# The LearningOnline Network with CAPA
# Handler to upload files into construction space
#
# $Id: lonupload.pm,v 1.23 2003/11/08 11:11:01 albertel 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::lonupload;

use strict;
use Apache::File;
use File::Copy;
use File::Basename;
use Apache::Constants qw(:common :http :methods);
use Apache::loncacc;
use Apache::loncommon();
use Apache::Log();
use Apache::lonnet;
use HTML::Entities();
use Apache::lonlocal;

my $DEBUG=0;

sub Debug {
  
    # Marshall the parameters.
  
    my $r       = shift;
    my $log     = $r->log;
    my $message = shift;
  
    # Put out the indicated message butonly if DEBUG is false.
  
    if ($DEBUG) {
	$log->debug($message);
    }
}

sub upfile_store {
    my $r=shift;
	
    my $fname=$ENV{'form.upfile.filename'};
    $fname=~s/\W//g;
    
    chomp($ENV{'form.upfile'});
  
    my $datatoken=$ENV{'user.name'}.'_'.$ENV{'user.domain'}.
		  '_upload_'.$fname.'_'.time.'_'.$$;
    {
       my $fh=Apache::File->new('>'.$r->dir_config('lonDaemons').
                                   '/tmp/'.$datatoken.'.tmp');
       print $fh $ENV{'form.upfile'};
    }
    return $datatoken;
}


sub phaseone {
    my ($r,$fn,$uname,$udom)=@_;
    $ENV{'form.upfile.filename'}=~s/\\/\//g;
    $ENV{'form.upfile.filename'}=~s/^.*\/([^\/]+)$/$1/;
    if ($ENV{'form.upfile.filename'}) {
	$fn=~s/\/[^\/]+$//;
	$fn=~s/([^\/])$/$1\//;
	$fn.=$ENV{'form.upfile.filename'};
	$fn=~s/^\///;
	$fn=~s/(\/)+/\//g;

#    Fn is the full path to the destination filename.
#    

	&Debug($r, "Filename for upload: $fn");
	if (($fn) && ($fn!~/\/$/)) {
	    $r->print('<form action="/adm/upload" method="post">'.
		      '<input type="hidden" name="phase" value="two" />'.
		      '<input type="hidden" name="datatoken" value="'.
		      &upfile_store.'" />'.
		      '<input type="hidden" name="uploaduname" value="'.$uname.
		      '" />'.&mt('Store uploaded file as ').
		      "<tt>/priv/$uname/</tt>".
		      '<input type="text" size="50" name="filename" value="'.$fn.
		      '" /><br />'.
		      '<input type="submit" value="'.&mt('Store').'" /></form>');
	    # Check for bad extension and warn user
	    if ($fn=~/\.(\w+)$/ && 
		(&Apache::loncommon::fileembstyle($1) eq 'hdn')) {
		$r->print('<font color="red">'.&mt('The extension on this file,').
			  ' "'.$1.'"'.&mt(', is reserved internally by LON-CAPA.').
			  ' <br />'.&mt('Please change the extension.').'</font>');
	    } elsif($fn=~/\.(\w+)$/ && 
		    !defined(&Apache::loncommon::fileembstyle($1))) {
		$r->print('<font color="red">'.&mt('The extension on this file,').
			  ' "'.$1.'"'.&mt(', is not recognized by LON-CAPA.').
			  ' <br />'.&mt('Please change the extension.').
			  '</font>');
	    }
	} else {
	    $r->print('<font color="red">'.&mt('Illegal filename.').'</font>');
	}
    } else {
	$r->print('<font color="red">'.&mt('No upload file specified.').'</font>');
    }
}

sub phasetwo {
    my ($r,$tfn,$uname,$udom)=@_;
    my $fn='/priv/'.$uname.'/'.$tfn;
    $fn=~s/\/+/\//g;
    &Debug($r, "Filename is ".$tfn);
    if ($tfn) {
	&Debug($r, "Filename for tfn = ".$tfn);
	my $target='/home/'.$uname.'/public_html'.$tfn;
	&Debug($r, "target -> ".$target);
#     target is the full filesystem path of the destination file.
	my $base = &File::Basename::basename($fn);
	my $path = &File::Basename::dirname($fn);
	$base    = &HTML::Entities::encode($base);
	my $url  = $path."/".$base; 
	&Debug($r, "URL is now ".$url);
	my $datatoken=$ENV{'form.datatoken'};
	if (($fn) && ($datatoken)) {
	    if ((-e $target) && ($ENV{'form.override'} ne 'Yes')) {
		$r->print('<form action="/adm/upload" method="post">'.
			  &mt('File').' <tt>'.$fn.'</tt> '.
			  &mt('exists. Overwrite?').' '.
			  '<input type="hidden" name="phase" value="two" />'.
			  '<input type="hidden" name="filename" value="'."$url".'" />'.
			  '<input type="hidden" name="datatoken" value="'.$datatoken.'" />'.
			  '<input type="submit" name="override" value="'.&mt('Yes').'" /></form>');
	    } else {
		my $source=$r->dir_config('lonDaemons').'/tmp/'.$datatoken.'.tmp';
		# Check for bad extension and disallow upload
		if ($fn=~/\.(\w+)$/ && 
		    (&Apache::loncommon::fileembstyle($1) eq 'hdn')) {
		    $r->print(&mt('File').' <tt>'.$fn.'</tt> '.
			      &mt('could not be copied.').'<br />'.
			      '<font color="red">'.
			      &mt('The extension on this file is reserved internally by LON-CAPA.').
			      '</font>');
		    $r->print('<p><font size=+2><a href="'.$path.'">'.
			      &mt('Back to Directory').'</a></font>');
		} elsif ($fn=~/\.(\w+)$/ && 
			 !defined(&Apache::loncommon::fileembstyle($1))) {
		    $r->print(&mt('File').' <tt>'.$fn.'</tt> '.
			      &mt('could not be copied.').'<br />'.
			      '<font color="red">'.
			      &mt('The extension on this file is not recognized by LON-CAPA.').
			      '</font>');
		    $r->print('<br /><font size="+2"><a href="'.$path.'">'.
			      &mt('Back to Directory').'</a></font>');
		} elsif (-d $target) {
		    $r->print('File <tt>'.$fn.'</tt> could not be copied.<br />'.
			      '<font color="red">'.
			      &mt('The target is an existing directory.').
			      '</font><br />');
		    $r->print('<font size="+2"><a href="'.$path.'">'.
			      &mt('Back to Directory').'</a></font>');
		} elsif (copy($source,$target)) {
		    chmod(0660, $target); # Set permissions to rw-rw---.
		    $r->print(&mt('File copied.'));
		    $r->print('<br /><font size="+2"><a href="'.$url.'">'.
			      &mt('View file').'</a></font>');
		    $r->print('<font size="+2"><a href="'.$path.'">'.
			      &mt('Back to Directory').'</a></font><br />');
		} else {
		    $r->print('Failed to copy: '.$!);
		    $r->print('<br /><font size="+2"><a href="'.$path.'">'.
			      &mt('Back to Directory').'</a></font>');
		}
	    }
	} else {
	    $r->print('<font size="+1" color="red">'.
		      &mt('Please use browser "Back" button and pick a filename').
		      '</font><br />>');
	}
    } else {
	$r->print('<font size=+1 color=red>'.
		  &mt('Please use browser "Back" button and pick a filename').
		  '</font><p>');
    }
}

# ---------------------------------------------------------------- Main Handler
sub handler {

    my $r=shift;

    my $uname;
    my $udom;
#
# phase two: re-attach user
#
    if ($ENV{'form.uploaduname'}) {
	$ENV{'form.filename'}='/priv/'.$ENV{'form.uploaduname'}.'/'.
	    $ENV{'form.filename'};
    }
#

    ($uname,$udom)=
	&Apache::loncacc::constructaccess($ENV{'form.filename'},
					  $r->dir_config('lonDefDomain'));
    unless (($uname) && ($udom)) {
	$r->log_reason($uname.' at '.$udom.
		       ' trying to publish file '.$ENV{'form.filename'}.
		       ' - not authorized', 
		       $r->filename); 
	return HTTP_NOT_ACCEPTABLE;
    }
    
    my $fn;
    if ($ENV{'form.filename'}) {
	$fn=$ENV{'form.filename'};
	$fn=~s/^http\:\/\/[^\/]+\///;
	$fn=~s/^\///;
	$fn=~s/(\~|priv\/)(\w+)//;
	$fn=~s/\/+/\//g;
    } else {
	$r->log_reason($ENV{'user.name'}.' at '.$ENV{'user.domain'}.
		       ' unspecified filename for upload', $r->filename); 
	return HTTP_NOT_FOUND;
    }

# ----------------------------------------------------------- Start page output


    &Apache::loncommon::content_type($r,'text/html');
    $r->send_http_header;

    $r->print('<html><head><title>LON-CAPA Construction Space</title></head>');

    $r->print(&Apache::loncommon::bodytag('Upload file to Construction Space'));
  
    if (($uname ne $ENV{'user.name'}) || ($udom ne $ENV{'user.domain'})) {
	$r->print('<h3><font color=red>'.&mt('Co-Author').': '.$uname.
		  &mt(' at ').$udom.'</font></h3>');
    }

    if ($ENV{'form.phase'} eq 'two') {
	&phasetwo($r,$fn,$uname,$udom);
    } else {
	&phaseone($r,$fn,$uname,$udom);
    }

    $r->print('</body></html>');
    return OK;  
}

1;
__END__

=head1 NAME

Apache::lonupload - upload files into construction space

=head1 SYNOPSIS

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

 <Location /adm/upload>
 PerlAccessHandler       Apache::lonacc
 SetHandler perl-script
 PerlHandler Apache::lonupload
 ErrorDocument     403 /adm/login
 ErrorDocument     404 /adm/notfound.html
 ErrorDocument     406 /adm/unauthorized.html
 ErrorDocument	  500 /adm/errorhandler
 </Location>

=head1 INTRODUCTION

This module uploads a file sitting on a client computer into 
library server construction space.

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

=head1 HANDLER SUBROUTINE

This routine is called by Apache and mod_perl.

=over 4

=item *

Initialize variables

=item *

Start page output

=item *

output relevant interface phase (phaseone or phasetwo)

=item *

(phase one is to specify upload file; phase two is to handle conditions
subsequent to specification--like overwriting an existing file)

=back

=head1 OTHER SUBROUTINES

=over 4

=item *

phaseone() : Interface for specifying file to upload.

=item *

phasetwo() : Interface for handling post-conditions about uploading (such
as overwriting an existing file).

=item *

upfile_store() : Store contents of uploaded file into temporary space.  Invoked
by phaseone subroutine.

=back

=cut