    $currentSequence=$hash{'map_pc_'.$hash{'src_'.$currentResourceID}};
	    $lastResourceID=$hash{'map_finish_'.
				  $hash{'src_'.$currentResourceID}};
	    $currentResourceID=$hash{'map_start_'.
				     $hash{'src_'.$currentResourceID}};

	    if(!($currentResourceID) || !($lastResourceID)) {
		$currentSequence=pop(@sequences);
		$currentResourceID=pop(@currentResource);
		$lastResourceID=pop(@finishResource);
		if($currentSequence eq $topLevelSequenceNumber) {
		    last;
		}
	    }
	}

	# Handle gradable resources: exams, problems, etc
	$currentResourceID=~/(\d+)\.(\d+)/;
        my $partA=$1;
        my $partB=$2;
	if($hash{'src_'.$currentResourceID}=~
	   /\.(problem|exam|quiz|assess|survey|form)$/ &&
	   $partA eq $currentSequence) {
	    my $Problem = &Apache::lonnet::symbclean(
			  &Apache::lonnet::declutter($hash{'map_id_'.$partA}).
			  '___'.$partB.'___'.
			  &Apache::lonnet::declutter($hash{'src_'.
							 $currentResourceID}));

	    $CacheData{$currentResourceID.':problem'}=$Problem;
	    if(!defined($CacheData{$currentSequence.':problems'})) {
		$CacheData{$currentSequence.':problems'}=$currentResourceID;
	    } else {
		$CacheData{$currentSequence.':problems'}.=
		    ':'.$currentResourceID;
	    }

            #Get Parts for problem
	    my $meta=$hash{'src_'.$currentResourceID};
	    foreach (split(/\,/,&Apache::lonnet::metadata($meta,'keys'))) {
		if($_=~/^stores\_(\d+)\_tries$/) {
		    my $Part=&Apache::lonnet::metadata($meta,$_.'.part');
                    if(!defined($CacheData{$currentSequence.':'.
                                          $currentResourceID.':parts'})) {
                        $CacheData{$currentSequence.':'.$currentResourceID.
                                   ':parts'}=$Part;
                    } else {
                        $CacheData{$currentSequence.':'.$currentResourceID.
                                   ':parts'}.=':'.$Part;
                    }
		}
	    }
	}

	#if resource == finish resource
	if($currentResourceID eq $lastResourceID) {
	    #pop off last resource of sequence
	    $currentResourceID=pop(@currentResource);
	    $lastResourceID=pop(@finishResource);

	    if(defined($CacheData{$currentSequence.':problems'})) {
		# Capture sequence information here
		if(!defined($CacheData{'orderedSequences'})) {
		    $CacheData{'orderedSequences'}=$currentSequence;
		} else {
		    $CacheData{'orderedSequences'}.=':'.$currentSequence;
		}

		$CacheData{$currentSequence.':title'}=
		    $hash{'title_'.$currentResourceID};

                my $totalProblems=0;
                foreach my $currentProblem (split(/\:/,
                                               $CacheData{$currentSequence.
                                               ':problems'})) {
                    foreach (split(/\:/,$CacheData{$currentSequence.':'.
                                                   $currentProblem.
                                                   ':parts'})) {
                        $totalProblems++;
                    }
                }
		my @titleLength=split(//,$CacheData{$currentSequence.
                                                    ':title'});
                # $extra is 3 for problems correct and 3 for space
                # between problems correct and problem output
                my $extra = 6;
		if(($totalProblems + $extra) > (scalar @titleLength)) {
		    $CacheData{$currentSequence.':columnWidth'}=
                        $totalProblems + $extra;
		} else {
		    $CacheData{$currentSequence.':columnWidth'}=
                        (scalar @titleLength);
		}
	    }

	    $currentSequence=pop(@sequences);
	    if($currentSequence eq $topLevelSequenceNumber) {
		last;
	    }
	#else
	}

	# MOVE!!!
	#move to next resource
	unless(defined($hash{'to_'.$currentResourceID})) {
	    # big problem, need to handle.  Next is probably wrong
	    last;
	}
	my @nextResources=();
	foreach (split(/\,/,$hash{'to_'.$currentResourceID})) {
	    push(@nextResources, $hash{'goesto_'.$_});
	}
	push(@currentResource, @nextResources);
	# Set the next resource to be processed
	$currentResourceID=pop(@currentResource);
    }

    unless (untie(%hash)) {
        &Apache::lonnet::logthis("<font color=blue>WARNING: ".
                                 "Could not untie coursemap $fn (browse)".
                                 ".</font>"); 
    }

    unless (untie(%CacheData)) {
        &Apache::lonnet::logthis("<font color=blue>WARNING: ".
                                 "Could not untie Cache Hash (browse)".
                                 ".</font>"); 
    }

    return 'OK';
}

sub ProcessSection {
    my ($sectionData, $courseid,$ActiveFlag)=@_;
    $courseid=~s/\_/\//g;
    $courseid=~s/^(\w)/\/$1/;

    my $cursection='-1';
    my $oldsection='-1';
    my $status='Expired';
    my $section='';
    foreach my $key (keys (%$sectionData)) {
	my $value = $sectionData->{$key};
        if ($key=~/^$courseid(?:\/)*(\w+)*\_st$/) {
	    $section=$1;
	    if($key eq $courseid.'_st') {
		$section='';
	    }
	    my ($dummy,$end,$start)=split(/\_/,$value);
	    my $now=time;
	    my $notactive=0;
	    if ($start) {
		if($now<$start) {
		    $notactive=1;
		}
	    }
	    if($end) {
		if ($now>$end) {
		    $notactive=1;
		}
	    }
	    if($notactive == 0) {
		$status='Active';
		$cursection=$section;
		last;
	    }
	    if($notactive == 1) {
		$oldsection=$section;
	    }
	}
    }
    if($status eq $ActiveFlag) {
	if($cursection eq '-1') {
	    return $oldsection;
	}
	return $cursection;
    }
    if($ActiveFlag eq 'Any') {
	if($cursection eq '-1') {
	    return $oldsection;
	}
	return $cursection;
    }
    return '-1';
}

sub ProcessStudentInformation {
    my ($CacheData,$studentInformation,$section,$date,$name,$courseID,$c)=@_;
    my ($studentName,$studentDomain) = split(/\:/,$name);

    $CacheData->{$name.':username'}=$studentName;
    $CacheData->{$name.':domain'}=$studentDomain;
    $CacheData->{$name.':date'}=$date;

    my ($checkForError)=keys(%$studentInformation);
    if($checkForError =~ /^(con_lost|error|no_such_host)/i) {
	$CacheData->{$name.':error'}=
	    'Could not download student environment data.';
	$CacheData->{$name.':fullname'}='';
	$CacheData->{$name.':id'}='';
    } else {
	$CacheData->{$name.':fullname'}=&ProcessFullName(
                                          $studentInformation->{'lastname'},
				          $studentInformation->{'generation'},
				          $studentInformation->{'firstname'},
                                          $studentInformation->{'middlename'});
	$CacheData->{$name.':id'}=$studentInformation->{'id'};
    }

    # Get student's section number
    my $sec=&ProcessSection($section, $courseID, $ENV{'form.status'});
    if($sec != -1) {
	$CacheData->{$name.':section'}=$sec;
    } else {
	$CacheData->{$name.':section'}='';
    }

    return 0;
}

sub ProcessClassList {
    my ($classlist,$courseID,$ChartDB,$c)=@_;
    my @names=();

    my %CacheData;
    if(tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_WRCREAT,0640)) {
        foreach my $name (keys(%$classlist)) {
            if($name =~ /\:section/ || $name =~ /\:studentInformation/ ||
               $name eq '') {
                next;
            }
            if($c->aborted()) {
                last;
            }
            push(@names,$name);
            &ProcessStudentInformation(
                                    \%CacheData,
                                    $classlist->{$name.':studentInformation'},
                                    $classlist->{$name.':section'},
                                    $classlist->{$name},
                                    $name,$courseID,$c);
        }

	untie(%CacheData);
    }

    return @names;
}

# ----- END PROCESSING FUNCTIONS ---------------------------------------

# ----- HELPER FUNCTIONS -----------------------------------------------

sub SpaceColumns {
    my ($students,$studentInformation,$headings,$ChartDB)=@_;

    my %CacheData;
    if(tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_WRCREAT,0640)) {
        # Initialize Lengths
        for(my $index=0; $index<(scalar @$headings); $index++) {
	    my @titleLength=split(//,$$headings[$index]);
	    $CacheData{$$studentInformation[$index].'Length'}=
                scalar @titleLength;
	}

        foreach my $name (@$students) {
            foreach (@$studentInformation) {
		my @dataLength=split(//,$CacheData{$name.':'.$_});
		my $length=scalar @dataLength;
		if($length > $CacheData{$_.'Length'}) {
		    $CacheData{$_.'Length'}=$length;
		}
            }
        }
        untie(%CacheData);
    }

    return;
}

sub ProcessFullName {
    my ($lastname, $generation, $firstname, $middlename)=@_;
    my $Str = '';

    if($lastname ne '') {
	$Str .= $lastname.' ';
	if($generation ne '') {
	    $Str .= $generation;
	} else {
	    chop($Str);
	}
	$Str .= ', ';
	if($firstname ne '') {
	    $Str .= $firstname.' ';
	}
	if($middlename ne '') {
	    $Str .= $middlename;
	} else {
	    chop($Str);
	    if($firstname eq '') {
		chop($Str);
	    }
	}
    } else {
	if($firstname ne '') {
	    $Str .= $firstname.' ';
	}
	if($middlename ne '') {
	    $Str .= $middlename.' ';
	}
	if($generation ne '') {
	    $Str .= $generation;
	} else {
	    chop($Str);
	}
    }

    return $Str;
}

sub SortStudents {
    my ($students,$CacheData)=@_;

    my @sorted1Students=();
    foreach (@$students) {
        my ($end,$start)=split(/\:/,$CacheData->{$_.':date'});
        my $active=1;
        my $now=time;
        my $Status=$ENV{'form.status'};
        $Status = ($Status) ? $Status : 'Active';
        if((($end) && $now > $end) && (($Status eq 'Active'))) { 
            $active=0; 
        }
        if(($Status eq 'Expired') && ($end == 0 || $now < $end)) {
            $active=0;
        }
        if($active) {
            push(@sorted1Students, $_);
        }
    }

    my $Pos = $ENV{'form.sort'};
    my %sortData;
    if($Pos eq 'Last Name') {
	for(my $index=0; $index<scalar @sorted1Students; $index++) {
	    $sortData{$CacheData->{$sorted1Students[$index].':fullname'}}=
		$sorted1Students[$index];
	}
    } elsif($Pos eq 'Section') {
	for(my $index=0; $index<scalar @sorted1Students; $index++) {
	    $sortData{$CacheData->{$sorted1Students[$index].':section'}.
		      $sorted1Students[$index]}=$sorted1Students[$index];
	}
    } else {
	# Sort by user name
	for(my $index=0; $index<scalar @sorted1Students; $index++) {
	    $sortData{$sorted1Students[$index]}=$sorted1Students[$index];
	}
    }

    my @order = ();
    foreach my $key (sort(keys(%sortData))) {
	push (@order,$sortData{$key});
    }

    return @order;
}

sub TestCacheData {
    my ($ChartDB)=@_;
    my $isCached=-1;
    my %testData;
    my $tieTries=0;

    if ((-e "$ChartDB") && ($ENV{'form.sort'} ne 'Recalculate Chart')) {
	$isCached = 1;
    } else {
	$isCached = 0;
    }

    while($tieTries < 3) {
        my $result=0;
        if($isCached) {
            $result=tie(%testData,'GDBM_File',$ChartDB,&GDBM_READER,0640);
        } else {
            $result=tie(%testData,'GDBM_File',$ChartDB,&GDBM_NEWDB,0640);
        }
        if($result) {
            last;
        }
        $tieTries++;
        sleep 1;
    }
    if($tieTries >= 3) {
        return -1;
    }

    untie(%testData);

    return $isCached;
}

sub ExtractStudentData {
    my ($courseData, $name, $ChartDB)=@_;

    my %CacheData;
    if(tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_WRCREAT,0640)) {
        my ($checkForError) = keys(%$courseData);
        if($checkForError =~ /^(con_lost|error|no_such_host)/i) {
            $CacheData{$name.':error'}='Could not download course data.';
        } else {
            foreach my $key (keys (%$courseData)) {
                $CacheData{$name.':'.$key}=$courseData->{$key};
            }
            if(defined($CacheData{'NamesOfStudents'})) {
                $CacheData{'NamesOfStudents'}.=':::'.$name;
            } else {
                $CacheData{'NamesOfStudents'}=$name;
            }
        }
        untie(%CacheData);
    }

    return;
}

sub ShouldShowColumn {
    my ($reselected,$type,$value)=@_;

    if($ENV{'form.sort'} eq 'Recalculate Chart') {
        return 1;
    }

    if(defined($ENV{'form.'.$type.$value})) {
        return 1;
    }

    return &CheckForStringInArray($reselected, $type.$value);
}

sub CheckForStringInArray {
    my ($inputArray,$checkString)=@_;
    foreach (@$inputArray) {
#        $jr->print('a:'.$_.' b:'.$checkString.'<br>');
        if($_ eq $checkString) {
            return 1;
        }
    }
    return 0;
}

# ----- END HELPER FUNCTIONS --------------------------------------------

sub BuildChart {
    my ($r)=@_;
    my $c = $r->connection;

    # Start the lonchart document
    $r->content_type('text/html');
    $r->send_http_header;
    $r->print(&StartDocument());
    $r->rflush();

    # Test for access to the CacheData
    my $isCached=0;
    my $cid=$ENV{'request.course.id'};
    my $ChartDB = "/home/httpd/perl/tmp/$ENV{'user.name'}".
                  "_$ENV{'user.domain'}_$cid\_chart.db";
    # $ENV{'form.domains'} can be either a scalar or an array reference.
    # We need an array.
    my @reselected = (ref($ENV{'form.reselect'}) ? @{$ENV{'form.reselect'}}
                      : ($ENV{'form.reselect'}));

    $isCached=&TestCacheData($ChartDB);
    if($isCached < 0) {
        $r->print("Unable to tie hash to db file");
        $r->rflush();
        return;
    }

    # Download class list information if not using cached data
    my %CacheData;
    my @students=();
    my @studentInformation=('username','domain','section','id','fullname');
    my @headings=('User Name','Domain','Section','PID','Full Name');
    my $spacePadding='   ';
    if(!$isCached) {
        my $processTopResourceMapReturn=&ProcessTopResourceMap($ChartDB,$c);
        if($processTopResourceMapReturn ne 'OK') {
            $r->print($processTopResourceMapReturn);
            return;
        }
        if($c->aborted()) { return; }
        my $classlist=&DownloadPrerequisiteData($cid, $c);
        my ($checkForError)=keys(%$classlist);
        if($checkForError =~ /^(con_lost|error|no_such_host)/i ||
           defined($classlist->{'error'})) {
            return;
        }
        if($c->aborted()) { return; }
        @students=&ProcessClassList($classlist,$cid,$ChartDB,$c);
        if($c->aborted()) { return; }
        &SpaceColumns(\@students,\@studentInformation,\@headings,
                      $ChartDB);
        if($c->aborted()) { return; }
    } else {
        if(!$c->aborted() && tie(%CacheData,'GDBM_File',$ChartDB,
                                 &GDBM_READER,0640)) {
            @students=split(/:::/,$CacheData{'NamesOfStudents'});
        }
    }

    # Sort students and print out table desciptive data
    if(tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_READER,0640)) {
        if(!$c->aborted()) { @students=&SortStudents(\@students,\%CacheData); }
	if(!$c->aborted()) { $r->print(&CreateLegend()); }
	if(!$c->aborted()) { $r->rflush(); }
	if(!$c->aborted()) { $r->print(&CreateForm()); }
	if(!$c->aborted()) { $r->print(&CreateColumnSelectionBox(
                                                       \%CacheData,
                                                       \@studentInformation, 
						       \@headings, 
                                                       \@reselected,
                                                       $spacePadding)); }
        if(!$c->aborted()) { $r->print('<h3>'.(scalar @students).
                                       ' students</h3>'); }
	if(!$c->aborted()) { $r->print(&CreateColumnSelectors(
                                                       \%CacheData,
                                                       \@studentInformation, 
						       \@headings, 
                                                       \@reselected,
                                                       $spacePadding)); }
	if(!$c->aborted()) { $r->print(&CreateTableHeadings(
                                                         \%CacheData,
                                                         \@studentInformation, 
							 \@headings, 
                                                         \@reselected,
							 $spacePadding)); }
	if(!$c->aborted()) { $r->rflush(); }
	untie(%CacheData);
    } else {
	$r->print("Init2: Unable to tie hash to db file");
	return;
    }

    my @updateStudentList = ();
    my $courseData;
    foreach (@students) {
        if($c->aborted()) {
            if(!$isCached && 
               tie(%CacheData,'GDBM_File',$ChartDB,&GDBM_WRCREAT,0640)) {
                $CacheData{'NamesOfStudents'}=join(":::", @updateStudentList);
#		    $CacheData{'NamesOfStudents'}=
#		            &Apache::lonnet::arrayref2str(\@updateStudentList);
                untie(%CacheData);
            }
            last;
        }

        if(!$isCached) {
            $courseData=&DownloadStudentCourseInformation($_, $cid);
            if($c->aborted()) { next; }
            push(@updateStudentList, $_);
            &ExtractStudentData($courseData, $_, $ChartDB);
        }
        $r->print(&FormatStudentData(\@reselected, $_, $cid, 
                                     \@studentInformation,
                                     $spacePadding, $ChartDB));
        $r->rflush();
    }

    $r->print('</body></html>');
    $r->rflush();

    return;
}

# ================================================================ Main Handler

sub handler {
    my $r=shift;
    $jr=$r;
    unless(&Apache::lonnet::allowed('vgr',$ENV{'request.course.id'})) {
	$ENV{'user.error.msg'}=
        $r->uri.":vgr:0:0:Cannot view grades for complete course";
	return HTTP_NOT_ACCEPTABLE; 
    }

    # Set document type for header only
    if ($r->header_only) {
        if($ENV{'browser.mathml'}) {
            $r->content_type('text/xml');
        } else {
            $r->content_type('text/html');
        }
        &Apache::loncommon::no_cache($r);
        $r->send_http_header;
        return OK;
    }
    
    unless($ENV{'request.course.fn'}) {
        my $requrl=$r->uri;
        $ENV{'user.error.msg'}="$requrl:bre:0:0:Course not initialized";
        return HTTP_NOT_ACCEPTABLE; 
    }

    &BuildChart($r);

    return OK;
}
1;
__END__