# The LearningOnline Network with CAPA
#
# $Id: loncorrectproblemplot.pm,v 1.7 2004/02/20 16:38:49 matthew 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::loncorrectproblemplot;

use strict;
use Apache::lonnet();
use Apache::loncommon();
use Apache::lonhtmlcommon();
use Apache::loncoursedata();
use Apache::lonstatistics;
use Apache::lonstathelpers;
use Apache::lonlocal;

my @SubmitButtons = (
                     { name => 'CreatePlot',
                       text => 'Create Plot' },
                     { name => 'ClearCache',
                       text => 'Clear Caches' },
                     { name => 'updatecaches',
                       text => 'Update Student Data' },
                     );

#########################################################
#########################################################

=pod

=item &BuildCorrectProblemsPage

Entry point from lonstatistics to the correct problems plot page.

=cut

#########################################################
#########################################################

sub BuildCorrectProblemsPage {
    my ($r,$c)=@_;
    #
    my %Saveable_Parameters = ('Status' => 'scalar',
                               'Section' => 'array');
    &Apache::loncommon::store_course_settings('correct_problems_plot',
                                              \%Saveable_Parameters);
    &Apache::loncommon::restore_course_settings('correct_problems_plot',
                                                \%Saveable_Parameters);
    #
    &Apache::lonstatistics::PrepareClasslist();    
    #
    $r->print(&CreateInterface());
    #
    my @Students = @Apache::lonstatistics::Students;
    #
    if (@Students < 1) {
        $r->print('<h2>'.
                  &mt('There are no students in the sections selected').
                  '</h2>');
    }
    #
    &Apache::loncoursedata::clear_internal_caches();
    if (exists($ENV{'form.ClearCache'}) || 
        exists($ENV{'form.updatecaches'}) ||
        (exists($ENV{'form.firstanalysis'}) &&
         $ENV{'form.firstanalysis'} ne 'no')) {
        &Apache::lonstatistics::Gather_Full_Student_Data($r);
    }
    if (! exists($ENV{'form.firstanalysis'})) {
        $r->print('<input type="hidden" name="firstanalysis" value="yes" />');
    } else {
        $r->print('<input type="hidden" name="firstanalysis" value="no" />');
    }
    foreach my $button (@SubmitButtons) {
        $r->print('<input type="submit" name="'.$button->{'name'}.'" '.
                  'value="'.&mt($button->{'text'}).'" />');
        $r->print('&nbsp;'x5);
    }
    $r->rflush();
    #
    # Determine which problem symbs we are to sum over
    if (exists($ENV{'form.CreatePlot'})) {
        my @ProblemSymbs;
        if ($Apache::lonstatistics::SelectedMaps[0] ne 'all') {
            foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()){
                foreach my $res (@{$seq->{'contents'}}) {
                    next if ($res->{'type'} ne 'assessment');
                    foreach my $part (@{$res->{'parts'}}) {
                        push(@ProblemSymbs,{symb=>$res->{'symb'},
                                            part=>$part});
                    }
                }
            }
        }
        my $score_data = &Apache::loncoursedata::get_student_scores
            (\@Apache::lonstatistics::SelectedSections,
             \@ProblemSymbs,
             $Apache::lonstatistics::enrollment_status);
        $r->print(&AnalyzeScoreData($score_data));
    }
    return;
}

#########################################################
#########################################################

=pod

=item & AnalyzeScoreData($score_data)

Analyze the result of &Apache::loncoursedata::get_student_scores() and
return html with a plot of the data and a table of the values and bins.

=cut

#########################################################
#########################################################
sub AnalyzeScoreData {
    my ($score_data) = @_;
    #
    # Basic check first
    if (@$score_data < 1) {
        return '<h2>There is no data to plot</h2>';
    }
    #
    # Determine which bins to use
    my $lowest  = $score_data->[0]->[0];
    $lowest = 0;
    my $highest = $score_data->[-1]->[0];
    my $binsize = 1;
    if ($highest > 50) { $binsize = 2; }
    if ($highest > 100) { $binsize = 5; }
    if ($highest > 200) { $binsize = 10; }
    if ($highest > 500) { $binsize = 20; }
    if ($highest > 1000) { $binsize = 50; }
    if ($highest > 2000) { $binsize = 100; }
    #
    # Get the data into the bins (destroying $score_data in the process)
    my @Bins = &bin_data($score_data,$binsize,$lowest,$highest);
    my @Xdata; my @Ydata; my $max;
    my $Str = '<table border="1">'."\n".'<tr><th>Range</th><th>Count</th></tr>'."\n";
    while (my $bin = shift(@Bins)) {
        push (@Xdata,$bin->{'start'});
        push (@Ydata,$bin->{'count'});
        if ($bin->{'count'} > $max) {
            $max = $bin->{'count'};
        }
        $Str.= '<tr><td>'.$bin->{'start'}.' - '.$bin->{'end'}.'</td>'.
            '<td>'.$bin->{'count'}.'</td></tr>'."\n";
    }
    # scale max to an integer.
    $max = 5*(int($max/5)+1);
    my $title = 'Correct Problems Plot';
    $Str .= "</table><br />\n";
    $Str = "<br />\n".&Apache::loncommon::DrawBarGraph($title,
                                                       'Num Correct Problems',
                                                       'Number of students',
                                                       $max,
                                                       undef, # colors
                                                       \@Xdata,
                                                       \@Ydata).
                                                           "\n<br />\n".$Str;
    return $Str;                                               
}


#########################################################
#########################################################

=pod

=item &bin_data($data,$binsize,$startbin,$endbin)

Note: This routine destroys the array of data passed to it.

Inputs: $data: array reference - the contents of @$data must
        be arrays with x and y data.  $data = [ [x1,y1],[x2,y2],...];
        $binsize: Width of bins to put data in
        $startbin: the starting bin.
        $endbin: the ending bin.
Returns: Array of Bins.  Each bin is a hash reference with the following
         keys: 'start', 'count', and 'end'.

=cut

#########################################################
#########################################################
sub bin_data {
    my ($data,$binsize,$startbin,$endbin)=@_;
    return () if (! defined($data) || ref($data) ne 'ARRAY');
    #
    # Determine bin geometry
    my $binstart = $startbin;
    my $binend = $startbin+$binsize;
    # put the data into bins
    my @Bins;
    my $count=0;
    my $idx=0;
    while ($idx < scalar(@$data) && ($binend-$endbin)<$binsize) {
        my $dataset = $data->[$idx++];
        my ($x,$y) = @{$dataset};
        while ($x > $binend) {
            # store the old data
            push (@Bins,{ start => $binstart,
                          count => $count,
                          end   => $binend });
            # start counting again
            $binstart += $binsize;
            $binend += $binsize;
            $count = 0;
        }
        $count+=$y;
    }
    return @Bins;
}

#########################################################
#########################################################

=pod

=item &CreateInterface

Inputs: none.

Returns: HTML for the correct problems plot interface.

=cut

#########################################################
#########################################################
sub CreateInterface {
    ##
    ## Environment variable initialization
    my $Str;
    $Str .= &Apache::lonhtmlcommon::breadcrumbs
        (undef,&mt('Correct Problems Plot'));
    $Str .= '<table cellspacing="5">'."\n";
    $Str .= '<tr>';
    $Str .= '<td align="center"><b>'.&mt('Sections').'</b></td>';
    $Str .= '<td align="center"><b>'.&mt('Enrollment Status').'</b></td>';
    $Str .= '<td align="center"><b>'.&mt('Sequences and Folders').'</b></td>';
    $Str .= '</tr>'."\n";
    ##
    ## 
    $Str .= '<tr><td align="center">'."\n";
    $Str .= &Apache::lonstatistics::SectionSelect('Section','multiple',5);
    $Str .= '</td>';
    #
    $Str .= '<td align="center">';
    $Str .= &Apache::lonhtmlcommon::StatusOptions(undef,undef,5);
    $Str .= '</td><td>'."\n";
    #
    my $only_seq_with_assessments = sub { 
        my $s=shift;
        if ($s->{'num_assess'} < 1) { 
            return 0;
        } else { 
            return 1;
        }
    };
    $Str .= &Apache::lonstatistics::MapSelect('Maps','multiple,all',5,
                                              $only_seq_with_assessments);
    $Str .= '</td><td>'."\n";
    ##
    $Str .= '</tr>'."\n";
    $Str .= '</table>'."\n";
    return $Str;
}

1;

__END__