# The LearningOnline Network with CAPA
#
# $Id: lonstudentsubmissions.pm,v 1.54 2009/04/21 13:28:23 bisitz Exp $
#
# Copyright Michigan State University Board of Trustees
#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
#
# LON-CAPA is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# LON-CAPA is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with LON-CAPA; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# /home/httpd/html/adm/gpl.txt
#
# http://www.lon-capa.org/
#
package Apache::lonstudentsubmissions;

use strict;
use Apache::lonnet;
use Apache::loncommon();
use Apache::lonhtmlcommon();
use Apache::loncoursedata();
use Apache::lonstatistics;
use Apache::lonlocal;
use Apache::lonstathelpers;
use HTML::Entities();
use Time::Local();
use Spreadsheet::WriteExcel();
use lib '/home/httpd/lib/perl/';
use LONCAPA;
  

my @SubmitButtons = ({ name => 'SelectAnother',
                       text => 'Choose a different Problem' },
                     { name => 'Generate',
                       text => 'Generate Report'},
                     );

sub BuildStudentSubmissionsPage {
    my ($r,$c)=@_;
    #
    my %Saveable_Parameters = ('Status' => 'scalar',
                               'Section' => 'array',
                               'NumPlots' => 'scalar',
                               );
    &Apache::loncommon::store_course_settings('student_submissions',
                                              \%Saveable_Parameters);
    &Apache::loncommon::restore_course_settings('student_submissions',
                                                \%Saveable_Parameters);
    #
    &Apache::lonstatistics::PrepareClasslist();
    #
    $r->print(&CreateInterface());
    #
    my @Students = @Apache::lonstatistics::Students;
    #
    if (@Students < 1) {
        $r->print('<div class="LC_warning">'
                 .&mt('There are no students in the sections selected.')
                 .'</div>');
    }
    #
    my @CacheButtonHTML = 
        &Apache::lonstathelpers::manage_caches($r,'Statistics','stats_status',
                                   '<div class="LC_info">'.&mt('Loading student data...').'</div>');
    $r->rflush();
    #
    if (exists($env{'form.problemchoice'}) && 
        ! exists($env{'form.SelectAnother'})) {
        foreach my $button (@SubmitButtons) {
            if ($button->{'name'} eq 'break') {
                $r->print("<br />\n");
            } else {
                $r->print('<input type="submit" name="'.$button->{'name'}.'" '.
                          'value="'.&mt($button->{'text'}).'" />');
                $r->print('&nbsp;'x5);
            }
        }
        foreach my $html (@CacheButtonHTML) {
            $r->print($html.('&nbsp;'x5));
        }
        #
        $r->print('<hr />'.$/);
        $r->rflush();
        #
        # Determine which problems we are to analyze
        my @Symbs = 
            &Apache::lonstathelpers::get_selected_symbs('problemchoice');
        foreach my $selected (@Symbs) {
            $r->print('<input type="hidden" name="problemchoice" value="'.
                      $selected.'" />'.$/);
        }
        #
        # Get resource objects
        my $navmap = Apache::lonnavmaps::navmap->new();
        if (!defined($navmap)) {
            $r->print('<div class="LC_error">'.&mt("Internal error").'</div>');
            return;
        }
        my %already_seen;
        my @Problems;
        foreach my $symb (@Symbs) {
            my $resource = $navmap->getBySymb($symb);
            push(@Problems,$resource);
        }
        # 
        $r->print('<h4>'.
                  &Apache::lonstatistics::section_and_enrollment_description().
                  '</h4>');
        if (! scalar(@Problems) || ! defined($Problems[0])) {
            $r->print('resource is undefined');
        } else {
            if (scalar(@Problems) == 1) {
                my $resource = $Problems[0];
                $r->print('<h1>'.$resource->title.'</h1>');
                $r->print('<h3>'.$resource->src.'</h3>');
                if ($env{'form.renderprob'} eq 'true') {
                    $r->print(&Apache::lonstathelpers::render_resource($resource));
                    $r->rflush();
                }
            }
            if ($env{'form.output'} eq 'excel') {
                &prepare_excel_output($r,\@Problems,\@Students);
            } elsif ($env{'form.output'} eq 'csv') {
                &prepare_csv_output($r,\@Problems,\@Students);
            } else {
                &prepare_html_output($r,\@Problems,\@Students);
            }
        }
        $r->print('<hr />');
    } else {
        $r->print('<input type="submit" name="Generate" value="'.
                  &mt('Prepare Report').'" />');
        $r->print('&nbsp;'x5);
        $r->print('<p>'.
                  &mt('Computing correct answers greatly increasese the amount of time required to prepare a report.').
                  '</p>');
        $r->print('<p>'.
                  &mt('Please select problems and use the [_1]Prepare Report[_2] button to continue.','<b>','</b>').
                  '</p>');
        $r->print(&Apache::lonstathelpers::MultipleProblemSelector
                  (undef,'problemchoice','Statistics'));
    }
}

##
## get_extra_response_headers
##
sub get_extra_response_headers {
    my @extra_resp_headers;
    if ($env{'form.correctans'} eq 'true') {
        push(@extra_resp_headers,'Correct');
    } 
    if ($env{'form.prob_status'} eq 'true') {
        push(@extra_resp_headers,'Award Detail'); 
        push(@extra_resp_headers,'Time');
        push(@extra_resp_headers,'Attempt');
        push(@extra_resp_headers,'Awarded');
    }
    return @extra_resp_headers;
}

##
## get_headers:
##     return the proper headers for the given response 
sub get_headers {
    my ($prob,$partid,$respid,$resptype,$analysis,$output,$purpose,
        @basic_headers) = @_;
    my @headers;
    if ($resptype eq 'essay' && $purpose eq 'display' &&
        ($output eq 'html')) {# || scalar(@{$prob->parts})!=1)) {
        @headers = ();
    } elsif ($resptype =~ /^(option|match|rank)$/) {
        my $prefix = '_';
        if ($purpose eq 'display') {
            $prefix = '';
        }
        my @foils = 
            map { 
                $prefix.$_; 
            } sort(keys(%{$analysis->{$partid.'.'.$respid}->{'_Foils'}}));
        if (scalar(@basic_headers) && $basic_headers[0] eq 'Correct') {
            @foils = map { ($_ , $_.' Correct') } @foils;
            shift(@basic_headers);  # Get rid of 'Correct'
        }
        @headers = (@foils,@basic_headers);
    } elsif (lc($resptype) eq 'task') {
        @headers = ('Grader','Status',@basic_headers,'Submission');
    } else {
        @headers = ('Submission',@basic_headers);
    }
    return @headers;
}

#########################################################
#########################################################
##
##    HTML Output Routines
##
#########################################################
#########################################################
sub prepare_html_output {
    my ($r,$problems,$students) = @_;
    my $c = $r->connection();
    #
    # Set a flag for the case when there is just one problem
    my $single_response = 0;
    if (scalar(@$problems) == 1 &&
        $problems->[0]->countResponses == 1) {
        $single_response = 1;
    }
    #
    # Compute the number of columns per response
    my @extra_resp_headers = &get_extra_response_headers();
    #
    # Create the table header
    my @student_columns = ('username','domain','id','section');
    #
    my %headers;
    my $student_column_count = scalar(@student_columns);
    $headers{'problem'} = qq{<th colspan="$student_column_count">\&nbsp;</th>};
    foreach (@student_columns) {
        $headers{'student'}.= '<th>'.ucfirst($_).'</th>';
    }
    #
    # we put the headers into the %headers hash
    my $total_col = scalar(@student_columns);
    my $nonempty_part_headers = 0;
    #
    my %problem_analysis;
    foreach my $prob (@$problems) {
        my %analysis = &Apache::lonstathelpers::get_problem_data($prob->src);
        $problem_analysis{$prob->src}=\%analysis;
        #
        my $prob_span = 0;
        my $single_part = 0;
        if (scalar(@{$prob->parts}) == 1) {
            $single_part = 1;
        }
        foreach my $partid (@{$prob->parts}) {
            my $part_span = 0;
            my $responses = [$prob->responseIds($partid)];
            my $resptypes = [$prob->responseType($partid)];
            for (my $i=0;$i<scalar(@$responses);$i++) {
                my $respid = $responses->[$i];
                my @headers = &get_headers($prob,$partid,$respid,
                                           $resptypes->[$i],
                                           $problem_analysis{$prob->src},
                                           'html','display',
                                           @extra_resp_headers);
                if (scalar(@headers)>0) {
                    $total_col += scalar(@headers);
                    $part_span += scalar(@headers);
                    $headers{'response'} .=
                        '<th colspan="'.scalar(@headers).'">'.
                        &mt('Response [_1]',$responses->[$i]).'</th>';
                    $headers{'student'}.= '<th><span class="LC_nobreak">'.
                                          join('</span></th><th><span class="LC_nobreak">',
                                                      @headers).
                                                          '</span></th>';
                }
            }
            if ($part_span == 0) {
                next;
            }
            if (! $single_part) {
                my $tmpname = $partid;
                if ($partid =~/^\d+$/) {
                    $tmpname = $prob->part_display($partid);
                }
                if ($tmpname !~ /^part/) {
                    $tmpname = 'Part '.$tmpname;
                }
                $headers{'part'} .= qq{<th colspan="$part_span">$tmpname</th>};
                $nonempty_part_headers = 1;
            } else {
                $headers{'part'} .= qq{<th colspan="$part_span">&nbsp;</th>};
            }
            $prob_span += $part_span;
        }
        my $title = $prob->compTitle;
        if ($prob_span > 0) {
            $headers{'problem'}.= qq{<th colspan="$prob_span">$title</th>};
        } elsif ($single_response) {
            $prob_span = scalar(@student_columns);
            $headers{'problem'} = qq{<th colspan="$prob_span">$title</th>};
        }
    }
    if (exists($headers{'part'})) {
        $headers{'part'} = qq{<th colspan="$student_column_count">\&nbsp;</th>}.
            $headers{'part'};
    }
    if (exists($headers{'response'})) {
        $headers{'response'}=
            qq{<th colspan="$student_column_count">\&nbsp;</th>}.
            $headers{'response'};
    }
    my $full_header = $/.'<table>'.$/;
    $full_header .= '<tr align="left">'.$headers{'problem'}.'</tr>'.$/;
    if ($nonempty_part_headers) {
        $full_header .= '<tr align="left">'.$headers{'part'}.'</tr>'.$/;
    }
    $full_header .= '<tr align="left">'.$headers{'response'}.'</tr>'.$/;
    $full_header .= '<tr align="left">'.$headers{'student'}.'</tr>'.$/;
    #
    # Main loop
    my $count;
    $r->print($/.$full_header.$/);
    my $row_class = 'odd';   # css 
    foreach my $student (@$students) {
        my $student_row_data;
        if ($count++ >= 30) {
            $r->print('</table>'.$/.$full_header.$/);
            $count = 0;
        }
        last if ($c->aborted());
        foreach my $field (@student_columns) {
            $student_row_data .= 
                '<td valign="top">'.$student->{$field}.'</td>';
        }
        #
        # Figure out what it is we need to output for this student
        my @essays;
        my %prob_data;
        my $maxrow;
        foreach my $prob (@$problems) {
            $prob_data{$prob->symb}={};
            foreach my $partid (@{$prob->parts}) {
                my @responses = $prob->responseIds($partid);
                my @response_type = $prob->responseType($partid);
                for (my $i=0;$i<=$#responses;$i++) {
                    my $respid  = $responses[$i];
                    my $results = 
                        &Apache::loncoursedata::get_response_data_by_student
                        ($student,$prob->symb(),$respid);
                    my $resptype = $response_type[$i];
                    my @headers = &get_headers($prob,$partid,$respid,
                                               $resptype,
                                               $problem_analysis{$prob->src},
                                               'html','normal',
                                               @extra_resp_headers);
                    my $width = scalar(@headers);
                    next if ($width < 1);
                    my $resp_data;
                    $resp_data->{'fake'} = qq{<td colspan="$width">&nbsp;</td>};
                    if (! defined($results)) {
                        $results = [];
                    }
                    # 
                    if (scalar(@$results) > $maxrow && $resptype ne 'essay') {
                        $maxrow = scalar(@$results);
                    }
                    for (my $j=scalar(@$results)-1;$j>=0;$j--) {
                        if ($env{'form.all_sub'} ne 'true') {
                            next if ($j ne scalar(@$results)-1);
                        }
                        my $response = &hashify_response($results->[$j],
                                                         $prob,
                                                         $student,
                                                         $partid,
                                                         $respid);
                        if ($resptype eq 'essay') {
                            push(@essays,
                                 &html_essay_results(\@headers,
                                                     $prob,$partid,$respid,
                                                     $response,
                                                     $single_response).
                                 '</td>');
			} elsif (lc($resptype) eq 'task') {
			    my $results = 
				&html_task_results(\@headers,
						   $prob,$partid,$respid,
						   $response,$resptype);
			    if ($results) {
				push(@{$resp_data->{'real'}},$results);
			    }
                        } else {
                            push(@{$resp_data->{'real'}},
                                 &html_non_essay_results(\@headers,
                                                         $prob,$partid,$respid,
                                                         $response,$resptype));
                        }
                    }
                    $prob_data{$prob->symb}->{$partid}->{$respid}=$resp_data;
                } # end of $i loop
            } # end of partid loop
        } # end of prob loop
        #
        # if there is no data, skip this student.
        next if (! $maxrow && ! scalar(@essays));
        #
        # Go through the problem data and output a row.
        if ($row_class eq 'even') {
            $row_class = 'odd'; 
        } else {
            $row_class = 'even'; 
        }
        my $printed_something;
        for (my $rows_output = 0;$rows_output<$maxrow;$rows_output++) {
            my $html;
            my $no_data = 1;
            foreach my $prob (@$problems) {
                foreach my $partid (@{$prob->parts}) {
                    my @responses     = $prob->responseIds($partid);
                    my @response_type = $prob->responseType($partid);
                    for (my $i=0;$i<=$#responses;$i++) {
                        my $respid   = $responses[$i];
                        my $resp_data = 
                            $prob_data{$prob->symb}->{$partid}->{$respid};
                        next if ($response_type[$i] eq 'essay');
                        if (defined($resp_data->{'real'}->[$rows_output])) {
                            $html .= $resp_data->{'real'}->[$rows_output];
                            $no_data = 0;
                        } else {
                            $html .= $resp_data->{'fake'};
                        }
                    }
                }
            }
            if (! $no_data) {
                $r->print(qq{<tr class="$row_class">$student_row_data$html</tr>}.$/);
                $printed_something=1;
            }
        }
        if (@essays) {
            my $tr = qq{<tr class="$row_class">};
            my $td = qq{<td  valign="top" class="essay" colspan="$total_col">};
            if (! $printed_something) {
                $r->print($tr.$student_row_data.'</tr>'.$/);
            }
            $r->print($tr.$td.
                      join('</td></tr>'.$/.$tr.$td,@essays).'</td></tr>'.$/);
            undef(@essays);
        }
    } # end of student loop
    return;
}

sub hashify_response {
    my ($response,$prob,$student,$partid,$respid) =@_;
    my $resp_hash = {};
    if ($env{'form.correctans'} eq 'true') {
        $resp_hash->{'Correct'} = 
            &Apache::lonstathelpers::get_student_answer
            ($prob,$student->{'username'},$student->{'domain'},
             $partid,$respid);
    }
    $resp_hash->{'Submission'} = 
        $response->[&Apache::loncoursedata::RDs_submission()];
    $resp_hash->{'Time'} = 
        $response->[&Apache::loncoursedata::RDs_timestamp()];
    $resp_hash->{'Attempt'} =
        $response->[&Apache::loncoursedata::RDs_tries()];
    $resp_hash->{'Awarded'} = 
        $response->[&Apache::loncoursedata::RDs_awarded()];
    if ($prob->is_task()) {
	$resp_hash->{'Grader'} = 
	    $response->[&Apache::loncoursedata::RDs_response_eval_2()];
	if ($resp_hash->{'Attempt'} eq '0') {
	    $resp_hash->{'Attempt'} = '';
	}
	$resp_hash->{'Award Detail'} = 
	    $response->[&Apache::loncoursedata::RDs_part_award()];
	$resp_hash->{'Status'} = 
	    $response->[&Apache::loncoursedata::RDs_response_eval()];
    } else {
	$resp_hash->{'Award Detail'} = 
	    $response->[&Apache::loncoursedata::RDs_awarddetail()];
    }

    return $resp_hash;
}

#####################################################
##
##     HTML helper routines
##
#####################################################
sub html_essay_results {
    my ($headers,$prob,$partid,$respid,$response,$single_response)=@_;
    if (! ref($headers) || ref($headers) ne 'ARRAY') {
        return '';
    }
    # Start of telling them what problem, part, and response
    my $Str;
    if (! $single_response) {
        my $id = $prob->compTitle;
        if (defined($partid) && $partid ne '0') {
            $id .= ' '.$prob->part_display($partid);
        }
        if (defined($respid)) {
            $id .= ' '.$respid;
        }
        $Str .= '<span class="LC_nobreak">'.$id.'</span>'.('&nbsp;'x4);
    }
    #
    shift(@$headers); # Get rid of the Submission header
    my $correct = '';
    if ($headers->[0] eq 'Correct') {
        $correct = &html_format_essay_sub($response->{'Correct'});
        shift(@$headers);
    }
    $Str .= '<span class="LC_nobreak">'.
        join('',
             map {
                 ('&nbsp;'x4).&mt($_.': [_1]',$response->{$_});
             } @$headers).'</span>';
    if (@$headers || ! $single_response) {
        $Str .= '<br />';
    }
    $Str .= &html_format_essay_sub($response->{'Submission'});
    #
    if (defined($correct) && $correct !~ /^\s*$/) {
        $Str .= '<hr /><b>'.&mt('Correct').'</b>'.$correct
    }
    return $Str;
}

sub html_format_essay_sub {
    my ($submission) = @_;
    return '' if (! defined($submission) || $submission eq '');
    $submission = &HTML::Entities::decode($submission);
    $submission =~ s/\\\"/\"/g;
    $submission =~ s/\\\'/\'/g;
    $submission =~ s|\\r\\n|$/|g;
    $submission = &HTML::Entities::encode($submission,'<>&"');
    $submission =~ s|$/\s*$/|$/</p><p>$/|g;
    $submission =~ s|\\||g;
    $submission = '<p>'.$submission.'</p>';
    return $submission;
}

sub html_task_results {
    my ($headers,$prob,$partid,$respid,$response,$resptype) = @_;
    if (! ref($headers) || ref($headers) ne 'ARRAY' || ! scalar(@$headers)) {
        return '';
    }

    my @values;
    @values = map { $response->{$_}; } @$headers;

    my $td = '<td valign="top">';
    my $str = $td.join('</td>'.$td,@values).'</td>';
    return $str;
}

sub html_non_essay_results {
    my ($headers,$prob,$partid,$respid,$response,$resptype) = @_;
    if (! ref($headers) || ref($headers) ne 'ARRAY' || ! scalar(@$headers)) {
        return '';
    }
    # 
    my $submission = &HTML::Entities::decode(&unescape($response->{'Submission'})); 
    return '' if (! defined($submission) || $submission eq '');
    $submission =~ s/\\\"/\"/g;
    $submission =~ s/\\\'/\'/g;
    if ($resptype eq 'radiobutton') {
        $submission = &HTML::Entities::encode($submission,'<>&"');
        $submission =~ s/=([^=])$//;
        $submission = '<span class="LC_nobreak">'.$submission.'</span>';
    }
    $response->{'Submission'} = $submission;
    #
    my @values;
    if ($resptype =~ /^(option|match|rank)$/) {
        my %submission = 
            map { 
                my ($foil,$value) = split('=',&unescape($_));
                ($foil,$value);
            } split('&',$response->{'Submission'});
        my %correct;
        if (exists($response->{'Correct'})) {
            %correct = 
                map { 
                    my ($foil,$value)=split('=',&unescape($_));
                    ($foil,$value);
                } split('&',$response->{'Correct'});
        }
        #
        foreach my $original_header (@$headers) {
            if ($original_header =~ /^_/) {
                # '_' denotes a foil column
                my ($header) = ($original_header =~ m/^_(.*)$/);
                my $option = '';
                if ( my ($foil) = ($header =~ /(.*) Correct$/)) {
                    if (exists($correct{$foil})) {
                        $option = $correct{$foil};
                    }
                } elsif (exists($submission{$header})) {
                    $option = $submission{$header};
                }
                push(@values,&HTML::Entities::encode($option));
            } elsif ($original_header eq 'Time') {
                push(@values,&Apache::lonlocal::locallocaltime($response->{$original_header}));
            } else {
                # A normal column
                push(@values,$response->{$original_header});
            }
        }
    } else {
        @values = map { $response->{$_}; } @$headers;
    }
    my $td = '<td valign="top">';
    my $str = $td.join('</td>'.$td,@values).'</td>';
    return $str;
}


#########################################################
#########################################################
##
##    Excel Output Routines
##
#########################################################
#########################################################
sub prepare_excel_output {
    my ($r,$Problems,$Students) = @_;
    my $c = $r->connection();
    #
    #
    # Determine the number of columns in the spreadsheet
    my $columncount = 3; # username, domain, id
    my @extra_resp_headers = &get_extra_response_headers();
    my $lastprob;
    my %problem_analysis;
    foreach my $prob (@$Problems) {
        my %analysis = &Apache::lonstathelpers::get_problem_data($prob->src);
        $problem_analysis{$prob->src}=\%analysis;
        foreach my $partid (@{$prob->parts}) {
            my $responses = [$prob->responseIds($partid)];
            my $resptypes = [$prob->responseType($partid)];
            for (my $i=0;$i<scalar(@$responses);$i++) {
                my @headers = &get_headers($prob,$partid,$responses->[$i],
                                           $resptypes->[$i],
                                           $problem_analysis{$prob->src},
                                           'excel','display',
                                           @extra_resp_headers);
                $columncount += scalar(@headers);
            }
        }
        last if ($columncount > 255);
        $lastprob = $prob;
    }
    if ($columncount > 255) {
        $r->print('<h1>'.&mt('Unable to complete request').'</h1>'.$/.
                  '<p>'.&mt('LON-CAPA is unable to produce your Excel spreadsheet because your selections will result in more than 255 columns.  Excel allows only 255 columns in a spreadsheet.').'</p>'.$/.
                  '<p>'.&mt('Consider selecting fewer problems to generate reports on, or reducing the number of items per problem.  Or use HTML or CSV output.').'</p>'.$/.
                  '<p>'.&mt('The last problem that will fit in the current spreadsheet is [_1].',$lastprob->compTitle).'</p>');
        $r->rflush();
        return;
    }
    #
    # Print out a message telling them what we are doing
    if (scalar(@$Problems) > 1) {
        $r->print('<h2>'.
                  &mt('Preparing Excel spreadsheet of student responses to [_1] problems',
                      scalar(@$Problems)).
                  '</h2>');
    } else {
        $r->print('<h2>'.
                  &mt('Preparing Excel spreadsheet of student responses').
                  '</h2>');
    }
    $r->rflush();
    #
    # Create the excel spreadsheet
    my ($workbook,$filename,$format) = 
        &Apache::loncommon::create_workbook($r);
    return if (! defined($workbook));
    my $worksheet  = $workbook->addworksheet('Student Submission Data');
    #
    # Add headers to the worksheet
    my $rows_output = 0;
    $worksheet->write($rows_output++,0,
                    $env{'course.'.$env{'request.course.id'}.'.description'},
                      $format->{'h1'});
    $rows_output++;
    my $cols_output = 0;
    my $title_row  = $rows_output++;
    my $partid_row = $rows_output++;
    my $respid_row = $rows_output++;
    my $header_row = $rows_output++;
    $worksheet->write($title_row ,0,'Problem Title',$format->{'bold'});
    $worksheet->write($partid_row,0,'Part ID',$format->{'bold'});
    $worksheet->write($respid_row,0,'Response ID',$format->{'bold'});
    # Student headers
    my @StudentColumns = ('username','domain','id','section');
    foreach (@StudentColumns) {
        $worksheet->write($header_row,$cols_output++,ucfirst($_),
                          $format->{'bold'});
    }
    # Problem headers
    my %start_col;
    foreach my $prob (@$Problems) {
        my $title = $prob->compTitle;
        $worksheet->write($title_row,$cols_output,
                          $title,$format->{'h3'});
        foreach my $partid (@{$prob->parts}) {
            $worksheet->write($partid_row,$cols_output,
                              $prob->part_display($partid));
            my $responses = [$prob->responseIds($partid)];
            my $resptypes = [$prob->responseType($partid)];
            for (my $i=0;$i<scalar(@$responses);$i++) {
                $start_col{$prob->symb}->{$partid}->{$responses->[$i]}=
                    $cols_output;
                $worksheet->write($respid_row,$cols_output,
                                  $resptypes->[$i].', '.$responses->[$i]);
                my @headers = &get_headers($prob,$partid,$responses->[$i],
                                           $resptypes->[$i],
                                           $problem_analysis{$prob->src},
                                           'excel','display',
                                           @extra_resp_headers);
                foreach my $text (@headers) {
                    if ($text eq 'Time') {
                        $worksheet->set_column($cols_output,$cols_output,undef,
                                               $format->{'date'});
                    } 
                    $worksheet->write($header_row,$cols_output++,$text);
                }
            }
        }
    }
    #
    # Populate the worksheet with the student data
    my %prog_state=&Apache::lonhtmlcommon::Create_PrgWin
        ($r,'Excel File Compilation Status',
         'Excel File Compilation Progress', 
         scalar(@$Students),'inline',undef,'Statistics','stats_status');
    my $max_row = $rows_output;
    foreach my $student (@$Students) {
        last if ($c->aborted());
        $cols_output = 0;
        my $student_row = $max_row;
        foreach my $field (@StudentColumns) {
            $worksheet->write($student_row,$cols_output++,
                              $student->{$field});
        }
        my $last_student_col = $cols_output-1;
        foreach my $prob (@$Problems) {
            foreach my $partid (@{$prob->parts}) {
                my @Response = $prob->responseIds($partid);
                my @ResponseType = $prob->responseType($partid);
                for (my $i=0;$i<=$#Response;$i++) {
                    my $respid   = $Response[$i];
                    my $resptype = $ResponseType[$i];
                    my $results = 
                        &Apache::loncoursedata::get_response_data_by_student
                        ($student,$prob->symb(),$respid);
                    my @headers = &get_headers($prob,$partid,$respid,
                                               $resptype,
                                               $problem_analysis{$prob->src},
                                               'excel','normal',
                                               @extra_resp_headers);

                    if (! defined($results)) {
                        $results = [];
                    }
                    #
                    $rows_output = $student_row;
                    #
                    my $response_start_col = $start_col{$prob->symb}->{$partid}->{$respid};
                    for (my $j=scalar(@$results)-1;$j>=0;$j--) {
                        $cols_output = $response_start_col;
                        if ($env{'form.all_sub'} ne 'true') {
                            next if ($j ne scalar(@$results)-1);
                        }
                        my $response = &hashify_response($results->[$j],
                                                         $prob,
                                                         $student,
                                                         $partid,
                                                         $respid);
                        my @response_data = 
                            &compile_response_data(\@headers,$response,
                                                   $prob,$partid,$respid,
                                                   $resptype,
                                                   \&excel_format_item);
                        $worksheet->write_row($rows_output++,$cols_output,
                                              \@response_data);
                        $cols_output+=scalar(@response_data);
                        if ($rows_output > $max_row) {
                            $max_row = $rows_output;
                        }
                    }
                }
            }
        }
        # Fill in the remaining rows with the students data
        for (my $row = $student_row+1;$row<$max_row;$row++) {
            my $cols = 0;
            foreach my $field (@StudentColumns) {
                $worksheet->write($row,$cols++,
                                  $student->{$field});
            }
        }
        &Apache::lonhtmlcommon::Increment_PrgWin($r,\%prog_state,
                                                 'last student');
    }
    &Apache::lonhtmlcommon::Close_PrgWin($r,\%prog_state);
    #
    # Close the excel file
    $workbook->close();
    #
    # Write a link to allow them to download it
    $r->print('<p><a href="'.$filename.'">'.
              &mt('Your Excel spreadsheet.').
              '</a></p>'."\n");
    $r->print('<script>'.
              'window.document.Statistics.stats_status.value="'.
              'Done compiling spreadsheet.  See link below to download.'.
              '";</script>');
    $r->rflush();
    return;
}

sub compile_response_data {
    my ($headers,$response,$prob,$partid,$respid,$resptype,$format) = @_;
    if (! ref($headers) || ref($headers) ne 'ARRAY' || ! scalar(@$headers)) {
        return ();
    }
    if (ref($format) ne 'CODE') {
        $format = sub { return $_[0]; };
    }
    #
    my $submission = 
        &HTML::Entities::decode
        (&unescape($response->{'Submission'}));
    if (!$prob->is_task()) {
	return () if (! defined($submission) || $submission eq '');
    }
    $submission =~ s/\\\"/\"/g;
    $submission =~ s/\\\'/\'/g;
    if ($resptype eq 'radiobutton') {
        $submission =~ s/=([^=])$//;
    }
    $response->{'Submission'} = $submission;
    #
    my @values;
    if ($resptype =~ /^(option|match|rank)$/) {
        my %submission = 
            map { 
                my ($foil,$value) = split('=',&unescape($_));
                ($foil,$value);
            } split('&',$response->{'Submission'});
        my %correct;
        if (exists($response->{'Correct'})) {
            %correct = 
                map { 
                    my ($foil,$value)=split('=',&unescape($_));
                    ($foil,$value);
                } split('&',$response->{'Correct'});
        }
        #
        foreach my $original_header (@$headers) {
            if ($original_header =~ /^_/) {
                # '_' denotes a foil column
                my ($header) = ($original_header =~ m/^_(.*)$/);
                my $option = '';
                if ( my ($foil) = ($header =~ /(.*) Correct$/)) {
                    if (exists($correct{$foil})) {
                        $option = $correct{$foil};
                    }
                } elsif (exists($submission{$header})) {
                    $option = $submission{$header};
                }
                push(@values,&{$format}($option,$header));
            } else {
                # A normal column
                push(@values,&{$format}($response->{$original_header},
                                        $original_header));
            }
        }
    } else {
        @values = map { &{$format}($response->{$_},$_); } @$headers;
    }
    return @values;
}

sub excel_format_item {
    my ($item,$type) = @_;
    if ($type eq 'Time') {
        $item = &Apache::lonstathelpers::calc_serial($item);
    } else {
        if ($item =~ m/^=/) {
            $item = ' '.$item;
        }
        $item =~ s/\\r//g;
        $item =~ s/\\n/\n/g;
        $item =~ s/(\s*$|^\s*)//g;
        $item =~ s/\\\'/\'/g;
    }
    return $item;
}

#########################################################
#########################################################
##
##      CSV output of student answers
##
#########################################################
#########################################################
sub prepare_csv_output {
    my ($r,$problems,$students) = @_;
    my $c = $r->connection();
    #
    $r->print('<h2>'.
              &mt('Generating CSV report of student responses').'</h2>');
    #
    # Progress window
    my %prog_state=&Apache::lonhtmlcommon::Create_PrgWin
        ($r,'CSV File Compilation Status',
         'CSV File Compilation Progress', 
         scalar(@$students),'inline',undef,'Statistics','stats_status');
    
    $r->rflush();
    #
    # Open a file
    my $outputfile;
    my $filename = '/prtspool/'.
        $env{'user.name'}.'_'.$env{'user.domain'}.'_'.
            time.'_'.rand(1000000000).'.csv';
    unless ($outputfile = Apache::File->new('>/home/httpd'.$filename)) {
        $r->log_error("Couldn't open $filename for output $!");
        $r->print('<div class="LC_error">'
                 .&mt('Problems occurred in writing the CSV file. '
                     .'This error has been logged. '
                     .'Please alert your LON-CAPA administrator.')
                 .'</div>');
        $outputfile = undef;
    }
    #
    # Compute the number of columns per response
    my @extra_resp_headers = &get_extra_response_headers();
    #
    # Create the table header
    my @student_columns = ('username','domain','id','section');
    #
    my %headers;
    push(@{$headers{'student'}},@student_columns);
    # Pad for the student data
    foreach my $row ('problem','part','response') {
        $headers{$row}=[map {''} @student_columns];
    }
    #
    # we put the headers into the %headers hash
    my %problem_analysis;
    my %start_col;
    my $max_column = scalar(@student_columns);
    foreach my $prob (@$problems) {
        my %analysis = &Apache::lonstathelpers::get_problem_data($prob->src);
        $problem_analysis{$prob->src}=\%analysis;
        $headers{'problem'}->[$max_column] = $prob->compTitle;
        foreach my $partid (@{$prob->parts}) {
            $headers{'part'}->[$max_column] = $prob->part_display($partid);
            my $responses = [$prob->responseIds($partid)];
            my $resptypes = [$prob->responseType($partid)];
            for (my $i=0;$i<scalar(@$responses);$i++) {
                my @headers = &get_headers($prob,$partid,$responses->[$i],
                                           $resptypes->[$i],
                                           $problem_analysis{$prob->src},
                                           'csv','display',
                                           @extra_resp_headers);
                $start_col{$prob->symb}->{$partid}->{$responses->[$i]}=
                    $max_column;
                $headers{'response'}->[$max_column]=
                    &mt('Response [_1]',$responses->[$i]);
                for (my $j=0;$j<=$#headers;$j++) {
                    $headers{'student'}->[$max_column+$j]=$headers[$j];
                }
                $max_column += scalar(@headers);
            }
        }
    }
    foreach my $row ('problem','part','response','student') {
        print $outputfile '"'.
            join('","',
                 map { 
                     &Apache::loncommon::csv_translate($_); 
                 } @{$headers{$row}}).'"'.$/;
    }
    #
    # Main loop
    foreach my $student (@$students) {
        last if ($c->aborted());
        my @rows;
        foreach my $prob (@$problems) {
            foreach my $partid (@{$prob->parts}) {
                my @responses = $prob->responseIds($partid);
                my @response_type = $prob->responseType($partid);
                for (my $i=0;$i<=$#responses;$i++) {
                    my $respid   = $responses[$i];
                    my $resptype = $response_type[$i];
                    my @headers = &get_headers($prob,$partid,$respid,$resptype,
                                               $problem_analysis{$prob->src},
                                               'csv','normal',
                                               @extra_resp_headers);
                    my $results = 
                        &Apache::loncoursedata::get_response_data_by_student
                        ($student,$prob->symb(),$respid);
                    if (! defined($results)) {
                        $results = [];
                    }
                    for (my $j=0; $j<scalar(@$results);$j++) {
                        if ($env{'form.all_sub'} ne 'true') {
                            next if ($j != 0);
                        }
                        my $idx = scalar(@$results) - $j - 1;
                        my $response = &hashify_response($results->[$idx],
                                                         $prob,$student,
                                                         $partid,$respid);
                        my @data = &compile_response_data(\@headers,$response,
                                                          $prob,$partid,
                                                          $respid,$resptype,
                                                          \&csv_format_item);
                        my $resp_start_idx =
                            $start_col{$prob->symb}->{$partid}->{$respid};
                        for (my $k=0;$k<=$#data;$k++) {
                            $rows[$j]->[$resp_start_idx + $k] = $data[$k];
                        }
                    }
                }
            }
        }
        foreach my $row (@rows) {
            print $outputfile '"'.join('","',
                                       map { $student->{$_}; }
                                       @student_columns).'"';
            for (my $i=scalar(@student_columns);$i<$max_column;$i++) {
                my $value = &Apache::loncommon::csv_translate($row->[$i]);
                $value ||='';
                print $outputfile ',"'.$value.'"';
            }
            print $outputfile $/;
        }
        undef(@rows);
        &Apache::lonhtmlcommon::Increment_PrgWin($r,\%prog_state,
                                                 'last student');
    }
    close($outputfile);
    #
    # Close the progress window
    &Apache::lonhtmlcommon::Close_PrgWin($r,\%prog_state);
    #
    # Tell the user where to get their CSV file
    $r->print('<br />'.
              '<a href="'.$filename.'">'.&mt('Your CSV file.').'</a>'."\n");
    $r->rflush();
    return;
}

sub csv_format_item {
    my ($item,$type) = @_;
    if ($type eq 'Time') {
        $item = localtime($item);
    }
    $item =&Apache::loncommon::csv_translate($item); 
    return $item;
}

#########################################################
#########################################################
##
##   Generic Interface Routines
##
#########################################################
#########################################################
sub CreateInterface {
    ##
    ## Output Selection
    my $output_selector = $/.'<select name="output">'.$/;
    foreach ('HTML','Excel','CSV') {
        $output_selector .= '    <option value="'.lc($_).'"';
        if ($env{'form.output'} eq lc($_)) {
            $output_selector .= ' selected ';
        }
        $output_selector .='>'.&mt($_).'</option>'.$/;
    } 
    $output_selector .= '</select>'.$/;
    ##
    ## Environment variable initialization
    my $Str = '';
    $Str .= &Apache::lonhtmlcommon::breadcrumbs('Student Submission Reports');
    $Str .= '<p>';
    $Str .= &Apache::loncommon::start_data_table();
    $Str .= &Apache::loncommon::start_data_table_header_row();
    $Str .= '<th>'.&mt('Sections').'</th>';
    $Str .= '<th>'.&mt('Groups').'</th>';
    $Str .= '<th>'.&mt('Access Status').'</th>';
    $Str .= '<th>'.&mt('Options').'</th>';
    $Str .= '<th>'.&mt('Output Format').'</th>';
    $Str .= &Apache::loncommon::end_data_table_header_row();
    #
    $Str .= &Apache::loncommon::start_data_table_row();
    $Str .= '<td align="center">'."\n";
    $Str .= &Apache::lonstatistics::SectionSelect('Section','multiple',5);
    $Str .= '</td>';
    #
    $Str .= '<td align="center">'."\n";
    $Str .= &Apache::lonstatistics::GroupSelect('Group','multiple',5);
    $Str .= '</td>';
    #
    $Str .= '<td align="center">';
    $Str .= &Apache::lonhtmlcommon::StatusOptions(undef,undef,5);
    $Str .= '</td>';
    #
    # Render problem checkbox
    my $prob_checkbox = '<input type="checkbox" name="renderprob" ';
    if (exists($env{'form.renderprob'}) && $env{'form.renderprob'} eq 'true') {
        $prob_checkbox .= 'checked="checked" ';
    }
    $prob_checkbox .= 'value="true" />';
    #
    # Compute correct answers checkbox
    my $ans_checkbox = '<input type="checkbox" name="correctans" ';
    if (exists($env{'form.correctans'}) && $env{'form.correctans'} eq 'true') {
        $ans_checkbox .= 'checked="checked" ';
    }
    $ans_checkbox .= 'value="true" />';
    #
    # Show all submissions checkbox
    my $all_sub_checkbox = '<input type="checkbox" name="all_sub" ';
    if (exists($env{'form.all_sub'}) && 
        $env{'form.all_sub'} eq 'true') {
        $all_sub_checkbox .= 'checked="checked" ';
    }
    $all_sub_checkbox.= 'value="true" />';
    #
    # problem status checkbox
    my $prob_status_checkbox = '<input type="checkbox" name="prob_status" ';
    if (exists($env{'form.prob_status'}) && 
        $env{'form.prob_status'} eq 'true') {
        $prob_status_checkbox .= 'checked="checked" ';
    }
    $prob_status_checkbox .= 'value="true" />';
    #
    $Str .= '<td align="right" valign="top">'.
        '<label><b>'.
        &mt('Show problem').' '.$prob_checkbox.'</b></label><br />'.
        '<label><b>'.
        &mt('Show correct answers').' '.$ans_checkbox.'</b></label><br />'.
        '<label><b>'.
        &mt('Show all submissions').' '.$all_sub_checkbox.
        '</b></label><br />'.
        '<label><b>'.
        &mt('Show problem grading').' '.$prob_status_checkbox.
        '</b></label><br />'.
        '</td>';
    #
    $Str .= '<td align="center" valign="top">'.$output_selector.'</td>';
    #
    $Str .= &Apache::loncommon::end_data_table_row();
    $Str .= &Apache::loncommon::end_data_table();
    #
    $Str .= '<p><span class="LC_nobreak">'
           .&mt('Status: [_1]',
                    '<input type="text" name="stats_status"'
                   .' size="60" value="" readonly="readonly" />')
           .'</span></p>';
    $Str .= '</p>';
    ##
    return $Str;
}

1;

__END__
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</head><body>
<h1>Internal Server Error</h1>
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<p>Please contact the server administrator at 
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