# The LearningOnline Network with CAPA
# Handler to upload files into construction space
#
# $Id: lonupload.pm,v 1.70 2019/03/06 03:39:54 raeburn 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/
#
###

=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, phasetwo, phasethree or phasefour)

=item *

(phase one is to specify upload file; phase two is to handle conditions
subsequent to specification--like overwriting an existing file; phase three
is to handle processing of secondary uploads - of embedded objects in an
html file).

=back

=head1 OTHER SUBROUTINES

=over

=item phaseone()

Interface for specifying file to upload.

=item phasetwo()

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

=item phasethree()

Interface for handling secondary uploads of embedded objects
in an html file.

=item phasefour()

Interface for handling optional renaming of links to embedded
objects. 

=item upfile_store()

Store contents of uploaded file into temporary space.  Invoked
by phaseone subroutine.

=item check_extension()

Checks if filename extension is permitted and checks type
 of file - if html file, calls parser to check for embedded objects.
 Invoked by phasetwo subroutine.

=back

=cut

package Apache::lonupload;

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

my $DEBUG=0;

sub Debug {
    # Put out the indicated message but only if DEBUG is true.
    if ($DEBUG) {
	my ($r,$message) = @_;
	$r->log_reason($message);
    }
}

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

sub phaseone {
    my ($r,$fn,$mode,$uname,$udom)=@_;
    my $action = '/adm/upload';
    if ($mode eq 'testbank') {
        $action = '/adm/testbank';
    } elsif ($mode eq 'imsimport') {
        $action = '/adm/imsimport';
    }

    # Check for file to be uploaded
    $env{'form.upfile.filename'}=~s/\\/\//g;
    $env{'form.upfile.filename'}=~s/^.*\/([^\/]+)$/$1/;
    $env{'form.upfile.filename'}=~s/(\s+$|^\s+)//g;
    if (!$env{'form.upfile.filename'}) {
        $r->print('<p class="LC_warning">'.&mt('No upload file specified.').'</p>'.
                  &earlyout($fn,$uname,$udom));
        return;
    }

    # Append the name of the uploaded file
    $fn.=$env{'form.upfile.filename'};
    $fn=~s/(\/)+/\//g;

    # Check for illegal filename
    &Debug($r, "Filename for upload: $fn");
    if (!(($fn) && ($fn!~/\/$/))) {
        $r->print('<p class="LC_warning">'.&mt('Illegal filename.').'</p>');
        return;
    }
    # Check if quota exceeded
    my $filesize = length($env{'form.upfile'});
    if (!$filesize) {
        $r->print('<p class="LC_warning">'.
                  &mt('Unable to upload [_1]. (size = [_2] bytes)',
                      '<span class="LC_filename">'.$env{'form.upfile.filename'}.'</span>',
                      $filesize).'<br />'.
                  &mt('Either the file you attempted to upload was empty, or your web browser was unable to read its contents.').'<br />'.
                  '</p>'.
                  &earlyout($fn,$uname,$udom));
        return;
    }
    $filesize = int($filesize/1000); #expressed in kb
    my $output = &Apache::loncommon::excess_filesize_warning($uname,$udom,'author',
                                                             $env{'form.upfile.filename'},$filesize,'upload');
    if ($output) {
        $r->print($output.&earlyout($fn,$uname,$udom));
        return;
    }

# Split part that I can change from the part that I cannot change
    my ($fn1,$fn2)=($fn=~/^(\/priv\/[^\/]+\/[^\/]+\/)(.*)$/);
# Check for pattern: .number.extension which is reserved for LON-CAPA versioning. 
# Check for disallowed characters: #?&%:<>`|, and remove
    if ($fn2 ne '') {
        ($fn2,my $warning) = &check_filename($fn2);
        if ($warning ne '') {
            $r->print($warning);
        }
    }
    # Display additional options for upload
    # and upload button
    $r->print(
        '<form action="'.$action.'" method="post" name="fileupload">'
       .'<input type="hidden" name="phase" value="two" />'
       .'<input type="hidden" name="datatoken" value="'.&upfile_store.'" />'
    );
    $r->print(
        &Apache::lonhtmlcommon::start_pick_box()
       .&Apache::lonhtmlcommon::row_title(&mt('Save uploaded file as'))
       .'<span class="LC_filename">'.$fn1.'</span>'
       .'<input type="hidden" name="filename1" value="'.$fn1.'" />'
       .'<input type="text" size="50" name="filename2" value="'.$fn2.'" />'
       .&Apache::lonhtmlcommon::row_closure()
       .&Apache::lonhtmlcommon::row_title(&mt('File Type'))
       .'<select name="filetype">'
       .'<option value="standard" selected="selected">'.&mt('Regular file').'</option>'
       .'<option value="testbank">'.&mt('Testbank file').'</option>'
       .'<option value="imsimport">'.&mt('IMS package').'</option>'
       .'</select>'.&Apache::loncommon::help_open_topic("Uploading_File_Options")
       .&Apache::lonhtmlcommon::row_closure(1)
       .&Apache::lonhtmlcommon::end_pick_box()
    );
    $r->print(
        '<p>'
       .'<input type="button" value="'.&mt('Upload').'" onclick="javascript:verifyForm()"/>'
       .'</p>'
       .'</form>'
    );

   # Check for bad extension and warn user
    if ($fn=~/\.(\w+)$/ && 
        (&Apache::loncommon::fileembstyle($1) eq 'hdn')) {
                $r->print('<p class="LC_error">'
                          .&mt('The extension on this file, [_1], is reserved internally by LON-CAPA.',
                               '<span class="LC_filename">'.$1.'</span>')
                          .' <br />'.&mt('Please change the extension.')
                          .'</p>');
    } elsif($fn=~/\.(\w+)$/ && 
                    !defined(&Apache::loncommon::fileembstyle($1))) {
                $r->print('<p class="LC_error">'
                         .&mt('The extension on this file, [_1], is not recognized by LON-CAPA.',
                              '<span class="LC_filename">'.$1.'</span>')
                         .' <br />'.&mt('Please change the extension.')
                         .'</p>');
    }
}

sub phasetwo {
    my ($r,$fn,$mode)=@_;

    my $output;
    my $action = '/adm/upload';
    my $returnflag = '';
    if ($mode eq 'testbank') {
        $action = '/adm/testbank';
    } elsif ($mode eq 'imsimport') {
        $action = '/adm/imsimport';
    }
    $fn=~s/\/+/\//g;
    if ($fn) {
	my $target= $r->dir_config('lonDocRoot').'/'.$fn;
	&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 $datatoken;
        if ($env{'form.datatoken'} =~ /^$match_username\_$match_domain\_upload_\w*_\d+_\d+$/) {
            $datatoken = $env{'form.datatoken'};
        }
	if (($fn) && ($datatoken)) {
            if ($env{'form.cancel'}) {
                my $source=$r->dir_config('lonDaemons').'/tmp/'.$datatoken.'.tmp';
                my $dirpath=$path.'/';
                $dirpath=~s/\/+/\//g;
                $output .= '<p class="LC_warning">'.&mt('Upload cancelled.').'</p>'
                          .'<p><a href="'.$dirpath.'">'.
                          &mt('Back to Directory').'</a></p>';
            } elsif ((-e $target) && (!$env{'form.override'})) {
                $output .= '<form action="'.$action.'" method="post">'
                          .'<p class="LC_warning">'
                          .&mt('File [_1] already exists.',
                               '<span class="LC_filename">'.$fn.'</span>')
                         .'<input type="hidden" name="phase" value="two" />'
                         .'<input type="hidden" name="filename" value="'.$url.'" />'
                         .'<input type="hidden" name="datatoken" value="'.$datatoken.'" />'
                         .'<p>'
                         .'<input type="submit" name="cancel" value="'.&mt('Cancel').'" />'
                         .' <input type="submit" name="override" value="'.&mt('Overwrite').'" />'
                         .'</p>'
                         .'</form>';
            } else {
		my $source=$r->dir_config('lonDaemons').'/tmp/'.$datatoken.'.tmp';
		my $dirpath=$path.'/';
		$dirpath=~s/\/+/\//g;
		# Check for bad extension and disallow upload
                my $result;
                ($result,$returnflag) = &check_extension($fn,$mode,$source,$target,$action,$dirpath,$url);
                $output .= $result;
	    }
	} else {
	    $output .= '<span class="LC_error">'.
		      &mt('Please use browser "Back" button and pick a filename').
		      '</span><br />';
	}
    } else {
	$output .= '<span class="LC_error">'.
		   &mt('Please use browser "Back" button and pick a filename').
		   '</span><br />';
    }
    return ($output,$returnflag);
}

sub check_extension {
    my ($fn,$mode,$source,$target,$action,$dirpath,$url) = @_;
    my ($result,$returnflag);
    # Check for bad extension and disallow upload
    if ($fn=~/\.(\w+)$/ &&
        (&Apache::loncommon::fileembstyle($1) eq 'hdn')) {
        $result .= '<p class="LC_warning">'.
                   &mt('File [_1] could not be copied.',
                       '<span class="LC_filename">'.$fn.'</span> ').
                   '<br />'.
                   &mt('The extension on this file is reserved internally by LON-CAPA.').
                   '</p>';
    } elsif ($fn=~/\.(\w+)$/ &&
             !defined(&Apache::loncommon::fileembstyle($1))) {
        $result .= '<p class="LC_warning">'.
                   &mt('File [_1] could not be copied.',
                       '<span class="LC_filename">'.$fn.'</span> ').
                   '<br />'.
                   &mt('The extension on this file is not recognized by LON-CAPA.').
                   '</p>';
    } elsif (-d $target) {
        $result .= '<p class="LC_warning">'.
                   &mt('File [_1] could not be copied.',
                       '<span class="LC_filename">'.$fn.'</span>').
                   '<br />'.
                   &mt('The target is an existing directory.').
                   '</p>';
    } elsif (copy($source,$target)) {
        chmod(0660, $target); # Set permissions to rw-rw---.
        if ($mode eq 'testbank' || $mode eq 'imsimport') {
            $returnflag = 'ok';
            $result .= '<p class="LC_success">'
                      .&mt('Your file - [_1] - was uploaded successfully.',
                           '<span class="LC_filename">'.$fn.'<span>')
                      .'</p>';
        } else {
            $result .= '<p class="LC_success">'
                      .&mt('File copied.')  
                      .'</p>';
        }
        # Check for embedded objects.
        my (%allfiles,%codebase);
        my ($text,$header,$css,$js);
        if (($mode ne 'imsimport') && ($target =~ /\.(htm|html|shtml)$/i)) {
            my (%allfiles,%codebase);
            &Apache::lonnet::extract_embedded_items($target,\%allfiles,\%codebase);
            if (keys(%allfiles) > 0) {
                my ($currentpath) = ($url =~ m{^(.+)/[^/]+$});
                my $state = &embedded_form_elems('upload_embedded',$url,$mode);
                my ($embedded,$num,$pathchg) = 
                    &Apache::loncommon::ask_for_embedded_content($action,$state,\%allfiles,
                                                                 \%codebase,
                                                                 {'error_on_invalid_names'   => 1,
                                                                  'ignore_remote_references' => 1,
                                                                  'current_path'             => $currentpath});
                if ($embedded) {
                    $result .= '<h3>'.&mt('Reference Warning').'</h3>';
                    if ($num) {
                        $result .= '<p>'.&mt('Completed upload of the file.').' '.&mt('This file contained references to other files.').'</p>'.
                                   '<p>'.&mt('Please select the locations from which the referenced files are to be uploaded.').'</p>'.
                                   $embedded;
                        if ($mode eq 'testbank') {
                            $returnflag = 'embedded';
                            $result .=  '<p>'.&mt('Or [_1]continue[_2] the testbank import without these files.','<a href="javascript:document.testbankForm.submit();">','</a>').'</p>';
                        }
                    } else {
                        $result .= '<p>'.&mt('Completed upload of the file.').'</p>'.$embedded;
                        if ($pathchg) {
                            if ($mode eq 'testbank') {
                                $returnflag = 'embedded';
                                $result .=  '<p>'.&mt('Or [_1]continue[_2] the testbank import without modifying the reference(s).','<a href="javascript:document.testbankForm.submit();">','</a>').'</p>';
                            }
                        }
                    }
                }
            }
        }
        if (($mode ne 'imsimport') && ($mode ne 'testbank')) {
            $result .= '<br /><a href="'.$url.'">'.
                        &mt('View file').'</a>';
        }
    } else {
        $result .= &mt('Failed to copy: [_1].',$!);
    }
    if ($mode ne 'imsimport' && $mode ne 'testbank') {
        $result .= '<br /><a href="'.$dirpath.'">'.
                   &mt('Back to Directory').'</a><br />';
    }
    return ($result,$returnflag);
}

sub check_filename {
    my ($fname) = @_;
    my $warning;
    if ($fname =~/[#\?&%":<>`|]/) {
        $fname =~s/[#\?&%":<>`|]//g;
        $warning .= '<p class="LC_warning">'
                   .&mt('Removed one or more disallowed characters from filename')
                   .'</p>';
    }
    if ($fname=~ /\.(\d+)\.(\w+)$/) {
        my $num = $1;
        $warning .= '<p class="LC_warning">'
                   .&mt('Bad filename [_1]','<span class="LC_filename">'.$fname.'</span>')
                   .'<br />'
                   .&mt('[_1](name).(number).(extension)[_2] not allowed.','<tt>','</tt>')
                   .'<br />'
                   .&mt('Replacing the [_1].number.[_2] with [_1]_letter.[_2] in requested filename.','<tt>','</tt>')
                   .'</p>';
        if ($num eq '0') {
            $fname =~ s/\.(\d+)(\.\w+)$/_A$2/;
        } else {
            my $letts = '';
            my %digletter = reverse &Apache::lonnet::letter_to_digits();
            if ($num >= 100) {
                $num = substr($num,-2);
            }
            foreach my $digit (split('',$num)) {
                $letts .= $digletter{$digit};
            }
            $fname =~ s/\.(\d+)(\.\w+)$/_$letts$2/;
        }
    }
    if ($fname =~/___/) {
        $fname =~s/_+/_/g;
        $warning .= '<p class="LC_warning">'
                    .&mt('Changed ___ to a single _ in filename')
                    .'</p>';
    }
    return ($fname,$warning);
}

sub phasethree {
    my ($r,$fn,$uname,$udom,$mode) = @_;

    my $action = '/adm/upload'; 
    if ($mode eq 'testbank') {
        $action = '/adm/testbank';
    } elsif ($mode eq 'imsimport') {
        $action = '/adm/imsimport';
    }
    my $url_root = "/priv/$udom/$uname";
    my $dir_root = $r->dir_config('lonDocRoot').$url_root;
    my $path = &File::Basename::dirname($fn);
    $path =~ s{^\Q$url_root\E}{};
    my $dirpath = $url_root.$path.'/';
    $dirpath=~s{/+}{/}g;
    my $filename = &HTML::Entities::encode($env{'form.filename'},'<>&"');
    my $state = &embedded_form_elems('modify_orightml',$filename,$mode).
                '<input type="hidden" name="phase" value="four" />';
    my ($result,$returnflag) = 
        &Apache::loncommon::upload_embedded($mode,$path,$uname,$udom,
                                            $dir_root,$url_root,undef,
                                            undef,undef,$state,$action);
    if ($mode ne 'imsimport' && $mode ne 'testbank') {
        $result .= '<br /><h3><a href="'.$fn.'">'.
                  &mt('View main file').'</a></h3>'.
                  '<h3><a href="'.$dirpath.'">'.
                  &mt('Back to Directory').'</a></h3><br />';
    }
    return ($result,$returnflag);
}

sub embedded_form_elems {
    my ($action,$filename,$mode) = @_;
    return <<STATE;
    <input type="hidden" name="action" value="$action" />
    <input type="hidden" name="mode" value="$mode" />
    <input type="hidden" name="filename" value="$filename" />
STATE
}

sub phasefour {
    my ($r,$fn,$uname,$udom,$mode) = @_;

    my $action = '/adm/upload';
    if ($mode eq 'testbank') {
        $action = '/adm/testbank';
    } elsif ($mode eq 'imsimport') {
        $action = '/adm/imsimport';
    }
    my $result;
    my $url_root = "/priv/$udom/$uname";
    my $dir_root = $r->dir_config('lonDocRoot').$url_root;
    my $path = &File::Basename::dirname($fn);
    $path =~ s{^\Q$url_root\E}{};
    my $dirpath = $url_root.$path.'/';
    $dirpath=~s{/+}{/}g;
    my $outcome = 
        &Apache::loncommon::modify_html_refs($mode,$path,$uname,$udom,$dir_root);
    $result .= $outcome;
    if ($mode ne 'imsimport' && $mode ne 'testbank') {
        $result .= '<br /><h3><a href="'.$fn.'">'.
                  &mt('View main file').'</a></h3>'.
                  '<h3><a href="'.$dirpath.'">'.
                  &mt('Back to Directory').'</a></h3><br />';
    }
    return $result;
}

sub earlyout {
    my ($fn,$uname,$udom) = @_;
    if ($fn =~ m{^(/priv/$udom/$uname(?:.*)/)[^/]*}) {
        return &Apache::lonhtmlcommon::actionbox(
               ['<a href="'.$1.'">'.&mt('Return to Directory').'</a>']);
    }
    return;
}

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

    my $r=shift;
    my $javascript = '';
    my $fn;
    my $warning;

    if ($env{'form.filename1'}) {
        my $fn1 = $env{'form.filename1'};
        my $fn2 = $env{'form.filename2'};
        $fn2 =~ s/(\s+$|^\s+)//g;
        $fn2 =~ s/\/+/\//g;
        ($fn2,$warning) = &check_filename($fn2);
        $fn = $fn1.$fn2;
    } else {
        $fn = $env{'form.filename'};
    }
    $fn=~s/\/+/\//g;
    if ($fn =~ m{/\.\./}) {
        $warning .= '<p class="LC_warning">'
                   .&mt('Path modified as a result of one or more instances of /../')
                   .'</p>';
        while ($fn =~ m{/\.\./}) {
            $fn =~ s{/[^/]+/\.\./}{/}g;
        }
    }

    unless ($fn) {
        $r->log_reason($env{'user.name'}.' at '.$env{'user.domain'}.
                       ' unspecified filename for upload', $r->filename);
        return HTTP_NOT_FOUND;
    }

    my ($uname,$udom)=&Apache::lonnet::constructaccess($fn);

    unless (($uname) && ($udom)) {
        $r->log_reason($env{'user.name'}.' at '.$env{'user.domain'}.
                       ' trying to upload file '.$fn.
                       ' - not authorized',
                       $r->filename);
        return HTTP_NOT_ACCEPTABLE;
    }

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

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

    unless ($env{'form.phase'} eq 'two') {
        $javascript = <<"ENDJS";
<script type="text/javascript">
// <![CDATA[
function verifyForm() {
    var mode = document.fileupload.filetype.options[document.fileupload.filetype.selectedIndex].value
    if (mode == "testbank") {
        document.fileupload.action = "/adm/testbank";
    }
    if (mode == "imsimport") {
        document.fileupload.action = "/adm/imsimport";
    }
    if (mode == "standard") {
        document.fileupload.action = "/adm/upload";
    }
    document.fileupload.submit();
}
// ]]>
</script>
ENDJS
    }

    my $londocroot = $r->dir_config('lonDocRoot');
    my $trailfile = $fn;
    $trailfile =~ s{^/(priv/)}{$londocroot/$1};

    # Breadcrumbs
    my $brcrum = [{'href' => &Apache::loncommon::authorspace($fn),
                   'text' => 'Authoring Space'},
                  {'href' => '/adm/upload',
                   'text' => 'Upload file to Authoring Space'}];
    $r->print(&Apache::loncommon::start_page('Upload file to Authoring Space',
                                             $javascript,
                                             {'bread_crumbs' => $brcrum,})
             .&Apache::loncommon::head_subbox(
                &Apache::loncommon::CSTR_pageheader($trailfile))
    );
  
    if (($uname ne $env{'user.name'}) || ($udom ne $env{'user.domain'})) {
        $r->print('<p class="LC_info">'
                 .&mt('Co-Author [_1]',$uname.':'.$udom)
                 .'</p>'
        );
    }
    if ($warning) {
        $r->print($warning);
    }
    if ($env{'form.phase'} eq 'four') {
        my $output = &phasefour($r,$fn,$uname,$udom,'author');
        $r->print($output);
    } elsif ($env{'form.phase'} eq 'three') {
        my ($output,$rtnflag) = &phasethree($r,$fn,$uname,$udom,'author');
        $r->print($output);
    } elsif ($env{'form.phase'} eq 'two') {
	my ($output,$returnflag) = &phasetwo($r,$fn);
        $r->print($output);
    } else {
	&phaseone($r,$fn,undef,$uname,$udom);
    }

    $r->print(&Apache::loncommon::end_page());
    return OK;
}

1;
__END__