# The LearningOnline Network with CAPA
# Source Code handler
#
# $Id: lonsource.pm,v 1.38 2017/10/07 21:07:17 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/
#
###


package Apache::lonsource;

use strict;
use Apache::lonnet;
use Apache::loncommon();
use Apache::lonhtmlcommon();
use Apache::lonsequence();
use Apache::Constants qw(:common :http);
use Apache::lonmeta;
use Apache::lonenc();
use Apache::File;
use Apache::lonlocal;
use HTML::Entities;
use LONCAPA qw(:DEFAULT :match);

sub make_link {
    my ($filename, $listname) = @_;
    my $sourcelink = '/adm/source?inhibitmenu=yes&filename='.
                     &escape(&escape($filename)).'&listname='.
                     &escape(&escape($listname));
    return $sourcelink;
}

sub stage_2 {
    my ($r, $filename, $listname) = @_;
    my ($author)=($filename=~/\/res\/[^\/]+\/([^\/]+)\//);
    $r->print(&Apache::loncommon::start_page('Copy Problem Source Code to Authoring Space',undef,
                                             {'only_body' => 1,})
             .&mt('Please enter the directory that you would like the source code to go into.')
             .'<p>'
             .&mt('Note: the path is in reference to the root of your Authoring Space,'
                 .' and new directories will be automatically created.')
             .'</p>');
    $r->print('<form name="copy" action="/adm/source" target="_parent" method="post">
              <input type="hidden" name="filename" value="'.$filename.'" />
              <input type="hidden" name="listname" value="'.$listname.'" />
              <input type="hidden" name="action" value="copy_stage" />
              <input type="text" size="50" name="newpath" value="/'.&mt('shared_source').'/'.$author.'" />&nbsp;
              <input type="submit" value="'.&mt('Copy').'" />
              </form>'.
              &Apache::loncommon::end_page());
    return OK;
}

sub copy_author {
    my $role;
    my $domain;
    my $author_name;
    if ($env{'request.role'} =~ m{^ca\.}) {
        ($role, $domain, $author_name) = split(/\//,$env{'request.role'});
    } else {
        $role = "au.";
        $domain = $env{'user.domain'};
        $author_name = $env{'user.name'};
    }
    return ($role,$author_name,$domain);
}


sub copy_stage {
    my ($r, $filename, $listname, $newpath) = @_;

    my ($path_to_new_file,$uname,$udom) = &get_path_to_newfile($r,$newpath,$listname);

    #allowed
    if ($path_to_new_file) {
        $r->print(&Apache::loncommon::start_page('Copying Source',undef,{'only_body' => 1}));
        my $result = &Apache::loncfile::exists($uname, $udom, $path_to_new_file);
        $r->print($result);
        if (($result) && ($result =~ /published/)) {
	    &delete_copy_file($r, $newpath, $filename, $path_to_new_file, '1');
        } elsif (($result) && ($result =~ /exists\!/)) {
	    &confirm($r, $newpath, $filename, $listname);
        } else {
	    &copy_file($r, $newpath, $filename, $path_to_new_file);
        }
        $r->print(&Apache::loncommon::end_page());
    }
    return;
}

sub confirm {
    my ($r, $newpath, $filename, $listname) = @_;
    $r->print('<b>'.&mt('Press delete to remove file and replace it with a copy of the source you are viewing.').'</b><br /><br />');
    $r->print('<form name="delete_confirm" action="/adm/source" target="_parent" method="post">
              <input type="hidden" name="filename" value="'.$filename.'" />
              <input type="hidden" name="listname" value="'.$listname.'" />
              <input type="hidden" name="newpath" value="'.$newpath.'" />
              <input type="hidden" name="action" value="delete_confirm" />
              <input type="submit" value="Delete" />
              </form>');
    return;
}

sub delete_copy_file {
    my ($r, $newpath, $filename, $path_to_new_file, $type) = @_;
    if ($type eq '1') {
        $r->print('<p><span class="LC_warning">'
                 .&mt('Cannot delete non-obsolete published file.')
                 .'</span><br />'
                 .&mt('Please use the code view in previous window to use shared code.')
                 .'<br /><br />');
        $r->print('<form name="delete_done" action="/adm/source" target="_parent" method="post">'
                 .'<input type="button" value="'.&mt('Close Window').'" name="close"'
                 .' onclick="window.close()" />'
                 .'</form></p>');
        return;
    } else {
        $r->print(&Apache::loncommon::start_page('Copying Source',undef,{'only_body' => 1}));
        if (-e $path_to_new_file) {
            unless (unlink($path_to_new_file)) {
                $r->print('<p class="LC_error"">'.&mt('Error:').' '.$!.'</p>');
                return 0;
            }
        } else {
            $r->print('<p class="LC_error">'.&mt('No such file').'</p>');
            return 0;
        }
        &copy_file($r, $newpath, $filename, $path_to_new_file);
        $r->print(&Apache::loncommon::end_page());
        return;
    }
}

sub copy_file {
    my ($r, $newpath, $filename, $path_to_new_file) = @_;
    $r->print('<b>'.&mt('Creating directories').'</b>');

#Figure out if we are author or co-author
    my ($role,$author_name,$domain)=&copy_author();

    my $path = $r->dir_config('lonDocRoot')."/priv/$domain/$author_name/";
    my @directories = split(/\//,$newpath);

    foreach my $now_checking (@directories) {
        if($now_checking ne '') {
            $path = $path.'/'.$now_checking;
            if(-e $path) {} #More moving along, isn't recursion fun'

            else {
                unless(mkdir($path, 02770)) {
                    $r->print('<p class="LC_error">'.&mt('Error:').' '.$!.'</p>');
                    return 0;
                }
                unless(chmod(02770, ($path))) {
                    $r->print('<p class="LC_error"> '.&mt('Error:').' '.$!.'</p>');
                    return 0;
                }
            }
        } else { } #Just move along

    }
    $r->print('<br /><b>'.&mt('Copying File').'</b>');
    my $problem_filename = $Apache::lonnet::perlvar{'lonDocRoot'}.$filename;
    my $file_output = &includemeta(&Apache::lonnet::getfile($problem_filename),$filename);
    my $fs=Apache::File->new(">$path_to_new_file");
    if (defined($fs)) {
        print $fs $file_output;
    }
    $r->print("<br /><br />");
    $r->print('<form name="copied_file" action="/adm/source" target="_parent" method="post">'
              .'<input type="button" value="'
              .&mt('Close Window').'" name="close" onclick="window.close()" />'
              .'</form>');
    #Some 1.3'ish feature is to include the derivative feature, will go here..'
    return;
}

sub print_item {
    my ($r,$filename,$listname,$context) = @_;
    my $file_output;
    if ($context eq 'view') {
        $file_output =
            &Apache::lonnet::getfile($Apache::lonnet::perlvar{'lonDocRoot'}.$filename);
    } else {
        $file_output =
            &includemeta(&Apache::lonnet::getfile($Apache::lonnet::perlvar{'lonDocRoot'}.$filename),
                                                  $filename);
    }
    $r->print(&Apache::loncommon::start_page('View Source Code',undef,
                                             {'only_body' => 1}));
    if ($file_output ne '') {
        my $access_to_cstr;
        my $lonhost = $r->dir_config('lonHostID');
        if ($context eq 'view') {
            $r->print('<form name="view" action="" target="_parent" method="post"><span class="LC_info">'.
                      &mt('Source code is displayed below.').
                      '</span>'.('&nbsp;' x4).'<input type="button" name="close" onclick="window.close();"'.
                      ' value="'.&mt('Close Window').'" /></form><hr />');
        } elsif (&Apache::lonnet::is_library($lonhost)) {
            my @possdoms = &Apache::lonnet::current_machine_domains();
            foreach my $dom (@possdoms) {
                if ($env{"user.role.au./$dom/"}) {
                    $access_to_cstr = 1;
                    last;  
                }
            }
            unless ($access_to_cstr) {
                foreach my $key (keys(%env)) {
                    if ($key =~ m{^\Quser.role.ca./\E($match_domain)/}) {
                        my $adom = $1;
                        if (grep(/^\Q$adom\E$/,@possdoms)) {
                            $access_to_cstr = 1;
                            last;
                        }
                    }
                }
            }
            if ($access_to_cstr) {
                $r->print('
             <form name="copy" action="/adm/source" target="_parent" method="post">
              <input type="button" value="'.&mt('Close Window').'" name="close" onclick="window.close();" />
              <input type="hidden" name="filename" value="'.$filename.'" />
              <input type="hidden" name="listname" value="'.$listname.'" />
              <input type="hidden" name="action" value="stage2" />
              <input type="submit" value="'.&mt('Copy to Authoring Space').'" />
             </form><hr />
                ');
            } else {
                $r->print('<p><span class="LC_info">'.
                          &mt('Source code is displayed, but you can not copy to Authoring Space, as you do not have an author or co-author role on this server.').
                          '</span></p><a href="javascript:window.close();">'.&mt('Close Window').
                          '</a><br /><hr />'
                         );
            }
        } else {
            $r->print('<p><span class="LC_info">'.
                      &mt('Source code is displayed, but you can not copy to Authoring Space on this server.').
                          '</span></p><a href="javascript:window.close();">'.&mt('Close Window').
                          '</a><br /><hr />'
                     );

        }
        my $count=0;
        my $maxlength=-1;
        foreach (split ("\n", $file_output)) {
            $count+=int(length($_)/79);
            $count++;
            if (length($_) > $maxlength) {
                $maxlength = length($_);
            }
        }
        my $rows = $count;
        my $cols = $maxlength;
        $r->print('<form name="showsrc" action="" method="post" onsubmit="return false">'."\n".
                  '<textarea rows="'.$rows.'" cols="'.$cols.'" name="editxmltext">'.
                  &HTML::Entities::encode($file_output,'<>&"').'</textarea></form>');
    } else {
        $r->print('<p class="LC_warning">'.
                  &mt('Unable to retrieve file contents.').
                  '</p><a href="javascript:window.close();">'.&mt('Close Window').'</a>'
                 );
    }
    $r->print(&Apache::loncommon::end_page());
    return;
}

sub includemeta {
    my ($file_output,$orgfilename)=@_;
    my $escfilename=&escape($orgfilename);
    my $copytime=time;
    if ($file_output=~/\<meta\s*name\=\"isbasedonres\"/i) {
	$file_output=~s/(\<meta\s*name\=\"isbasedonres\"\s*content\=\"[^\"]*)\"/$1\,\Q$escfilename\E\"/i;
    } else {
	$file_output=~s/(\<(?:html|problem)[^\>]*\>)/$1\n\<meta name=\"isbasedonres\" content=\"\Q$escfilename\E\" \/\>/i;
    }
    if ($file_output=~/\<meta\s*name\=\"isbasedontime\"/i) {
	$file_output=~s/(\<meta\s*name\=\"isbasedontime\"\s*content\=\"[^\"]*)\"/$1\,\Q$copytime\E\"/i;
    } else {
	$file_output=~s/(\<(?:html|problem)[^\>]*\>)/$1\n\<meta name=\"isbasedontime\" content=\"\Q$copytime\E\" \/\>/i;
    }
    if ($file_output eq '-1') {
        return;
    } else {
        return $file_output;
    }
}

sub get_path_to_newfile {
    my ($r,$newpath,$listname) = @_;

    #Figure out if we are author or co-author
    my ($role,$author_name,$domain) = &copy_author();

    # Construct path to copy and filter out any possibly nasty stuff
    my $path = $r->dir_config('lonDocRoot')."/priv/$domain/$author_name/";
    my $path_to_new_file = $path."$newpath/$listname";
    $path_to_new_file=~s/\.\.//g;
    $path_to_new_file=~s/\~//g;
    $path_to_new_file=~s/\/+/\//g;

    #Just checking again for access as we want to make sure that it is really ok
    #now that we have the real path

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

    if (!$uname || !$udom) {
        $r->print(&Apache::loncommon::start_page('Not Allowed',undef,{'only_body' => 1}));
        $r->print(&mt('Not allowed to create file [_1]', $path_to_new_file));
        $r->print(&Apache::loncommon::end_page());
        if (wantarray) {
            return();
        } else {
            return;
        }
    }
    if (wantarray) {
        return ($path_to_new_file,$uname,$udom);
    } else {
        return $path_to_new_file;
    }
}

sub handler {
    my $r=shift;
    &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},
                                            ['filename','listname','viewonly']);
    my $filename = $env{'form.filename'};
    my $shownfilename = $filename;
    $shownfilename =~ s/(`)/'/g;
    $shownfilename =~ s/\$/\(\$\)/g;
    my $listname = $env{'form.listname'};
    my $viewonly = $env{'form.viewonly'};

    if ($viewonly) {
        my $canview;
        $filename =~ s/\.\.//g;
        $filename =~ s/\~//g;
        $filename =~ s/\/+/\//g;
        if (($env{'request.course.id'}) && (&Apache::lonnet::is_on_map($filename))) {
            if ((&Apache::lonnet::metadata(&Apache::lonenc::check_decrypt($filename)) eq 'open') &&
                (&Apache::lonnet::allowed('cre','/'))) {
                $canview = 1;
            } elsif (&Apache::lonnet::allowed('vxc',$env{'request.course.id'})) {
                my $cdom = $env{'course.'.$env{'request.course.id'}.'.domain'};
                &Apache::lonenc::check_decrypt(\$filename);
                if (($env{'request.role.domain'} eq $cdom) && ($filename =~ /$LONCAPA::assess_re/)) {
                    my ($auname) = ($filename =~ m{^\Q/res/$cdom/\E($match_username)/});
                    if (($auname ne '') && ($env{'request.course.adhocsrcaccess'} ne '') &&
                        (grep(/^\Q$auname\E$/,split(/,/,$env{'request.course.adhocsrcaccess'})))) {
                        $canview = 1;
                    } elsif ((&Apache::lonnet::metadata($filename) eq 'open') &&
                             ($filename =~ m{^\Q/res/$cdom/}) &&
                             (&Apache::lonnet::allowed('bre','/'))) {
                        $canview = 1;
                    }
                }
            }
        }
        unless ($canview) {
            $env{'user.error.msg'}="$shownfilename:cre:1:1:Source code not available";
            return HTTP_NOT_ACCEPTABLE;
        }
    } elsif (&Apache::lonnet::metadata($filename,'sourceavail') ne 'open') {
        $env{'user.error.msg'}="$shownfilename:cre:1:1:Source code not available";
        return HTTP_NOT_ACCEPTABLE;
    }
    unless (&Apache::lonnet::allowed('bre',$filename)) {
        $env{'user.error.msg'}="$shownfilename:bre:1:1:Access to resource denied";
        return HTTP_NOT_ACCEPTABLE;
    }
    unless ($viewonly) {
        unless (&Apache::lonnet::allowed('cre','/')) {
            $env{'user.error.msg'}="$shownfilename:cre:1:1:Access to source code denied";
            return HTTP_NOT_ACCEPTABLE;
        }
    }
    my $newpath = $env{'form.newpath'};

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

    if ($viewonly) {
        &print_item($r,$filename,$listname,'view');
    } elsif ($env{'form.action'} eq 'stage2') {
        &stage_2($r,$filename,$listname);
    } elsif($env{'form.action'} eq 'copy_stage') {
        &copy_stage($r,$filename,$listname,$newpath);
    } elsif($env{'form.action'} eq 'delete_confirm') {
        my $path_to_new_file = &get_path_to_newfile($r,$newpath,$listname);
        if ($path_to_new_file) {
            &delete_copy_file($r, $newpath, $filename, $path_to_new_file, '0');
        }
    } else {
        &print_item($r,$filename,$listname);
    }
    return OK;
}

1;