# The LearningOnline Network
# Preferences
#
# $Id: lonpreferences.pm,v 1.93 2006/06/26 18:56:50 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/
#
# This package uses the "londes.js" javascript code. 
#
# TODOs that have to be completed:
#    interface with lonnet to change the password
 
package Apache::lonpreferences;

use strict;
use LONCAPA;
use Apache::Constants qw(:common);
use Apache::File;
use Crypt::DES;
use DynaLoader; # for Crypt::DES version
use Apache::loncommon();
use Apache::lonhtmlcommon();
use Apache::lonlocal;
use Apache::lonnet;

#
# Write lonnet::passwd to do the call below.
# Use:
#   my $answer=reply("encrypt:passwd:$udom:$uname:$upass",$tryserver);
#
##################################################
#          password associated functions         #
##################################################
sub des_keys {
    # Make a new key for DES encryption.
    # Each key has two parts which are returned separately.
    # Please note:  Each key must be passed through the &hex function
    # before it is output to the web browser.  The hex versions cannot
    # be used to decrypt.
    my @hexstr=('0','1','2','3','4','5','6','7',
                '8','9','a','b','c','d','e','f');
    my $lkey='';
    for (0..7) {
        $lkey.=$hexstr[rand(15)];
    }
    my $ukey='';
    for (0..7) {
        $ukey.=$hexstr[rand(15)];
    }
    return ($lkey,$ukey);
}

sub des_decrypt {
    my ($key,$cyphertext) = @_;
    my $keybin=pack("H16",$key);
    my $cypher;
    if ($Crypt::DES::VERSION>=2.03) {
        $cypher=new Crypt::DES $keybin;
    } else {
        $cypher=new DES $keybin;
    }
    my $plaintext=
	$cypher->decrypt(unpack("a8",pack("H16",substr($cyphertext,0,16))));
    $plaintext.=
	$cypher->decrypt(unpack("a8",pack("H16",substr($cyphertext,16,16))));
    $plaintext=substr($plaintext,1,ord(substr($plaintext,0,1)) );
    return $plaintext;
}

################################################################
#                       Handler subroutines                    #
################################################################

################################################################
#         Language Change Subroutines                          #
################################################################

sub wysiwygchanger {
    my $r = shift;
    my %userenv = &Apache::lonnet::get
        ('environment',['wysiwygeditor']);
    my $onselect='checked="checked"';
    my $offselect='';
    if ($userenv{'wysiwygeditor'} eq 'on') {
	$onselect='';
	$offselect='checked="checked"';
    }
    my $switchoff=&mt('Disable WYSIWYG editor');
    my $switchon=&mt('Enable WYSIWYG editor');
    $r->print(<<ENDLSCREEN);
<form name="prefs" action="/adm/preferences" method="post">
<input type="hidden" name="action" value="set_wysiwyg" />
<br />
<label><input type="radio" name="wysiwyg" value="off" $onselect /> $switchoff</label><br />
<label><input type="radio" name="wysiwyg" value="on" $offselect /> $switchon</label>
ENDLSCREEN
    $r->print('<br /><input type="submit" value="'.&mt('Change').'" />');
}


sub verify_and_change_wysiwyg {
    my $r = shift;
    my $newsetting=$env{'form.wysiwyg'};
    &Apache::lonnet::put('environment',{'wysiwygeditor' => $newsetting});
    &Apache::lonnet::appenv('environment.wysiwygeditor' => $newsetting);
    $r->print('<p>'.&mt('Setting WYSIWYG editor to:').' '.&mt($newsetting).'</p>');
}

################################################################
#         Language Change Subroutines                          #
################################################################
sub languagechanger {
    my $r = shift;
    my $user       = $env{'user.name'};
    my $domain     = $env{'user.domain'};
    my %userenv = &Apache::lonnet::get
        ('environment',['languages']);
    my $language=$userenv{'languages'};

    my $pref=&mt('Preferred language');
    my %langchoices=('' => 'No language preference');
    foreach (&Apache::loncommon::languageids()) {
	if (&Apache::loncommon::supportedlanguagecode($_)) {
	    $langchoices{&Apache::loncommon::supportedlanguagecode($_)}
	               = &Apache::loncommon::plainlanguagedescription($_);
	}
    }
    my $selectionbox=&Apache::loncommon::select_form($language,'language',
						     %langchoices);
    $r->print(<<ENDLSCREEN);
<form name="prefs" action="/adm/preferences" method="post">
<input type="hidden" name="action" value="verify_and_change_languages" />
<br />$pref: $selectionbox
ENDLSCREEN
    $r->print('<br /><input type="submit" value="'.&mt('Change').'" />');
}


sub verify_and_change_languages {
    my $r = shift;
    my $user       = $env{'user.name'};
    my $domain     = $env{'user.domain'};
# Screenname
    my $newlanguage  = $env{'form.language'};
    $newlanguage=~s/[^\-\w]//g;
    my $message='';
    if ($newlanguage) {
        &Apache::lonnet::put('environment',{'languages' => $newlanguage});
        &Apache::lonnet::appenv('environment.languages' => $newlanguage);
        $message='Set new preferred languages to '.$newlanguage;
    } else {
        &Apache::lonnet::del('environment',['languages']);
        &Apache::lonnet::delenv('environment\.languages');
        $message='Reset preferred language';
    }
    $r->print(<<ENDVCSCREEN);
$message
ENDVCSCREEN
}

################################################################
#         Tex Engine Change Subroutines                        #
################################################################
sub texenginechanger {
    my $r = shift;
    my $user       = $env{'user.name'};
    my $domain     = $env{'user.domain'};
    my %userenv = &Apache::lonnet::get('environment',['texengine']);
    my $texengine=$userenv{'texengine'};

    my $pref=&mt('Preferred method to display Math');
    my %mathchoices=('' => 'Default',
		     'tth' => 'TeX to HTML',
		     #'ttm' => 'TeX to MathML',
		     'jsMath' => 'jsMath',
		     'mimetex' => 'Convert to Images'
                     );
    my $selectionbox=&Apache::loncommon::select_form($texengine,'texengine',
						     %mathchoices);
    my $jsMath_start=&Apache::lontexconvert::jsMath_header();
    my $change=&mt('Change');
    $r->print(<<ENDLSCREEN);
<br />

<form name="prefs" action="/adm/preferences" method="post">
<input type="hidden" name="action" value="verify_and_change_texengine" />
<p>$pref: $selectionbox</p>
<p><input type="submit" value="$change" /></p>
</form>
Examples:
<p> TeX to HTML <br /> 
<iframe src="/res/adm/pages/math_example.tex?inhibitmenu=yes&texengine=tth" width="400" hieght="200"></iframe>
</p>
<p>jsMath <br /> 
$jsMath_start
<script type="text/javascript">
if (jsMath.nofonts == 1) {
    document.writeln
        ('<center><div style="padding: 10; border-style: solid; border-width:3;'
	 +' border-color: #DD0000; background-color: #FFF8F8; width: 75%; text-align: left">'
	 +'<small><font color="#AA0000"><b>Warning:</b> '
	 +'It looks like you don\\\'t have the TeX math fonts installed. '
	 +'The jsMath example on this page may not look right without them. '
	 +'The <a href="http://www.math.union.edu/locate/jsMath/" target="_blank"> '
	 +'jsMath Home Page</a> has information on how to download the '
	 +'needed fonts.  In the meantime, jsMath will do the best it can '
	 +'with the fonts you have, but it may not be pretty and some equations '
	 +'may not be rendered correctly. '
	 +'</font></small></div></center>');
}
</script>
<iframe src="/res/adm/pages/math_example.tex?inhibitmenu=yes&texengine=jsMath" width="400" hieght="200"></iframe>

</p>
<p> Convert to Images <br />
<br />
<iframe src="/res/adm/pages/math_example.tex?inhibitmenu=yes&texengine=mimetex" width="400" hieght="200"></iframe>
</p>
ENDLSCREEN
    if ($env{'environment.texengine'} ne 'jsMath') {
	$r->print('<script type="text/javascript">jsMath.Process()</script>');
    }
}


sub verify_and_change_texengine {
    my $r = shift;
    my $user       = $env{'user.name'};
    my $domain     = $env{'user.domain'};
# Screenname
    my $newtexengine  = $env{'form.texengine'};
    $newtexengine=~s/[^\-\w]//g;
    if ($newtexengine eq 'ttm') {
	&Apache::lonnet::appenv('browser.mathml' => 1);
    } else {
	if ($env{'environment.texengine'} eq 'ttm') {
	    &Apache::lonnet::appenv('browser.mathml' => 0);
	}
    }
    my $message='';
    if ($newtexengine) {
        &Apache::lonnet::put('environment',{'texengine' => $newtexengine});
        &Apache::lonnet::appenv('environment.texengine' => $newtexengine);
        $message='Set new preferred math display to '.$newtexengine;
    } else {
        &Apache::lonnet::del('environment',['texengine']);
        &Apache::lonnet::delenv('environment\.texengine');
        $message='Reset preferred math display.';
    }


    $r->print(<<ENDVCSCREEN);
$message
ENDVCSCREEN
}

################################################################
#         Roles Page Preference Change Subroutines         #
################################################################
sub rolesprefchanger {
    my $r = shift;
    my $user       = $env{'user.name'};
    my $domain     = $env{'user.domain'};
    my %userenv = &Apache::lonnet::get
        ('environment',['recentroles','recentrolesn']);
    my $hotlist_flag=$userenv{'recentroles'};
    my $hotlist_n=$userenv{'recentrolesn'};
    my $checked;
    if ($hotlist_flag) {
	$checked = 'checked="checked"';
    }
    
    if (!$hotlist_n) { $hotlist_n=3; }
    my $options;
    for (my $i=1; $i<10; $i++) {
	my $select;
	if ($hotlist_n == $i) { $select = 'selected="selected"'; }
	$options .= "<option $select>$i</option>\n";
    }

# Get list of recent roles and display with checkbox in front
    my $roles_check_list = '';
    my $role_key='';
    if ($env{'environment.recentroles'}) {
        my %recent_roles =
               &Apache::lonhtmlcommon::get_recent('roles',$env{'environment.recentrolesn'});
        my %frozen_roles =
               &Apache::lonhtmlcommon::get_recent_frozen('roles',$env{'environment.recentrolesn'});
        
        my %role_text = &rolespref_get_role_text([keys(%recent_roles)]);
        my @sorted_roles = sort {$role_text{$a} cmp $role_text{$b}} keys(%role_text);

        $roles_check_list .=
	    &Apache::loncommon::start_data_table().
	    &Apache::loncommon::start_data_table_header_row().
	    "<th>".&mt('Freeze Role')."</th>".
	    "<th>".&mt('Role')."</td>".
	    &Apache::loncommon::end_data_table_header_row().
	    "\n";
	my $count;
        foreach $role_key (@sorted_roles) {
            my $checked = "";
            my $value = $recent_roles{$role_key};
            if ($frozen_roles{$role_key}) {
                $checked = "checked=\"checked\"";
            }
	    $count++;
            $roles_check_list .=
		&Apache::loncommon::start_data_table_row().
		'<td class="LC_table_cell_checkbox">'.
		"<input type=\"checkbox\" $checked name=\"freezeroles\"".
		" id=\"freezeroles$count\" value=\"$role_key\" /></td>".
		"<td><label for=\"freezeroles$count\">".
		"$role_text{$role_key}</label></td>".
		&Apache::loncommon::end_data_table_row(). "\n";
        }
        $roles_check_list .= "</table>\n";
    }

    $r->print('
<p>'.&mt('Some LON-CAPA users have a long list of roles. The Recent Roles Hotlist feature keeps track of the last N roles which have been visited and places a table of these at the top of the roles page. People with very few roles should leave this feature disabled.').'
</p>
<form name="prefs" action="/adm/preferences" method="POST">
<input type="hidden" name="action" value="verify_and_change_rolespref" />
<br /><label>'.&mt('Enable Recent Roles Hotlist:').'
<input type="checkbox" '.$checked.' name="recentroles" value="true" /></label>
<br />'.&mt('Number of roles in Hotlist:').'
<select name="recentrolesn" size="1">
'.$options.'
</select>
<p>'.&mt('This list below can be used to <q>freeze</q> roles on your screen. Those marked as frozen will not be removed from the list, even if they have not been used recently.').'
</p>
'.$roles_check_list.'
<br />
<input type="submit" value="'.&mt('Change').'" />
</form>');
}

sub rolespref_get_role_text {
# Get a line of text for each role
    my ($roles) = @_;
    my %roletext = ();

    foreach my $item (@$roles) {
# get course information
        my ($role,$rest) = split(/\./, $item);
        my $trole = "";
        $trole = &Apache::lonnet::plaintext($role);
        my ($tdomain,$other,$tsection)= split(/\//,Apache::lonnet::declutter($rest));
        my $tother = '-';
        if ($role =~ /^(cc|st|in|ta|ep|cr)/ ) {
            my %newhash=&Apache::lonnet::coursedescription($tdomain."_".$other);
            $tother = " - ".$newhash{'description'};
        } elsif ($role =~ /dc/) {
            $tother = "";
        } else {
            $tother = " - $other";
        }
 
        my $section="";
        if ($tsection) {
            $section = " - Section/Group: $tsection";
        }
        $roletext{$item} = $tdomain." - ".$trole.$tother.$section;
    }
    return %roletext;
}

sub verify_and_change_rolespref {
    my $r = shift;
    my $user       = $env{'user.name'};
    my $domain     = $env{'user.domain'};
# Recent Roles Hotlist Flag
    my $hotlist_flag  = $env{'form.recentroles'};
    my $hotlist_n  = $env{'form.recentrolesn'};
    my $message='<hr />';
    if ($hotlist_flag) {
        &Apache::lonnet::put('environment',{'recentroles' => $hotlist_flag});
        &Apache::lonnet::appenv('environment.recentroles' => $hotlist_flag);
        $message=&mt('Recent Roles Hotlist is Enabled');
    } else {
        &Apache::lonnet::del('environment',['recentroles']);
        &Apache::lonnet::delenv('environment\.recentroles');
        $message=&mt('Recent Roles Hotlist is Disabled');
    }
    if ($hotlist_n) {
        &Apache::lonnet::put('environment',{'recentrolesn' => $hotlist_n});
        &Apache::lonnet::appenv('environment.recentrolesn' => $hotlist_n);
        if ($hotlist_flag) {
            $message.="<br />".
		&mt('Display [_1] Most Recent Roles',$hotlist_n)."\n";
        }
    }

# Get list of froze roles and list of recent roles
    my @freeze_list = &Apache::loncommon::get_env_multiple('form.freezeroles');
    my %freeze = ();
    my %roletext = ();

    foreach my $key (@freeze_list) {
        $freeze{$key}='1';
    }

    my %recent_roles =
        &Apache::lonhtmlcommon::get_recent('roles',$env{'environment.recentrolesn'});
    my %frozen_roles =
        &Apache::lonhtmlcommon::get_recent_frozen('roles',$env{'environment.recentrolesn'});
    my %role_text = &rolespref_get_role_text([keys(%recent_roles)]);

# Unset any roles that were previously frozen but aren't in list
    foreach my $role_key (sort(keys(%recent_roles))) {
        if (($frozen_roles{$role_key}) && (!exists($freeze{$role_key}))) {
	    $message .= "<br />".&mt('Unfreezing Role: [_1]',$role_text{$role_key})."\n";
	    &Apache::lonhtmlcommon::store_recent('roles',$role_key,' ',0);
        }
    }

# Freeze selected roles
    foreach my $role_key (@freeze_list) {
        if (!$frozen_roles{$role_key}) {
             $message .= "<br />".&mt('Freezing Role: [_1]',$role_text{$role_key})."\n";
             &Apache::lonhtmlcommon::store_recent('roles',
                                          $role_key,' ',1);
        }
    }
    $message .= "<hr /><br />\n";

    $r->print(<<ENDRPSCREEN);
$message
ENDRPSCREEN
}



################################################################
#         Anonymous Discussion Name Change Subroutines         #
################################################################
sub screennamechanger {
    my $r = shift;
    my $user       = $env{'user.name'};
    my $domain     = $env{'user.domain'};
    my %userenv = &Apache::lonnet::get
        ('environment',['screenname','nickname']);
    my $screenname=$userenv{'screenname'};
    my $nickname=$userenv{'nickname'};
    $r->print(<<ENDSCREEN);
<form name="prefs" action="/adm/preferences" method="post">
<input type="hidden" name="action" value="verify_and_change_screenname" />
<br />New screenname (shown if you post anonymously):
<input type="text" size="20" value="$screenname" name="screenname" />
<br />New nickname (shown if you post non-anonymously):
<input type="text" size="20" value="$nickname" name="nickname" />
<input type="submit" value="Change" />
</form>
ENDSCREEN
}

sub verify_and_change_screenname {
    my $r = shift;
    my $user       = $env{'user.name'};
    my $domain     = $env{'user.domain'};
# Screenname
    my $newscreen  = $env{'form.screenname'};
    $newscreen=~s/[^ \w]//g;
    my $message='';
    if ($newscreen) {
        &Apache::lonnet::put('environment',{'screenname' => $newscreen});
        &Apache::lonnet::appenv('environment.screenname' => $newscreen);
        $message='Set new screenname to '.$newscreen;
    } else {
        &Apache::lonnet::del('environment',['screenname']);
        &Apache::lonnet::delenv('environment\.screenname');
        $message='Reset screenname';
    }
# Nickname
    $message.='<br />';
    $newscreen  = $env{'form.nickname'};
    $newscreen=~s/[^ \w]//g;
    if ($newscreen) {
        &Apache::lonnet::put('environment',{'nickname' => $newscreen});
        &Apache::lonnet::appenv('environment.nickname' => $newscreen);
        $message.='Set new nickname to '.$newscreen;
    } else {
        &Apache::lonnet::del('environment',['nickname']);
        &Apache::lonnet::delenv('environment\.nickname');
        $message.='Reset nickname';
    }
    &Apache::lonnet::devalidate_cache_new('namescache',$user.':'.$domain);
    $r->print(<<ENDVCSCREEN);
$message
ENDVCSCREEN
}

################################################################
#         Message Forward                                      #
################################################################

sub msgforwardchanger {
    my $r = shift;
    my $user       = $env{'user.name'};
    my $domain     = $env{'user.domain'};
    my %userenv = &Apache::lonnet::get('environment',['msgforward','notification','critnotification']);
    my $msgforward=$userenv{'msgforward'};
    my $notification=$userenv{'notification'};
    my $critnotification=$userenv{'critnotification'};
    my $forwardingHelp = Apache::loncommon::help_open_topic("Prefs_Forwarding",
							    "What are forwarding ".
							    "and notification ".
							    "addresses");
    my $criticalMessageHelp = Apache::loncommon::help_open_topic("Course_Critical_Message",
								 "What are critical messages");

    $r->print(<<ENDMSG);
$forwardingHelp <br />
<form name="prefs" action="/adm/preferences" method="post">
<input type="hidden" name="action" value="verify_and_change_msgforward" />
New Forwarding Address(es) (<tt>user:domain,user:domain,...</tt>):
<input type="text" size="40" value="$msgforward" name="msgforward" /><hr />
New Message Notification Email Address(es) (<tt>joe\@doe.com,jane\@doe.edu,...</tt>):
<input type="text" size="40" value="$notification" name="notification" /><hr />
New Critical Message Notification Email Address(es) (<tt>joe\@doe.com,jane\@doe.edu,...</tt>):
<input type="text" size="40" value="$critnotification" name="critnotification" />$criticalMessageHelp<hr />
<input type="submit" value="Change" />
</form>
ENDMSG
}

sub verify_and_change_msgforward {
    my $r = shift;
    my $user       = $env{'user.name'};
    my $domain     = $env{'user.domain'};
    my $newscreen  = '';
    my $message='';
    foreach (split(/\,/,$env{'form.msgforward'})) {
	my ($msuser,$msdomain)=split(/[\@\:]/,$_);
        $msuser=~s/\W//g;
        $msdomain=~s/\W//g;
        if (($msuser) && ($msdomain)) {
	    if (&Apache::lonnet::homeserver($msuser,$msdomain) ne 'no_host') {
               $newscreen.=$msuser.':'.$msdomain.',';
	   } else {
               $message.='No such user: '.$msuser.':'.$msdomain.'<br>';
           }
        }
    }
    $newscreen=~s/\,$//;
    if ($newscreen) {
        &Apache::lonnet::put('environment',{'msgforward' => $newscreen});
        &Apache::lonnet::appenv('environment.msgforward' => $newscreen);
        $message.='Set new message forwarding to '.$newscreen.'<br />';
    } else {
        &Apache::lonnet::del('environment',['msgforward']);
        &Apache::lonnet::delenv('environment\.msgforward');
        $message.='Reset message forwarding<br />';
    }
    my $notification=$env{'form.notification'};
    $notification=~s/\s//gs;
    if ($notification) {
        &Apache::lonnet::put('environment',{'notification' => $notification});
        &Apache::lonnet::appenv('environment.notification' => $notification);
        $message.='Set message notification address to '.$notification.'<br />';
    } else {
        &Apache::lonnet::del('environment',['notification']);
        &Apache::lonnet::delenv('environment\.notification');
        $message.='Reset message notification<br />';
    }
    my $critnotification=$env{'form.critnotification'};
    $critnotification=~s/\s//gs;
    if ($critnotification) {
        &Apache::lonnet::put('environment',{'critnotification' => $critnotification});
        &Apache::lonnet::appenv('environment.critnotification' => $critnotification);
        $message.='Set critical message notification address to '.$critnotification;
    } else {
        &Apache::lonnet::del('environment',['critnotification']);
        &Apache::lonnet::delenv('environment\.critnotification');
        $message.='Reset critical message notification<br />';
    }
    $r->print(<<ENDVCMSG);
$message
ENDVCMSG
}

################################################################
#         Colors                                               #
################################################################

sub colorschanger {
    my $r = shift;
# figure out colors
    my $function=&Apache::loncommon::get_users_function();
    my $domain=&Apache::loncommon::determinedomain();
    my %colortypes=('pgbg'  => 'Page Background',
                    'tabbg' => 'Header Background',
                    'sidebg'=> 'Header Border',
                    'font'  => 'Font',
                    'link'  => 'Un-Visited Link',
                    'vlink' => 'Visited Link',
                    'alink' => 'Active Link');
    my $start_data_table = &Apache::loncommon::start_data_table();
    my $chtable='';
    foreach my $item (sort(keys(%colortypes))) {
       my $curcol=&Apache::loncommon::designparm($function.'.'.$item,$domain);
       $chtable.=&Apache::loncommon::start_data_table_row().
	   '<td>'.$colortypes{$item}.'</td><td style="background: '.$curcol.
        '">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td><td><input name="'.$item.
        '" size="10" value="'.$curcol.
'" /></td><td><a href="javascript:pjump('."'color_custom','".$colortypes{$item}.
"','".$curcol."','"
	    .$item."','parmform.pres','psub'".');">Select</a></td>'.
	    &Apache::loncommon::end_data_table_row()."\n";
    }
    my $end_data_table = &Apache::loncommon::end_data_table();
    my $pjump_def = &Apache::lonhtmlcommon::pjump_javascript_definition();
    $r->print(<<ENDCOL);
<script type="text/javascript">

    function pclose() {
        parmwin=window.open("/adm/rat/empty.html","LONCAPAparms",
                 "height=350,width=350,scrollbars=no,menubar=no");
        parmwin.close();
    }

    $pjump_def

    function psub() {
        pclose();
        if (document.parmform.pres_marker.value!='') {
            if (document.parmform.pres_type.value!='') {
                eval('document.prefs.'+
                     document.parmform.pres_marker.value+
		     '.value=document.parmform.pres_value.value;');
	    }
        } else {
            document.parmform.pres_value.value='';
            document.parmform.pres_marker.value='';
        }
    }


</script>
<form name="parmform">
<input type="hidden" name="pres_marker" />
<input type="hidden" name="pres_type" />
<input type="hidden" name="pres_value" />
</form>
<form name="prefs" action="/adm/preferences" method="post">
<input type="hidden" name="action" value="verify_and_change_colors" />
$start_data_table
$chtable
$end_data_table
</table>
<input type="submit" value="Change Custom Colors" />
<input type="submit" name="resetall" value="Reset All Colors to Default" />
</form>
ENDCOL
}

sub verify_and_change_colors {
    my $r = shift;
# figure out colors
    my $function=&Apache::loncommon::get_users_function();
    my $domain=&Apache::loncommon::determinedomain();
    my %colortypes=('pgbg'  => 'Page Background',
                    'tabbg' => 'Header Background',
                    'sidebg'=> 'Header Border',
                    'font'  => 'Font',
                    'link'  => 'Un-Visited Link',
                    'vlink' => 'Visited Link',
                    'alink' => 'Active Link');

    my $message='';
    foreach my $item (keys %colortypes) {
        my $color=$env{'form.'.$item};
        my $entry='color.'.$function.'.'.$item;
	if (($color=~/^\#[0-9A-Fa-f]{6}$/) && (!$env{'form.resetall'})) {
	    &Apache::lonnet::put('environment',{$entry => $color});
	    &Apache::lonnet::appenv('environment.'.$entry => $color);
	    $message.='Set '.$colortypes{$item}.' to '.$color.'<br />';
	} else {
	    &Apache::lonnet::del('environment',[$entry]);
	    &Apache::lonnet::delenv('environment\.'.$entry);
	    $message.='Reset '.$colortypes{$item}.'<br />';
	}
    }
    my $now = time;
    &Apache::lonnet::put('environment',{'color.timestamp' => $now});
    &Apache::lonnet::appenv('environment.color.timestamp' => $now);

    $r->print(<<ENDVCCOL);
$message
<form name="client" action="/adm/preferences" method="post">
<input type="hidden" name="action" value="changecolors" />
</form>
ENDVCCOL
}

######################################################
#            password handler subroutines            #
######################################################
sub passwordchanger {
    # This function is a bit of a mess....
    # Passwords are encrypted using londes.js (DES encryption)
    my $r = shift;
    my $errormessage = shift;
    $errormessage = ($errormessage || '');
    my $user       = $env{'user.name'};
    my $domain     = $env{'user.domain'};
    my $homeserver = $env{'user.home'};
    my $currentauth=&Apache::lonnet::queryauthenticate($user,$domain);
    # Check for authentication types that allow changing of the password.
    return if ($currentauth !~ /^(unix|internal):/);
    #
    # Generate keys
    my ($lkey_cpass ,$ukey_cpass ) = &des_keys();
    my ($lkey_npass1,$ukey_npass1) = &des_keys();
    my ($lkey_npass2,$ukey_npass2) = &des_keys();
    # Store the keys in the log files
    my $lonhost = $r->dir_config('lonHostID');
    my $logtoken=Apache::lonnet::reply('tmpput:'
				       .$ukey_cpass  . $lkey_cpass .'&'
				       .$ukey_npass1 . $lkey_npass1.'&'
				       .$ukey_npass2 . $lkey_npass2,
				       $lonhost);
    # Hexify the keys for output as javascript variables
    $ukey_cpass = hex($ukey_cpass);
    $lkey_cpass = hex($lkey_cpass);
    $ukey_npass1= hex($ukey_npass1);
    $lkey_npass1= hex($lkey_npass1);
    $ukey_npass2= hex($ukey_npass2);
    $lkey_npass2= hex($lkey_npass2);
    # Output javascript to deal with passwords
    # Output DES javascript
    {
	my $include = $r->dir_config('lonIncludes');
	my $jsh=Apache::File->new($include."/londes.js");
	$r->print(<$jsh>);
    }
    $r->print(<<ENDFORM);
<script language="JavaScript">

    function send() {
        uextkey=this.document.client.elements.ukey_cpass.value;
        lextkey=this.document.client.elements.lkey_cpass.value;
        initkeys();

        this.document.pserver.elements.currentpass.value
            =crypted(this.document.client.elements.currentpass.value);

        uextkey=this.document.client.elements.ukey_npass1.value;
        lextkey=this.document.client.elements.lkey_npass1.value;
        initkeys();
        this.document.pserver.elements.newpass_1.value
            =crypted(this.document.client.elements.newpass_1.value);

        uextkey=this.document.client.elements.ukey_npass2.value;
        lextkey=this.document.client.elements.lkey_npass2.value;
        initkeys();
        this.document.pserver.elements.newpass_2.value
            =crypted(this.document.client.elements.newpass_2.value);

        this.document.pserver.submit();
    }

</script>
$errormessage

<p>
<!-- We separate the forms into 'server' and 'client' in order to
     ensure that unencrypted passwords will not be sent out by a
     crappy browser -->

<form name="pserver" action="/adm/preferences" method="post">
<input type="hidden" name="logtoken"    value="$logtoken" />
<input type="hidden" name="action"      value="verify_and_change_pass" />
<input type="hidden" name="currentpass" value="" />
<input type="hidden" name="newpass_1"   value="" />
<input type="hidden" name="newpass_2"   value="" />
</form>

<form name="client" >
<table>
<tr><td align="right"> Current password:                      </td>
    <td><input type="password" name="currentpass" size="10"/> </td></tr>
<tr><td align="right"> New password:                          </td>
    <td><input type="password" name="newpass_1" size="10"  /> </td></tr>
<tr><td align="right"> Confirm password:                      </td>
    <td><input type="password" name="newpass_2" size="10"  /> </td></tr>
<tr><td colspan="2" align="center">
    <input type="button" value="Change Password" onClick="send();">
</table>
<input type="hidden" name="ukey_cpass"  value="$ukey_cpass" />
<input type="hidden" name="lkey_cpass"  value="$lkey_cpass" />
<input type="hidden" name="ukey_npass1" value="$ukey_npass1" />
<input type="hidden" name="lkey_npass1" value="$lkey_npass1" />
<input type="hidden" name="ukey_npass2" value="$ukey_npass2" />
<input type="hidden" name="lkey_npass2" value="$lkey_npass2" />
</form>
</p>
ENDFORM
    #
    return;
}

sub verify_and_change_password {
    my $r = shift;
    my $user       = $env{'user.name'};
    my $domain     = $env{'user.domain'};
    my $homeserver = $env{'user.home'};
    my $currentauth=&Apache::lonnet::queryauthenticate($user,$domain);
    # Check for authentication types that allow changing of the password.
    return if ($currentauth !~ /^(unix|internal):/);
    #
    my $currentpass = $env{'form.currentpass'}; 
    my $newpass1    = $env{'form.newpass_1'}; 
    my $newpass2    = $env{'form.newpass_2'};
    my $logtoken    = $env{'form.logtoken'};
    # Check for empty data 
    unless (defined($currentpass) && 
	    defined($newpass1)    && 
	    defined($newpass2)    ){
	&passwordchanger($r,"<p>\n<font color='#ff0000'>ERROR</font>".
			 "Password data was blank.\n</p>");
	return;
    }
    # Get the keys
    my $lonhost = $r->dir_config('lonHostID');
    my $tmpinfo = Apache::lonnet::reply('tmpget:'.$logtoken,$lonhost);
    if (($tmpinfo=~/^error/) || ($tmpinfo eq 'con_lost')) {
        # I do not a have a better idea about how to handle this
	$r->print(<<ENDERROR);
<p>
<font color="#ff0000">ERROR:</font> Unable to retrieve stored token for
password decryption.  Please log out and try again.
</p>
ENDERROR
        # Probably should log an error here
        return 1;
    }
    my ($ckey,$n1key,$n2key)=split(/&/,$tmpinfo);
    # 
    $currentpass = &des_decrypt($ckey ,$currentpass);
    $newpass1    = &des_decrypt($n1key,$newpass1);
    $newpass2    = &des_decrypt($n2key,$newpass2);
    # 
    if ($newpass1 ne $newpass2) {
	&passwordchanger($r,
			 '<font color="#ff0000">ERROR:</font>'.
			 'The new passwords you entered do not match.  '.
			 'Please try again.');
	return 1;
    }
    if (length($newpass1) < 7) {
	&passwordchanger($r,
			 '<font color="#ff0000">ERROR:</font>'.
			 'Passwords must be a minimum of 7 characters long.  '.
			 'Please try again.');
	return 1;
    }
    #
    # Check for bad characters
    my $badpassword = 0;
    foreach (split(//,$newpass1)) {
	$badpassword = 1 if ((ord($_)<32)||(ord($_)>126));
    }
    if ($badpassword) {
	# I can't figure out how to enter bad characters on my browser.
	&passwordchanger($r,<<ENDERROR);
<font color="#ff0000">ERROR:</font>
The password you entered contained illegal characters.<br />
Valid characters are: space and <br />
<pre>
!&quot;\#$%&amp;\'()*+,-./0123456789:;&lt;=&gt;?\@
ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_\`abcdefghijklmnopqrstuvwxyz{|}~
</pre>
ENDERROR
    }
    # 
    # Change the password (finally)
    my $result = &Apache::lonnet::changepass
	($user,$domain,$currentpass,$newpass1,$homeserver);
    # Inform the user the password has (not?) been changed
    if ($result =~ /^ok$/) {
	$r->print(<<"ENDTEXT");
<h2>The password for $user was successfully changed</h2>
ENDTEXT
    } else {
	# error error: run in circles, scream and shout
        $r->print(<<ENDERROR);
<h2><font color="#ff0000">The password for $user was not changed</font></h2>
Please make sure your old password was entered correctly.
ENDERROR
        return 1;
    }
    return;
}

################################################################
#            discussion display subroutines 
################################################################
sub discussionchanger {
    my $r = shift;
    my $user       = $env{'user.name'};
    my $domain     = $env{'user.domain'};
    my %userenv = &Apache::lonnet::get
        ('environment',['discdisplay','discmarkread']);
    my $discdisp = 'allposts';
    my $discmark = 'onmark';

    if (defined($userenv{'discdisplay'})) {
        unless ($userenv{'discdisplay'} eq '') { 
            $discdisp = $userenv{'discdisplay'};
        }
    }
    if (defined($userenv{'discmarkread'})) {
        unless ($userenv{'discdisplay'} eq '') { 
            $discmark = $userenv{'discmarkread'};
        }
    }

    my $newdisp = 'unread';
    my $newmark = 'ondisp';

    my $function = &Apache::loncommon::get_users_function();
    my $color = &Apache::loncommon::designparm($function.'.tabbg',
                                                    $env{'user.domain'});
    my %lt = &Apache::lonlocal::texthash(
        'pref' => 'Display Preference',
        'curr' => 'Current setting ',
        'actn' => 'Action',
        'sdpf' => 'Set display preferences for discussion posts for both bulletin boards and individual resources in all your courses.',
        'prca' => 'Preferences can be set that determine',
        'whpo' => 'Which posts are displayed when you display a bulletin board or resource, and',
        'unwh' => 'Under what circumstances posts are identfied as "New"',
        'allposts' => 'All posts',
        'unread' => 'New posts only',
        'ondisp' => 'Once displayed',
        'onmark' => 'Once marked as read',
        'disa' => 'Posts displayed?',
        'npmr' => 'New posts cease to be identified as "New"?',
        'thde'  => 'The preferences you set here can be overridden within each individual discussion.',
        'chgt' => 'Change to '
    );
    my $dispchange = $lt{'unread'};
    my $markchange = $lt{'ondisp'};
    my $currdisp = $lt{'allposts'};
    my $currmark = $lt{'onmark'};

    if ($discdisp eq 'unread') {
        $dispchange = $lt{'allposts'};
        $currdisp = $lt{'unread'};
        $newdisp = 'allposts';
    }

    if ($discmark eq 'ondisp') {
        $markchange = $lt{'onmark'};
        $currmark = $lt{'ondisp'};
        $newmark = 'onmark';
    }
    
    $r->print(<<"END");
<form name="prefs" action="/adm/preferences" method="post">
<input type="hidden" name="action" value="verify_and_change_discussion" />
<br />
$lt{'sdpf'}<br /> $lt{'prca'}  <ol><li>$lt{'whpo'}</li><li>$lt{'unwh'}</li></ol> 
<br />
<br />
END
    $r->print(&Apache::loncommon::start_data_table());
    $r->print(<<"END");
       <tr>
        <th>$lt{'pref'}</th>
        <th>$lt{'curr'}</th>
        <th>$lt{'actn'}?</th>
       </tr>
END
    $r->print(&Apache::loncommon::start_data_table_row());
    $r->print(<<"END");
       <td>$lt{'disa'}</td>
       <td>$lt{$discdisp}</td>
       <td><label><input type="checkbox" name="discdisp" /><input type="hidden" name="newdisp" value="$newdisp" />&nbsp;$lt{'chgt'} "$dispchange"</label></td>
END
    $r->print(&Apache::loncommon::end_data_table_row().
	      &Apache::loncommon::start_data_table_row());
    $r->print(<<"END");
       <td>$lt{'npmr'}</td>
       <td>$lt{$discmark}</td>
       <td><label><input type="checkbox" name="discmark" /><input type="hidden" name="newmark" value="$newmark" />&nbsp;$lt{'chgt'} "$markchange"</label></td>
      </tr>
END
    $r->print(&Apache::loncommon::end_data_table_row().
	      &Apache::loncommon::end_data_table());
    $r->print(<<"END");
<br />
<br />
<input type="submit" name="sub" value="Store Changes" />
<br />
<br />
Note: $lt{'thde'}
</form>
END
}
                                                                                                                
sub verify_and_change_discussion {
    my $r = shift;
    my $user     = $env{'user.name'};
    my $domain   = $env{'user.domain'};
    my $message='';
    if (defined($env{'form.discdisp'}) ) {
        my $newdisp  = $env{'form.newdisp'};
        if ($newdisp eq 'unread') {
            $message .='In discussions: only new posts will be displayed.<br />';
            &Apache::lonnet::put('environment',{'discdisplay' => $newdisp});
            &Apache::lonnet::appenv('environment.discdisplay' => $newdisp);
        } else {
            $message .= 'In discussions: all posts will be displayed.<br />';
            &Apache::lonnet::del('environment',['discdisplay']);
            &Apache::lonnet::delenv('environment\.discdisplay');
        }
    }
    if (defined($env{'form.discmark'}) ) {
        my $newmark = $env{'form.newmark'};
        if ($newmark eq 'ondisp') {
           $message.='In discussions: new posts will be cease to be identified as "new" after display.<br />';
            &Apache::lonnet::put('environment',{'discmarkread' => $newmark});
            &Apache::lonnet::appenv('environment.discmarkread' => $newmark);
        } else {
            $message.='In discussions: posts will be identified as "new" until marked as read by the reader.<br />';
            &Apache::lonnet::del('environment',['discmarkread']);
            &Apache::lonnet::delenv('environment\.discmarkread');
        }
    }
    $r->print(<<ENDVCSCREEN);
$message
ENDVCSCREEN
}

################################################################
# Subroutines for page display on course access (Course Coordinators)
################################################################
sub coursedisplaychanger {
    my $r = shift;
    my $user       = $env{'user.name'};
    my $domain     = $env{'user.domain'};
    my %userenv = &Apache::lonnet::get('environment',['course_init_display']);
    my $currvalue = 'whatsnew';
    my $firstselect = '';
    my $whatsnewselect = 'checked="checked"';
    if (exists($userenv{'course_init_display'})) {
        if ($userenv{'course_init_display'} eq 'firstres') {
            $currvalue = 'firstres';
            $firstselect = 'checked="checked"';
	    $whatsnewselect = '';
        }
    }
    my %pagenames = (
                       firstres => 'First resource',
                       whatsnew => "What's new page",
                    );
    my $whatsnew_off=&mt('Display the [_1] in the course.','<b>first resource</b>');
    my $whatsnew_on=&mt('Display the "[_1]" page - a summary of items in the course which require attention.',"<b>What's New</b>");

    $r->print('<br /><b>'.&mt('Set the default page to be displayed when you select a course role').'</b>&nbsp;'.&mt('(Currently: [_1])',$pagenames{$currvalue}).'<br />'.&mt('The global user preference you set for your courses can be overridden in an individual course by setting a course specific setting via the "[_1]" page in the course',"<i>What's New</i>").'<br /><br />');
    $r->print(<<ENDLSCREEN);
<form name="prefs" action="/adm/preferences" method="post">
<input type="hidden" name="action" value="verify_and_change_coursepage" />
<br />
<label><input type="radio" name="newdisp" value="firstres" $firstselect /> $whatsnew_off</label><br />
<label><input type="radio" name="newdisp" value="whatsnew" $whatsnewselect /> $whatsnew_on</label><input type="hidden" name="refpage" value="$env{'form.refpage'}" />
ENDLSCREEN
    $r->print('<br /><br /><input type="submit" value="'.&mt('Change').'" />
</form>');
}

sub verify_and_change_coursepage {
    my $r = shift;
    my $message='';
    my %lt = &Apache::lonlocal::texthash(
        'defs' => 'Default now set',
        'when' => 'when you select a course role from the roles screen',
        'ywbt' => 'you will be taken to the start of the course.',
        'apwb' => 'a page will be displayed that lists items in the course that may require action from you.',
        'gtts' => 'Go to the start of the course',
        'dasp' => "Display the What's New page listing course action items", 
    );
    my $newdisp  = $env{'form.newdisp'};
    $message = '<b>'.$lt{'defs'}.'</b>: '.$lt{'when'}.', ';
    if ($newdisp eq 'firstres') {
        $message .= $lt{'ywbt'}.'<br />';
        &Apache::lonnet::put('environment',{'course_init_display' => $newdisp});
        &Apache::lonnet::appenv('environment.course_init_display' => $newdisp);
    } else {
        $message .= $lt{'apwb'}.'<br />';
        &Apache::lonnet::del('environment',['course_init_display']);
        &Apache::lonnet::delenv('environment\.course_init_display');
    }
    my $refpage = $env{'form.refpage'};
    if (($env{'request.course.fn'}) && ($env{'request.course.id'})) {
        if ($newdisp eq 'firstres') {
            my $cdom = $env{'course.'.$env{'request.course.id'}.'.domain'};
            my $cnum = $env{'course.'.$env{'request.course.id'}.'.num'}; 
            my ($furl,$ferr)=
                &Apache::lonuserstate::readmap($cdom.'/'.$cnum);
            $message .= '<br /><font size="+1"><a href="'.$furl.'">'.$lt{'gtts'}.' <i>'.&mt('now').'</i></a></font>';
        } else {
            $message .= '<br /><font size="+1"><a href="/adm/whatsnew?refpage='.
                        $refpage.'">'.$lt{'dasp'}.'</a></font>';
        }
    }
    $r->print(<<ENDVCSCREEN);
$message
<br /><br />
ENDVCSCREEN
}


######################################################
#            other handler subroutines               #
######################################################

################################################################
#                          Main handler                        #
################################################################
sub handler {
    my $r = shift;
    my $user = $env{'user.name'};
    my $domain = $env{'user.domain'};
    &Apache::loncommon::content_type($r,'text/html');
    # Some pages contain DES keys and should not be cached.
    &Apache::loncommon::no_cache($r);
    $r->send_http_header;
    return OK if $r->header_only;
    #
    &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},
                                   ['action','wysiwyg','returnurl','refpage']);
    #
    &Apache::lonhtmlcommon::clear_breadcrumbs();
    &Apache::lonhtmlcommon::add_breadcrumb
        ({href => '/adm/preferences',
          text => 'Set User Preferences'});

    my @Options;
    # Determine current authentication method
    my $currentauth=&Apache::lonnet::queryauthenticate($user,$domain);
    if ($currentauth =~ /^(unix|internal):/) {
        push (@Options,({ action   => 'changepass',
                          linktext => 'Change Password',
                          href     => '/adm/preferences',
                          help     => 'Change_Password',
                          subroutine => \&passwordchanger,
                          breadcrumb => 
                              { href => '/adm/preferences?action=changepass',
                                text => 'Change Password'},
                          },
                        { action => 'verify_and_change_pass',
                          subroutine => \&verify_and_change_password,
                          breadcrumb => 
                              { href =>'/adm/preferences?action=changepass',
                                text => 'Change Password'},
                          printmenu => 'not_on_error',
                          }));
    }
    push (@Options,({ action   => 'changescreenname',
                      linktext => 'Change Screen Name',
                      href     => '/adm/preferences',
                      help     => 'Prefs_Screen_Name_Nickname',
                      subroutine => \&screennamechanger,
                      breadcrumb => 
                          { href => '/adm/preferences?action=changescreenname',
                            text => 'Change Screen Name'},
                      },
                    { action   => 'verify_and_change_screenname',
                      subroutine => \&verify_and_change_screenname,
                      breadcrumb => 
                          { href => '/adm/preferences?action=changescreenname',
                            text => 'Change Screen Name'},
                      printmenu => 'yes',
                      }));

    push (@Options,({ action   => 'changemsgforward',
                      linktext => 'Change Message Forwarding and Notification Addresses',
                      href     => '/adm/preferences',
                      help     => 'Prefs_Forwarding',
                      breadcrumb => 
                          { href => '/adm/preferences?action=changemsgforward',
                            text => 'Change Message Forwarding'},
                      subroutine => \&msgforwardchanger,
                      },
                    { action => 'verify_and_change_msgforward',
                      breadcrumb => 
                          { href => '/adm/preferences?action=changemsgforward',
                            text => 'Change Message Forwarding'},
                      printmenu => 'yes',
                      subroutine => \&verify_and_change_msgforward }));
    my $aboutmeaction=
        '/adm/'.$env{'user.domain'}.'/'.$env{'user.name'}.'/aboutme';
    push (@Options,{ action => 'none', 
                     linktext =>
                         q{Edit the 'About Me' Personal Information Screen},
		     help => 'Prefs_About_Me',
                     href => $aboutmeaction});
    push (@Options,({ action => 'changecolors',
                      linktext => 'Change Color Scheme',
                      href => '/adm/preferences',
                      help => 'Change_Colors',
                      breadcrumb => 
                          { href => '/adm/preferences?action=changecolors',
                            text => 'Change Colors'},
                      subroutine => \&colorschanger,
                  },
                    { action => 'verify_and_change_colors',
                      breadcrumb => 
                          { href => '/adm/preferences?action=changecolors',
                            text => 'Change Colors'},
                      printmenu => 'yes',
                      subroutine => \&verify_and_change_colors,
                      }));
    push (@Options,({ action => 'changelanguages',
                      linktext => 'Change Language Preferences',
                      href => '/adm/preferences',
		      help => 'Prefs_Language',
                      breadcrumb=>
                          { href => '/adm/preferences?action=changelanguages',
                            text => 'Change Language'},
                      subroutine =>  \&languagechanger,
                  },
                    { action => 'verify_and_change_languages',
                      breadcrumb=>
                          {href => '/adm/preferences?action=changelanguages',
                           text => 'Change Language'},
                      printmenu => 'yes',
                      subroutine=>\&verify_and_change_languages, }
                    ));
    push (@Options,({ action => 'changewysiwyg',
                      linktext => 'Change WYSIWYG Editor Preferences',
                      href => '/adm/preferences',
                      breadcrumb => 
                            { href => '/adm/preferences?action=changewysiwyg',
                              text => 'Change WYSIWYG Preferences'},
                      subroutine => \&wysiwygchanger,
                  },
                    { action => 'set_wysiwyg',
                      breadcrumb =>
                          { href => '/adm/preferences?action=changewysiwyg',
                            text => 'Change WYSIWYG Preferences'},
                      printmenu => 'yes',
                      subroutine => \&verify_and_change_wysiwyg, }
                    ));
    push (@Options,({ action => 'changediscussions',
                      linktext => 'Change Discussion Display Preferences',
                      href => '/adm/preferences',
                      help => 'Change_Discussion_Display',
                      breadcrumb => 
                            { href => '/adm/preferences?action=changediscussions',
                              text => 'Change Discussion Preferences'},
                      subroutine => \&discussionchanger,
                  },
                    { action => 'verify_and_change_discussion',
                      breadcrumb =>
                          { href => '/adm/preferences?action=changediscussions',
                            text => 'Change Discussion Preferences'},
                      printmenu => 'yes',
                      subroutine => \&verify_and_change_discussion, }
                    ));
                       
    push (@Options,({ action   => 'changerolespref',
                      linktext => 'Change Roles Page Preferences',
                      href     => '/adm/preferences',
                      subroutine => \&rolesprefchanger,
                      breadcrumb =>
                          { href => '/adm/preferences?action=changerolespref',
                            text => 'Change Roles Pref'},
                      },
                    { action   => 'verify_and_change_rolespref',
                      subroutine => \&verify_and_change_rolespref,
                      breadcrumb =>
                          { href => '/adm/preferences?action=changerolespref',
                            text => 'Change Roles Preferences'},
                      printmenu => 'yes',
                      }));

    push (@Options,({ action   => 'changetexenginepref',
                      linktext => 'Change How Math Equations Are Displayed',
                      href     => '/adm/preferences',
                      subroutine => \&texenginechanger,
                      breadcrumb =>
                          { href => '/adm/preferences?action=changetexenginepref',
                            text => 'Change Math Pref'},
                      },
                    { action   => 'verify_and_change_texengine',
                      subroutine => \&verify_and_change_texengine,
                      breadcrumb =>
                          { href => '/adm/preferences?action=changetexenginepref',
                            text => 'Change Math Preferences'},
                      printmenu => 'yes',
                      }));

    if ($env{'environment.remote'} eq 'off') {
	push (@Options,({ action => 'launch',
			  linktext => 'Launch Remote Control',
			  href => '/adm/remote?url=/adm/preferences',
		      }));
    } else {
	push (@Options,({ action => 'collapse',
			  linktext => 'Collapse Remote Control',
			  href => '/adm/remote?url=/adm/preferences',
		      }));
    }

    if (&Apache::lonnet::allowed('whn',$env{'request.course.id'})
	|| &Apache::lonnet::allowed('whn',$env{'request.course.id'}.'/'
				    .$env{'request.course.sec'})) {
        push (@Options,({ action => 'changecourseinit',
                          linktext => 'Change Course Initialization Preference',
                          href => '/adm/preferences',
                          subroutine => \&coursedisplaychanger,
                          breadcrumb =>
                              { href => '/adm/preferences?action=changecourseinit',
                                text => 'Change Course Init. Pref.'},
                          },
                        { action => 'verify_and_change_coursepage',
                          breadcrumb =>
                          { href => '/adm/preferences?action=changecourseinit',                               text => 'Change Course Initialization Preference'},
                        printmenu => 'yes',
                        subroutine => \&verify_and_change_coursepage,
                       }));
    }

    if ($env{'user.name'} =~ /^(albertel|fox|foxr|koretemey|korte|hallmat3|turtle|raeburn)$/) {
        push (@Options,({ action => 'debugtoggle',
                          printmenu => 'yes',
                          subroutine => \&toggle_debug,
                          }));
    }

    $r->print(&Apache::loncommon::start_page('Change Preferences'));

    my $call = undef;
    my $help = undef;
    my $printmenu = 'yes';
    foreach my $option (@Options) {
        if ($option->{'action'} eq $env{'form.action'}) {
            $call = $option->{'subroutine'};
            $printmenu = $option->{'printmenu'};
            if (exists($option->{'breadcrumb'})) {
                &Apache::lonhtmlcommon::add_breadcrumb
                    ($option->{'breadcrumb'});
            }
	    $help=$option->{'help'};
        }
    }
    $r->print(&Apache::lonhtmlcommon::breadcrumbs('Change Preferences',$help));
    my $error;
    if (defined($call)) {
        $error = $call->($r);
    }
    if ( ( ($printmenu eq 'yes')
	   || ($printmenu eq 'not_on_error' && !$error) )
	 && (!$env{'form.returnurl'})) {
        my $optionlist = '<table cellpadding="5">';
        if ($env{'user.name'} =~ 
                         /^(albertel|kortemey|fox|foxr|korte|hallmat3|turtle|raeburn)$/
            ) {
            push (@Options,({ action => 'debugtoggle',
                              linktext => 'Toggle Debug Messages',
                              text => 'Current Debug status is -'.
                                  $env{'user.debug'}.'-.',
                              href => '/adm/preferences',
                              printmenu => 'yes',
                              subroutine => \&toggle_debug,
                              }));
        }
        foreach my $option(@Options) {
            my $optiontext = '';
            if (exists($option->{'href'})) {
		$option->{'href_args'}{'action'}=$option->{'action'};
		$optiontext .= 
                    '<a href="'.&add_get_param($option->{'href'},
					       $option->{'href_args'}).'">'.
                    &mt($option->{'linktext'}).'</a>';
            }
            if (exists($option->{'text'})) {
                $optiontext .= ' '.&mt($option->{'text'});
            }
            if ($optiontext ne '') {
                $optiontext = '<font size="+1">'.$optiontext.'</font>'; 
                my $helplink = '&nbsp;';
                if (exists($option->{'help'})) {
                    $helplink = &Apache::loncommon::help_open_topic
                                                    ($option->{'help'});
                }
                $optionlist .= '<tr>'.
                    '<td>'.$helplink.'</td>'.
                    '<td>'.$optiontext.'</td>'.
                    '</tr>';
            }
        }
        $optionlist .= '</table>';
        $r->print($optionlist);
    } elsif ($env{'form.returnurl'}) {
	$r->print('<br /><a href="'.$env{'form.returnurl'}.'"><font size="+1">'.
		  &mt('Return').'</font></a>');
    }
    $r->print(&Apache::loncommon::end_page());
    return OK;
}

sub toggle_debug {
    if ($env{'user.debug'}) {
        &Apache::lonnet::delenv('user\.debug');
    } else {
        &Apache::lonnet::appenv('user.debug' => 1);
    }
}

1;
__END__