# The LearningOnline Network with CAPA
# Directory Indexer
#
# $Id: lonindexer.pm,v 1.67 2003/06/16 17:27:33 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/
#
# YEAR=1999
# 5/21/99, 5/22,5/25,5/26,5/31,6/2,6/10,7/12,7/14 Gerd Kortemeyer)
# 11/23 Gerd Kortemeyer
# YEAR=2000
# 07/20-08/04 H.K. Ng
# YEAR=2001
# 05/9-05/19/2001 H. K. Ng
# 05/21/2001 H. K. Ng
# 05/23/2001 H. K. Ng
# 6/26,7/8 H. K. Ng
# 8/14 H. K. Ng
# 11/30 Matthew Hall
# YEAR=2002
# 6/29/2002 H. K. Ng
#
###

###############################################################################
##                                                                           ##
## ORGANIZATION OF THIS PERL MODULE                                          ##
##                                                                           ##
## 1. Description of functions                                               ##
## 2. Modules used by this module                                            ##
## 3. Choices for different output views (detailed, summary, xml, etc)       ##
## 4. BEGIN block (to be run once after compilation)                         ##
## 5. Handling routine called via Apache and mod_perl                        ##
## 6. Other subroutines                                                      ##
##                                                                           ##
###############################################################################

package Apache::lonindexer;

# ------------------------------------------------- modules used by this module
use strict;
use Apache::lonnet();
use Apache::loncommon();
use Apache::Constants qw(:common);
use Apache::File;
use GDBM_File;

# ---------------------------------------- variables used throughout the module
my %hash; # tied to a user-specific gdbm file
my %dirs; # keys are directories, values are the open/close status
my %language; # has the reference information present in language.tab

# ----- Values which are set by the handler subroutine and are accessible to
# -----     other methods.
my $extrafield; # default extra table cell
my $fnum; # file counter
my $dnum; # directory counter

# ----- Used to include or exclude files with certain extensions.
my @Only = ();
my @Omit = ();


# ----------------------------- Handling routine called via Apache and mod_perl
sub handler {
    my $r = shift;
    my $c = $r->connection();
    $r->content_type('text/html');
    &Apache::loncommon::no_cache($r);
    $r->send_http_header;
    return OK if $r->header_only;
    $fnum=0;
    $dnum=0;

    # Deal with stupid global variables (is there a way around making
    # these global to this package?  It is just so wrong....)
    undef (@Only);
    undef (@Omit);

# ------------------------------------- read in machine configuration variables
    my $iconpath= $r->dir_config('lonIconsURL') . "/";
    my $domain  = $r->dir_config('lonDefDomain');
    my $role    = $r->dir_config('lonRole');
    my $loadlim = $r->dir_config('lonLoadLim');
    my $servadm = $r->dir_config('lonAdmEMail');
    my $sysadm  = $r->dir_config('lonSysEMail');
    my $lonhost = $r->dir_config('lonHostID');
    my $tabdir  = $r->dir_config('lonTabDir');

    my $fileclr='#ffffe6';
    my $line;
    my (@attrchk,@openpath);
    my $uri=$r->uri;

# -------------------------------------- see if called from an interactive mode
    # Get the parameters from the query string
    &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},
	     ['catalogmode','launch','acts','mode','form','element',
              'only','omit']);
    #-------------------------------------------------------------------
    my $closebutton='';
    my $groupimportbutton='';
    my $colspan=''; 

    $extrafield='';
    my $diropendb = 
	"/home/httpd/perl/tmp/$ENV{'user.domain'}_$ENV{'user.name'}_indexer.db";
    %hash = ();
    my %dbfile;
    if (tie(%dbfile,'GDBM_File',$diropendb,&GDBM_WRCREAT(),0640)) {
        while(my($key,$value)=each(%dbfile)) {
            $hash{$key}=$value;
        }
        untie(%dbfile);

	if ($ENV{'form.launch'} eq '1') {
	    &start_fresh_session();
        }
# -------------------- refresh environment with user database values (in %hash)
	&setvalues(\%hash,'form.catalogmode',\%ENV,'form.catalogmode'   );

# --------------------- define extra fields and buttons in case of special mode
	if ($ENV{'form.catalogmode'} eq 'interactive') {
	    $extrafield='<td bgcolor="'.$fileclr.'" valign="bottom">'.
		'<a name="$anchor"><img src="'.$iconpath.'whitespace1.gif"'.
		' border="0" /></td>';
	    $colspan=" colspan='2' ";
            $closebutton=<<END;
<input type="button" name="close" value='CLOSE' onClick="self.close()">
END
        }
	elsif ($ENV{'form.catalogmode'} eq 'groupimport') {
	    $extrafield='<td bgcolor="'.$fileclr.'" valign="bottom">'.
		'<a name="$anchor"><img src="'.$iconpath.'whitespace1.gif"'.
		' border="0" /></td>';
	    $colspan=" colspan='2' ";
            $closebutton=<<END;
<input type="button" name="close" value='CLOSE' onClick="self.close()">
END
            $groupimportbutton=<<END;
<input type="button" name="groupimport" value='GROUP IMPORT'
onClick="javascript:select_group()">
END
        }
	# Additions made by Matthew to make the browser a little easier to deal
	# with in the future.
	#
	# $mode (at this time) indicates if we are in edit mode.
	# $form is the name of the form that the URL is placed when the
	#       selection is made.
	# $element is the name of the element in $formname which receives
	#       the URL.
	# &Apache::lonxml::debug('Checking mode, form, element');
	&setvalues(\%hash,'form.mode'   ,\%ENV,'form.mode'   );
	&setvalues(\%hash,'form.form'   ,\%ENV,'form.form'   );
	&setvalues(\%hash,'form.element',\%ENV,'form.element');
	&setvalues(\%hash,'form.only'   ,\%ENV,'form.only'   );
	&setvalues(\%hash,'form.omit'   ,\%ENV,'form.omit'   );

        # Deal with 'omit' and 'only' 
        if (exists $ENV{'form.omit'}) {
            @Omit = split(',',$ENV{'form.omit'});
        }
        if (exists $ENV{'form.only'}) {
            @Only = split(',',$ENV{'form.only'});
        }
        
	my $mode = $ENV{'form.mode'};
	my ($form,$element);
	if ($mode eq 'edit' || $mode eq 'parmset') {
	    $form    = $ENV{'form.form'};
	    $element = $ENV{'form.element'};
	}
	&Apache::lonxml::debug("mode=$mode form=$form element=$element");
# ------ set catalogmodefunctions to have extra needed javascript functionality
	my $catalogmodefunctions='';
	if ($ENV{'form.catalogmode'} eq 'interactive' or
	    $ENV{'form.catalogmode'} eq 'groupimport') {
	    # The if statement below sets us up to use the old version
	    # by default (ie. if $mode is undefined).  This is the easy
	    # way out.  Hopefully in the future I'll find a way to get 
	    # the calls dealt with in a more comprehensive manner.

#
# There is now also mode "simple", which is for the simple version of the rat
#
#
	    if (!defined($mode) || ($mode ne 'edit' && $mode ne 'parmset')) {
                my $location = "/adm/groupsort?catalogmode=groupimport&";
                $location .= "mode=".$mode."&";
                $location .= "acts=";
		$catalogmodefunctions=<<"END";
function select_data(title,url) {
    changeTitle(title);
    changeURL(url);
    self.close();
}
function select_group() {
    window.location="$location"+document.forms.fileattr.acts.value;
}
function changeTitle(val) {
    if (opener.inf) {
        if (opener.inf.document.forms.resinfo.elements.t) {
            opener.inf.document.forms.resinfo.elements.t.value=val;
        }
    }
}
function changeURL(val) {
    if (opener.inf) {
        if (opener.inf.document.forms.resinfo.elements.u) {
	    opener.inf.document.forms.resinfo.elements.u.value=val;
        }
    }
}
END
            } elsif ($mode eq 'edit') { # we are in 'edit' mode
                my $location = "/adm/groupsort?catalogmode=interactive&";
                $location .= "form=$form&element=$element&mode=edit&acts=";
		$catalogmodefunctions=<<END;
// mode = $mode
function select_data(title,url) {
    changeURL(url);
    self.close();
}

function select_group() {
    window.location="$location"+document.forms.fileattr.acts.value;
}

function changeURL(val) {
    if (window.opener.document) {
	window.opener.document.forms["$form"].elements["$element"].value=val;
    } else {
	    alert("The file you selected is: "+val);
    }
}

END
            } elsif ($mode eq 'parmset') {
                my $location = "/adm/groupsort?catalogmode=interactive&";
                $location .= "form=$form&element=$element&mode=parmset&acts=";
		$catalogmodefunctions=<<END;
// mode = $mode
function select_data(title,url) {
    changeURL(url);
    self.close();
}

function select_group() {
    window.location="$location"+document.forms.fileattr.acts.value;
}

function changeURL(val) {
    if (window.opener.document) {
        var elementname  = "$element"+"_value";
        var checkboxname = "$element"+"_setparmval";
	window.opener.document.forms["$form"].elements[elementname].value=val;
        window.opener.document.forms["$form"].elements[checkboxname].checked=true;
    } else {
	    alert("The file you selected is: "+val);
    }
}

END
            }
        }
        $catalogmodefunctions.=<<END;
var acts='';
function rep_dirpath(suffix,val) {
    eval("document.forms.dirpath"+suffix+".acts.value=val");
}
END
	if ($ENV{'form.catalogmode'} eq 'groupimport') {
            $catalogmodefunctions.=<<END;
function queue(val) {
    if (eval("document.forms."+val+".filelink.checked")) {
	var l=val.length;
	var v=val.substring(4,l);
	document.forms.fileattr.acts.value+='1a'+v+'b';
    }
    else {
	var l=val.length;
	var v=val.substring(4,l);
	document.forms.fileattr.acts.value+='0a'+v+'b';
    }
}
END
	}

# ---------------------------------------------------------------- Print Header
	$r->print(<<ENDHEADER);
<html>
<head>
<title>The LearningOnline Network With CAPA Directory Browser</title>

<script type="text/javascript">
$catalogmodefunctions
function openWindow(url, wdwName, w, h, toolbar,scrollbar) {
    var options = "width=" + w + ",height=" + h + ",";
    options += "resizable=yes,scrollbars="+scrollbar+",status=no,";
    options += "menubar=no,toolbar="+toolbar+",location=no,directories=no";
    var newWin = window.open(url, wdwName, options);
    newWin.focus();
}
function gothere(val) {
    window.location=val+'?acts='+document.forms.fileattr.acts.value;
}
</script>

</head>
ENDHEADER
$r->print(&Apache::loncommon::bodytag('Browse Resources'));
# - Evaluate actions from previous page (both cumulatively and chronologically)
        if ($ENV{'form.catalogmode'} eq 'groupimport') {
	    my $acts=$ENV{'form.acts'};
	    my @Acts=split(/b/,$acts);
	    my %ahash;
	    my %achash;
	    my $ac=0;
	    # some initial hashes for working with data
	    foreach (@Acts) {
		my ($state,$ref)=split(/a/);
		$ahash{$ref}=$state;
		$achash{$ref}=$ac;
		$ac++;
	    }
	    # sorting through the actions and changing the tied database hash
	    foreach (sort {$achash{$a}<=>$achash{$b}} (keys %ahash)) {
		my $key=$_;
		if ($ahash{$key} eq '1') {
		    $hash{'store_'.$hash{'pre_'.$key.'_link'}}=
			$hash{'pre_'.$key.'_title'};
		    $hash{'storectr_'.$hash{'pre_'.$key.'_link'}}=
			$hash{'storectr'}+0;
		    $hash{'storectr'}++;
		}
		if ($ahash{$key} eq '0') {
		    if ($hash{'store_'.$hash{'pre_'.$key.'_link'}}) {
			delete $hash{'store_'.$hash{'pre_'.$key.'_link'}};
		    }
		}
	    }
	    # deleting the previously cached listing
	    foreach (keys %hash) {
		if ($_ =~ /^pre_/ && $_ =~/link$/) {
		    my $key = $_;
		    $key =~ s/^pre_//;
		    $key =~ s/_[^_]*$//;
		    delete $hash{'pre_'.$key.'_title'};
		    delete $hash{'pre_'.$key.'_link'};
		}
	    }
	}
	
# ---------------------------------- get state of file attributes to be showing
	if ($ENV{'form.attrs'} ne '') {
	    for (my $i=0; $i<=8; $i++) {
		delete $hash{'display_attrs_'.$i};
		if ($ENV{'form.attr'.$i} == 1) {
		    $attrchk[$i] = 'checked';
		    $hash{'display_attrs_'.$i} = 1;
		}
	    }
	} else {
	    for (my $i=0; $i<=8; $i++) {
		$attrchk[$i] = 'checked' if $hash{'display_attrs_'.$i} == 1;
	    }
	}
# ------------------------------- output state of file attributes to be showing
	$r->print(<<END);
<form method="post" name="fileattr" action="$uri"
 enctype="application/x-www-form-urlencoded">
<b><font color="#666666">Display file attributes</font></b><br />
<table border=0><tr>
<td><input type="checkbox" name="attr0" value="1" $attrchk[0] /> Title</td>
<td><input type="checkbox" name="attr1" value="1" $attrchk[1] /> Size</td>
<td><input type="checkbox" name="attr2" value="1" $attrchk[2] /> Last access</td>
<td><input type="checkbox" name="attr3" value="1" $attrchk[3] /> Last modified</td>
<td><input type="checkbox" name="attr8" value="1" $attrchk[8] /> All versions</td></tr><tr>
<td><input type="checkbox" name="attr4" value="1" $attrchk[4] /> Author</td>
<td><input type="checkbox" name="attr5" value="1" $attrchk[5] /> Keywords</td>
<td><input type="checkbox" name="attr6" value="1" $attrchk[6] /> Language</td>
<td><input type="checkbox" name="attr7" value="1" $attrchk[7] /> Show Resource</td>
<td>&nbsp;</td>
</tr></table>
<input type="hidden" name="dirPointer" value="on" />
<input type="hidden" name="acts" value="" />
<input type="submit" name="attrs" value="Review" />&nbsp;
<input type="submit" name="attrs" value="Refresh" />
$closebutton
$groupimportbutton
</form>
END

# ----------------- output starting row to the indexed file/directory hierarchy
        my $titleclr="#ddffff";
#        $r->print(&initdebug());
#        $r->print(&writedebug("Omit:@Omit")) if (@Omit);
#        $r->print(&writedebug("Only:@Only")) if (@Only);
        $r->print("<table width='100\%' border=0><tr><td bgcolor=#777777>\n");
	$r->print("<table width='100\%' border=0><tr bgcolor=$titleclr>\n");
	$r->print("<td $colspan><b>Name</b></td>\n");
	$r->print("<td><b>Title</b></td>\n") 
	    if ($hash{'display_attrs_0'} == 1);
	$r->print("<td align=right><b>Size (bytes) ".
		  "</b></td>\n") if ($hash{'display_attrs_1'} == 1);
	$r->print("<td><b>Last accessed</b></td>\n") 
	    if ($hash{'display_attrs_2'} == 1);
	$r->print("<td><b>Last modified</b></td>\n")
	    if ($hash{'display_attrs_3'} == 1);
	$r->print("<td><b>Author(s)</b></td>\n")
	    if ($hash{'display_attrs_4'} == 1);
	$r->print("<td><b>Keywords</b></td>\n")
	    if ($hash{'display_attrs_5'} == 1);
	$r->print("<td><b>Language</b></td>\n")
	    if ($hash{'display_attrs_6'} == 1);
	$r->print("<td><b>Resource</b></td>\n")
	    if ($hash{'display_attrs_7'} == 1);
	$r->print('</tr>');

# ----------------- read in what directories have previously been set to "open"
	foreach (keys %hash) {
	    if ($_ =~ /^diropen_status_/) {
		my $key = $_;
		$key =~ s/^diropen_status_//;
		$dirs{$key} = $hash{$_};
	    }
	}

	if ($ENV{'form.openuri'}) {  # take care of review and refresh options
	    my $uri=$ENV{'form.openuri'};
	    if (exists($hash{'diropen_status_'.$uri})) {
		my $cursta = $hash{'diropen_status_'.$uri};
		$dirs{$uri} = 'open';
		$hash{'diropen_status_'.$uri} = 'open';
		if ($cursta eq 'open') {
		    $dirs{$uri} = 'closed';
		    $hash{'diropen_status_'.$uri} = 'closed';
		}
	    } else {
		$hash{'diropen_status_'.$uri} = 'open';
		$dirs{$uri} = 'open';
	    }
	}
	
	my $bredir = $ENV{'form.dirPointer'};
	my $toplevel;
	my $indent = 0;
	$uri = $uri.'/' if $uri !~ /.*\/$/;

	if ($bredir ne 'on') {
	    $hash{'top.level'} = $uri;
	    $toplevel = $uri;

	} else {
	    $toplevel = $hash{'top.level'};
	}

# -------------------------------- if not at top level, provide an uplink arrow
	if ($toplevel ne '/res/'){
	    my (@uri_com) = split(/\//,$uri);
	    pop @uri_com;
	    my $upone = join('/',@uri_com);
	    my @list = qw (0);
	    &display_line ($r,'opened',$upone.'&viewOneUp',0,$upone,@list);
	    $indent = 1;
	}

# -------- recursively go through all the directories and output as appropriate
	&scanDir ($r,$toplevel,$indent,\%hash);
	
# ---------------------------- embed hidden information useful for group import
	$r->print("<form name='fnum'>");
	$r->print("<input type='hidden' name='fnum' value='$fnum'></form>");

# -------------------------------------------------------------- end the tables
	$r->print('</table>');
	$r->print('</td></tr></table>');

# --------------------------------------------------- end the output and return
	$r->print('</body></html>'."\n");
    } else {
	$r->print('<html><head></head><body>Unable to tie hash to db '.
		  'file</body></html>');
	return OK;
    }
    if(! $c->aborted()) {
        if (tie(%dbfile,'GDBM_File',$diropendb,&GDBM_NEWDB(),0640)) {
            while (my($key,$value) = each(%hash)) {
                $dbfile{$key}=$value;
            }
            untie(%dbfile);
        }
    }

    return OK;
}

# ----------------------------------------------- recursive scan of a directory
sub scanDir {
    my ($r,$startdir,$indent,$hashref)=@_;
    my $c = $r->connection();
    my ($compuri,$curdir);
    my $dirptr=16384;
    $indent++;

    my %dupdirs = %dirs;
    my @list=&get_list($r,$startdir);
    foreach my $line (@list) {
        return if ($c->aborted());
	my ($strip,$dom,undef,$testdir,undef)=split(/\&/,$line,5); 
	next if $strip =~ /.*\.meta$/;
	my (@fileparts) = split(/\./,$strip);
	if ($hash{'display_attrs_8'} != 1) {
	    if (scalar(@fileparts) >= 3) {
		my $fext = pop @fileparts;
		my $ov = pop @fileparts;
		my $fname = join ('.',@fileparts,$fext);
		next if (grep /\Q$fname\E/,@list and $ov =~ /\d+/);
	    }
	}

	if ($dom eq 'domain') {
	    $compuri = join('',$strip,'/');  # dom list has /res/<domain name>
	    $curdir = $compuri;
	} else {
	    # user, dir & file have name only, i.e., w/o path
	    $compuri = join('',$startdir,$strip,'/');
	    $curdir = $startdir;
	}
	my $diropen = 'closed';
	if (($dirptr&$testdir) or ($dom =~ /^(domain|user)$/)) {
	    while (my ($key,$val)= each %dupdirs) {
		if ($key eq $compuri and $val eq "open") {
		    $diropen = "opened";
		    delete($dupdirs{$key});
		    delete($dirs{$key});
		}
	    }
	}
	&display_line($r,$diropen,$line,$indent,$curdir,$hashref,@list);
	&scanDir ($r,$compuri,$indent) if $diropen eq 'opened';
    }
    $indent--;
}

# --------------- get complete matched list based on the uri (returns an array)
sub get_list {
    my ($r,$uri)=@_;
    my @list;
    (my $luri = $uri) =~ s/\//_/g;

    if ($ENV{'form.attrs'} eq 'Refresh') {
	foreach (keys %hash) {
	    delete $hash{$_} if ($_ =~ /^dirlist_files_/);
	    }
    }

    if ($hash{'dirlist_files'.$luri}) {
	@list = split(/\n/,$hash{'dirlist_files_'.$luri});
    } else {
	@list = &Apache::lonnet::dirlist($uri);
	$hash{'dirlist_files_'.$luri} = join('\n',@list);
    }
    return @list=&match_ext($r,@list);
}

sub initdebug {
    return <<ENDJS;
<script>
var debugging = true;
if (debugging) {
    var debuggingWindow = window.open('','Debug','width=400,height=300',true);
} 

function output(text) {
    if (debugging) {
        debuggingWindow.document.writeln(text);
    }
}
output("<html><head><title>Debugging Window</title></head><body><pre>");   
</script>
ENDJS
}

sub writedebug {
    my $text = shift;
    return "<script>output('$text');</script>";
}

# -------------------- filters out files based on extensions (returns an array)
sub match_ext {
    my ($r,@packlist)=@_;
    my @trimlist;
    my $nextline;
    my @fileext;
    my $dirptr=16384;

    foreach my $line (@packlist) {
	chomp $line;
	$line =~ s/^\/home\/httpd\/html//;
	my @unpackline = split (/\&/,$line);
	next if ($unpackline[0] eq '.');
	next if ($unpackline[0] eq '..');
	my @filecom = split (/\./,$unpackline[0]);
	my $fext = pop(@filecom);
	my $fnptr = $unpackline[3]&$dirptr;
 	if ($fnptr == 0 and $unpackline[3] ne "") {
	    my $embstyle = &Apache::loncommon::fileembstyle($fext);
            push @trimlist,$line if (defined($embstyle) && 
				     ($embstyle ne 'hdn' or $fext eq 'meta'));
	} else {
	    push @trimlist,$line;
	}
    }
    @trimlist = sort (@trimlist);
    return @trimlist;
}

# ------------------------------- displays one line in appropriate table format
sub display_line {
    my ($r,$diropen,$line,$indent,$startdir,$hashref,@list)=@_;
    my (@pathfn, $fndir);
    my $dirptr=16384;
    my $fileclr="#ffffe6";
    my $iconpath= $r->dir_config('lonIconsURL') . '/';

    my @filecom = split (/\&/,$line);
    my @pathcom = split (/\//,$filecom[0]);
    my $listname = $pathcom[scalar(@pathcom)-1];
    my $fnptr = $filecom[3]&$dirptr;
    my $msg = 'View '.$filecom[0].' resources';
    $msg = 'Close '.$filecom[0].' directory' if $diropen eq 'opened';

    my $tabtag='</td>';
    my $i=0;

    while ($i<=7) {
	$tabtag=join('',$tabtag,"<td>&nbsp;</td>")
	    if $hash{'display_attrs_'.$i} == 1;
	$i++;
    }
	
    my $valign = ($hash{'display_attrs_7'} == 1 ? 'top' : 'bottom');

# display uplink arrow
    if ($filecom[1] eq 'viewOneUp') {
	$r->print("<tr bgcolor=$fileclr>$extrafield");
	$r->print("<td valign=$valign>\n");
	$r->print ('<form method="post" name="dirpathUP" action="'.$startdir.
		   '/" '.
		   'onSubmit="return rep_dirpath(\'UP\','.
		   'document.forms.fileattr.acts.value)" '.
		   'enctype="application/x-www-form-urlencoded"'.
                   '>'."\n");
	$r->print ('<input type=hidden name=openuri value="'.
		   $startdir.'">'."\n");
	$r->print ('<input type="hidden" name="acts" value="">'."\n");
	$r->print ('<input src="'.$iconpath.'arrow_up.gif"');
	$r->print (' name="'.$msg.'" height="22" type="image" border="0">'.
		   "\n");
	$r->print("Up $tabtag</tr></form>\n");
	return OK;
    }
# Do we have permission to look at this?

    return OK if (!&Apache::lonnet::allowed('bre',$startdir.$filecom[0]));

# display domain
    if ($filecom[1] eq 'domain') {
	$r->print ('<input type="hidden" name="dirPointer" value="on">'."\n")
	    if ($ENV{'form.dirPointer'} eq "on");
	$r->print("<tr bgcolor=$fileclr>$extrafield");
	$r->print("<td valign=$valign>");
	&begin_form ($r,$filecom[0].'/');
	my $anchor = $filecom[0].'/';
	$anchor =~ s/\///g;
	$r->print ('<a name="'.$anchor.'">');
	$r->print ('<input type="hidden" name="acts" value="">');
	$r->print ('<input src="'.$iconpath.'folder_pointer_'.
		   $diropen.'.gif"'); 
	$r->print (' name="'.$msg.'" height="22" type="image" border="0">'.
		   "\n");
	$r->print ('<a href="javascript:gothere(\''.$filecom[0].
		   '/\')"><img src="'.$iconpath.'server.gif"');
	$r->print (' border="0" /></a>'."\n");
	$r->print ("Domain - $listname ");
	if ($Apache::lonnet::domaindescription{$listname}) {
	    $r->print("(".$Apache::lonnet::domaindescription{$listname}.
		      ")");
	}
	$r->print (" $tabtag</tr></form>\n");
	return OK;

# display user directory
    }
    if ($filecom[1] eq 'user') {
	$r->print("<tr bgcolor=$fileclr>$extrafield");
	$r->print("<td valign=$valign nowrap>\n");
	my $curdir = $startdir.$filecom[0].'/';
	my $anchor = $curdir;
	$anchor =~ s/\///g;
	&begin_form ($r,$curdir);
	$r->print ('<a name="'.$anchor.'"><img src="'.$iconpath.
		   'whitespace1.gif" border="0" />'."\n");
	$r->print ('<input type="hidden" name="acts" value="">');
	$r->print ('<input src="'.$iconpath.'folder_pointer_'.$diropen.
		   '.gif"'); 
	$r->print (' name="'.$msg.'" height="22" type="image" border="0">'.
		   "\n");
	$r->print ('<a href="javascript:gothere(\''.$curdir.'\')"><img src='.
		   $iconpath.'quill.gif border="0" name="'.$msg.
		   '" height="22" /></a>');
	my $domain=(split(m|/|,$startdir))[2];
	my $plainname=&Apache::loncommon::plainname($listname,$domain);
	$r->print ($listname);
	if (defined($plainname) && $plainname) { $r->print(" ($plainname) "); }
	$r->print ($tabtag.'</tr></form>'."\n");
	return OK;
    }

# display file
    if ($fnptr == 0 and $filecom[3] ne '') {
	my $filelink = $startdir.$filecom[0];
	my @file_ext = split (/\./,$listname);
	my $curfext = $file_ext[-1];
        if (@Omit) {
            foreach (@Omit) { return OK if ($curfext eq $_); }
        }
        if (@Only) {
            my $skip = 1;
            foreach (@Only) { $skip = 0 if ($curfext eq $_); }
            return OK if ($skip > 0);
        }
	# Set the icon for the file
	my $iconname = "unknown.gif";
	my $embstyle = &Apache::loncommon::fileembstyle($curfext);
	# The unless conditional that follows is a bit of overkill
	$iconname = $curfext.".gif" unless
	    (!defined($embstyle) || $embstyle eq 'unk' || $embstyle eq 'hdn');
	#
	$r->print("<tr bgcolor=$fileclr><td nowrap valign='$valign'>");
	my $metafile = grep /^\Q$filecom[0]\E\.meta\&/, @list;
	my $title;
        if ($ENV{'form.catalogmode'} eq 'interactive') {
	    $title=$listname;
	    $title = &Apache::lonnet::metadata($filelink,'title')
		if ($metafile == 1);
	    $title=$listname unless $title;
	    my $titleesc=HTML::Entities::encode($title);
	    $titleesc=~s/\'/\\'/; #' (clean up this spare quote)
            $r->print("<a href=\"javascript:select_data(\'",
                      $titleesc,"','",$filelink,"')\">");
	    $r->print("<img src='",$iconpath,"select.gif' border='0' /></a>".
		      "\n");
	    $r->print("</td><td valign='$valign' nowrap>");
	}
        elsif ($ENV{'form.catalogmode'} eq 'groupimport') {
	    $title=$listname;
	    $title = &Apache::lonnet::metadata($filelink,'title')
		if ($metafile == 1);
	    $title=$listname unless $title;
	    my $titleesc=&HTML::Entities::encode($title);
	    $r->print("<form name='form$fnum'>\n");
	    $r->print("<input type='checkbox' name='filelink"."' ".
		      "value='$filelink' onClick='".
		      "javascript:queue(\"form$fnum\")' ");
	    if ($hash{'store_'.$filelink}) {
		$r->print("checked");
	    }
	    $r->print(">\n");
	    $r->print("<input type='hidden' name='title"."' ".
		      "value='$titleesc'>\n");
	    $r->print("</form>\n");
	    $r->print("</td><td valign='$valign' nowrap>");
	    $hash{"pre_${fnum}_link"}=$filelink;
	    $hash{"pre_${fnum}_title"}=$titleesc;
  	    $fnum++;
	}

	if ($indent > 0 and $indent < 11) {
	    $r->print("<img src=",$iconpath,"whitespace",$indent,
		      ".gif border='0' />\n");
	} elsif ($indent >0) {
	    my $ten = int($indent/10.);
	    my $rem = $indent%10.0;
	    my $count = 0;
	    while ($count < $ten) {
		$r->print("<img src=",$iconpath,
			  "whitespace10.gif border='0' />\n");
	    $count++;
	    }
	    $r->print("<img src=",$iconpath,"whitespace",$rem,
		      ".gif border='0' />\n") if $rem > 0;
	}

	$r->print("<img src=$iconpath$iconname border='0' />\n");
	$r->print (" <a href=\"javascript:openWindow('".$filelink.
		   "', 'metadatafile', '450', '500', 'no', 'yes')\";".
		   " TARGET=_self>$listname</a> ");

	$r->print (" (<a href=\"javascript:openWindow('".$filelink.
		   ".meta', 'metadatafile', '400', '450', 'no', 'yes')\"; ".
		   "TARGET=_self>metadata</a>) ") if ($metafile == 1);

	$r->print("</td>\n");
	if ($hash{'display_attrs_0'} == 1) {
	    my $title = &Apache::lonnet::metadata($filelink,'title')
		if ($metafile == 1);
	    $r->print('<td valign=$valign> '.($title eq '' ? '&nbsp;' : $title).
		      ' </td>'."\n");
	}
	$r->print('<td align=right valign=$valign> ',
		  $filecom[8]," </td>\n") 
	    if $hash{'display_attrs_1'} == 1;
	$r->print('<td valign=$valign> '.
		  (localtime($filecom[9]))." </td>\n") 
	    if $hash{'display_attrs_2'} == 1;
	$r->print('<td valign=$valign> '.
		  (localtime($filecom[10]))." </td>\n") 
	    if $hash{'display_attrs_3'} == 1;

	if ($hash{'display_attrs_4'} == 1) {
	    my $author = &Apache::lonnet::metadata($filelink,'author')
		if ($metafile == 1);
	    $r->print('<td valign=$valign> '.($author eq '' ? '&nbsp;' : $author).
		      " </td>\n");
	}
	if ($hash{'display_attrs_5'} == 1) {
	    my $keywords = &Apache::lonnet::metadata($filelink,'keywords')
		if ($metafile == 1);
	    # $keywords = '&nbsp;' if (!$keywords);
	    $r->print('<td valign=$valign> '.($keywords eq '' ? '&nbsp;' : $keywords).
		      " </td>\n");
	}
	if ($hash{'display_attrs_6'} == 1) {
	    my $lang = &Apache::lonnet::metadata($filelink,'language')
		if ($metafile == 1);
	    $lang = &Apache::loncommon::languagedescription($lang);
	    $r->print('<td valign=$valign> '.($lang eq '' ? '&nbsp;' : $lang).
		      " </td>\n");
	}
        if ($hash{'display_attrs_7'} == 1) {
            my $output='';
            my $embstyle=&Apache::loncommon::fileembstyle($curfext);
	    if ($embstyle eq 'ssi') {
	       $output=&Apache::lonnet::ssi_body($filelink);
               $output='<font size="-2">'.$output.'</font>';
	   } elsif ($embstyle eq 'img') {
               $output='<img src="'.$filelink.'" />';
           } elsif ($filelink=~/^\/res\/(\w+)\/(\w+)\//) {
               $output='<img src="http://'.
		 $Apache::lonnet::hostname{&Apache::lonnet::homeserver($2,$1)}.
                 '/cgi-bin/thumbnail.gif?url='.$filelink.'" />';
           }
	   $r->print('<td valign=$valign> '.($output eq '' ? '&nbsp;':$output).
		      " </td>\n");
        }
	$r->print("</tr>\n");
    }

# -- display directory
    if ($fnptr == $dirptr) {
	my @file_ext = split (/\./,$listname);
	my $curfext = $file_ext[scalar(@file_ext)-1];
	my $curdir = $startdir.$filecom[0].'/';
	my $anchor = $curdir;
	$anchor =~ s/\///g;
	$r->print("<tr bgcolor=$fileclr>$extrafield<td valign=$valign>");
	&begin_form ($r,$curdir);
	my $indentm1 = $indent-1;
	if ($indentm1 < 11 and $indentm1 > 0) {
	    $r->print("<img src=",$iconpath,"whitespace",$indentm1,
		      ".gif border='0' />\n");
	} else {
	    my $ten = int($indentm1/10.);
	    my $rem = $indentm1%10.0;
	    my $count = 0;
	    while ($count < $ten) {
		$r->print ("<img src=",$iconpath
			   ,"whitespace10.gif border='0' />\n");
		$count++;
	    }
	    $r->print ("<img src=",$iconpath,"whitespace",$rem,
		       ".gif border='0' />\n") if $rem > 0;
	}
	$r->print ('<input type="hidden" name="acts" value="">');
	$r->print ('<a name="'.$anchor.'"><input src="'.$iconpath.
		   'folder_pointer_'.$diropen.'.gif"');
	$r->print (' name="'.$msg.'" height="22" type="image" border="0">'.
		   "\n");
	$r->print ('<a href="javascript:gothere(\''.$curdir.'\')"><img src="'.
		   $iconpath.'folder_'.$diropen.'.gif" border="0" /></a>'.
		   "\n");
	$r->print ("$listname$tabtag</tr></form>\n");
    }

}

# ------------------- prints the beginning of a form for directory or file link
sub begin_form {
    my ($r,$uri) = @_;
    my $anchor = $uri;
    $anchor =~ s/\///g;
    $r->print ('<form method="post" name="dirpath'.$dnum.'" action="'.$uri.
	       '#'.$anchor.
	       '" onSubmit="return rep_dirpath(\''.$dnum.'\''.
	       ',document.forms.fileattr.acts.value)" '.
	       'enctype="application/x-www-form-urlencoded">'."\n");
    $r->print ('<input type="hidden" name="openuri" value="'.$uri.'">'.
	       "\n");
    $r->print ('<input type="hidden" name="dirPointer" value="on">'."\n");
    $dnum++;
}

# --------- settings whenever the user causes the indexer window to be launched
sub start_fresh_session {
    delete $hash{'form.catalogmode'};
    delete $hash{'form.mode'};
    delete $hash{'form.form'};
    delete $hash{'form.element'};
    delete $hash{'form.omit'};
    delete $hash{'form.only'};
    foreach (keys %hash) {
        delete $hash{$_} if (/^(pre_|store)/);
    }
}

# ------------------------------------------------------------------- setvalues
sub setvalues {
    # setvalues is used in registerurl to synchronize the database
    # hash and environment hashes
    my ($H1,$h1key,$H2,$h2key) =@_;
    #
    if (exists $H2->{$h2key}) {
	$H1->{$h1key} = $H2->{$h2key};
    } elsif (exists $H1->{$h1key}) {
	$H2->{$h2key} = $H1->{$h1key};
    } 
}

1;

sub cleanup {
    if (tied(%hash)){
	&Apache::lonnet::logthis('Cleanup indexer: hash');
    }
}

=head1 NAME

Apache::lonindexer - mod_perl module for cross server filesystem browsing

=head1 SYNOPSIS

Invoked by /etc/httpd/conf/srm.conf:

 <LocationMatch "^/res.*/$">
 SetHandler perl-script
 PerlHandler Apache::lonindexer
 </LocationMatch>

=head1 INTRODUCTION

This module enables a scheme of browsing across a cross server.

This is part of the LearningOnline Network with CAPA project
described at http://www.lon-capa.org.

=head1 BEGIN SUBROUTINE

This routine is only run once after compilation.

=over 4

=item *

Initializes %language hash table.

=back

=head1 HANDLER SUBROUTINE

This routine is called by Apache and mod_perl.

=over 4

=item *

read in machine configuration variables

=item *

see if called from an interactive mode

=item *

refresh environment with user database values (in %hash)

=item *

define extra fields and buttons in case of special mode

=item *

set catalogmodefunctions to have extra needed javascript functionality

=item *

print header

=item *

evaluate actions from previous page (both cumulatively and chronologically)

=item *

output title

=item *

get state of file attributes to be showing

=item *

output state of file attributes to be showing

=item *

output starting row to the indexed file/directory hierarchy

=item *

read in what directories have previously been set to "open"

=item *

if not at top level, provide an uplink arrow

=item *

recursively go through all the directories and output as appropriate

=item *

information useful for group import

=item *

end the tables

=item *

end the output and return

=back

=head1 OTHER SUBROUTINES

=over 4

=item *

scanDir - recursive scan of a directory

=item *

get_list - get complete matched list based on the uri (returns an array)

=item *

match_ext - filters out files based on extensions (returns an array)

=item *

display_line - displays one line in appropriate table format

=item *

begin_form - prints the beginning of a form for directory or file link

=item *

start_fresh_session - settings whenever the user causes the indexer window
to be launched

=back

=cut