# The LearningOnline Network with CAPA
# Spreadsheet/Grades Display Handler
#
# 11/11,11/15,11/27,12/04,12/05,12/06,12/07,
# 12/08,12/09,12/11,12/12,12/15,12/16,12/18,12/19,12/30,
# 01/01/01,02/01 Gerd Kortemeyer

package Apache::lonspreadsheet;

use strict;
use Safe;
use Safe::Hole;
use Opcode;
use Apache::lonnet;
use Apache::Constants qw(:common :http);
use GDBM_File;
use HTML::TokeParser;

#
# These cache hashes need to be independent of user, resource and course
# (user and course can/should be in the keys)
#
use vars qw(%spreadsheets %courserdatas %userrdatas %defaultsheets);

#
# These global hashes are dependent on user, course and resource, 
# and need to be initialized every time when a sheet is calculated
#
my %courseopt;
my %useropt;
my %parmhash;

# =============================================================================
# ===================================== Implements an instance of a spreadsheet

sub initsheet {
    my $safeeval = new Safe;
    my $safehole = new Safe::Hole;
    $safeeval->permit("entereval");
    $safeeval->permit(":base_math");
    $safeeval->permit("sort");
    $safeeval->deny(":base_io");
    $safehole->wrap(\&Apache::lonnet::EXT,$safeeval,'&EXT');
    my $code=<<'ENDDEFS';
# ---------------------------------------------------- Inside of the safe space

#
# f: formulas
# t: intermediate format (variable references expanded)
# v: output values
# c: preloaded constants (A-column)
# rl: row label

%v=(); 
%t=();
%f=();
%c=();
%rl=();

$maxrow=0;
$sheettype='';

# filename/reference of the sheet

$filename='';

# user data
$uname='';
$uhome='';
$udom='';

# course data

$csec='';
$chome='';
$cnum='';
$cdom='';

# symb

$usymb='';

sub mask {
    my ($lower,$upper)=@_;

    $lower=~/([A-Za-z]|\*)(\d+|\*)/;
    my $la=$1;
    my $ld=$2;

    $upper=~/([A-Za-z]|\*)(\d+|\*)/;
    my $ua=$1;
    my $ud=$2;
    my $alpha='';
    my $num='';

    if (($la eq '*') || ($ua eq '*')) {
       $alpha='[A-Za-z]';
    } else {
       if (($la=~/[A-Z]/) && ($ua=~/[A-Z]/) ||
           ($la=~/[a-z]/) && ($ua=~/[a-z]/)) {
          $alpha='['.$la.'-'.$ua.']';
       } else {
          $alpha='['.$la.'-Za-'.$ua.']';
       }
    }   

    if (($ld eq '*') || ($ud eq '*')) {
	$num='\d+';
    } else {
        if (length($ld)!=length($ud)) {
           $num.='(';
	   map {
              $num.='['.$_.'-9]';
           } ($ld=~m/\d/g);
           if (length($ud)-length($ld)>1) {
              $num.='|\d{'.(length($ld)+1).','.(length($ud)-1).'}';
	   }
           $num.='|';
           map {
               $num.='[0-'.$_.']';
           } ($ud=~m/\d/g);
           $num.=')';
       } else {
           my @lda=($ld=~m/\d/g);
           my @uda=($ud=~m/\d/g);
           my $i; $j=0; $notdone=1;
           for ($i=0;($i<=$#lda)&&($notdone);$i++) {
               if ($lda[$i]==$uda[$i]) {
		   $num.=$lda[$i];
                   $j=$i;
               } else {
                   $notdone=0;
               }
           }
           if ($j<$#lda-1) {
	       $num.='('.$lda[$j+1];
               for ($i=$j+2;$i<=$#lda;$i++) {
                   $num.='['.$lda[$i].'-9]';
               }
               if ($uda[$j+1]-$lda[$j+1]>1) {
		   $num.='|['.($lda[$j+1]+1).'-'.($uda[$j+1]-1).']\d{'.
                   ($#lda-$j-1).'}';
               }
	       $num.='|'.$uda[$j+1];
               for ($i=$j+2;$i<=$#uda;$i++) {
                   $num.='[0-'.$uda[$i].']';
               }
               $num.=')';
           } else {
               if ($lda[$#lda]!=$uda[$#uda]) {
                  $num.='['.$lda[$#lda].'-'.$uda[$#uda].']';
	       }
           }
       }
    }
    return '^'.$alpha.$num."\$";
}

sub NUM {
    my $mask=mask(@_);
    my $num=0;
    map {
        $num++;
    } grep /$mask/,keys %v;
    return $num;   
}

sub BIN {
    my ($low,$high,$lower,$upper)=@_;
    my $mask=mask($lower,$upper);
    my $num=0;
    map {
        if (($v{$_}>=$low) && ($v{$_}<=$high)) {
            $num++;
        }
    } grep /$mask/,keys %v;
    return $num;   
}


sub SUM {
    my $mask=mask(@_);
    my $sum=0;
    map {
        $sum+=$v{$_};
    } grep /$mask/,keys %v;
    return $sum;   
}

sub MEAN {
    my $mask=mask(@_);
    my $sum=0; my $num=0;
    map {
        $sum+=$v{$_};
        $num++;
    } grep /$mask/,keys %v;
    if ($num) {
       return $sum/$num;
    } else {
       return undef;
    }   
}

sub STDDEV {
    my $mask=mask(@_);
    my $sum=0; my $num=0;
    map {
        $sum+=$v{$_};
        $num++;
    } grep /$mask/,keys %v;
    unless ($num>1) { return undef; }
    my $mean=$sum/$num;
    $sum=0;
    map {
        $sum+=($v{$_}-$mean)**2;
    } grep /$mask/,keys %v;
    return sqrt($sum/($num-1));    
}

sub PROD {
    my $mask=mask(@_);
    my $prod=1;
    map {
        $prod*=$v{$_};
    } grep /$mask/,keys %v;
    return $prod;   
}

sub MAX {
    my $mask=mask(@_);
    my $max='-';
    map {
        unless ($max) { $max=$v{$_}; }
        if (($v{$_}>$max) || ($max eq '-')) { $max=$v{$_}; }
    } grep /$mask/,keys %v;
    return $max;   
}

sub MIN {
    my $mask=mask(@_);
    my $min='-';
    map {
        unless ($max) { $max=$v{$_}; }
        if (($v{$_}<$min) || ($min eq '-')) { $min=$v{$_}; }
    } grep /$mask/,keys %v;
    return $min;   
}

sub SUMMAX {
    my ($num,$lower,$upper)=@_;
    my $mask=mask($lower,$upper);
    my @inside=();
    map {
	$inside[$#inside+1]=$v{$_};
    } grep /$mask/,keys %v;
    @inside=sort(@inside);
    my $sum=0; my $i;
    for ($i=$#inside;(($i>$#inside-$num) && ($i>=0));$i--) { 
        $sum+=$inside[$i];
    }
    return $sum;   
}

sub SUMMIN {
    my ($num,$lower,$upper)=@_;
    my $mask=mask($lower,$upper);
    my @inside=();
    map {
	$inside[$#inside+1]=$v{$_};
    } grep /$mask/,keys %v;
    @inside=sort(@inside);
    my $sum=0; my $i;
    for ($i=0;(($i<$num) && ($i<=$#inside));$i++) { 
        $sum+=$inside[$i];
    }
    return $sum;   
}

sub sett {
    %t=();
    my $pattern='';
    if ($sheettype eq 'assesscalc') {
	$pattern='A';
    } else {
        $pattern='[A-Z]';
    }
    map {
	if ($_=~/template\_(\w)/) {
	  my $col=$1;
          unless ($col=~/^$pattern/) {
            map {
	      if ($_=~/A(\d+)/) {
		my $trow=$1;
                if ($trow) {
		    my $lb=$col.$trow;
                    $t{$lb}=$f{'template_'.$col};
                    $t{$lb}=~s/\#/$trow/g;
                    $t{$lb}=~s/\.\.+/\,/g;
                    $t{$lb}=~s/(^|[^\"\'])([A-Za-z]\d+)/$1\$v\{\'$2\'\}/g;
                }
	      }
            } keys %f;
	  }
      }
    } keys %f;
    map {
	if (($f{$_}) && ($_!~/template\_/)) {
            if ($_=~/^$pattern/) {
	        unless ($f{$_}=~/^\!/) {
		    $t{$_}=$c{$_};
                }
            } else {
	       $t{$_}=$f{$_};
               $t{$_}=~s/\.\.+/\,/g;
               $t{$_}=~s/(^|[^\"\'])([A-Za-z]\d+)/$1\$v\{\'$2\'\}/g;
            }
        }
    } keys %f;
    $t{'A0'}=$f{'A0'};
    $t{'A0'}=~s/\.\.+/\,/g;
    $t{'A0'}=~s/(^|[^\"\'])([A-Za-z]\d+)/$1\$v\{\'$2\'\}/g;
}

sub calc {
    %v=();
    &sett();
    my $notfinished=1;
    my $depth=0;
    while ($notfinished) {
	$notfinished=0;
        map {
            my $old=$v{$_};
            $v{$_}=eval($t{$_});
	    if ($@) {
		%v=();
                return $@;
            }
	    if ($v{$_} ne $old) { $notfinished=1; }
        } keys %t;
        $depth++;
        if ($depth>100) {
	    %v=();
            return 'Maximum calculation depth exceeded';
        }
    }
    return '';
}

sub templaterow {
    my @cols=();
    $cols[0]='<b><font size=+1>Template</font></b>';
    map {
        my $fm=$f{'template_'.$_};
        $fm=~s/[\'\"]/\&\#34;/g;
        $cols[$#cols+1]="'template_$_','$fm'".'___eq___'.$fm;
    } ('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',
       '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');
    return @cols;
}

sub outrowassess {
    my $n=shift;
    my @cols=();
    if ($n) {
       $cols[0]=$rl{$f{'A'.$n}};
    } else {
       $cols[0]='<b><font size=+1>Export</font></b>';
    }
    map {
        my $fm=$f{$_.$n};
        $fm=~s/[\'\"]/\&\#34;/g;
        $cols[$#cols+1]="'$_$n','$fm'".'___eq___'.$v{$_.$n};
    } ('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',
       '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');
    return @cols;
}

sub outrow {
    my $n=shift;
    my @cols=();
    if ($n) {
       $cols[0]=$rl{$f{'A'.$n}};
    } else {
       $cols[0]='<b><font size=+1>Export</font></b>';
    }
    map {
        my $fm=$f{$_.$n};
        $fm=~s/[\'\"]/\&\#34;/g;
        $cols[$#cols+1]="'$_$n','$fm'".'___eq___'.$v{$_.$n};
    } ('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',
       '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');
    return @cols;
}

sub exportrowa {
    my $rowa='';
    map {
	$rowa.=$v{$_.'0'}."___;___";
    } ('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');
    $rowa=~s/\_\_\_\;\_\_\_$//;
    return $rowa;
}

# ------------------------------------------- End of "Inside of the safe space"
ENDDEFS
    $safeeval->reval($code);
    return $safeeval;
}

# ------------------------------------------------ Add or change formula values

sub setformulas {
    my ($safeeval,@f)=@_;
    $safeeval->reval('%f='."('".join("','",@f)."');");
}

# ------------------------------------------------ Add or change formula values

sub setconstants {
    my ($safeeval,@c)=@_;
    $safeeval->reval('%c='."('".join("','",@c)."');");
}

# ------------------------------------------------ Add or change formula values

sub setrowlabels {
    my ($safeeval,@rl)=@_;
    $safeeval->reval('%rl='."('".join("','",@rl)."');");
}

# ------------------------------------------------------- Calculate spreadsheet

sub calcsheet {
    my $safeeval=shift;
    $safeeval->reval('&calc();');
}

# ------------------------------------------------------------------ Get values

sub getvalues {
    my $safeeval=shift;
    return $safeeval->reval('%v');
}

# ---------------------------------------------------------------- Get formulas

sub getformulas {
    my $safeeval=shift;
    return $safeeval->reval('%f');
}

# -------------------------------------------------------------------- Set type

sub settype {
    my ($safeeval,$type)=@_;
    $safeeval->reval('$sheettype="'.$type.'";');
}

# -------------------------------------------------------------------- Get type

sub gettype {
    my $safeeval=shift;
    return $safeeval->reval('$sheettype');
}

# ------------------------------------------------------------------ Set maxrow

sub setmaxrow {
    my ($safeeval,$row)=@_;
    $safeeval->reval('$maxrow='.$row.';');
}

# ------------------------------------------------------------------ Get maxrow

sub getmaxrow {
    my $safeeval=shift;
    return $safeeval->reval('$maxrow');
}

# ---------------------------------------------------------------- Set filename

sub setfilename {
    my ($safeeval,$fn)=@_;
    $safeeval->reval('$filename="'.$fn.'";');
}

# ---------------------------------------------------------------- Get filename

sub getfilename {
    my $safeeval=shift;
    return $safeeval->reval('$filename');
}

# ----------------------------------------------------------- Get course number

sub getcnum {
    my $safeeval=shift;
    return $safeeval->reval('$cnum');
}

# ------------------------------------------------------------- Get course home

sub getchome {
    my $safeeval=shift;
    return $safeeval->reval('$chome');
}

# ----------------------------------------------------------- Get course domain

sub getcdom {
    my $safeeval=shift;
    return $safeeval->reval('$cdom');
}

# ---------------------------------------------------------- Get course section

sub getcsec {
    my $safeeval=shift;
    return $safeeval->reval('$csec');
}

# --------------------------------------------------------------- Get user name

sub getuname {
    my $safeeval=shift;
    return $safeeval->reval('$uname');
}

# ------------------------------------------------------------- Get user domain

sub getudom {
    my $safeeval=shift;
    return $safeeval->reval('$udom');
}

# --------------------------------------------------------------- Get user home

sub getuhome {
    my $safeeval=shift;
    return $safeeval->reval('$uhome');
}

# -------------------------------------------------------------------- Get symb

sub getusymb {
    my $safeeval=shift;
    return $safeeval->reval('$usymb');
}

# ------------------------------------------------------------- Export of A-row

sub exportrow {
    my $safeeval=shift;
    return $safeeval->reval('&exportrowa()');
}

# ========================================================== End of Spreadsheet
# =============================================================================

#
# Procedures for screen output
#
# --------------------------------------------- Produce output row n from sheet

sub rown {
    my ($safeeval,$n)=@_;
    my $defaultbg;
    my $rowdata='';
    unless ($n eq '-') {
       $defaultbg=((($n-1)/5)==int(($n-1)/5))?'#E0E0':'#FFFF';
    } else {
       $defaultbg='#E0FF';
    }
    if ((($n-1)/25)==int(($n-1)/25)) {
        my $what='Student';
        if (&gettype($safeeval) eq 'assesscalc') {
	    $what='Item';
	} elsif (&gettype($safeeval) eq 'studentcalc') {
            $what='Assessment';
        }
	$rowdata.="</table>\n<br><table border=2>".
        '<tr><td>&nbsp;<td>'.$what.'</td>';
        map {
           $rowdata.='<td>'.$_.'</td>';
        } ('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',
           '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');
        $rowdata.='</tr>';
    }
    $rowdata.="\n<tr><td><b><font size=+1>$n</font></b></td>";
    my $showf=0;
    my $proc;
    my $maxred;
    if (&gettype($safeeval) eq 'assesscalc') {
        $proc='&outrowassess';
        $maxred=1;
    } else {
        $proc='&outrow';
        $maxred=26;
    }
    if ($n eq '-') { $proc='&templaterow'; $n=-1; }
    map {
       my $bgcolor=$defaultbg.((($showf-1)/5==int(($showf-1)/5))?'99':'DD');
       my ($fm,$vl)=split(/\_\_\_eq\_\_\_/,$_);
       if ($showf==0) { $vl=$_; }
       if ($showf<=$maxred) { $bgcolor='#FFDDDD'; }
       if (($n==0) && ($showf<=26)) { $bgcolor='#CCCCFF'; } 
       if (($showf>$maxred) || ((!$n) && ($showf>0))) {
	   if ($vl eq '') {
	       $vl='<font size=+2 color='.$bgcolor.'>&#35;</font>';
           }
           $rowdata.=
       '<td bgcolor='.$bgcolor.'><a href="javascript:celledit('.$fm.');">'.$vl.
	       '</a></td>';
       } else {
           $rowdata.='<td bgcolor='.$bgcolor.'>&nbsp;'.$vl.'&nbsp;</td>';
       }
       $showf++;
    } $safeeval->reval($proc.'('.$n.')');
    return $rowdata.'</tr>';
}

# ------------------------------------------------------------- Print out sheet

sub outsheet {
    my ($r,$safeeval)=@_;
    my $maxred;
    my $realm;
    if (&gettype($safeeval) eq 'assesscalc') {
        $maxred=1;
        $realm='Assessment';
    } elsif (&gettype($safeeval) eq 'studentcalc') {
        $maxred=26;
        $realm='User';
    } else {
        $maxred=26;
        $realm='Course';
    }
    my $maxyellow=52-$maxred;
    my $tabledata=
        '<table border=2><tr><th colspan=2 rowspan=2><font size=+2>'.
                  $realm.'</font></th>'.
                  '<td bgcolor=#FFDDDD colspan='.$maxred.
                  '><b><font size=+1>Import</font></b></td>'.
                  '<td colspan='.$maxyellow.
		  '><b><font size=+1>Calculations</font></b></td></tr><tr>';
    my $showf=0;
    map {
        $showf++;
        if ($showf<=$maxred) { 
           $tabledata.='<td bgcolor="#FFDDDD">'; 
        } else {
           $tabledata.='<td>';
        }
        $tabledata.="<b><font size=+1>$_</font></b></td>";
    } ('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',
       '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');
    $tabledata.='</tr>';
    my $row;
    my $maxrow=&getmaxrow($safeeval);
    $tabledata.=&rown($safeeval,'-');
    $r->print($tabledata);
    for ($row=0;$row<=$maxrow;$row++) {
        $r->print(&rown($safeeval,$row));
    }
    $r->print('</table>');
}

#
# -------------------------------------- Read spreadsheet formulas for a course
#

sub readsheet {
  my ($safeeval,$fn)=@_;
  my $stype=&gettype($safeeval);
  my $cnum=&getcnum($safeeval);

# --------- There is no filename. Look for defaults in course and global, cache

  unless($fn) {
      unless ($fn=$defaultsheets{$cnum.'_'.$stype}) {
         $fn=&Apache::lonnet::reply('get:'.
                $ENV{'course.'.$ENV{'request.course.id'}.'.domain'}.':'.
                $ENV{'course.'.$ENV{'request.course.id'}.'.num'}.
                ':environment:spreadsheet_default_'.&gettype($safeeval),
                     $ENV{'course.'.$ENV{'request.course.id'}.'.home'});
         unless (($fn) && ($fn!~/^error\:/)) {
	     $fn='default_'.$stype;
         }
         $defaultsheets{$cnum.'_'.$stype}=$fn; 
      }
  }

# ---------------------------------------------------------- fn now has a value

  &setfilename($safeeval,$fn);

# ------------------------------------------------------ see if sheet is cached
  my $fstring='';
  if ($fstring=$spreadsheets{$cnum.'_'.$stype.'_'.$fn}) {
      &setformulas($sheetone,split(/\_\_\_\;\_\_\_/,$fstring));
  } else {

# ---------------------------------------------------- Not cached, need to read

     my %f=();

     if ($fn=~/^default\_/) {
	my $sheetxml='';
       {
         my $fh;
         if ($fh=Apache::File->new($r->dir_config('lonIncludes').
                         '/default.'.&gettype($safeeval))) {
               $sheetxml=join('',<$fh>);
          }
       }
        my $parser=HTML::TokeParser->new(\$sheetxml);
        my $token;
        while ($token=$parser->get_token) {
          if ($token->[0] eq 'S') {
 	     if ($token->[1] eq 'field') {
 		 $f{$token->[2]->{'col'}.$token->[2]->{'row'}}=
 		     $parser->get_text('/field');
 	     }
             if ($token->[1] eq 'template') {
                 $f{'template_'.$token->[2]->{'col'}}=
                     $parser->get_text('/template');
             }
          }
        }
      } else {
        my $sheet='';
        my $reply=&Apache::lonnet::reply('dump:'.
              $ENV{'course.'.$ENV{'request.course.id'}.'.domain'}.':'.
              $ENV{'course.'.$ENV{'request.course.id'}.'.num'}.':'.$fn,
              $ENV{'course.'.$ENV{'request.course.id'}.'.home'});
          unless ($reply=~/^error\:/) {
             $sheet=$reply;
	  }
          map {
             my ($name,$value)=split(/\=/,$_);
             $f{&Apache::lonnet::unescape($name)}=
	        &Apache::lonnet::unescape($value);
          } split(/\&/,$sheet);
       }
# --------------------------------------------------------------- Cache and set
       $spreadsheets{$cnum.'_'.$stype.'_'.$fn}=join('___;___',%f);       
       &setformulas($safeeval,%f);
    }
}

# ------------------------------------------------------------ Save spreadsheet

sub writesheet {
  my $safeeval=shift;
  if (&Apache::lonnet::allowed('opa',$ENV{'request.course.id'})) {
    my %f=&getformulas($safeeval);
    my $sheetdata='';
    map {
       $sheetdata.=&Apache::lonnet::escape($_).'='.
	   &Apache::lonnet::escape($f{$_}).'&';
    } keys %f;
    $sheetdata=~s/\&$//;
    my $reply=&Apache::lonnet::reply('put:'.
              $ENV{'course.'.$ENV{'request.course.id'}.'.domain'}.':'.
              $ENV{'course.'.$ENV{'request.course.id'}.'.num'}.':'.
              &getfilename($safeeval).':'.
              $sheetdata,
              $ENV{'course.'.$ENV{'request.course.id'}.'.home'});
    if ($reply eq 'ok') {
          return &Apache::lonnet::reply('put:'.
              $ENV{'course.'.$ENV{'request.course.id'}.'.domain'}.':'.
              $ENV{'course.'.$ENV{'request.course.id'}.'.num'}.':'.
              &gettype($safeeval).'_spreadsheets:'.
              &Apache::lonnet::escape(&getfilename($safeeval)).'='.
              $ENV{'user.name'},
              $ENV{'course.'.$ENV{'request.course.id'}.'.home'});    
      } else {
	  return $reply;
      }
  }
  return 'unauthorized';
}

# ----------------------------------------------- Make a temp copy of the sheet

sub tmpwrite {
    my ($safeeval,$tmpdir,$symb)=@_;
    my $fn=$uname.'_'.$udom.'_spreadsheet_'.$symb.'_'.&getfilename($safeeval);
    $fn=~s/\W/\_/g;
    $fn=$tmpdir.$fn.'.tmp';
    my $fh;
    if ($fh=Apache::File->new('>'.$fn)) {
	print $fh join("\n",&getformulas($safeeval));
    }
}

# ---------------------------------------------------------- Read the temp copy

sub tmpread {
    my ($safeeval,$tmpdir,$symb,$nfield,$nform)=@_;
    my $fn=$uname.'_'.$udom.'_spreadsheet_'.$symb.'_'.&getfilename($safeeval);
    $fn=~s/\W/\_/g;
    $fn=$tmpdir.$fn.'.tmp';
    my $fh;
    my %fo=();
    if ($fh=Apache::File->new($fn)) {
        my $name;
        while ($name=<$fh>) {
	    chomp($name);
            my $value=<$fh>;
            chomp($value);
            $fo{$name}=$value;
        }
    }
    if ($nfield) { $fo{$nfield}=$nform; }
    &setformulas($safeeval,%fo);
}

# --------------------------------------------------------------- Read metadata

sub readmeta {
    my $fn=shift;
    unless ($fn=~/\.meta$/) { $fn.='meta'; }
    my $content;
    my %returnhash=();
    {
      my $fh=Apache::File->new($fn);
      $content=join('',<$fh>);
    }
   my $parser=HTML::TokeParser->new(\$content);
   my $token;
   while ($token=$parser->get_token) {
      if ($token->[0] eq 'S') {
         my $entry=$token->[1];
         if (($entry eq 'stores') || ($entry eq 'parameter')) {
             my $unikey=$entry;
             $unikey.='_'.$token->[2]->{'part'}; 
             $unikey.='_'.$token->[2]->{'name'}; 
             $returnhash{$unikey}=$token->[2]->{'display'};
         }
     }
  }
    return %returnhash;
}

# ================================================================== Parameters
# -------------------------------------------- Figure out a cascading parameter

sub parmval {
    my ($what,$symb)=@_;

    unless ($symb) { return ''; }
    my $result='';

    my ($mapname,$id,$fn)=split(/\_\_\_/,$symb);
# ----------------------------------------------------- Cascading lookup scheme
       my $rwhat=$what;
       $what=~s/^parameter\_//;
       $what=~s/\_/\./;

       my $symbparm=$symb.'.'.$what;
       my $mapparm=$mapname.'___(all).'.$what;

       my $seclevel=
            $ENV{'request.course.id'}.'.['.
		$csec.'].'.$what;
       my $seclevelr=
            $ENV{'request.course.id'}.'.['.
		$csec.'].'.$symbparm;
       my $seclevelm=
            $ENV{'request.course.id'}.'.['.
		$csec.'].'.$mapparm;

       my $courselevel=
            $ENV{'request.course.id'}.'.'.$what;
       my $courselevelr=
            $ENV{'request.course.id'}.'.'.$symbparm;
       my $courselevelm=
            $ENV{'request.course.id'}.'.'.$mapparm;

# ---------------------------------------------------------- fourth, check user
      
      if ($uname) { 

       if ($useropt{$courselevelr}) { return $useropt{$courselevelr}; }

       if ($useropt{$courselevelm}) { return $useropt{$courselevelm}; }

       if ($useropt{$courselevel}) { return $useropt{$courselevel}; }

      }

# --------------------------------------------------------- third, check course
     
       if ($csec) {
 
        if ($courseopt{$seclevelr}) { return $courseopt{$seclevelr}; }

        if ($courseopt{$seclevelm}) { return $courseopt{$seclevelm}; }  

        if ($courseopt{$seclevel}) { return $courseopt{$seclevel}; }
  
      }

       if ($courseopt{$courselevelr}) { return $courseopt{$courselevelr}; }

       if ($courseopt{$courselevelm}) { return $courseopt{$courselevelm}; }

       if ($courseopt{$courselevel}) { return $courseopt{$courselevel}; }

# ----------------------------------------------------- second, check map parms

       my $thisparm=$parmhash{$symbparm};
       if ($thisparm) { return $thisparm; }

# -------------------------------------------------------- first, check default

       return &Apache::lonnet::metadata($fn,$rwhat.'.default');
        
}

# ---------------------------------------------- Update rows for course listing

sub updatestudentrows {
    my $safeeval=shift;
    my $cid=$ENV{'request.course.id'};
    my $classlst=&Apache::lonnet::reply
                 ('dump:'.$ENV{'course.'.$cid.'.domain'}.':'.
	                  $ENV{'course.'.$cid.'.num'}.':classlist',
	                  $ENV{'course.'.$cid.'.home'});
    my %currentlist=();
    my $now=time;
    unless ($classlst=~/^error\:/) {
        map {
            my ($name,$value)=split(/\=/,$_);
            my ($end,$start)=split(/\:/,&Apache::lonnet::unescape($value));
            my $active=1;
            if (($end) && ($now>$end)) { $active=0; }
            if ($active) {
                my $rowlabel='';
                $name=&Apache::lonnet::unescape($name);
                my ($cname,$cdom)=split(/\:/,$name);
                my $csec=
             &Apache::lonnet::usection($cdom,$cname,$ENV{'request.course.id'});
                if ($csec==-1) {
                    $rowlabel='<font color=red>Data not available: '.$name.
			      '</font>';
                } else {
                    my %reply=&Apache::lonnet::idrget($cdom,$cname);
                    my $reply=&Apache::lonnet::reply('get:'.$cdom.':'.$cname.
		      ':environment:firstname&middlename&lastname&generation',
                      &Apache::lonnet::homeserver($cname,$cdom));
                    $rowlabel=$csec.'&nbsp;'.$reply{$cname}.'<br>';
                    map {
                        $rowlabel.=&Apache::lonnet::unescape($_).' ';
                    } split(/\&/,$reply);
                }
               
		$currentlist{&Apache::lonnet::unescape($name)}=$rowlabel;
            }
        } split(/\&/,$classlst);
#
# -------------------- Find discrepancies between the course row table and this
#
        my %f=&getformulas($safeeval);
        my $changed=0;

        my $maxrow=0;
        my %existing=();

# ----------------------------------------------------------- Now obsolete rows
	map {
	    if ($_=~/^A(\d+)/) {
                $maxrow=($1>$maxrow)?$1:$maxrow;
                $existing{$f{$_}}=1;
		unless ((defined($currentlist{$f{$_}})) || (!$1)) {
		   $f{$_}='!!! Obsolete';
                   $changed=1;
                }
            }
        } keys %f;

# -------------------------------------------------------- New and unknown keys
     
        map {
            unless ($existing{$_}) {
		$changed=1;
                $maxrow++;
                $f{'A'.$maxrow}=$_;
            }
        } sort keys %currentlist;        
     
        if ($changed) { &setformulas($safeeval,%f); }

        &setmaxrow($safeeval,$maxrow);
        &setrowlabels($safeeval,%currentlist);

    } else {
        return 'Could not access course data';
    }
}
# ----------------------------------------------------------------- Update rows

sub updaterows {
    my $safeeval=shift;
    my %bighash;
# -------------------------------------------------------------------- Tie hash
      if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
                       &GDBM_READER,0640)) {
# --------------------------------------------------------- Get all assessments

	my %allkeys=();
        my %allassess=();

        my $stype=&gettype($safeeval);

        map {
	    if ($_=~/^src\_(\d+)\.(\d+)$/) {
	       my $mapid=$1;
               my $resid=$2;
               my $id=$mapid.'.'.$resid;
               my $srcf=$bighash{$_};
               if ($srcf=~/\.(problem|exam|quiz|assess|survey|form)$/) {
                 my $symb=
                     &Apache::lonnet::declutter($bighash{'map_id_'.$mapid}).
			    '___'.$resid.'___'.
			    &Apache::lonnet::declutter($srcf);
		 $allassess{$symb}=$bighash{'title_'.$id};

                 if ($stype eq 'assesscalc') {
                   map {
                       if (($_=~/^stores\_(.*)/) || ($_=~/^parameter\_(.*)/)) {
			  my $key=$_;
                          my $display=
			      &Apache::lonnet::metadata($srcf,$key.'.display');
                          unless ($display) {
                              $display=
			         &Apache::lonnet::metadata($srcf,$key.'.name');
                          }
                          $allkeys{$key}=$display;
		       }
                   } split(/\,/,&Apache::lonnet::metadata($srcf,'keys'));
	         }
	      }
	   }
        } keys %bighash;
        untie(%bighash);
    
#
# %allkeys has a list of storage and parameter displays by unikey
# %allassess has a list of all resource displays by symb
#
# -------------------- Find discrepancies between the course row table and this
#
        my %f=&getformulas($safeeval);
        my $changed=0;

        my %current=();
        if ($stype eq 'assesscalc') {
	    %current=%allkeys;
        } elsif ($stype eq 'studentcalc') {
            %current=%allassess;
        }

        my $maxrow=0;
        my %existing=();

# ----------------------------------------------------------- Now obsolete rows
	map {
	    if ($_=~/^A(\d+)/) {
                $maxrow=($1>$maxrow)?$1:$maxrow;
                $existing{$f{$_}}=1;
		unless ((defined($current{$f{$_}})) || (!$1)) {
		   $f{$_}='!!! Obsolete';
                   $changed=1;
                }
            }
        } keys %f;

# -------------------------------------------------------- New and unknown keys
     
        map {
            unless ($existing{$_}) {
		$changed=1;
                $maxrow++;
                $f{'A'.$maxrow}=$_;
            }
        } keys %current;        
     
        if ($changed) { &setformulas($safeeval,%f); }

        &setmaxrow($safeeval,$maxrow);
        &setrowlabels($safeeval,%current);

    } else {
        return 'Could not access course data';
    }
}

# ------------------------------------------------ Load data for one assessment

sub rowazstudent {
    my $safeeval=shift;
    my %c=();
    my %f=&getformulas($safeeval);
    map {
	if ($_=~/^A(\d+)/) {
	   my $row=$1;
           unless ($f{$_}=~/^\!/) {
              my @assessdata=split(/\_\_\_\;\_\_\_/,
                             &Apache::lonnet::ssi(
                       '/adm/assesscalc',('utarget' => 'export',
                                          'uname'   => $uname,
                                          'udom'    => $udom,
			                  'usymb'   => $f{$_})));
              my $index=0;
              map {
                  if ($assessdata[$index]) {
		     $c{$_.$row}=$assessdata[$index];
                     unless ($_ eq 'A') { 
			 $f{$_.$row}='import';
                     }
		  }
                  $index++;
              } ('A','B','C','D','E','F','G','H','I','J','K','L','M',
                 'N','O','P','Q','R','S','T','U','V','W','X','Y','Z');
	   }
        }
    } keys %f;
    &setformulas($safeeval,%f);
    &setconstants($safeeval,%c);
}

# --------------------------------------------------- Load data for one student

sub rowazclass {
    my $safeeval=shift;
    my %c=();
    my %f=&getformulas($safeeval);
    map {
	if ($_=~/^A(\d+)/) {
	   my $row=$1;
           unless ($f{$_}=~/^\!/) {
	      my ($tname,$tdom)=split(/\:/,$_);
              my @assessdata=split(/\_\_\_\;\_\_\_/,
                             &Apache::lonnet::ssi(
                      '/adm/studentcalc',('utarget' => 'export',
                                          'uname'   => $tname,
                                          'udom'    => $tdom)));
              my $index=0;
              map {
                  if ($assessdata[$index]) {
		     $c{$_.$row}=$assessdata[$index];
                     unless ($_ eq 'A') { 
			 $f{$_.$row}='import';
                     }
		  }
                  $index++;
              } ('A','B','C','D','E','F','G','H','I','J','K','L','M',
                 'N','O','P','Q','R','S','T','U','V','W','X','Y','Z');
	   }
        }
    } keys %f;
    &setformulas($safeeval,%f);
    &setconstants($safeeval,%c);
}

# ------------------------------------------------ Load data for one assessment

sub rowaassess {
    my ($safeeval,$symb)=@_;
    my $uhome=&Apache::lonnet::homeserver($uname,$udom);
    my $namespace;
    unless ($namespace=$ENV{'request.course.id'}) { return ''; }

# ----------------------------------------------------------- Get stored values
    my $answer=&Apache::lonnet::reply(
       "restore:$udom:$uname:".
       &Apache::lonnet::escape($namespace).":".
       &Apache::lonnet::escape($symb),$uhome);
    my %returnhash=();
    map {
	my ($name,$value)=split(/\=/,$_);
        $returnhash{&Apache::lonnet::unescape($name)}=
                    &Apache::lonnet::unescape($value);
    } split(/\&/,$answer);
    my $version;
    for ($version=1;$version<=$returnhash{'version'};$version++) {
       map {
          $returnhash{$_}=$returnhash{$version.':'.$_};
       } split(/\:/,$returnhash{$version.':keys'});
    }
# ----------------------------- returnhash now has all stores for this resource

# ---------------------------- initialize coursedata and userdata for this user
    %courseopt=();
    %useropt=();
    my $uhome=&Apache::lonnet::homeserver($uname,$udom);
    unless ($uhome eq 'no_host') { 
# -------------------------------------------------------------- Get coursedata
      unless
        ((time-$courserdatas{$ENV{'request.course.id'}.'.last_cache'})<120) {
         my $reply=&Apache::lonnet::reply('dump:'.
              $ENV{'course.'.$ENV{'request.course.id'}.'.domain'}.':'.
              $ENV{'course.'.$ENV{'request.course.id'}.'.num'}.':resourcedata',
              $ENV{'course.'.$ENV{'request.course.id'}.'.home'});
         if ($reply!~/^error\:/) {
            $courserdatas{$ENV{'request.course.id'}}=$reply;
            $courserdatas{$ENV{'request.course.id'}.'.last_cache'}=time;
         }
      }
      map {
         my ($name,$value)=split(/\=/,$_);
         $courseopt{&Apache::lonnet::unescape($name)}=
                    &Apache::lonnet::unescape($value);  
      } split(/\&/,$courserdatas{$ENV{'request.course.id'}});
# --------------------------------------------------- Get userdata (if present)
      unless
        ((time-$userrdatas{$uname.'___'.$udom.'.last_cache'})<120) {
         my $reply=
       &Apache::lonnet::reply('dump:'.$udom.':'.$uname.':resourcedata',$uhome);
         if ($reply!~/^error\:/) {
	     $userrdatas{$uname.'___'.$udom}=$reply;
	     $userrdatas{$uname.'___'.$udom.'.last_cache'}=time;
         }
      }
      map {
         my ($name,$value)=split(/\=/,$_);
         $useropt{&Apache::lonnet::unescape($name)}=
	          &Apache::lonnet::unescape($value);
      } split(/\&/,$userrdatas{$uname.'___'.$udom});
   }
# -- now courseopt, useropt initialized for this user and course (used parmval)

    my %c=();
    my %f=&getformulas($safeeval);
    map {
	if ($_=~/^A/) {
            unless ($f{$_}=~/^\!/) {
  	       if ($f{$_}=~/^parameter/) {
	          $c{$_}=&parmval($f{$_},$symb);
	       } else {
		  my $key=$f{$_};
                  $key=~s/^stores\_/resource\./;
                  $key=~s/\_/\./;
 	          $c{$_}=$returnhash{$key};
	       }
	   }
        }
    } keys %f;

    &setconstants($safeeval,%c);
}

# --------------------------------------------------------- Various form fields

sub textfield {
    my ($title,$name,$value)=@_;
    return "\n<p><b>$title:</b><br>".
           '<input type=text name="'.$name.'" size=80 value="'.$value.'">';
}

sub hiddenfield {
    my ($name,$value)=@_;
    return "\n".'<input type=hidden name="'.$name.'" value="'.$value.'">';
}

sub selectbox {
    my ($title,$name,$value,%options)=@_;
    my $selout="\n<p><b>$title:</b><br>".'<select name="'.$name.'">';
    map {
        $selout.='<option value="'.$_.'"';
        if ($_ eq $value) { $selout.=' selected'; }
        $selout.='>'.$options{$_}.'</option>';
    } sort keys %options;
    return $selout.'</select>';
}

# ================================================================ Main handler

sub handler {
    my $r=shift;

    $uname='';
    $udom='';
    $csec='';

   if ($r->header_only) {
      $r->content_type('text/html');
      $r->send_http_header;
      return OK;
   }

# ----------------------------------------------------- Needs to be in a course

  if (($ENV{'request.course.fn'}) || 
      ($ENV{'request.state'} eq 'construct')) { 

# --------------------------- Get query string for limited number of parameters

    map {
       my ($name, $value) = split(/=/,$_);
       $value =~ tr/+/ /;
       $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
       if (($name eq 'uname') || ($name eq 'udom') || 
           ($name eq 'usymb') || ($name eq 'ufn')) {
           unless ($ENV{'form.'.$name}) {
              $ENV{'form.'.$name}=$value;
	   }
       }
    } (split(/&/,$ENV{'QUERY_STRING'}));

# ------------------------------------------- Nothing there? Must be login user
    unless ($ENV{'form.uname'}) {
	$uname=$ENV{'user.name'};
        $udom=$ENV{'user.domain'};
    } else {
        $uname=$ENV{'form.uname'};
        $udom=$ENV{'form.udom'};
    }
# ----------------------------------------------------------- Change of target?

    my $reroute=($ENV{'form.utarget'} eq 'export');

# ------------------------------------------------------------------- Open page

    $r->content_type('text/html');
    $r->header_out('Cache-control','no-cache');
    $r->header_out('Pragma','no-cache');
    $r->send_http_header;

# --------------------------------------------------------------- Screen output

  unless ($reroute) {
    $r->print('<html><head><title>LON-CAPA Spreadsheet</title>');
    $r->print(<<ENDSCRIPT);
<script language="JavaScript">

    function celledit(cn,cf) {
        var cnf=prompt(cn,cf);
	if (cnf!=null) {
	    document.sheet.unewfield.value=cn;
            document.sheet.unewformula.value=cnf;
            document.sheet.submit();
        }
    }

</script>
ENDSCRIPT
    $r->print('</head><body bgcolor="#FFFFFF">'.
       '<img align=right src=/adm/lonIcons/lonlogos.gif>'.
       '<h1>LON-CAPA Spreadsheet</h1>'.
       '<form action="'.$r->uri.'" name=sheet method=post>'.
       &hiddenfield('uname',$ENV{'form.uname'}).
       &hiddenfield('udom',$ENV{'form.udom'}).
       &hiddenfield('usymb',$ENV{'form.usymb'}).
       &hiddenfield('unewfield','').
       &hiddenfield('unewformula',''));
  }
    $r->rflush();
# ---------------------------------------- Read new sheet or modified worksheet

    my $sheetone=initsheet();
    $r->uri=~/\/(\w+)$/;
    &settype($sheetone,$1);
    if ($ENV{'form.unewfield'}) {
        $r->print('<h2>Modified Workcopy</h2>');
        $ENV{'form.unewformula'}=~s/\'/\"/g;
        $r->print('<p>New formula: '.$ENV{'form.unewfield'}.'='.
                  $ENV{'form.unewformula'}.'<p>');
        &setfilename($sheetone,$ENV{'form.ufn'});
	&tmpread($sheetone,$r->dir_config('lonDaemons').'/tmp/',
                 $ENV{'form.usymb'},
                 $ENV{'form.unewfield'},$ENV{'form.unewformula'});
    } elsif ($ENV{'form.saveas'}) {
        &setfilename($sheetone,$ENV{'form.ufn'});
	&tmpread($sheetone,$r->dir_config('lonDaemons').'/tmp/',
                 $ENV{'form.usymb'});
    } else {
        unless ($ENV{'form.ufn'}) {
    }

  if (&gettype($sheetone) eq 'classcalc') {
# ---------------------------------- For course view: get courselist and update
       &updatestudentrows($sheetone);
  } else {
# ----------------- For assessment and student: See if all import rows uptodate

    if (tie(%parmhash,'GDBM_File',
       $ENV{'request.course.fn'}.'_parms.db',&GDBM_READER,0640)) {
       $csec=&Apache::lonnet::usection($udom,$uname,$ENV{'request.course.id'});
       if ($csec eq '-1') {
          $r->print('<h3><font color=red>'.
   "User '$uname' at domain '$udom' not a student in this course</font></h3>");
       }
       &updaterows($sheetone);
       untie(%parmhash);
   } else {
       $r->print('<h3><font color=red>'.
	   'Could not initialize import fields (not in a course)</font></h3>');
   }
 }
# ---------------------------------------------------- See if something to save
    if (&Apache::lonnet::allowed('opa',$ENV{'request.course.id'})) {
        my $fname='';
	if ($ENV{'form.saveas'} && ($fname=$ENV{'form.newfn'})) {
            $fname=~s/\W/\_/g;
            if ($fname eq 'default') { $fname='course_default'; }
            $fname.='_'.&gettype($sheetone);
            &setfilename($sheetone,$fname);
            $ENV{'form.ufn'}=$fname;
            my $reply=&writesheet($sheetone);
            unless ($reroute) {
		$r->print('<p>Saving spreadsheet: '.$reply.'<p>');
            }
            if ($ENV{'form.makedefufn'}) {
                my $reply=&Apache::lonnet::reply('put:'.
                     $ENV{'course.'.$ENV{'request.course.id'}.'.domain'}.':'.
                     $ENV{'course.'.$ENV{'request.course.id'}.'.num'}.
                     ':environment:spreadsheet_default_'.
                     &gettype($sheetone).'='.
                     &Apache::lonnet::escape($fname),
                     $ENV{'course.'.$ENV{'request.course.id'}.'.home'});
               unless ($reroute) {
	           $r->print('<p>Making default spreadsheet: '.$reply.'<p>');
               }
            }
        }
    }
# ------------------------------------------------ Write the modified worksheet

   &tmpwrite($sheetone,$r->dir_config('lonDaemons').'/tmp/',
              $ENV{'form.usymb'});

# ----------------------------------------------------- Print user, course, etc
   unless ($reroute) {
    if (&Apache::lonnet::allowed('opa',$ENV{'request.course.id'})) {
        my $fname=$ENV{'form.ufn'};
        $fname=~s/\_[^\_]+$//;
        if ($fname eq 'default') { $fname='course_default'; }
        $r->print('<input type=submit name=saveas value="Save as ...">'.
              '<input type=text size=20 name=newfn value="'.$fname.
              '"> (make default: <input type=checkbox name="makedefufn">)<p>');
    }
    $r->print(&hiddenfield('ufn',$ENV{'form.ufn'}));
    unless (&gettype($sheetone) eq 'classcalc') {
        $r->print('<br><b>User:</b> '.$uname.'<br><b>Domain:</b> '.$udom);
    }
    $r->print('<h1>'.
            $ENV{'course.'.$ENV{'request.course.id'}.'.description'}.'</h1>');
    if ($csec) {
       $r->print('<h3>Group/Section: '.$csec.'</h3>');
    }
   }
# -------------------------------------------------------- Import and calculate

    if (&gettype($sheetone) eq 'assesscalc') {
	&rowaassess($sheetone,$ENV{'form.usymb'});
    } elsif  (&gettype($sheetone) eq 'studentcalc') {
	&rowazstudent($sheetone);
    } else {
        &rowazclass($sheetone);
    }
    my $calcoutput=&calcsheet($sheetone);
    unless ($reroute) {
       $r->print('<h3><font color=red>'.$calcoutput.'</h3></font>');
    }

# ------------------------------------------------------- Print or export sheet
   unless ($reroute) {   
    &outsheet($r,$sheetone);

    $r->print('</form></body></html>');
  } else {
     $r->print(&exportrow($sheetone));
  }
# ------------------------------------------------------------------------ Done
  } else {
# ----------------------------- Not in a course, or not allowed to modify parms
      $ENV{'user.error.msg'}=
        $r->uri.":opa:0:0:Cannot modify spreadsheet";
      return HTTP_NOT_ACCEPTABLE; 
  }
    return OK;
}

1;
__END__