# The LearningOnline Network with CAPA
# Handler for requesting to have slots added to a students record
#
# $Id: slotrequest.pm,v 1.125.2.10.2.2 2023/07/10 01:49:09 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::slotrequest;

use strict;
use Apache::Constants qw(:common :http :methods);
use Apache::loncommon();
use Apache::lonlocal;
use Apache::lonnet;
use Apache::lonnavmaps();
use Date::Manip;
use lib '/home/httpd/lib/perl/';
use LONCAPA qw(:DEFAULT :match);

sub fail {
    my ($r,$code)=@_;
    if ($code eq 'not_valid') {
	$r->print('<p>'.&mt('Unable to understand what resource you wanted to sign up for.').'</p>');
    } elsif ($code eq 'not_available') {
	$r->print('<p>'.&mt('No slots are available.').'</p>');
    } elsif ($code eq 'not_allowed') {
	$r->print('<p>'.&mt('Not allowed to sign up or change reservations at this time.').'</p>');
    } else {
	$r->print('<p>'.&mt('Failed.').'</p>');
    }
    
    &return_link($r);
    &end_page($r);
}

sub start_page {
    my ($r,$title,$brcrum,$bread_crumbs_component,$js,$mgr)=@_;
    my $args;
    if (ref($brcrum) eq 'ARRAY') {
        $args = {bread_crumbs => $brcrum};
        if ($bread_crumbs_component) {    
            $args->{bread_crumbs_component} = $bread_crumbs_component;    
        }
    }
    if (($env{'form.requestattempt'}) || ($env{'form.command'} eq 'manageresv')) {
        my %loaditems = (
                           onload => 'javascript:uncheckSlotRadio();',
                        );
        if (ref($args) eq 'HASH') {
            $args->{'add_entries'} = \%loaditems;
        } else {
            $args = { 'add_entries' => \%loaditems };
        }
    }
    unless (($env{'form.context'} eq 'usermanage') || (($mgr eq 'F') &&
            (($env{'form.command'} eq 'release') ||
             ($env{'form.command'} eq 'remove_registration')))) {
        if ($env{'form.symb'}) {
            my $symb=&unescape($env{'form.symb'});
            my ($mapurl,$id,$resurl) = &Apache::lonnet::decode_symb($symb);
            if ($resurl =~ /ext\.tool$/) {
                my $target;
                my ($marker,$exttool) = (split(m{/},$resurl))[3,4];
                $marker=~s/\D//g;
                if (($marker) && ($exttool) && ($env{'request.course.id'})) {
                    my $cdom = $env{'course.'.$env{'request.course.id'}.'.domain'};
                    my $cnum = $env{'course.'.$env{'request.course.id'}.'.num'};
                    my ($idx,$crstool,$is_tool,%toolhash,%toolsettings);
                    if ($resurl eq "adm/$cdom/$cnum/$marker/$exttool") {
                        my %toolsettings=&Apache::lonnet::dump('exttool_'.$marker,$cdom,$cnum);
                        $target = $toolsettings{'target'};
                    }
                }
                if ($target eq 'iframe') {
                    $args->{'only_body'} = 1;
                }
            }
        }
    }
    $r->print(&Apache::loncommon::start_page($title,$js,$args));
}

sub end_page {
    my ($r)=@_;
    $r->print(&Apache::loncommon::end_page());
}

sub reservation_js {
    my ($slots,$consumed_uniqueperiods,$available,$got_slots,$symb) = @_;
    return unless ((ref($slots) eq 'HASH') && (ref($available) eq 'ARRAY'));
    my $toskip;
    if ($symb eq '') {
        $toskip = { symb => 1, };
    }
    my ($i,$j) = (0,0);
    my $js;
    foreach my $slot (sort
        { return $slots->{$a}->{'starttime'} <=> $slots->{$b}->{'starttime'} }
                    (keys(%{$slots})))  {

        next if (!&allowed_slot($slot,$slots->{$slot},$symb,$slots,
                                $consumed_uniqueperiods,$toskip));
        $js .= "    slotstart[$i]='$slots->{$slot}->{'starttime'}';\n".
               "    slotend[$i]='$slots->{$slot}->{'endtime'}';\n".
               "    slotname[$i]='$slot';\n";
        if (($symb) && (ref($got_slots) eq 'ARRAY')) {
            if (grep(/^\Q$slot\E$/,@{$got_slots})) {
                $js .= "    currslot[$j]='$slot';\n";
                $j++;
            }
        }
        $i++;
        push(@{$available},$slot);
    }
    if ($j) {
        $js = "    var currslot = new Array($j);\n\n$js";
    }
    my %alerts = &Apache::lonlocal::texthash (
                                                none    => 'No reservable time slots found',
                                                invalid => 'Invalid date format',
                                             );
    return <<"ENDSCRIPT";
<script type="text/javascript">
// <![CDATA[
function updateSlotDisplay(form,num,slotpickradio) {
    var slotstart = new Array($i);
    var slotend = new Array($i);
    var slotname = new Array($i);
$js

    if (slotpickradio == 'all') {
        for (var i=0; i<$i; i++) {
            if (document.getElementById('LC_slotrow_'+num+'_'+slotname[i])) {
                document.getElementById('LC_slotrow_'+num+'_'+slotname[i]).style.display = '';
            }
            if (document.getElementById('LC_slotsearch_'+num)) {
                document.getElementById('LC_slotsearch_'+num).style.display = 'block';
            }
        }
    } else {
        if (slotpickradio == 'show') {
            for (var i=0; i<$i; i++) {
                if (document.getElementById('LC_slotrow_'+num+'_'+slotname[i])) {
                    document.getElementById('LC_slotrow_'+num+'_'+slotname[i]).style.display = 'none';
                }
            }
            for (var j=0; j<$j; j++) {
                if (document.getElementById('LC_slotrow_'+num+'_'+currslot[j])) {
                    document.getElementById('LC_slotrow_'+num+'_'+currslot[j]).style.display = '';
                }
            }
            if (document.getElementById('LC_slotsearch_'+num)) {
                document.getElementById('LC_slotsearch_'+num).style.display = 'block';
            }
        } else {
            var numberRegExp = /^[0-9]+\$/;
            var startm = form.start_month.options[form.start_month.selectedIndex].value;
            var startd = form.start_day.value;
            startd=startd.trim();
            var starty = form.start_year.value;
            starty=starty.trim();
            var endm = form.end_month.options[form.end_month.selectedIndex].value;
            var endd = form.end_day.value;
            endd=endd.trim();
            var endy = form.end_year.value;
            endy=endy.trim();
            if (numberRegExp.test(endd) && numberRegExp.test(endy) && numberRegExp.test(startd) && numberRegExp.test(starty)) {
                var startdate = startm+"/"+startd+"/"+starty;
                var starttime = new Date(startdate).getTime();
                starttime = starttime/1000;
                var starth = form.start_hour.options[form.start_hour.selectedIndex].value;
                if (numberRegExp.test(starth)) {
                    starth = parseInt(starth);
                    if (starth > 0 && starth <= 23) {
                        starttime += 3600 * starth;
                    }
                }
                var enddate = endm+"/"+endd+"/"+endy;
                var endtime = new Date(enddate).getTime();
                endtime = endtime/1000;
                var endh = form.end_hour.options[form.end_hour.selectedIndex].value;
                if (numberRegExp.test(endh)) {
                    endh = parseInt(endh);
                    if (endh > 0 && endh <= 23) {
                        endtime += 3600 * endh;
                    }
                }

                var shown = 0;
                for (var i=0; i<$i; i++) {
                    if ((slotstart[i] >= starttime) && (slotend[i] <= endtime)) {
                        if (document.getElementById('LC_slotrow_'+num+'_'+slotname[i])) {
                            document.getElementById('LC_slotrow_'+num+'_'+slotname[i]).style.display = '';
                            shown ++;
                        }
                    } else {
                        if (document.getElementById('LC_slotrow_'+num+'_'+slotname[i])) {
                            document.getElementById('LC_slotrow_'+num+'_'+slotname[i]).style.display = 'none';
                        }
                    }
                }
                if (document.getElementById('LC_slotsearch_'+num)) {
                    if (shown) {
                        document.getElementById('LC_slotsearch_'+num).style.display = 'block';
                    } else {
                        document.getElementById('LC_slotsearch_'+num).style.display = 'none';
                    }
                }
                if (shown == 0) {
                    alert('$alerts{"none"}');
                }
            } else {
                alert('$alerts{"invalid"}');
            }
        }
    }
    return;
}

function toggleSlotDisplay(form,num) {
    if (form.slotpick.length) {
        for (var i=0; i<form.slotpick.length; i++) {
            if (form.slotpick[i].checked) {
                var val = form.slotpick[i].value;
                if (document.getElementById('LC_slotfilter_'+num)) {
                    document.getElementById('LC_slotsearch_'+num).style.display = 'none';
                    if (val == 'filter') {
                        document.getElementById('LC_slotfilter_'+num).style.display = 'block';
                    } else {
                        document.getElementById('LC_slotfilter_'+num).style.display = 'none';
                        if (val == 'all') {
                            updateSlotDisplay(form,num,val);
                        } else {
                            updateSlotDisplay(form,num,val);
                        }
                    }
                }
                break;
            }
        }
    }
    return false;
}

if (!document.getElementsByClassName) {
    function getElementsByClassName(node, classname) {
        var a = [];
        var re = new RegExp('(^| )'+classname+'( |$)');
        var els = node.getElementsByTagName("*");
        for(var i=0,j=els.length; i<j; i++)
            if(re.test(els[i].className))a.push(els[i]);
        return a;
    }
}

function uncheckSlotRadio() {
    var slotpicks;
    if (document.getElementsByClassName) {
        slotpicks = document.getElementsByClassName('LC_slotpick_radio');
    } else {
        slotpicks = getElementsByClassName(document.body,'LC_slotpick_radio');
    }
    if (slotpicks.length) {
        for (var i=0; i<slotpicks.length; i++) {
            slotpicks[i].checked = false;  
        }
    }
}
// ]]>
</script>
ENDSCRIPT

}


=pod

 slot_reservations db
   - keys are 
    - slotname\0id -> value is an hashref of
                         name -> user@domain of holder
                         timestamp -> timestamp of reservation
                         symb -> symb of resource that it is reserved for

=cut

sub get_course {
    (undef,my $courseid)=&Apache::lonnet::whichuser();
    my $cdom=$env{'course.'.$courseid.'.domain'};
    my $cnum=$env{'course.'.$courseid.'.num'};
    return ($cnum,$cdom);
}

sub get_reservation_ids {
    my ($slot_name)=@_;
    
    my ($cnum,$cdom)=&get_course();

    my %consumed=&Apache::lonnet::dump('slot_reservations',$cdom,$cnum,
				       "^$slot_name\0");
    if (&Apache::lonnet::error(%consumed)) { 
	return 'error: Unable to determine current status';
    }
    my ($tmp)=%consumed;
    if ($tmp=~/^error: 2 / ) {
	return 0;
    }
    return keys(%consumed);
}

sub space_available {
    my ($slot_name,$slot)=@_;
    my $max=$slot->{'maxspace'};

    if (!defined($max)) { return 1; }

    my $consumed=scalar(&get_reservation_ids($slot_name));
    if ($consumed < $max) {
	return 1
    }
    return 0;
}

sub check_for_reservation {
    my ($symb,$mode)=@_;
    my $student = &Apache::lonnet::EXT("resource.0.availablestudent", $symb,
				       $env{'user.domain'}, $env{'user.name'});
    my $course = &Apache::lonnet::EXT("resource.0.available", $symb,
				    $env{'user.domain'}, $env{'user.name'});
    my @slots = (split(/:/,$student), split(/:/, $course));

    &Apache::lonxml::debug(" slot list is ".join(':',@slots));

    my ($cnum,$cdom)=&get_course();
    my %slots=&Apache::lonnet::get('slots', [@slots], $cdom, $cnum);

    if (&Apache::lonnet::error($student) 
	|| &Apache::lonnet::error($course)
	|| &Apache::lonnet::error(%slots)) {
	return 'error: Unable to determine current status';
    }    
    my @got;
    my @sorted_slots = &Apache::loncommon::sorted_slots(\@slots,\%slots,'starttime');
    foreach my $slot_name (@sorted_slots) {
	next if (!defined($slots{$slot_name}) ||
		 !ref($slots{$slot_name}));
	&Apache::lonxml::debug(time." $slot_name ".
			       $slots{$slot_name}->{'starttime'}." -- ".
			       $slots{$slot_name}->{'startreserve'}." -- ".
                               $slots{$slot_name}->{'endreserve'});
	if (($slots{$slot_name}->{'endtime'} > time) &&
	    ($slots{$slot_name}->{'startreserve'} < time) &&
            ((!$slots{$slot_name}->{'endreserve'}) || 
             ($slots{$slot_name}->{'endreserve'} > time))) {
	    # between start of reservation time and end of reservation time
            # and before end of slot
	    if ($mode eq 'allslots') {
		push(@got,$slot_name);
	    } else {
		return($slot_name, $slots{$slot_name});
	    }
	}
    }
    if ($mode eq 'allslots' && @got) {
	return @got;
    }
    return (undef,undef);
}

sub get_consumed_uniqueperiods {
    my ($slots) = @_;
    my $navmap=Apache::lonnavmaps::navmap->new;
    if (!defined($navmap)) {
        return 'error: Unable to determine current status';
    }
    my @problems = $navmap->retrieveResources(undef,
					      sub { $_[0]->is_problem() || $_[0]->is_tool() },1,0);
    my %used_slots;
    foreach my $problem (@problems) {
	my $symb = $problem->symb();
	my $student = &Apache::lonnet::EXT("resource.0.availablestudent",
					   $symb, $env{'user.domain'},
					   $env{'user.name'});
	my $course =  &Apache::lonnet::EXT("resource.0.available",
					   $symb, $env{'user.domain'},
					   $env{'user.name'});
	if (&Apache::lonnet::error($student) 
	    || &Apache::lonnet::error($course)) {
	    return 'error: Unable to determine current status';
	}
	foreach my $slot (split(/:/,$student), split(/:/, $course)) {
	    $used_slots{$slot}=1;
	}
    }

    if (!ref($slots)) {
	my ($cnum,$cdom)=&get_course();
	my %slots=&Apache::lonnet::get('slots', [keys(%used_slots)], $cdom, $cnum);
	if (&Apache::lonnet::error(%slots)) {
	    return 'error: Unable to determine current status';
	}
	$slots = \%slots;
    }

    my %consumed_uniqueperiods;
    foreach my $slot_name (keys(%used_slots)) {
	next if (!defined($slots->{$slot_name}) ||
		 !ref($slots->{$slot_name}));
	
        next if (!defined($slots->{$slot_name}{'uniqueperiod'}) ||
		 !ref($slots->{$slot_name}{'uniqueperiod'}));
	$consumed_uniqueperiods{$slot_name} = 
	    $slots->{$slot_name}{'uniqueperiod'};
    }
    return \%consumed_uniqueperiods;
}

sub check_for_conflict {
    my ($symb,$new_slot_name,$new_slot,$slots,$consumed_uniqueperiods)=@_;

    if (!defined($new_slot->{'uniqueperiod'})) { return undef; }

    if (!ref($consumed_uniqueperiods)) {
        if ($consumed_uniqueperiods =~ /^error: /) {
            return $consumed_uniqueperiods;
        } else {
	    $consumed_uniqueperiods = &get_consumed_uniqueperiods($slots);
            if (ref($consumed_uniqueperiods) eq 'HASH') {
	        if (&Apache::lonnet::error(%$consumed_uniqueperiods)) {
	            return 'error: Unable to determine current status';
	        }
            } else {
                return 'error: Unable to determine current status';
            }
        }
    } 
    my ($new_uniq_start,$new_uniq_end) = @{$new_slot->{'uniqueperiod'}};
    foreach my $slot_name (keys(%$consumed_uniqueperiods)) {
	my ($start,$end)=@{$consumed_uniqueperiods->{$slot_name}};
	if (!
	    ($start < $new_uniq_start &&  $end < $new_uniq_start) ||
	    ($start > $new_uniq_end   &&  $end > $new_uniq_end  )) {
	    return $slot_name;
	}
    }
    return undef;
}

sub make_reservation {
    my ($slot_name,$slot,$symb,$cnum,$cdom)=@_;

    my $value=&Apache::lonnet::EXT("resource.0.availablestudent",$symb,
				   $env{'user.domain'},$env{'user.name'});
    &Apache::lonxml::debug("value is  $value<br />");

    my $use_slots = &Apache::lonnet::EXT("resource.0.useslots",$symb,
					 $env{'user.domain'},$env{'user.name'});
    &Apache::lonxml::debug("use_slots is  $use_slots<br />");

    if (&Apache::lonnet::error($value) 
	|| &Apache::lonnet::error($use_slots)) { 
	return 'error: Unable to determine current status';
    }

    my $symb_for_db = $symb;
    my $parm_level = 1;
    if ($use_slots eq 'map' || $use_slots eq 'map_map') {
	my ($map) = &Apache::lonnet::decode_symb($symb);
	$symb_for_db = &Apache::lonnet::symbread($map);
	$parm_level = 2;
    }

    foreach my $other_slot (split(/:/, $value)) {
	if ($other_slot eq $slot_name) {
	    my %consumed=&Apache::lonnet::dump('slot_reservations', $cdom,
					       $cnum, "^$slot_name\0");   
	    if (&Apache::lonnet::error($value)) { 
		return 'error: Unable to determine current status';
	    }
	    my $me=$env{'user.name'}.':'.$env{'user.domain'};
	    foreach my $key (keys(%consumed)) {
		if ($consumed{$key}->{'name'} eq $me) {
		    my $num=(split('\0',$key))[1];
		    return -$num;
		}
	    }
	}
    }

    my $max=$slot->{'maxspace'};
    if (!defined($max)) { $max=99999; }

    my (@ids)=&get_reservation_ids($slot_name);
    if (&Apache::lonnet::error(@ids)) { 
	return 'error: Unable to determine current status';
    }
    my $last=0;
    foreach my $id (@ids) {
	my $num=(split('\0',$id))[1];
	if ($num > $last) { $last=$num; }
    }
    
    my $wanted=$last+1;
    &Apache::lonxml::debug("wanted $wanted<br />");
    if (scalar(@ids) >= $max) {
	# full up
	return undef;
    }
    
    my %reservation=('name'      => $env{'user.name'}.':'.$env{'user.domain'},
		     'timestamp' => time,
		     'symb'      => $symb_for_db);

    my $success=&Apache::lonnet::newput('slot_reservations',
					{"$slot_name\0$wanted" =>
					     \%reservation},
					$cdom, $cnum);

    if ($success eq 'ok') {
	my $new_value=$slot_name;
	if ($value) {
	    $new_value=$value.':'.$new_value;
	}
        my $result = &store_slot_parm($symb,$symb_for_db,$slot_name,$parm_level,
                                      $new_value,$cnum,$cdom,$env{'user.name'},
                                      $env{'user.domain'},'reserve',$env{'form.context'});
	return $wanted;
    }

    # someone else got it
    return undef;
}

sub store_slot_parm {
    my ($symb_for_parm,$symb_for_db,$slot_name,$parm_level,$new_value,
        $cnum,$cdom,$uname,$udom,$action,$context,$delflag) = @_;

    # store new parameter string
    my $result=&Apache::lonparmset::storeparm_by_symb($symb_for_parm,
                                                      '0_availablestudent',
                                                      $parm_level,$new_value,
                                                      'string',$uname,$udom);
    &Apache::lonxml::debug("hrrm $result");
    my %storehash = (
                       symb    => $symb_for_db,
                       slot    => $slot_name,
                       action  => $action,
                       context => $context,
                    );

    &Apache::lonnet::write_log('course','slotreservationslog',\%storehash,
                               $delflag,$uname,$udom,$cnum,$cdom);
    &Apache::lonnet::write_log('course',$cdom.'_'.$cnum.'_slotlog',\%storehash,
                               $delflag,$uname,$udom,$uname,$udom);
    return $result;
}

sub remove_registration {
    my ($r) = @_;
    if ($env{'form.entry'} ne 'remove all') {
	return &remove_registration_user($r);
    }
    my $slot_name = $env{'form.slotname'};
    my %slot=&Apache::lonnet::get_slot($slot_name);

    my ($cnum,$cdom)=&get_course();
    my %consumed=&Apache::lonnet::dump('slot_reservations',$cdom,$cnum,
				       "^$slot_name\0");
    if (&Apache::lonnet::error(%consumed)) {
	$r->print("<p><span class=\"LC_error\">".&mt('A network error has occurred.').'</span></p>');
	return;
    }
    if (!%consumed) {
	$r->print('<p>'.&mt('Slot [_1] has no reservations.',
			    '<tt>'.$slot_name.'</tt>').'</p>');
	return;
    }

    my @names = map { $consumed{$_}{'name'} } (sort(keys(%consumed)));
    my $names = join(' ',@names);

    my $msg = &mt('Remove all of [_1] from slot [_2]?',$names,$slot_name);
    &remove_registration_confirmation($r,$msg,['entry','slotname','context']);
}

sub remove_registration_user {
    my ($r) = @_;
    
    my $slot_name = $env{'form.slotname'};

    my $name = &Apache::loncommon::plainname($env{'form.uname'},
					     $env{'form.udom'});

    my $title = &Apache::lonnet::gettitle($env{'form.symb'});

    my $msg = &mt('Remove [_1] from slot [_2] for [_3]',
		  $name,$slot_name,$title);
    
    &remove_registration_confirmation($r,$msg,['uname','udom','slotname',
					       'entry','symb','context']);
}

sub remove_registration_confirmation {
    my ($r,$msg,$inputs) =@_;

    my $hidden_input;
    foreach my $parm (@{$inputs}) {
	$hidden_input .=
	    '<input type="hidden" name="'.$parm.'" value="'
	    .&HTML::Entities::encode($env{'form.'.$parm},'"<>&\'').'" />'."\n";
    }
    my %lt = &Apache::lonlocal::texthash(
        'yes' => 'Yes',
        'no'  => 'No',
    );
    $r->print(<<"END_CONFIRM");
<p> $msg </p>
<form action="/adm/slotrequest" method="post">
    <input type="hidden" name="command" value="release" />
    <input type="hidden" name="button" value="yes" />
    $hidden_input
    <input type="submit" value="$lt{'yes'}" />
</form>
<form action="/adm/slotrequest" method="post">
    <input type="hidden" name="command" value="showslots" />
    <input type="submit" value="$lt{'no'}" />
</form>
END_CONFIRM

}

sub release_all_slot {
    my ($r,$mgr)=@_;
    
    my $slot_name = $env{'form.slotname'};

    my ($cnum,$cdom)=&get_course();

    my %consumed=&Apache::lonnet::dump('slot_reservations',$cdom,$cnum,
				       "^$slot_name\0");
    
    $r->print('<p>'.&mt('Releasing reservations').'</p>');

    foreach my $entry (sort { $consumed{$a}{'name'} cmp 
				  $consumed{$b}{'name'} } (keys(%consumed))) {
	my ($uname,$udom) = split(':',$consumed{$entry}{'name'});
	my ($result,$msg) =
	    &release_reservation($slot_name,$uname,$udom,
				 $consumed{$entry}{'symb'},$mgr);
        if (!$result) {
            $r->print('<p class="LC_error">'.&mt($msg).'</p>');
        } else {
	    $r->print("<p>$msg</p>");
        }
	$r->rflush();
    }
    $r->print('<p><a href="/adm/slotrequest?command=showslots">'.
	      &mt('Return to slot list').'</a></p>');
    &return_link($r);
}

sub release_slot {
    my ($r,$symb,$slot_name,$inhibit_return_link,$mgr)=@_;

    if ($slot_name eq '') { $slot_name=$env{'form.slotname'}; }

    my ($uname,$udom) = ($env{'user.name'}, $env{'user.domain'});
    if ($mgr eq 'F' 
	&& defined($env{'form.uname'}) && defined($env{'form.udom'})) {
	($uname,$udom) = ($env{'form.uname'}, $env{'form.udom'});
    }

    if ($mgr eq 'F' 
	&& defined($env{'form.symb'})) {
	$symb = &unescape($env{'form.symb'});
    }

    my ($result,$msg) =
	&release_reservation($slot_name,$uname,$udom,$symb,$mgr);
    if (!$result) {
        $r->print('<p class="LC_error">'.&mt($msg).'</p>');
    } else {
        $r->print("<p>$msg</p>");
    }
    
    if ($mgr eq 'F') {
	$r->print('<p><a href="/adm/slotrequest?command=showslots">'.
		  &mt('Return to slot list').'</a></p>');
    }

    if (!$inhibit_return_link) { &return_link($r);  }
    return $result;
}

sub release_reservation {
    my ($slot_name,$uname,$udom,$symb,$mgr) = @_;
    my %slot=&Apache::lonnet::get_slot($slot_name);
    my $description=&get_description($slot_name,\%slot);
    my $msg;

    if ($mgr ne 'F') {
	if ($slot{'starttime'} < time) {
	    return (0,&mt('Not allowed to release Reservation: [_1], as it has already started.',$description));
	}
    }
    my $context = $env{'form.context'};

    # get navmap object
    my $navmap=Apache::lonnavmaps::navmap->new;
    if (!defined($navmap)) {
        return (0,'error: Unable to determine current status');
    }

    my ($cnum,$cdom)=&get_course();

    # get slot reservations, check if user has reservation
    my %consumed=&Apache::lonnet::dump('slot_reservations',$cdom,$cnum,
                                       "^$slot_name\0");

    #
    # If release is because of a reservation *change*, symb(s) associated with reservation
    # being dropped may differ from the current symb.
    #
    # We need to get symb(s) from slot_reservations.db, and for each symb, update
    # the value of the availablestudent parameter, at the appropriate level
    # (as dictated by the value of the useslots parameter for the symb and user).
    #
    # We also delete all entries for the slot being released, for the specific user.
    #

    my $conflict;

    if (($env{'form.command'} eq 'change') && ($slot_name eq $env{'form.releaseslot'}) &&
        ($env{'form.slotname'} ne $slot_name)) {
        my %changedto = &Apache::lonnet::get_slot($env{'form.slotname'});

        # check for conflicts
        my ($to_uniq_start,$to_uniq_end,$from_uniq_start,$from_uniq_end);
        if (ref($changedto{'uniqueperiod'}) eq 'ARRAY') {
            ($to_uniq_start,$to_uniq_end) = @{$changedto{'uniqueperiod'}};
        }
        if (ref($slot{'uniqueperiod'}) eq 'ARRAY') {
            ($from_uniq_start,$from_uniq_end) = @{$slot{'uniqueperiod'}};
        }
        my $to_start = $changedto{'starttime'};
        my $to_end = $changedto{'endtime'};
        my $from_start = $slot{'starttime'};
        my $from_end = $slot{'endtime'};

        if (!
             ($from_start < $to_uniq_start && $from_end < $to_uniq_start) ||
             ($from_start > $to_uniq_end   && $from_end > $to_uniq_end  )) {
            $conflict = 1;
        }
        if (!
             ($to_start < $from_uniq_start && $to_end < $from_uniq_start) ||
             ($to_start > $from_uniq_end   && $to_end > $from_uniq_end  )) {
            $conflict = 1;
        }

        if ($conflict) {
            my %symbs_for_slot;
            my (%to_delete,%failed,%released);
            foreach my $entry (keys(%consumed)) {
                if ( $consumed{$entry}->{'name'} eq ($uname.':'.$udom) ) {
                    $symbs_for_slot{$consumed{$entry}->{'symb'}} = 1;
                    $to_delete{$entry} = 1;
                }
            }
            if (keys(%to_delete)) {
                my @removals = keys(%to_delete);
                if (&Apache::lonnet::del('slot_reservations',\@removals,
                                     $cdom,$cnum) eq 'ok') {
                    foreach my $item (keys(%symbs_for_slot)) {
                        my $result = &update_selectable($navmap,$slot_name,$item,$cdom,
                                                        $cnum,$udom,$uname,$context);
                        if ($result =~ /^error/) {
                            $failed{$item} = 1;
                        } else {
                            $released{$item} = 1;
                        }
                    }
                }
            }
            if (keys(%released)) {
                $msg = '<span style="font-weight: bold;">'.
                       &mt('Released Reservation: [_1]',$description).'</span>&nbsp;&nbsp;'.
                       &mt('The following items had their reservation status change').':';
                my (%folders,%pages,%container,%titles);
                foreach my $item (keys(%released)) {
                    my $res = $navmap->getBySymb($item);
                    if (ref($res)) {
                        $titles{$item} = $res->title();
                        if ($res->is_map()) {
                            $folders{$item}{'title'} = $titles{$item};
                            if ($res->is_page()) {
                                $pages{$item}{'title'} = $titles{$item};
                            } else {
                                $folders{$item}{'title'} = $titles{$item};
                            }
                        } else {
                            my $mapsrc = $res->enclosing_map_src();
                            my $map = $navmap->getResourceByUrl($mapsrc);
                            if (ref($map)) {
                                if ($map->id() eq '0.0') {
                                    $container{$mapsrc}{'title'} &mt('Top level of course');
                                } else {
                                    $container{$mapsrc}{'title'} = $map->title();
                                    if ($map->is_page()) {
                                        $container{$mapsrc}{'page'} = 1;
                                    }
                                }
                            }
                            $container{$mapsrc}{'resources'}{$item} = 1;
                        }
                    }
                }
                $msg .= '<ul>';
                if (keys(%folders)) {
                    $msg .= '<li>'.&mt('Folders').': '.
                            join(', ', map { $folders{$_}{'title'} } (sort { $folders{$b}{'title'} cmp $folders{$a}{'title'} } (keys(%folders)))).
                            '</li>';
                }
                if (keys(%pages)) {
                    $msg .= '<li>'.&mt('Composite Pages').': '.
                            join(', ', map { $pages{$_}{'title'} } (sort { $pages{$b}{'title'} cmp $pages{$a}{'title'} } (keys(%pages)))).
                            '</li>';
                }
                if (keys(%container)) {
                    $msg .= '<li>'.&mt('Resources').':<ul>';
                    foreach my $key (sort { $container{$b}{'title'} cmp $container{$a}{'title'} } (keys(%container))) {
                        if (ref($container{$key}{'resources'}) eq 'HASH') {
                            $msg .= '<li>'.
                                    join(', ', map { $titles{$_} } (sort(keys(%{$container{$key}{'resources'}}))));
                            if ($container{$key}{'page'}) {
                                $msg .= ' '.&mt('(in composite page [_1])',$container{$key}{'title'}).'</li>';
                            } else {
                                $msg .= ' '.&mt('(in folder [_1])',$container{$key}{'title'}).'</li>';
                            }
                        }
                    }
                    $msg .= '</ul></li>';
                }
                $msg .= '</ul>';
                my $person = &Apache::loncommon::plainname($env{'user.name'},$env{'user.domain'});
                my $subject = &mt('Reservation change: [_1]',$description);
                my $msgbody = &mt('Reservation released by [_1] for [_2].',$person,$description);
                $msg .= &slot_change_messaging($slot{'reservationmsg'},$subject,$msgbody,'release');
                return (1,$msg);
            } else {
                if (keys(%to_delete)) {
                    $msg = &mt('Reservation release partially complete for [_1]',$description);
                } else {
                    $msg = &mt('No entries found for this user to release for [_1].',$description);
                }
                return (0,$msg);
            }
        } else {
            $msg = &mt('No conflict found; not releasing: [_1].',$description);
            return (0,$msg);
        }
    }

    my $map_symb;
    my $parm_symb = $symb;
    my $passed_resource = $navmap->getBySymb($symb);

    # if the reservation symb is for a map get a resource in that map
    # to check slot parameters on
    my $parm_level = 1;
    if (ref($passed_resource)) {
        if ($passed_resource->is_map()) {
	    my ($a_resource) = 
                $navmap->retrieveResources($passed_resource, 
                    sub {$_[0]->is_problem() || $_[0]->is_tool() },0,1);
            $parm_symb = $a_resource->symb();
        }
    } else {
        unless ($mgr eq 'F') {
            return (0,'error: Unable to determine current status');
        }
    }

    # Get value of useslots parameter in effect for this user.
    # If value is map or map_map, then the parm level is 2 (i.e.,
    # non-recursive enclosing map/folder level for specific user)
    # and the symb for this reservation in slot_reservations.db
    # will be the symb of the map itself.

    my $use_slots = &Apache::lonnet::EXT('resource.0.useslots',
                                         $parm_symb,$udom,$uname);
    if (&Apache::lonnet::error($use_slots)) {
        return (0,'error: Unable to determine current status');
    }
    if ($use_slots eq 'map' || $use_slots eq 'map_map') {
        $parm_level = 2;
        if ($passed_resource->is_map()) {
            $map_symb = $passed_resource->symb();
        } else {
            my ($map) = &Apache::lonnet::decode_symb($symb);
            $map_symb = &Apache::lonnet::symbread($map);
        }
    }

    #
    # If release is *not* because of a reservation change, i.e., this is a "drop"
    # by a student, or a removal for a single student by an instructor then
    # only remove one entry from slot_reservations.db, where both the user
    # and the symb match the current context.  If useslots was set to map or
    # map_map, then the symb to match in slot_reservations.db is the symb of
    # the enclosing map/folder, not the symb of the resource.
    #

    my ($match,$symb_to_check);
    if ($parm_level == 2) {
        $symb_to_check = $map_symb;
    } else {
        $symb_to_check = $parm_symb;
    }
    foreach my $entry (keys(%consumed)) {
        if ( $consumed{$entry}->{'name'} eq ($uname.':'.$udom) ) {
            if ($consumed{$entry}->{'symb'} eq $symb_to_check) {
                if (&Apache::lonnet::del('slot_reservations',[$entry],
                                         $cdom,$cnum) eq 'ok') {
                    $match = $symb_to_check;
                }
                last;
            }
        }
    }
    if ($match) {
        if (&update_selectable($navmap,$slot_name,$symb,$cdom,
                               $cnum,$udom,$uname,$context) =~ /^error/) {
            if ($mgr eq 'F') {
                $msg = &mt('Reservation release partially complete for: [_1]',"$uname:$udom").'<br />'.
                       &mt('Update of availablestudent parameter for [_1] was not completed.',"$uname:$udom");
            } else {
                $msg = &mt('Release partially complete for: [_1]',$description);
            }
            return (0,$msg);
        } else {
            if ($mgr eq 'F') {
                $msg = &mt('Released Reservation for user: [_1]',"$uname:$udom");
            } else {
                $msg = '<span style="font-weight: bold;">'.&mt('Released reservation: [_1]',$description).'</span><br /><br />';
                my $person = &Apache::loncommon::plainname($env{'user.name'},$env{'user.domain'});
                my $subject = &mt('Reservation change: [_1]',$description);
                my $msgbody = &mt('Reservation released by [_1] for [_2].',$person,$description);
                $msg .= &slot_change_messaging($slot{'reservationmsg'},$subject,$msgbody,'release');
            }
            return (1,$msg);
        }
    } else {
        $msg = &mt('Release failed for: [_1]',$description);
        return (0,$msg);
    }
}

sub update_selectable {
    my ($navmap,$slot_name,$symb,$cdom,$cnum,$udom,$uname,$context) = @_;
    return 'error: ' unless (ref($navmap));
    my $symb_for_parm = $symb;
    my $passed_resource = $navmap->getBySymb($symb);
    return 'error: invalid symb' unless (ref($passed_resource));

    # if the reservation symb is for a map get a resource in that map
    # to check slot parameters on
    if ($passed_resource->is_map()) {
        my ($a_resource) =
            $navmap->retrieveResources($passed_resource,
                                       sub {$_[0]->is_problem() || $_[0]->is_tool() },0,1);
        $symb_for_parm = $a_resource->symb();
    }
    # get parameter string, check for existence, rebuild string with the slot
    my $student = &Apache::lonnet::EXT('resource.0.availablestudent',
                                       $symb_for_parm,$udom,$uname);

    # Get value of useslots parameter in effect for this user.
    # If value is map or map_map, then the parm level is 2 (i.e.,
    # non-recursive enclosing map/folder level for specific user)
    # and the symb for this reservation in slot_reservations.db
    # will be the symb of the map itself.

    my $use_slots = &Apache::lonnet::EXT('resource.0.useslots',
                                         $symb_for_parm,$udom,$uname);
    &Apache::lonxml::debug("use_slots is  $use_slots<br />");

    if (&Apache::lonnet::error($use_slots)) {
        return 'error: Unable to determine current status';
    }

    my $parm_level = 1;
    if ($use_slots eq 'map' || $use_slots eq 'map_map') {
        $parm_level = 2;
    }

    my @slots = split(/:/,$student);

    my @new_slots;
    foreach my $exist_slot (@slots) {
        next if ($exist_slot eq $slot_name);
        push(@new_slots,$exist_slot);
    }
    my $new_value = join(':',@new_slots);

    my $result = &store_slot_parm($symb_for_parm,$symb,$slot_name,$parm_level,
                                  $new_value,$cnum,$cdom,$uname,$udom,'release',
                                  $context,1);
    return $result;
}

sub delete_slot {
    my ($r)=@_;

    my $slot_name = $env{'form.slotname'};
    my %slot=&Apache::lonnet::get_slot($slot_name);

    my ($cnum,$cdom)=&get_course();
    my %consumed=&Apache::lonnet::dump('slot_reservations',$cdom,$cnum,
				       "^$slot_name\0");
    my ($tmp) = %consumed;
    if ($tmp =~ /error: 2/) { undef(%consumed); }

    if (%slot && !%consumed) {
	$slot{'type'} = 'deleted';
	my $ret = &Apache::lonnet::cput('slots', {$slot_name => \%slot},
					$cdom, $cnum);
	if ($ret eq 'ok') {
	    $r->print('<p>'.&mt('Slot [_1] marked as deleted.','<tt>'.$slot_name.'</tt>').'</p>');
	} else {
	    $r->print('<p class="LC_error">'.&mt('An error occurred when attempting to delete slot: [_1]','<tt>'.$slot_name.'</tt>')." ($ret)</p>");
	}
    } else {
	if (%consumed) {
	    $r->print('<p>'.&mt('Slot [_1] has active reservations.','<tt>'.$slot_name.'</tt>').'</p>');
	} else {
	    $r->print('<p>'.&mt('Slot [_1] does not exist.','<tt>'.$slot_name.'</tt>').'</p>');
	}
    }
    $r->print('<p><a href="/adm/slotrequest?command=showslots">'.
	      &mt('Return to slot list').'</a></p>');
    &return_link($r);
}

sub return_link {
    my ($r) = @_;
    my $target = &return_target();
    if (($env{'form.command'} eq 'manageresv') || ($env{'form.context'} eq 'usermanage')) {
	$r->print('<p><a href="/adm/slotrequest?command=manageresv" target="'.$target.'">'.
                  &mt('Return to reservations'));  
    } else {
        $r->print('<p><a href="/adm/flip?postdata=return:" target="'.$target.'">'.
	          &mt('Return to last resource').'</a></p>');
    }
}

sub return_target {
    my ($target,$ltitarget,$deeplinktarget);
    if ($env{'request.lti.login'}) {
         $ltitarget = $env{'request.lti.target'};
    }
    if ($env{'request.deeplink.login'}) {
        $deeplinktarget = $env{'request.deeplink.target'};
    }
    if (($ltitarget eq 'iframe') || ($deeplinktarget eq '_self')) {
        $target = '_self';
    } else {
        $target = '_top';
    }
    return $target;
}

sub get_slot {
    my ($r,$symb,$conflictable_slot,$inhibit_return_link)=@_;

    my %slot=&Apache::lonnet::get_slot($env{'form.slotname'});
    my $slot_name=&check_for_conflict($symb,$env{'form.slotname'},\%slot);

    if ($slot_name =~ /^error: (.*)/) {
	$r->print('<p class="LC_error">'
                 .&mt('An error occurred while attempting to make a reservation. ([_1])',$1)
                 .'</p>');
	&return_link($r);
	return 0;
    }
    if ($slot_name && $slot_name ne $conflictable_slot) {
	my %slot=&Apache::lonnet::get_slot($slot_name);
	my $description1=&get_description($slot_name,\%slot);
        my $slottype1=$slot{'type'};
	%slot=&Apache::lonnet::get_slot($env{'form.slotname'});
	my $description2=&get_description($env{'form.slotname'},\%slot);
        if ($slottype1 eq 'preassigned') {
            $r->print('<p>'.&mt('You already have a reservation: "[_1]", assigned by your instructor.',
                                $description1).'</p>'.
                      '<p>'.&mt('Your instructor must unassign it before you can make a new reservation.').
                      '</p>');
        } elsif ($slot_name ne $env{'form.slotname'}) {
	    $r->print(<<STUFF);
<form method="post" action="/adm/slotrequest">
   <input type="hidden" name="symb" value="$env{'form.symb'}" />
   <input type="hidden" name="slotname" value="$env{'form.slotname'}" />
   <input type="hidden" name="releaseslot" value="$slot_name" />
   <input type="hidden" name="command" value="change" />
STUFF
            $r->print('<p class="LC_error">'.&mt('Reservation currently unchanged').'</p>');
            if ($slot_name ne '') {
                $r->print('<p>'.&mt('To complete the transaction you [_1]must confirm[_2] you want to [_3]process the change[_4] to [_5].'
                         ,'<b>','</b>','<i>','</i>','<b>'.$description2.'</b>')
                         .'<br />'
                         .&mt('Or you can choose to [_1]make no change[_2] and continue[_2] with the reservation you already had: [_3].'
                         ,'<i>','</i>','<b>'.$description1.'</b>')
                         .'</p><p><span class="LC_nobreak">'
                         .'<input type="submit" name="change" value="'.&mt('Process the change').'" />' 
                         .('&nbsp;'x3)
                         .'<input type="submit" name="nochange" value="'.&mt('Make no change').'" />'
                         .'</span></p>');
            }
	    $r->print(<<STUFF);
</form>
STUFF
        } else {
            $r->print('<p>'.&mt('Already have a reservation: [_1].',$description1).'</p>');
	    &return_link($r);
	}
	return 0;
    }

    my ($cnum,$cdom)=&get_course();
    my $reserved=&make_reservation($env{'form.slotname'},
				   \%slot,$symb,$cnum,$cdom);
    my $description=&get_description($env{'form.slotname'},\%slot);
    if (defined($reserved)) {
	my $retvalue = 0;
	if ($slot_name =~ /^error: (.*)/) {
	    $r->print('<p class="LC_error">'
                     .&mt('An error occurred while attempting to make a reservation. ([_1])',$1)
                     .'</p>');
	} elsif ($reserved > -1) {
	    $r->print('<p style="font-weight: bold;">'.&mt('Successfully signed up:  [_1]',$description).'</p>');
	    $retvalue = 1;
            my $person = &Apache::loncommon::plainname($env{'user.name'},$env{'user.domain'});
            my $subject = &mt('Reservation change: [_1]',$description);
            my $msgbody = &mt('Successful reservation by [_1] for [_2].',$person,$description);
            my $msg = &slot_change_messaging($slot{'reservationmsg'},$subject,$msgbody,'reserve');
            if ($msg) {
                $r->print($msg);
            }
	} elsif ($reserved < 0) {
	    $r->print('<p>'.&mt('Already reserved: [_1]',$description).'</p>');
	}
	if (!$inhibit_return_link) { &return_link($r); }
	return 1;
    }

    my %lt = &Apache::lonlocal::texthash(
        'request' => 'Availability list',
        'try'     => 'Try again?',
        'or'      => 'or',
    );

    my $extra_input;
    if ($conflictable_slot) {
	$extra_input='<input type="hidden" name="releaseslot" value="'.$env{'form.slotname'}.'" />';
    }

    $r->print('<p>'.&mt('[_1]Failed[_2] to reserve a slot for [_3].','<span class="LC_warning">','</span>',$description).'</p>');
    $r->print(<<STUFF);
<p>
<form method="post" action="/adm/slotrequest">
   <input type="submit" name="Try Again" value="$lt{'try'}" />
   <input type="hidden" name="symb" value="$env{'form.symb'}" />
   <input type="hidden" name="slotname" value="$env{'form.slotname'}" />
   <input type="hidden" name="command" value="$env{'form.command'}" />
   $extra_input
</form>
</p>
<p>
$lt{'or'}
<form method="post" action="/adm/slotrequest">
    <input type="hidden" name="symb" value="$env{'form.symb'}" />
    <input type="submit" name="requestattempt" value="$lt{'request'}" />
</form>
STUFF

    if (!$inhibit_return_link) { 
        $r->print(&mt('or').'</p>');
        &return_link($r);
    } else {
        $r->print('</p>');
    }
    return 0;
}

sub allowed_slot {
    my ($slot_name,$slot,$symb,$slots,$consumed_uniqueperiods,$toskip)=@_;

    #already started
    if ($slot->{'starttime'} < time) {
	return 0;
    }
    &Apache::lonxml::debug("$slot_name starttime good");

    #already ended
    if ($slot->{'endtime'} < time) {
	return 0;
    }
    &Apache::lonxml::debug("$slot_name endtime good");

    # not allowed to pick this one
    if (defined($slot->{'type'})
	&& $slot->{'type'} ne 'schedulable_student') {
	return 0;
    }
    &Apache::lonxml::debug("$slot_name type good");

    # reserve time not yet started
    if ($slot->{'startreserve'} > time) {
	return 0;
    }
    # reserve time ended
    if (($slot->{'endreserve'}) &&
        ($slot->{'endreserve'} < time)) {
        return 0;
    }    
    &Apache::lonxml::debug("$slot_name reserve good");

    my $userallowed=0;
    # its for a different set of users
    if (defined($slot->{'allowedsections'})) {
	if (!defined($env{'request.role.sec'})
	    && grep(/^No section assigned$/,
		    split(',',$slot->{'allowedsections'}))) {
	    $userallowed=1;
	}
	if (defined($env{'request.role.sec'})
	    && grep(/^\Q$env{'request.role.sec'}\E$/,
		    split(',',$slot->{'allowedsections'}))) {
	    $userallowed=1;
	}
	if (defined($env{'request.course.groups'})) {
	    my @groups = split(/:/,$env{'request.course.groups'});
	    my @allowed_sec = split(',',$slot->{'allowedsections'});
	    foreach my $group (@groups) {
		if (grep {$_ eq $group} (@allowed_sec)) {
		    $userallowed=1;
		    last;
		}
	    }
	}
    }
    &Apache::lonxml::debug("$slot_name sections is $userallowed");

    # its for a different set of users
    if (defined($slot->{'allowedusers'})
	&& grep(/^\Q$env{'user.name'}:$env{'user.domain'}\E$/,
		split(',',$slot->{'allowedusers'}))) {
	$userallowed=1;
    }

    if (!defined($slot->{'allowedusers'})
	&& !defined($slot->{'allowedsections'})) {
	$userallowed=1;
    }

    &Apache::lonxml::debug("$slot_name user is $userallowed");
    return 0 if (!$userallowed);

    # not allowed for this resource
    if (defined($slot->{'symb'})
	&& $slot->{'symb'} ne $symb) {
        unless ((ref($toskip) eq 'HASH') && ($toskip->{'symb'})) {
	    return 0;
        }
    }

    my $conflict = &check_for_conflict($symb,$slot_name,$slot,$slots,
				       $consumed_uniqueperiods);
    if ($conflict =~ /^error: /) {
        return 0;
    } elsif ($conflict ne '') {
	if ($slots->{$conflict}{'starttime'} < time) {
	    return 0;
	}
    }
    &Apache::lonxml::debug("$slot_name symb good");
    return 1;
}

sub get_description {
    my ($slot_name,$slot)=@_;
    my $description=$slot->{'description'};
    if (!defined($description)) {
	$description=&mt('[_1] From [_2] to [_3]',$slot_name,
			 &Apache::lonlocal::locallocaltime($slot->{'starttime'}),
			 &Apache::lonlocal::locallocaltime($slot->{'endtime'}));
    }
    return $description;
}

sub show_choices {
    my ($r,$symb,$formname,$num,$slots,$consumed_uniqueperiods,$available,$got_slots)=@_;
    my $output;
    &Apache::lonxml::debug("Checking Slots");
    if (!ref($available) eq 'ARRAY') {
        return;
    }
    if (!@{$available}) {
        $output = '<span class="LC_info">'.&mt('No available times.').'</span>';
        if ($env{'form.command'} ne 'manageresv') {
            my $target = &return_target();
            $output .= ' <a href="/adm/flip?postdata=return:" target="'.$target.'">'.
                       &mt('Return to last resource').'</a>';
        }
        $r->print($output);
        return;
    }
    if (@{$available} > 1) {
        my $numavailable = scalar(@{$available});
        my $numreserved = 0;
        my $js;
        my $j = 0;
        foreach my $got (@{$got_slots}) {
            unless (($got eq '') || (!defined($got))) {
                $numreserved ++;
                if ($env{'form.command'} eq 'manageresv') {
                    $js .= "    currslot[$j]='$got';\n";
                    $j++;
                }
            }
        }
        my $showfilter = 'none';
        $output .= '<fieldset><legend>'.&mt('Actions').'</legend>'."\n".
                   '<form method="post" name="reservationdisplay_'.$num.
                   '" action="" onsubmit="toggleSlotDisplay(this.form,'."'$num'".');">';
        my @options = ('all','filter');
        if ($numreserved) {
            unshift(@options,'show');
        }
        my %resmenu = &Apache::lonlocal::texthash (
                                         show   => 'Show current reservation',
                                         all    => 'Show all', 
                                         filter => 'Search by date',
                     );
        foreach my $option (@options) {
            my $onclick = "toggleSlotDisplay(this.form,'$num');";
            if (($option eq 'show') && ($env{'form.command'} eq 'manageresv')) {  
                $onclick .= "currSlotDisplay$num(this.form,'$num');"; 
            }
            $output .= '<span class="LC_nobreak"><label>'.
                       '<input type="radio" class="LC_slotpick_radio" name="slotpick" value="'.
                       $option.'" onclick="'.$onclick.'" />'.
                       $resmenu{$option}.
                       '</label></span>'.('&nbsp;' x3)."\n";
        }
        $output .= '</form>';
        my $chooserform = 'reservationchooser_'.$num;
        my $starttime = $slots->{$available->[0]}->{'starttime'};
        my $endtime = $slots->{$available->[-1]}->{'starttime'};
        if ($env{'form.command'} eq 'manageresv') {
            $output .= <<"ENDSCRIPT";

<script type="text/javascript">
// <![CDATA[
function currSlotDisplay$num() {
    var currslot = new Array($numreserved);
$js    
    for (var j=0; j<$numreserved; j++) {
        if (document.getElementById('LC_slotrow_$num\_'+currslot[j])) {
            document.getElementById('LC_slotrow_$num\_'+currslot[j]).style.display = '';
        }
    }
}
// ]]>
</script>

ENDSCRIPT
        }
        $output .=
            '<div id="LC_slotfilter_'.$num.'" style="display:'.$showfilter.'">'.
            '<form method="post" name="'.$chooserform.'" action="">'.
            '<table><tr><td>'.&mt('Open after').'</td><td>'.
            &Apache::lonhtmlcommon::date_setter($chooserform,'start',$starttime,'','','','','','','',1,1).
            '</td></tr><tr><td>'.&mt('Closed before').'</td><td>'.
            &Apache::lonhtmlcommon::date_setter($chooserform,'end',$endtime,'','','','','','','',1,1).
            '</td></tr></table><br />'.
            '<input type="button" name="slotfilter" value="Search for reservable slots" onclick="updateSlotDisplay(this.form,'."'$num'".');" />'.
            '</form></div><div id="LC_slotsearch_'.$num.'" style="display:none"><hr />';
    }
    if ($env{'form.command'} eq 'manageresv') {
        $output .= '<table border="0">';
    } else {
        $output .= &Apache::loncommon::start_data_table();
    }
    foreach my $slot (@{$available}) {
	my $description=&get_description($slot,$slots->{$slot});
	my $form;
	if ((grep(/^\Q$slot\E$/,@{$got_slots})) ||
	    &space_available($slot,$slots->{$slot},$symb)) {
	    my $text=&mt('Select');
	    my $command='get';
	    if (grep(/^\Q$slot\E$/,@{$got_slots})) {
		$text=&mt('Drop Reservation');
		$command='release';
	    } else {
		my $conflict = &check_for_conflict($symb,$slot,$slots->{$slot},
						   $slots,$consumed_uniqueperiods);
                if ($conflict) {
                    if ($conflict =~ /^error: /) {
                        $form = '<span class="LC_error">'.
                                 &mt('Slot: [_1] has unknown status.',$description).
                                 '</span>';
                    } else {
		        $text=&mt('Change Reservation');
		        $command='get';
		    }
                }
	    }
	    my $escsymb=&escape($symb);
            if (!$form) {
                my $name;
                if ($formname) {
                     $name = 'name="'.$formname.'"';
                }
                my $context = 'user';
                if ($env{'form.command'} eq 'manageresv') {
                    $context = 'usermanage';
                }
	        $form=<<STUFF;
   <form method="post" action="/adm/slotrequest" $name>
     <input type="submit" name="Select" value="$text" />
     <input type="hidden" name="symb" value="$escsymb" />
     <input type="hidden" name="slotname" value="$slot" />
     <input type="hidden" name="command" value="$command" />
     <input type="hidden" name="context" value="$context" />
   </form>
STUFF
	    }
        } else {
            $form = &mt('Unavailable');
        }
        if ($env{'form.command'} eq 'manageresv') {
            $output .= '<tr id="LC_slotrow_'.$num.'_'.$slot.'" >';
        } else {
	    $output .= &Apache::loncommon::start_data_table_row('','LC_slotrow_'.$num.'_'.$slot);
        }
        $output .= " 
 <td>$form</td>
 <td>$description</td>\n";
        if ($env{'form.command'} eq 'manageresv') {
            $output .= '</tr>';
        } else {
            $output .= &Apache::loncommon::end_data_table_row();
        }
    }
    if ($env{'form.command'} eq 'manageresv') {
        $output .= '</table>';
    } else {
        $output .= &Apache::loncommon::end_data_table();
    }
    if (@{$available} > 1) {
        $output .= '</div></fieldset>';
    }
    $r->print($output);
    return;
}

sub to_show {
    my ($slotname,$slot,$when,$deleted,$name) = @_;
    my $time=time;
    my $week=60*60*24*7;

    if ($deleted eq 'hide' && $slot->{'type'} eq 'deleted') {
	return 0;
    }

    if ($name && $name->{'value'} =~ /\w/) {
	if ($name->{'type'} eq 'substring') {
	    if ($slotname !~ /\Q$name->{'value'}\E/) {
		return 0;
	    }
	}
	if ($name->{'type'} eq 'exact') {
	    if ($slotname eq $name->{'value'}) {
		return 0;
	    }
	}
    }

    if ($when eq 'any') {
	return 1;
    } elsif ($when eq 'now') {
	if ($time > $slot->{'starttime'} &&
	    $time < $slot->{'endtime'}) {
	    return 1;
	}
	return 0;
    } elsif ($when eq 'nextweek') {
	if ( ($time        < $slot->{'starttime'} &&
	      ($time+$week) > $slot->{'starttime'})
	     ||
	     ($time        < $slot->{'endtime'} &&
	      ($time+$week) > $slot->{'endtime'}) ) {
	    return 1;
	}
	return 0;
    } elsif ($when eq 'lastweek') {
	if ( ($time        > $slot->{'starttime'} &&
	      ($time-$week) < $slot->{'starttime'})
	     ||
	     ($time        > $slot->{'endtime'} &&
	      ($time-$week) < $slot->{'endtime'}) ) {
	    return 1;
	}
	return 0;
    } elsif ($when eq 'willopen') {
	if ($time < $slot->{'starttime'}) {
	    return 1;
	}
	return 0;
    } elsif ($when eq 'wereopen') {
	if ($time > $slot->{'endtime'}) {
	    return 1;
	}
	return 0;
    }
    
    return 1;
}

sub remove_link {
    my ($slotname,$entry,$uname,$udom,$symb) = @_;

    my $remove = &mt('Remove');

    if ($entry eq 'remove all') {
	$remove = &mt('Remove All');
	undef($uname);
	undef($udom);
    }

    $slotname  = &escape($slotname);
    $entry     = &escape($entry);
    $uname     = &escape($uname);
    $udom      = &escape($udom);
    $symb      = &escape($symb);

    return <<"END_LINK";
 <a href="/adm/slotrequest?command=remove_registration&amp;slotname=$slotname&amp;entry=$entry&amp;uname=$uname&amp;udom=$udom&amp;symb=$symb&amp;context=manage"
   >($remove)</a>
END_LINK

}

sub show_table {
    my ($r,$mgr)=@_;

    my ($cnum,$cdom)=&get_course();
    my $crstype=&Apache::loncommon::course_type($cdom.'_'.$cnum);
    my %slots=&Apache::lonnet::dump('slots',$cdom,$cnum);
    if ( (keys(%slots))[0] =~ /^error: 2 /) {
	undef(%slots);
    } 
    my $available;
    if ($mgr eq 'F') {
	$r->print('<div>');
	$r->print('<form method="post" action="/adm/slotrequest">
<input type="hidden" name="command" value="uploadstart" />
<input type="submit" name="start" value="'.&mt('Upload Slot List').'" />
</form>');
	$r->print(&Apache::loncommon::help_open_topic('Slot CommaDelimited'));
	$r->print('<form method="post" action="/adm/helper/newslot.helper">
<input type="submit" name="newslot" value="'.&mt('Create a New Slot').'" />
</form>');
	$r->print(&Apache::loncommon::help_open_topic('Slot About'));
	$r->print('</div>');
    }

    if (!keys(%slots)) {
        $r->print(
            '<p class="LC_info">'
           .&mt('No slots have been created in this '.lc($crstype).'.')
           .'</p>'
        );
        return;
    }
    
    my %Saveable_Parameters = ('show'              => 'array',
			       'when'              => 'scalar',
			       'order'             => 'scalar',
			       'deleted'           => 'scalar',
			       'name_filter_type'  => 'scalar',
			       'name_filter_value' => 'scalar',
			       );
    &Apache::loncommon::store_course_settings('slotrequest',
					      \%Saveable_Parameters);
    &Apache::loncommon::restore_course_settings('slotrequest',
						\%Saveable_Parameters);
    &Apache::grades::init_perm();
    my ($classlist,$section,$fullname)=&Apache::grades::getclasslist('all');
    &Apache::grades::reset_perm();

    # what to display filtering
    my %show_fields=&Apache::lonlocal::texthash(
	     'name'            => 'Slot Name',
	     'description'     => 'Description',
	     'type'            => 'Type',
	     'starttime'       => 'Start time',
	     'endtime'         => 'End Time',
             'startreserve'    => 'Time students can start reserving',
             'endreserve'      => 'Time students can no longer reserve',
             'reservationmsg'  => 'Message triggered by reservation',
	     'secret'          => 'Secret Word',
	     'space'           => '# of students/max',
	     'ip'              => 'IP or DNS restrictions',
	     'symb'            => 'Resource slot is restricted to.',
	     'allowedsections' => 'Sections slot is restricted to.',
	     'allowedusers'    => 'Users slot is restricted to.',
	     'uniqueperiod'    => 'Period of time slot is unique',
	     'scheduled'       => 'Scheduled Students',
	     'proctor'         => 'List of proctors');
    if ($crstype eq 'Community') {
        $show_fields{'startreserve'} = &mt('Time members can start reserving');
        $show_fields{'endreserve'} = &mt('Time members can no longer reserve');
        $show_fields{'scheduled'} = &mt('Scheduled Members');
    }
    my @show_order=('name','description','type','starttime','endtime',
		    'startreserve','endreserve','reservationmsg','secret','space',
		    'ip','symb','allowedsections','allowedusers','uniqueperiod',
		    'scheduled','proctor');
    my @show = 
	(exists($env{'form.show'})) ? &Apache::loncommon::get_env_multiple('form.show')
	                            : keys(%show_fields);
    my %show =  map { $_ => 1 } (@show);

    #when filtering setup
    my %when_fields=&Apache::lonlocal::texthash(
	     'now'      => 'Open now',
	     'nextweek' => 'Open within the next week',
	     'lastweek' => 'Were open last week',
	     'willopen' => 'Will open later',
	     'wereopen' => 'Were open',
	     'any'      => 'Anytime',
						);
    my @when_order=('any','now','nextweek','lastweek','willopen','wereopen');
    $when_fields{'select_form_order'} = \@when_order;
    my $when = 	(exists($env{'form.when'})) ? $env{'form.when'}
                                            : 'now';

    #display of students setup
    my %stu_display_fields=
	&Apache::lonlocal::texthash('username' => 'User name',
				    'fullname' => 'Full name',
				    );
    my @stu_display_order=('fullname','username');
    my @stu_display = 
	(exists($env{'form.studisplay'})) ? &Apache::loncommon::get_env_multiple('form.studisplay')
	                                  : keys(%stu_display_fields);
    my %stu_display =  map { $_ => 1 } (@stu_display);

    #name filtering setup
    my %name_filter_type_fields=
	&Apache::lonlocal::texthash('substring' => 'Substring',
				    'exact'     => 'Exact',
				    #'reg'       => 'Regular Expression',
				    );
    my @name_filter_type_order=('substring','exact');

    $name_filter_type_fields{'select_form_order'} = \@name_filter_type_order;
    my $name_filter_type = 
	(exists($env{'form.name_filter_type'})) ? $env{'form.name_filter_type'}
                                                : 'substring';
    my $name_filter = {'type'  => $name_filter_type,
		       'value' => $env{'form.name_filter_value'},};

    
    #deleted slot filtering
    #default to hide if no value
    $env{'form.deleted'} ||= 'hide';
    my $hide_radio = 
	&Apache::lonhtmlcommon::radio('deleted',$env{'form.deleted'},'hide');
    my $show_radio = 
	&Apache::lonhtmlcommon::radio('deleted',$env{'form.deleted'},'show');
	
    $r->print('<form method="post" action="/adm/slotrequest">
<input type="hidden" name="command" value="showslots" />');
    $r->print('<div>');
    $r->print('<table class="inline">
      <tr><th>'.&mt('Show').'</th>
          <th>'.&mt('Student Display').'</th>
          <th>'.&mt('Open').'</th>
          <th>'.&mt('Slot Name Filter').'</th>
          <th>'.&mt('Options').'</th>
      </tr>
      <tr><td valign="top">'.&Apache::loncommon::multiple_select_form('show',\@show,6,\%show_fields,\@show_order).
	      '</td>
           <td valign="top">
         '.&Apache::loncommon::multiple_select_form('studisplay',\@stu_display,
						    6,\%stu_display_fields,
						    \@stu_display_order).'
           </td>
           <td valign="top">'.&Apache::loncommon::select_form($when,'when',\%when_fields).
          '</td>
           <td valign="top">'.&Apache::loncommon::select_form($name_filter_type,
						 'name_filter_type',
						 \%name_filter_type_fields).
	      '<br />'.
	      &Apache::lonhtmlcommon::textbox('name_filter_value',
					      $env{'form.name_filter_value'},
					      15).
          '</td>
           <td valign="top">
            <table>
              <tr>
                <td rowspan="2">'.&mt('Deleted slots:').'</td>
                <td><label>'.$show_radio.&mt('Show').'</label></td>
              </tr>
              <tr>
                <td><label>'.$hide_radio.&mt('Hide').'</label></td>
              </tr>
            </table>
	  </td>
       </tr>
    </table>');
    $r->print('</div>');
    $r->print('<p><input type="submit" name="start" value="'.&mt('Update Display').'" /></p>');
    my $linkstart='<a href="/adm/slotrequest?command=showslots&amp;order=';
    my $tableheader = &Apache::loncommon::start_data_table().
                      &Apache::loncommon::start_data_table_header_row().'
                      <th></th>';
    foreach my $which (@show_order) {
	if ($which ne 'proctor' && exists($show{$which})) {
	    $tableheader .= '<th>'.$linkstart.$which.'">'.$show_fields{$which}.'</a></th>';
	}
    }
    $tableheader .= &Apache::loncommon::end_data_table_header_row();
    my $shownheader = 0;

    my %name_cache;
    my $slotsort = sub {
	if ($env{'form.order'}=~/^(type|description|endtime|startreserve|endreserve|ip|symb|allowedsections|allowedusers|reservationmsg)$/) {
	    if (lc($slots{$a}->{$env{'form.order'}})
		ne lc($slots{$b}->{$env{'form.order'}})) {
		return (lc($slots{$a}->{$env{'form.order'}}) 
			cmp lc($slots{$b}->{$env{'form.order'}}));
	    }
	} elsif ($env{'form.order'} eq 'space') {
	    if ($slots{$a}{'maxspace'} ne $slots{$b}{'maxspace'}) {
		return ($slots{$a}{'maxspace'} cmp $slots{$b}{'maxspace'});
	    }
	} elsif ($env{'form.order'} eq 'name') {
	    if (lc($a) cmp lc($b)) {
		return lc($a) cmp lc($b);
	    }
	} elsif ($env{'form.order'} eq 'uniqueperiod') {
	    
	    if ($slots{$a}->{'uniqueperiod'}[0] 
		ne $slots{$b}->{'uniqueperiod'}[0]) {
		return ($slots{$a}->{'uniqueperiod'}[0]
			cmp $slots{$b}->{'uniqueperiod'}[0]);
	    }
	    if ($slots{$a}->{'uniqueperiod'}[1] 
		ne $slots{$b}->{'uniqueperiod'}[1]) {
		return ($slots{$a}->{'uniqueperiod'}[1]
			cmp $slots{$b}->{'uniqueperiod'}[1]);
	    }
	}
	return $slots{$a}->{'starttime'} <=> $slots{$b}->{'starttime'};
    };

    my %consumed;
    if (exists($show{'scheduled'}) || exists($show{'space'}) ) {
	%consumed=&Apache::lonnet::dump('slot_reservations',$cdom,$cnum);
	my ($tmp)=%consumed;
	if ($tmp =~ /^error: /) { undef(%consumed); }
    }

    my %msgops = &slot_reservationmsg_options();

    foreach my $slot (sort $slotsort (keys(%slots)))  {
	if (!&to_show($slot,$slots{$slot},$when,
		      $env{'form.deleted'},$name_filter)) { next; }
        my $reservemsg;
	if (defined($slots{$slot}->{'type'})
	    && $slots{$slot}->{'type'} eq 'schedulable_student') {
	    $reservemsg = $msgops{$slots{$slot}->{'reservationmsg'}};
	}
	my $description=&get_description($slot,$slots{$slot});
	my ($id_count,$ids);
	    
	if (exists($show{'scheduled'}) || exists($show{'space'}) ) {
	    my $re_str = "$slot\0";
	    my @this_slot = grep(/^\Q$re_str\E/,keys(%consumed));
	    $id_count = scalar(@this_slot);
	    if (exists($show{'scheduled'})) {
		foreach my $entry (sort { $consumed{$a}{name} cmp 
					      $consumed{$b}{name} }
				   (@this_slot)) {
		    my (undef,$id)=split("\0",$entry);
		    my ($uname,$udom) = split(':',$consumed{$entry}{'name'});
		    $ids.= '<span class="LC_nobreak">';
		    foreach my $item (@stu_display_order) {
			if ($stu_display{$item}) {
			    if ($item eq 'fullname') {
				$ids.=$fullname->{"$uname:$udom"}.' ';
			    } elsif ($item eq 'username') {
				$ids.="<tt>$uname:$udom</tt> ";
			    }
			}
		    }
		    $ids.=&remove_link($slot,$entry,$uname,$udom,
				       $consumed{$entry}{'symb'}).'</span><br />';
		}
	    }
	}

	my $start=($slots{$slot}->{'starttime'}?
		   &Apache::lonlocal::locallocaltime($slots{$slot}->{'starttime'}):'');
	my $end=($slots{$slot}->{'endtime'}?
		 &Apache::lonlocal::locallocaltime($slots{$slot}->{'endtime'}):'');
	my $start_reserve=($slots{$slot}->{'startreserve'}?
			   &Apache::lonlocal::locallocaltime($slots{$slot}->{'startreserve'}):'');
        my $end_reserve=($slots{$slot}->{'endreserve'}?
                         &Apache::lonlocal::locallocaltime($slots{$slot}->{'endreserve'}):'');
	
	my $unique;
	if (ref($slots{$slot}{'uniqueperiod'})) {
	    $unique=localtime($slots{$slot}{'uniqueperiod'}[0]).', '.
		localtime($slots{$slot}{'uniqueperiod'}[1]);
	}

	my $title;
	if (exists($slots{$slot}{'symb'})) {
	    my (undef,undef,$res)=
		&Apache::lonnet::decode_symb($slots{$slot}{'symb'});
	    $res =   &Apache::lonnet::clutter($res);
	    $title = &Apache::lonnet::gettitle($slots{$slot}{'symb'});
	    $title='<a href="'.$res.'?symb='.$slots{$slot}{'symb'}.'">'.$title.'</a>';
	}

	my $allowedsections;
	if (exists($show{'allowedsections'})) {
	    $allowedsections = 
		join(', ',sort(split(/\s*,\s*/,
				     $slots{$slot}->{'allowedsections'})));
	}

	my @allowedusers;
	if (exists($show{'allowedusers'})) {
	    @allowedusers= map {
		my ($uname,$udom)=split(/:/,$_);
		my $fullname=$name_cache{$_};
		if (!defined($fullname)) {
		    $fullname = &Apache::loncommon::plainname($uname,$udom);
		    $fullname =~s/\s/&nbsp;/g;
		    $name_cache{$_} = $fullname;
		}
		&Apache::loncommon::aboutmewrapper($fullname,$uname,$udom);
	    } (sort(split(/\s*,\s*/,$slots{$slot}->{'allowedusers'})));
	}
	my $allowedusers=join(', ',@allowedusers);
	
	my @proctors;
	my $rowspan=1;
	my $colspan=1;
	if (exists($show{'proctor'})) {
	    $rowspan=2;
	    @proctors= map {
		my ($uname,$udom)=split(/:/,$_);
		my $fullname=$name_cache{$_};
		if (!defined($fullname)) {
		    $fullname = &Apache::loncommon::plainname($uname,$udom);
		    $fullname =~s/\s/&nbsp;/g;
		    $name_cache{$_} = $fullname;
		}
		&Apache::loncommon::aboutmewrapper($fullname,$uname,$udom);
	    } (sort(split(/\s*,\s*/,$slots{$slot}->{'proctor'})));
	}
	my $proctors=join(', ',@proctors);

        my %lt = &Apache::lonlocal::texthash (
                                               edit   => 'Edit',
                                               delete => 'Delete',
                                               slotlog => 'History',
        );
        my ($edit,$delete,$showlog,$remove_all);
        if ($mgr) {
	    $edit=(<<"EDITLINK");
<a href="/adm/helper/newslot.helper?name=$slot">$lt{'edit'}</a>
EDITLINK

	    $delete=(<<"DELETELINK");
<a href="/adm/slotrequest?command=delete&amp;slotname=$slot">$lt{'delete'}</a>
DELETELINK

            $remove_all=&remove_link($slot,'remove all').'<br />';

            if ($ids eq '') {
                undef($remove_all);
            } else {
                undef($delete);
            }
        }

        $showlog=(<<"LOGLINK");
<a href="/adm/slotrequest?command=slotlog&amp;slotname=$slot">$lt{'slotlog'}</a>
LOGLINK

	if ($slots{$slot}{'type'} ne 'schedulable_student') {
            undef($showlog); 
	    undef($remove_all);
	}

        unless ($shownheader) {
            $r->print($tableheader);
            $shownheader = 1;
        }

	my $row_start=&Apache::loncommon::start_data_table_row();
	my $row_end=&Apache::loncommon::end_data_table_row();
        $r->print($row_start.
		  "\n<td rowspan=\"$rowspan\">$edit $delete $showlog</td>\n");
	if (exists($show{'name'})) {
	    $colspan++;$r->print("<td>$slot</td>");
	}
	if (exists($show{'description'})) {
	    $colspan++;$r->print("<td>$description</td>\n");
	}
	if (exists($show{'type'})) {
	    $colspan++;$r->print("<td>$slots{$slot}->{'type'}</td>\n");
	}
	if (exists($show{'starttime'})) {
	    $colspan++;$r->print("<td>$start</td>\n");
	}
	if (exists($show{'endtime'})) {
	    $colspan++;$r->print("<td>$end</td>\n");
	}
	if (exists($show{'startreserve'})) {
	    $colspan++;$r->print("<td>$start_reserve</td>\n");
	}
        if (exists($show{'endreserve'})) {
            $colspan++;$r->print("<td>$end_reserve</td>\n");
        }
        if (exists($show{'reservationmsg'})) {
            $colspan++;$r->print("<td>$reservemsg</td>\n");
        }
	if (exists($show{'secret'})) {
	    $colspan++;$r->print("<td>$slots{$slot}{'secret'}</td>\n");
	}
	if (exists($show{'space'})) {
	    my $display = $id_count;
	    if ($slots{$slot}{'maxspace'}>0) {
		$display.='/'.$slots{$slot}{'maxspace'};
		if ($slots{$slot}{'maxspace'} <= $id_count) {
		    $display = '<strong>'.$display.' (full) </strong>';
		}
	    }
	    $colspan++;$r->print("<td>$display</td>\n");
	}
	if (exists($show{'ip'})) {
	    $colspan++;$r->print("<td>$slots{$slot}{'ip'}</td>\n");
	}
	if (exists($show{'symb'})) {
	    $colspan++;$r->print("<td>$title</td>\n");
	}
	if (exists($show{'allowedsections'})) {
	    $colspan++;$r->print("<td>$allowedsections</td>\n");
	}
	if (exists($show{'allowedusers'})) {
	    $colspan++;$r->print("<td>$allowedusers</td>\n");
	}
	if (exists($show{'uniqueperiod'})) {
	    $colspan++;$r->print("<td>$unique</td>\n");
	}
	if (exists($show{'scheduled'})) {
	    $colspan++;$r->print("<td>$remove_all $ids</td>\n");
	}
	$r->print("$row_end\n");
	if (exists($show{'proctor'})) {
	    $r->print(<<STUFF);
$row_start
 <td colspan="$colspan">$proctors</td>
$row_end
STUFF
        }
    }
    if ($shownheader) {
        $r->print(&Apache::loncommon::end_data_table());
    } else {
        $r->print('<p>'.&mt('No slots meet the criteria for display').'</p>');
    }
    $r->print('</form>');
    return;
}

sub manage_reservations {
    my ($r,$crstype,$slots,$consumed_uniqueperiods,$allavailable) = @_;
    my $navmap = Apache::lonnavmaps::navmap->new();
    $r->print('<p>'
             .&mt('Instructors may use a reservation system to place restrictions on when and where assignments can be worked on.')
             .'<br />'
             .&mt('One example is for management of laboratory space, which is only available at certain times, and has a limited number of seats.')
             .'</p>'
    );
    if (!defined($navmap)) {
        $r->print('<div class="LC_error">');
        if ($crstype eq 'Community') {
            $r->print(&mt('Unable to retrieve information about community contents'));
        } else {
            $r->print(&mt('Unable to retrieve information about course contents'));
        }
        $r->print('</div>');
        &Apache::lonnet::logthis('Manage Reservations - could not create navmap object in '.lc($crstype).':'.$env{'request.course.id'});
        return;
    }
    if (ref($consumed_uniqueperiods) eq 'HASH') {
        if (&Apache::lonnet::error(%$consumed_uniqueperiods)) {
            $r->print('<span class="LC_error">'.
                      &mt('An error occurred determining slot availability.').
                      '</span>');
            return;
        }
    } elsif ($consumed_uniqueperiods =~ /^error: /) {
        $r->print('<span class="LC_error">'.
                  &mt('An error occurred determining slot availability.').
                  '</span>');
        return;
    }
    my (%parent,%shownparent,%container,%container_title,%contents);
    my ($depth,$count,$reservable,$lastcontainer,$rownum) = (0,0,0,0,0);
    my @backgrounds = ("LC_odd_row","LC_even_row");
    my $numcolors = scalar(@backgrounds);
    my $location=&Apache::loncommon::lonhttpdurl("/adm/lonIcons/whitespace_21.gif");
    my $slotheader = '<p>'.
                 &mt('Your reservation status for any such assignments is listed below:').
                 '</p>'.
                 '<table class="LC_data_table LC_tableOfContent">'."\n";
    my $shownheader = 0;
    my $it=$navmap->getIterator(undef,undef,undef,1,undef,undef);
    while (my $resource = $it->next()) {
        if ($resource == $it->BEGIN_MAP()) {
            $depth++;
            $parent{$depth} = $lastcontainer;
        }
        if ($resource == $it->END_MAP()) {
            $depth--;
            $lastcontainer = $parent{$depth};
        }
        if (ref($resource)) {
            my $symb = $resource->symb();
            my $ressymb = $symb;
            $contents{$lastcontainer} ++;
            next if (!$resource->is_problem() && !$resource->is_tool() &&
                      !$resource->is_sequence() && !$resource->is_page()); 
            $count ++;
            if (($resource->is_sequence()) || ($resource->is_page())) {
                $lastcontainer = $count;
                $container{$lastcontainer} = $resource;
                $container_title{$lastcontainer} = $resource->compTitle();
            }
            if ($resource->is_problem() || $resource->is_tool()) {
                my ($useslots) = $resource->slot_control();
                next if (($useslots eq '') || ($useslots =~ /^\s*no\s*$/i));
                my ($msg,$get_choices,$slotdescription);
                my $title = $resource->compTitle();
                my $status = $resource->simpleStatus('0');
                my ($slot_status,$date,$slot_name) = $resource->check_for_slot('0');
                if ($slot_name ne '') {
                    my %slot=&Apache::lonnet::get_slot($slot_name);
                    $slotdescription=&get_description($slot_name,\%slot);
                }
                if ($slot_status == $resource->NOT_IN_A_SLOT) {
                    $msg=&mt('No current reservation.');
                    $get_choices = 1;
                } elsif ($slot_status == $resource->NEEDS_CHECKIN) {
                    $msg='<span class="LC_nobreak">'.&mt('Reserved:').
                         '&nbsp;'.$slotdescription.'</span><br />'.
                         &mt('Access requires proctor validation.');
                } elsif ($slot_status == $resource->WAITING_FOR_GRADE) {
                    $msg=&mt('Submitted and currently in grading queue.');
                } elsif ($slot_status == $resource->CORRECT) {
                    $msg=&mt('Problem is unavailable.');
                } elsif ($slot_status == $resource->RESERVED) {
                    $msg='<span class="LC_nobreak">'.&mt('Reserved:').
                         '&nbsp;'.$slotdescription.'</span><br />'.
                         &mt('Problem is currently available.');
                } elsif ($slot_status == $resource->RESERVED_LOCATION) {
                    $msg='<span class="LC_nobreak">'.&mt('Reserved:').
                         '&nbsp;'.$slotdescription.'</span><br />'.
                         &mt('Problem is available at a different location.');
                    $get_choices = 1;
                } elsif ($slot_status == $resource->RESERVED_LATER) {
                    $msg='<span class="LC_nobreak">'.&mt('Reserved:').
                         '&nbsp;'.$slotdescription.'</span><br />'.
                         &mt('Problem will be available later.');
                    $get_choices = 1;
                } elsif ($slot_status == $resource->RESERVABLE) {
                    $msg=&mt('Reservation needed');
                    $get_choices = 1;
                } elsif ($slot_status == $resource->RESERVABLE_LATER) {
                    $msg=&mt('Reservation needed: will be reservable later.');
                } elsif ($slot_status == $resource->NOTRESERVABLE) {
                    $msg=&mt('Reservation needed: none available.');
                } elsif ($slot_status == $resource->UNKNOWN) {
                    $msg=&mt('Unable to determine status due to network problems.');
                } else {
                    if ($status != $resource->OPEN) {
                        $msg = &Apache::lonnavmaps::getDescription($resource,'0'); 
                    }
                }
                $reservable ++;
                my $treelevel = $depth;
                my $higherup = $lastcontainer;
                if ($depth > 1) {
                    my @maprows;
                    while ($treelevel > 1) {
                        if (ref($container{$higherup})) {
                            my $res = $container{$higherup};
                            last if (defined($shownparent{$higherup}));
                            my $maptitle = $res->compTitle();
                            my $type = 'sequence';
                            if ($res->is_page()) {
                                $type = 'page';
                            }
                            &show_map_row($treelevel,$location,$type,$maptitle,
                                          \@maprows);
                            $shownparent{$higherup} = 1;
                        }
                        $treelevel --;
                        $higherup = $parent{$treelevel};
                    }
                    foreach my $item (@maprows) {
                        $rownum ++;
                        my $bgcolor = $backgrounds[$rownum % $numcolors];
                        if (!$shownheader) {
                            $r->print($slotheader);
                            $shownheader = 1;
                        }
                        $r->print('<tr class="'.$bgcolor.'">'.$item.'</tr>'."\n");
                    }
                }
                $rownum ++;
                my $bgcolor = $backgrounds[$rownum % $numcolors];
                if (!$shownheader) {
                    $r->print($slotheader);
                    $shownheader = 1;
                }
                $r->print('<tr class="'.$bgcolor.'"><td>'."\n");
                for (my $i=0; $i<$depth; $i++) {
                    $r->print('<img src="'.$location.'" alt="" />');
                }
                my $result = '<a href="'.$resource->src().'?symb='.$symb.'">'.
                             '<img class="LC_contentImage" src="/adm/lonIcons/';
                if ($resource->is_task()) {
                    $result .= 'task.gif" alt="'.&mt('Task');
                } else {
                    $result .= 'problem.gif" alt="'.&mt('Problem');
                }
                $result .= '" /><b>'.$title.'</b></a>'.('&nbsp;' x6).'</td>';
                my $hasaction;
                if ($status == $resource->OPEN) {
                    if ($get_choices) {
                        $hasaction = 1;
                    }
                }
                if ($hasaction) {
                    $result .= '<td valign="top">'.$msg.'</td>'.
                               '<td valign="top">';
                } else {
                    $result .= '<td colspan="2" valign="middle">'.$msg.'</td>';
                }
                $r->print($result);
                if ($hasaction) {
                    my @got_slots=&check_for_reservation($symb,'allslots');
                    if ($got_slots[0] =~ /^error: /) {
                        $r->print('<span class="LC_error">'.
                                  &mt('An error occurred determining slot availability.').
                                  '</span>');
                    } else {
                        my $formname = 'manageres_'.$reservable;
                        if (ref($allavailable) eq 'ARRAY') {
                            my @available;
                            if (ref($slots) eq 'HASH') {
                                foreach my $slot (@{$allavailable}) {
                                # not allowed for this resource
                                    if (ref($slots->{$slot}) eq 'HASH') {
                                        if ((defined($slots->{$slot}->{'symb'})) && 
                                            ($slots->{$slot}->{'symb'} ne $symb)) {
                                            next;
                                        }
                                    }
                                    push(@available,$slot);
                                }
                            }  
                            &show_choices($r,$symb,$formname,$reservable,$slots,$consumed_uniqueperiods,
                                          \@available,\@got_slots);
                        }
                    }
                    $r->print('</td>');
                }
                $r->print('</tr>');
            }
        }
    }
    if ($shownheader) {
        $r->print('</table>');
    }
    if (!$reservable) {
        $r->print('<span class="LC_info">');
        if ($crstype eq 'Community') {
            $r->print(&mt('No community items currently require a reservation to gain access.'));
        } else {
            $r->print(&mt('No course items currently require a reservation to gain access.'));
        }
        $r->print('</span>');
    }
    $r->print('<p><a href="/adm/slotrequest?command=showresv">'.
              &mt('Reservation History').'</a></p>');
}

sub show_map_row {
    my ($depth,$location,$type,$title,$maprows) = @_;
    my $output = '<td>';
    for (my $i=0; $i<$depth-1; $i++) {
        $output .= '<img src="'.$location.'" alt="" />';
    }
    if ($type eq 'page') {
        $output .= '<img src="/adm/lonIcons/navmap.page.open.gif" alt="" />&nbsp;'."\n";
    } else {
        $output .= '<img src="/adm/lonIcons/navmap.folder.open.gif" alt="" />&nbsp;'."\n";
    }
    $output .= $title.'</td><td colspan="2">&nbsp;</td>'."\n";
    unshift (@{$maprows},$output);
    return;
}

sub show_reservations {
    my ($r,$uname,$udom) = @_;
    if (!defined($uname)) {
        $uname = $env{'user.name'};
    }
    if (!defined($udom)) {
        $udom = $env{'user.domain'};
    }
    my $formname = 'slotlog';
    my $cdom = $env{'course.'.$env{'request.course.id'}.'.domain'};
    my $cnum = $env{'course.'.$env{'request.course.id'}.'.num'};
    my $crstype = &Apache::loncommon::course_type();
    my %log=&Apache::lonnet::dump('nohist_'.$cdom.'_'.$cnum.'_slotlog',$udom,$uname);
    if ($env{'form.origin'} eq 'aboutme') {
        $r->print('<div class="LC_fontsize_large">');
        my $name = &Apache::loncommon::plainname($env{'form.uname'},$env{'form.udom'},
                                                    'firstname');
        if ($crstype eq 'Community') {
            $r->print(&mt('History of member-reservable slots for: [_1]',
                          $name));
        } else {
            $r->print(&mt('History of student-reservable slots for: [_1]',
                          $name));

        }
        $r->print('</div>');
    }
    $r->print('<form action="/adm/slotrequest" method="post" name="'.$formname.'">');
    # set defaults
    my $now = time();
    my $defstart = $now - (7*24*3600); #7 days ago
    my %defaults = (
                     page           => '1',
                     show           => '10',
                     action         => 'any',
                     log_start_date => $defstart,
                     log_end_date   => $now,
                   );
    my $more_records = 0;

    # set current
    my %curr;
    foreach my $item ('show','page','action') {
        $curr{$item} = $env{'form.'.$item};
    }
    my ($startdate,$enddate) =
        &Apache::lonuserutils::get_dates_from_form('log_start_date',
                                                   'log_end_date');
    $curr{'log_start_date'} = $startdate;
    $curr{'log_end_date'} = $enddate;
    foreach my $key (keys(%defaults)) {
        if ($curr{$key} eq '') {
            $curr{$key} = $defaults{$key};
        }
    }
    my ($version) = ($r->dir_config('lonVersion') =~ /^([\d\.]+)\-/);
    $r->print(&display_filter($formname,$cdom,$cnum,\%curr,$version));
    my $showntablehdr = 0;
    my $tablehdr = &Apache::loncommon::start_data_table().
                   &Apache::loncommon::start_data_table_header_row().
                   '<th>&nbsp;</th><th>'.&mt('When').'</th><th>'.&mt('Action').'</th>'.
                   '<th>'.&mt('Description').'</th><th>'.&mt('Start time').'</th>'.
                   '<th>'.&mt('End time').'</th><th>'.&mt('Resource').'</th>'.
                   &Apache::loncommon::end_data_table_header_row();
    my ($minshown,$maxshown);
    $minshown = 1;
    my $count = 0;
    if ($curr{'show'} ne &mt('all')) {
        $maxshown = $curr{'page'} * $curr{'show'};
        if ($curr{'page'} > 1) {
            $minshown = 1 + ($curr{'page'} - 1) * $curr{'show'};
        }
    }
    my (%titles,%maptitles);
    my %lt = &reservationlog_contexts($crstype);
    foreach my $id (sort { $log{$b}{'exe_time'}<=>$log{$a}{'exe_time'} } (keys(%log))) {
        next if (($log{$id}{'exe_time'} < $curr{'log_start_date'}) ||
                 ($log{$id}{'exe_time'} > $curr{'log_end_date'}));
        if ($curr{'show'} ne &mt('all')) {
            if ($count >= $curr{'page'} * $curr{'show'}) {
                $more_records = 1;
                last;
            }
        }
        if ($curr{'action'} ne 'any') {
            next if ($log{$id}{'logentry'}{'action'} ne $curr{'action'});
        }
        $count ++;
        next if ($count < $minshown);
        if (!$showntablehdr) {
            $r->print($tablehdr);
            $showntablehdr = 1;
        }
        my $symb = $log{$id}{'logentry'}{'symb'};
        my $slot_name = $log{$id}{'logentry'}{'slot'};
        my %slot=&Apache::lonnet::get_slot($slot_name);
        my $description = $slot{'description'};
        my $start = ($slot{'starttime'}?
                     &Apache::lonlocal::locallocaltime($slot{'starttime'}):'');
        my $end = ($slot{'endtime'}?
                   &Apache::lonlocal::locallocaltime($slot{'endtime'}):'');
        my $title = &get_resource_title($symb,\%titles,\%maptitles);
        my $chgaction = $log{$id}{'logentry'}{'action'};
        if ($chgaction ne '' && $lt{$chgaction} ne '') {
            $chgaction = $lt{$chgaction};
        }
        $r->print(&Apache::loncommon::start_data_table_row().'<td>'.$count.'</td><td>'.&Apache::lonlocal::locallocaltime($log{$id}{'exe_time'}).'</td><td>'.$chgaction.'</td><td>'.$description.'</td><td>'.$start.'</td><td>'.$end.'</td><td>'.$title.'</td>'.&Apache::loncommon::end_data_table_row()."\n");
    }
    if ($showntablehdr) {
        $r->print(&Apache::loncommon::end_data_table().'<br />');
        if (($curr{'page'} > 1) || ($more_records)) {
            $r->print('<p>');
            if ($curr{'page'} > 1) {
                $r->print('<input type="button" onclick="javascript:chgPage('."'previous'".');" value="'.
                          &mt('Previous [_1] changes',$curr{'show'}).'" />');
            }
            if ($more_records) {
                $r->print('<input type="button" onclick="javascript:chgPage('."'next'".');" value="'.
                          &mt('Next [_1] changes',$curr{'show'}).'" />');
            }
            $r->print('</p>');
            $r->print(<<"ENDSCRIPT");
<script type="text/javascript">
// <![CDATA[
function chgPage(caller) {
    if (caller == 'previous') {
        document.$formname.page.value --;
    }
    if (caller == 'next') {
        document.$formname.page.value ++;
    }
    document.$formname.submit();
    return;
}
// ]]>
</script>
ENDSCRIPT
        }
    } else {
        $r->print('<span class="LC_info">'
                 .&mt('There are no transactions to display.')
                 .'</span>'
        );
    }
    $r->print('<input type="hidden" name="page" value="'.$curr{'page'}.'" />'."\n".
              '<input type="hidden" name="command" value="showresv" />'."\n");
    if ($env{'form.origin'} eq 'aboutme') {
        $r->print('<input type="hidden" name="origin" value="'.$env{'form.origin'}.'" />'."\n".
                  '<input type="hidden" name="uname" value="'.$env{'form.uname'}.'" />'."\n".
                  '<input type="hidden" name="udom" value="'.$env{'form.udom'}.'" />'."\n");
    }
    $r->print('</form>');
    return;
}

sub show_reservations_log {
    my ($r) = @_;
    my $badslot;
    my $crstype = &Apache::loncommon::course_type();
    if ($env{'form.slotname'} eq '') {
        $r->print('<div class="LC_warning">'.&mt('No slot name provided').'</div>');
        $badslot = 1;
    } else {
        my %slot=&Apache::lonnet::get_slot($env{'form.slotname'});
        if (keys(%slot) == 0) {
            $r->print('<div class="LC_warning">'.&mt('Invalid slot name: [_1]',$env{'form.slotname'}).'</div>');
            $badslot = 1;
        } elsif ($slot{type} ne 'schedulable_student') {
            my $description = &get_description($env{'form.slotname'},\%slot);
            $r->print('<div class="LC_warning">');
            if ($crstype eq 'Community') {
                $r->print(&mt('Reservation history unavailable for non-member-reservable slot: [_1].',$description));
            } else {
                $r->print(&mt('Reservation history unavailable for non-student-reservable slot: [_1].',$description));
            }
            $r->print('</div>');
            $badslot = 1;
        }
    }
    if ($badslot) {
        $r->print('<p><a href="/adm/slotrequest?command=showslots">'.
                  &mt('Return to slot list').'</a></p>');
        return;
    }
    my $formname = 'reservationslog';
    my $cdom = $env{'course.'.$env{'request.course.id'}.'.domain'};
    my $cnum = $env{'course.'.$env{'request.course.id'}.'.num'};
    my %slotlog=&Apache::lonnet::dump('nohist_slotreservationslog',$cdom,$cnum);
    if ((keys(%slotlog))[0]=~/^error\:/) { undef(%slotlog); }

    my (%log,@allsymbs);
    if (keys(%slotlog)) {
        foreach my $key (keys(%slotlog)) {
            if (ref($slotlog{$key}) eq 'HASH') {
                if (ref($slotlog{$key}{'logentry'}) eq 'HASH') {
                    if ($slotlog{$key}{'logentry'}{'slot'} eq $env{'form.slotname'}) {
                        $log{$key} = $slotlog{$key};
                        if ($slotlog{$key}{'logentry'}{'symb'} ne '') {
                            push(@allsymbs,$slotlog{$key}{'logentry'}{'symb'});
                        }
                    }
                }
            }
        }
    }

    $r->print('<form action="/adm/slotrequest" method="post" name="'.$formname.'">');
    my %saveable_parameters = ('show' => 'scalar',);
    &Apache::loncommon::store_course_settings('reservationslog',
                                              \%saveable_parameters);
    &Apache::loncommon::restore_course_settings('reservationslog',
                                                \%saveable_parameters);
    # set defaults
    my $now = time();
    my $defstart = $now - (7*24*3600); #7 days ago
    my %defaults = (
                     page           => '1',
                     show           => '10',
                     chgcontext     => 'any',
                     action         => 'any',
                     symb           => 'any',
                     log_start_date => $defstart,
                     log_end_date   => $now,
                   );
    my $more_records = 0;

    # set current
    my %curr;
    foreach my $item ('show','page','chgcontext','action','symb') {
        $curr{$item} = $env{'form.'.$item};
    }
    my ($startdate,$enddate) =
        &Apache::lonuserutils::get_dates_from_form('log_start_date',
                                                   'log_end_date');
    $curr{'log_start_date'} = $startdate;
    $curr{'log_end_date'} = $enddate;
    foreach my $key (keys(%defaults)) {
        if ($curr{$key} eq '') {
            $curr{$key} = $defaults{$key};
        }
    }
    my (%whodunit,%changed,$version);
    ($version) = ($r->dir_config('lonVersion') =~ /^([\d\.]+)\-/);

    my %slot=&Apache::lonnet::get_slot($env{'form.slotname'});
    my $description = $slot{'description'};
    $r->print('<span class="LC_fontsize_large">');
    if ($crstype eq 'Community') {
        $r->print(&mt('Reservation changes for member-reservable slot: [_1]',$description));
    } else {
        $r->print(&mt('Reservation changes for student-reservable slot: [_1]',$description));
    }
    $r->print('</span><br />');
    $r->print(&display_filter($formname,$cdom,$cnum,\%curr,$version,\@allsymbs));
    my $showntablehdr = 0;
    my $tablehdr = &Apache::loncommon::start_data_table().
                   &Apache::loncommon::start_data_table_header_row().
                   '<th>&nbsp;</th><th>'.&mt('When').'</th><th>'.&mt('Who made the change').
                   '</th><th>'.&mt('Affected User').'</th><th>'.&mt('Action').'</th>'.
                   '<th>'.&mt('Resource').'</th><th>'.&mt('Context').'</th>'.
                   &Apache::loncommon::end_data_table_header_row();
    my ($minshown,$maxshown);
    $minshown = 1;
    my $count = 0;
    if ($curr{'show'} ne &mt('all')) {
        $maxshown = $curr{'page'} * $curr{'show'};
        if ($curr{'page'} > 1) {
            $minshown = 1 + ($curr{'page'} - 1) * $curr{'show'};
        }
    }
    my %lt = &reservationlog_contexts($crstype);
    my (%titles,%maptitles);
    foreach my $id (sort { $log{$b}{'exe_time'}<=>$log{$a}{'exe_time'} } (keys(%log))) {
        next if (($log{$id}{'exe_time'} < $curr{'log_start_date'}) ||
                 ($log{$id}{'exe_time'} > $curr{'log_end_date'}));
        if ($curr{'show'} ne &mt('all')) {
            if ($count >= $curr{'page'} * $curr{'show'}) {
                $more_records = 1;
                last;
            }
        }
        if ($curr{'chgcontext'} ne 'any') {
            if ($curr{'chgcontext'} eq 'user') {
                next if (($log{$id}{'logentry'}{'context'} ne 'user') && 
                         ($log{$id}{'logentry'}{'context'} ne 'usermanage'));
            } else {
                next if ($log{$id}{'logentry'}{'context'} ne $curr{'chgcontext'});
            }
        }
        if ($curr{'action'} ne 'any') {
            next if ($log{$id}{'logentry'}{'action'} ne $curr{'action'});
        }
        if ($curr{'symb'} ne 'any') {
            next if ($log{$id}{'logentry'}{'symb'} ne $curr{'symb'});
        }
        $count ++;
        next if ($count < $minshown);
        if (!$showntablehdr) {
            $r->print($tablehdr);
            $showntablehdr = 1;
        }
        if ($whodunit{$log{$id}{'exe_uname'}.':'.$log{$id}{'exe_udom'}} eq '') {
            $whodunit{$log{$id}{'exe_uname'}.':'.$log{$id}{'exe_udom'}} =
                &Apache::loncommon::plainname($log{$id}{'exe_uname'},$log{$id}{'exe_udom'});
        }
        if ($changed{$log{$id}{'uname'}.':'.$log{$id}{'udom'}} eq '') {
            $changed{$log{$id}{'uname'}.':'.$log{$id}{'udom'}} =
                &Apache::loncommon::plainname($log{$id}{'uname'},$log{$id}{'udom'});
        }
        my $symb = $log{$id}{'logentry'}{'symb'};
        my $title = &get_resource_title($symb,\%titles,\%maptitles); 
        my $chgcontext = $log{$id}{'logentry'}{'context'};
        if ($chgcontext ne '' && $lt{$chgcontext} ne '') {
            $chgcontext = $lt{$chgcontext};
        }
        my $chgaction = $log{$id}{'logentry'}{'action'};
        if ($chgaction ne '' && $lt{$chgaction} ne '') {
            $chgaction = $lt{$chgaction}; 
        }
        $r->print(&Apache::loncommon::start_data_table_row().'<td>'.$count.'</td><td>'.&Apache::lonlocal::locallocaltime($log{$id}{'exe_time'}).'</td><td>'.$whodunit{$log{$id}{'exe_uname'}.':'.$log{$id}{'exe_udom'}}.'</td><td>'.$changed{$log{$id}{'uname'}.':'.$log{$id}{'udom'}}.'</td><td>'.$chgaction.'</td><td>'.$title.'</td><td>'.$chgcontext.'</td>'.&Apache::loncommon::end_data_table_row()."\n");
    }
    if ($showntablehdr) {
        $r->print(&Apache::loncommon::end_data_table().'<br />');
        if (($curr{'page'} > 1) || ($more_records)) {
            $r->print('<p>');
            if ($curr{'page'} > 1) {
                $r->print('<input type="button" onclick="javascript:chgPage('."'previous'".');" value="'.
                          &mt('Previous [_1] changes',$curr{'show'}).'" />');
            }
            if ($more_records) {
                $r->print('<input type="button" onclick="javascript:chgPage('."'next'".');" value="'.
                          &mt('Next [_1] changes',$curr{'show'}).'" />');
            }
            $r->print('</p>');
            $r->print(<<"ENDSCRIPT");
<script type="text/javascript">
function chgPage(caller) {
    if (caller == 'previous') {
        document.$formname.page.value --;
    }
    if (caller == 'next') {
        document.$formname.page.value ++;
    }
    document.$formname.submit();
    return;
}
</script>
ENDSCRIPT
        }
    } else {
        $r->print(&mt('There are no records to display.'));
    }
    $r->print('<input type="hidden" name="page" value="'.$curr{'page'}.'" />'.
              '<input type="hidden" name="slotname" value="'.$env{'form.slotname'}.'" />'.
              '<input type="hidden" name="command" value="slotlog" /></form>'.
              '<p><a href="/adm/slotrequest?command=showslots">'.
              &mt('Return to slot list').'</a></p>');
    return;
}

sub get_resource_title {
    my ($symb,$titles,$maptitles) = @_;
    my $title;
    if ((ref($titles) eq 'HASH') && (ref($maptitles) eq 'HASH')) { 
        if (defined($titles->{$symb})) {
            $title = $titles->{$symb};
        } else {
            $title = &Apache::lonnet::gettitle($symb);
            my $maptitle;
            my ($mapurl) = &Apache::lonnet::decode_symb($symb);
            if (defined($maptitles->{$mapurl})) {
                $maptitle = $maptitles->{$mapurl};
            } else {
                if ($mapurl eq $env{'course.'.$env{'request.course.id'}.'.url'}) {
                    $maptitle=&mt('Main Content');
                } else {
                    $maptitle=&Apache::lonnet::gettitle($mapurl);
                }
                $maptitles->{$mapurl} = $maptitle;
            }
            if ($maptitle ne '') {
                $title .= ' '.&mt('(in [_1])',$maptitle);
            }
            $titles->{$symb} = $title;
        }
    } else {
        $title = $symb;
    }
    return $title;
}

sub reservationlog_contexts {
    my ($crstype) = @_;
    my %lt = &Apache::lonlocal::texthash (
                                             any        => 'Any',
                                             user       => 'By student',
                                             manage     => 'Via Slot Manager',
                                             parameter  => 'Via Parameter Manager',
                                             reserve    => 'Made reservation',
                                             release    => 'Dropped reservation',
                                             usermanage => 'By student', 
                                         );
    if ($crstype eq 'Community') {
        $lt{'user'} = &mt('By member');
        $lt{'usermanage'} = $lt{'user'};
    }
    return %lt;
}

sub display_filter {
    my ($formname,$cdom,$cnum,$curr,$version,$allsymbs) = @_;
    my $nolink = 1;
    my (%titles,%maptitles);
    my $output = '<br /><table><tr><td valign="top">'.
                 '<span class="LC_nobreak"><b>'.&mt('Changes/page:').'</b><br />'.
                 &Apache::lonmeta::selectbox('show',$curr->{'show'},undef,
                                              (&mt('all'),5,10,20,50,100,1000,10000)).
                 '</td><td>&nbsp;&nbsp;</td>';
    my $startform =
        &Apache::lonhtmlcommon::date_setter($formname,'log_start_date',
                                            $curr->{'log_start_date'},undef,
                                            undef,undef,undef,undef,undef,undef,$nolink);
    my $endform =
        &Apache::lonhtmlcommon::date_setter($formname,'log_end_date',
                                            $curr->{'log_end_date'},undef,
                                            undef,undef,undef,undef,undef,undef,$nolink);
    my $crstype = &Apache::loncommon::course_type();
    my %lt = &reservationlog_contexts($crstype);
    $output .= '<td valign="top"><b>'.&mt('Window during which changes occurred:').
               '</b><br /><table><tr><td>'.&mt('After:').
               '</td><td>'.$startform.'</td></tr><tr><td>'.&mt('Before:').'</td><td>'.
               $endform.'</td></tr></table></td><td>&nbsp;&nbsp;</td>';
    if (ref($allsymbs) eq 'ARRAY') {
        $output .= '<td valign="top"><b>'.&mt('Resource').'</b><br />'.
                   '<select name="resource"><option value="any"';
        if ($curr->{'resource'} eq 'any') {
            $output .= ' selected="selected"';
        }
        $output .=  '>'.&mt('Any').'</option>'."\n";
        foreach my $symb (@{$allsymbs}) {
            my $title = &get_resource_title($symb,\%titles,\%maptitles);
            my $selstr = '';
            if ($curr->{'resource'} eq $symb) {
                $selstr = ' selected="selected"';
            }
            $output .= '  <option value="'.$symb.'"'.$selstr.'>'.$title.'</option>';
        }
        $output .= '</select></td><td>&nbsp;&nbsp;</td><td valign="top"><b>'.
                   &mt('Context:').'</b><br /><select name="chgcontext">';
        foreach my $chgtype ('any','user','manage','parameter') {
            my $selstr = '';
            if ($curr->{'chgcontext'} eq $chgtype) {
                $output .= $selstr = ' selected="selected"';
            }
            $output .= '<option value="'.$chgtype.'"'.$selstr.'>'.$lt{$chgtype}.'</option>'."\n";
        }
        $output .= '</select></td>';
    } else {
        $output .= '<td valign="top"><b>'.&mt('Action').'</b><br />'.
                   '<select name="action"><option value="any"';
        if ($curr->{'action'} eq 'any') {
            $output .= ' selected="selected"';
        }
        $output .=  '>'.&mt('Any').'</option>'."\n";
        foreach my $actiontype ('reserve','release') {
            my $selstr = '';
            if ($curr->{'action'} eq $actiontype) {
                $output .= $selstr = ' selected="selected"';
            }
            $output .= '<option value="'.$actiontype.'"'.$selstr.'>'.$lt{$actiontype}.'</option>'."\n";
        }
        $output .= '</select></td>';
    }
    $output .= '<td>&nbsp;&nbsp;</td></tr></table>'.
               '<p><input type="submit" value="'.
               &mt('Update Display').'" /></p>'.
               '<p class="LC_info">'.
               &mt('Only changes made from servers running LON-CAPA [_1] or later are displayed.'
                  ,'2.9.0');
    if ($version) {
        $output .= ' '.&mt('This LON-CAPA server is version [_1]',$version);
    }
    $output .= '</p><hr /><br />';
    return $output;
}

sub slot_change_messaging {
    my ($setting,$subject,$msg,$action) = @_;
    my $user = $env{'user.name'};
    my $domain = $env{'user.domain'};
    my ($message_status,$comment_status);
    if ($setting eq 'only_student'
        || $setting eq 'student_and_user_notes_screen') {
        $message_status =
            &Apache::lonmsg::user_normal_msg($user,$domain,$subject,$msg);
        $message_status = '<li>'.&mt('Sent to you: [_1]',
                                    $message_status).' </li>';
    }
    if ($setting eq 'student_and_user_notes_screen') {
        $comment_status =
            &Apache::lonmsg::store_instructor_comment($subject.'<br />'.
                                                      $msg,$user,$domain);
        $comment_status = '<li>'.&mt('Entry added to course record (viewable by instructor): [_1]',
                                    $comment_status).'</li>';
    }
    if ($message_status || $comment_status) {
        my $msgtitle;
        if ($action eq 'reserve') {
            $msgtitle = &mt('Status of messages about saved reservation');
        } elsif ($action eq 'release') {
            $msgtitle = &mt('Status of messages about dropped reservation');
        } elsif ($action eq 'nochange') {
            $msgtitle = &mt('Status of messages about unchanged existing reservation');
        }
        return '<span class="LC_info">'.$msgtitle.'</span>'
               .'<ul>'
               .$message_status
               .$comment_status
               .'</ul><hr />';
    }
}

sub upload_start {
    my ($r)=@_;    
    $r->print(
        &Apache::grades::checkforfile_js()
       .'<h2>'.&mt('Upload a file containing the slot definitions').'</h2>'
       .'<form method="post" enctype="multipart/form-data"'
       .' action="/adm/slotrequest" name="slotupload">'
       .'<input type="hidden" name="command" value="csvuploadmap" />'
       .&Apache::lonhtmlcommon::start_pick_box()
       .&Apache::lonhtmlcommon::row_title(&mt('File'))
       .&Apache::loncommon::upfile_select_html()
       .&Apache::lonhtmlcommon::row_closure()
       .&Apache::lonhtmlcommon::row_title(
            '<label for="noFirstLine">'
           .&mt('Ignore First Line')
           .'</label>')
       .'<input type="checkbox" name="noFirstLine" id="noFirstLine" />'
       .&Apache::lonhtmlcommon::row_closure(1)
       .&Apache::lonhtmlcommon::end_pick_box()
       .'<p>'
       .'<input type="button" onclick="javascript:checkUpload(this.form);"'
       .' value="'.&mt('Next').'" />'
       .'</p>'
      .'</form>'
    );
}

sub csvuploadmap_header {
    my ($r,$datatoken,$distotal)= @_;
    my $javascript;
    if ($env{'form.upfile_associate'} eq 'reverse') {
	$javascript=&csvupload_javascript_reverse_associate();
    } else {
	$javascript=&csvupload_javascript_forward_associate();
    }

    my $checked=(($env{'form.noFirstLine'})?' checked="checked"':'');
    my $ignore=&mt('Ignore First Line');
    my $buttontext = &mt('Reverse Association');

    $r->print(
        '<form method="post" enctype="multipart/form-data" action="/adm/slotrequest" name="slotupload">'
       .'<h2>'.&mt('Identify fields in uploaded list').'</h2>'
       .'<div class="LC_columnSection">'
       .&Apache::loncommon::help_open_topic(
            'Slot About',&mt('Help on slots'))
       .' '.&Apache::loncommon::help_open_topic(
            'Slot SelectingField',&mt('Help on selecting Fields'))
       ."</div>\n"
       .'<p class="LC_info">'
       .&mt('Total number of records found in file: [_1]','<b>'.$distotal.'</b>')
       ."</p>\n"
    );
    if ($distotal == 0) {
        $r->print('<p class="LC_warning">'.&mt('None found').'</p>');
    }
    $r->print(
        '<p>'
       .&mt('Enter as many fields as you can.').'<br />'
       .&mt('The system will inform you and bring you back to this page,[_1]if the data selected is insufficient to create the slots.','<br />')
       .'</p>'
    );
    $r->print(
        '<div class="LC_left_float">'
       .'<fieldset><legend>'.&mt('Functions').'</legend>'
       .'<label><input type="checkbox" name="noFirstLine"'.$checked.' />'.$ignore.'</label>'
       .' <input type="button" value="'.$buttontext
           .'" onclick="javascript:this.form.associate.value=\'Reverse Association\';submit(this.form);" />'
       .'</fieldset></div><br clear="all" />'
    );

    $r->print(<<ENDPICK);
<input type="hidden" name="associate"  value="" />
<input type="hidden" name="datatoken"  value="$datatoken" />
<input type="hidden" name="fileupload" value="$env{'form.fileupload'}" />
<input type="hidden" name="upfiletype" value="$env{'form.upfiletype'}" />
<input type="hidden" name="upfile_associate" 
                                       value="$env{'form.upfile_associate'}" />
<input type="hidden" name="command"    value="csvuploadassign" />
<script type="text/javascript" language="Javascript">
// <![CDATA[
$javascript
// ]]>
</script>
ENDPICK
    return '';

}

sub csvuploadmap_footer {
    my ($request,$i,$keyfields) =@_;
    my $buttontext = &mt('Create Slots');
    $request->print(<<ENDPICK);
<input type="hidden" name="nfields" value="$i" />
<input type="hidden" name="keyfields" value="$keyfields" />
<input type="button" onclick="javascript:verify(this.form)" value="$buttontext" /><br />
</form>
ENDPICK
}

sub csvupload_javascript_reverse_associate {
    my $error1=&mt('You need to specify the name, start time, end time and a type.');
    return(<<ENDPICK);
  function verify(vf) {
    var foundstart=0;
    var foundend=0;
    var foundname=0;
    var foundtype=0;
    for (i=0;i<=vf.nfields.value;i++) {
      tw=eval('vf.f'+i+'.selectedIndex');
      if (i==0 && tw!=0) { foundname=1; }
      if (i==1 && tw!=0) { foundtype=1; }
      if (i==2 && tw!=0) { foundstat=1; }
      if (i==3 && tw!=0) { foundend=1; }
    }
    if (foundstart==0 && foundend==0 && foundtype==0 && foundname==0) {
	alert('$error1');
	return;
    }
    vf.submit();
  }
  function flip(vf,tf) {
  }
ENDPICK
}

sub csvupload_javascript_forward_associate {
    my $error1=&mt('You need to specify the name, start time, end time and a type.');
  return(<<ENDPICK);
  function verify(vf) {
    var foundstart=0;
    var foundend=0;
    var foundname=0;
    var foundtype=0;
    for (i=0;i<=vf.nfields.value;i++) {
      tw=eval('vf.f'+i+'.selectedIndex');
      if (tw==1) { foundname=1; }
      if (tw==2) { foundtype=1; }
      if (tw==3) { foundstat=1; }
      if (tw==4) { foundend=1; }
    }
    if (foundstart==0 && foundend==0 && foundtype==0 && foundname==0) {
	alert('$error1');
	return;
    }
    vf.submit();
  }
  function flip(vf,tf) {
  }
ENDPICK
}

sub csv_upload_map {
    my ($r)= @_;

    my $datatoken;
    if (!$env{'form.datatoken'}) {
	$datatoken=&Apache::loncommon::upfile_store($r);
    } else {
        $datatoken=&Apache::loncommon::valid_datatoken($env{'form.datatoken'});
        if ($datatoken ne '') {
            &Apache::loncommon::load_tmp_file($r,$datatoken);
        }
    }
    my @records=&Apache::loncommon::upfile_record_sep();
    if ($env{'form.noFirstLine'}) { shift(@records); }
    &csvuploadmap_header($r,$datatoken,$#records+1);
    my ($i,$keyfields);
    if (@records) {
	my @fields=&csvupload_fields();

	if ($env{'form.upfile_associate'} eq 'reverse') {	
	    &Apache::loncommon::csv_print_samples($r,\@records);
	    $i=&Apache::loncommon::csv_print_select_table($r,\@records,
							  \@fields);
	    foreach (@fields) { $keyfields.=$_->[0].','; }
	    chop($keyfields);
	} else {
	    unshift(@fields,['none','']);
	    $i=&Apache::loncommon::csv_samples_select_table($r,\@records,
							    \@fields);
	    my %sone=&Apache::loncommon::record_sep($records[0]);
	    $keyfields=join(',',sort(keys(%sone)));
	}
    }
    &csvuploadmap_footer($r,$i,$keyfields);

    return '';
}

sub csvupload_fields {
    return (['name','Slot name'],
	    ['type','Type of slot'],
	    ['starttime','Start Time of slot'],
	    ['endtime','End Time of slot'],
	    ['startreserve','Reservation Start Time'],
            ['endreserve','Reservation End Time'],
            ['reservationmsg','Message when reservation changed'],
	    ['ip','IP or DNS restriction'],
	    ['proctor','List of proctor ids'],
	    ['description','Slot Description'],
	    ['maxspace','Maximum number of reservations'],
	    ['symb','Resource Restriction'],
	    ['uniqueperiod','Date range of slot exclusion'],
	    ['secret','Secret word proctor uses to validate'],
	    ['allowedsections','Sections slot is restricted to'],
	    ['allowedusers','Users slot is restricted to'],
	    );
}

sub csv_upload_assign {
    my ($r,$mgr)= @_;
    my $datatoken = &Apache::loncommon::valid_datatoken($env{'form.datatoken'});
    if ($datatoken ne '') {
        &Apache::loncommon::load_tmp_file($r,$datatoken);
    }
    my @slotdata = &Apache::loncommon::upfile_record_sep();
    if ($env{'form.noFirstLine'}) { shift(@slotdata); }
    my %fields=&Apache::grades::get_fields();
    $r->print('<h3>'.&mt('Creating Slots').'</h3>');
    my $cname=$env{'course.'.$env{'request.course.id'}.'.num'};
    my $cdom=$env{'course.'.$env{'request.course.id'}.'.domain'};
    my $countdone=0;
    my @errors;
    foreach my $slot (@slotdata) {
	my %slot;
	my %entries=&Apache::loncommon::record_sep($slot);
	my $domain;
	my $name=$entries{$fields{'name'}};
	if ($name=~/^\s*$/) {
	    push(@errors,"Did not create slot with no name");
	    next;
	}
	if ($name=~/\s/) { 
	    push(@errors,"$name not created -- Name must not contain spaces");
	    next;
	}
	if ($name=~/\W/) { 
	    push(@errors,"$name not created -- Name must contain only letters, numbers and _");
	    next;
	}
	if ($entries{$fields{'type'}}) {
	    $slot{'type'}=$entries{$fields{'type'}};
	} else {
	    $slot{'type'}='preassigned';
	}
	if ($slot{'type'} ne 'preassigned' &&
	    $slot{'type'} ne 'schedulable_student') {
	    push(@errors,"$name not created -- invalid type ($slot{'type'}) must be either preassigned or schedulable_student");
	    next;
	}
	if ($entries{$fields{'starttime'}}) {
	    $slot{'starttime'}=&UnixDate($entries{$fields{'starttime'}},"%s");
	}
	if ($entries{$fields{'endtime'}}) {
	    $slot{'endtime'}=&UnixDate($entries{$fields{'endtime'}},"%s");
	}

	# start/endtime must be defined and greater than zero
	if (!$slot{'starttime'}) {
	    push(@errors,"$name not created -- Invalid start time");
	    next;
	}
	if (!$slot{'endtime'}) {
	    push(@errors,"$name not created -- Invalid end time");
	    next;
	}
	if ($slot{'starttime'} > $slot{'endtime'}) {
	    push(@errors,"$name not created -- Slot starts after it ends");
	    next;
	}

	if ($entries{$fields{'startreserve'}}) {
            my $date = &UnixDate($entries{$fields{'startreserve'}},"%s");
            if ($date eq '') {
                push(@errors,"$name -- No reservation start time set for slot -- value provided had invalid format");
            } else {
                $slot{'startreserve'} = $date;
            }
	}
	if (defined($slot{'startreserve'})
	    && $slot{'startreserve'} > $slot{'starttime'}) {
	    push(@errors,"$name not created -- Slot's reservation start time is after the slot's start time.");
	    next;
	}

        if ($entries{$fields{'endreserve'}}) {
            my $date = &UnixDate($entries{$fields{'endreserve'}},"%s");
            if ($date eq '') {
                push(@errors,"$name -- No reservation end time set for slot -- value provided had invalid format");
            } else {
                $slot{'endreserve'} = $date;
            }
        }
        if (defined($slot{'endreserve'})
            && $slot{'endreserve'} > $slot{'starttime'}) {
            push(@errors,"$name not created -- Slot's reservation end time is after the slot's start time.");
            next;
        }

        if ($slot{'type'} eq 'schedulable_student') {
            if ($entries{$fields{'reservationmsg'}}) {
                 if (($entries{$fields{'reservationmsg'}} eq 'only_student') ||
                     ($entries{$fields{'reservationmsg'}} eq 'student_and_user_notes_screen')) {
                      $slot{'reservationmsg'}=$entries{$fields{'reservationmsg'}};
                 } else {
                      unless (($entries{$fields{'reservationmsg'}} eq 'none') ||
                              ($entries{$fields{'reservationmsg'}} eq '')) {
                          push(@errors,"$name -- Slot's reservationmsg setting ignored - not one of: 'only_student', 'student_and_user_notes_screen', 'none' or ''");
                      }
                 }
            }
        }

	foreach my $key ('ip','proctor','description','maxspace',
			 'secret','symb') {
	    if ($entries{$fields{$key}}) {
		$slot{$key}=$entries{$fields{$key}};
                if ($key eq 'maxspace') {
                    $slot{$key} =~ s/\D+//g;
                }
	    }
	}
        if ($entries{$fields{'allowedusers'}}) {
            $entries{$fields{'allowedusers'}} =~ s/^\s+//;
            $entries{$fields{'allowedusers'}} =~ s/\s+$//;
            my @allowedusers;
            foreach my $poss (split(/\s*,\s*/,$entries{$fields{'allowedusers'}})) {
                my ($possuname,$possudom) = split(/:/,$poss);
                if (($possuname =~ /^$match_username$/) && ($possudom =~ /^$match_domain$/)) {
                    unless (grep(/^\Q$poss\E$/,@allowedusers)) {
                        push(@allowedusers,$poss);
                    }
                }
            }
            if (@allowedusers > 0) {
                $slot{'allowedusers'} = join(',',@allowedusers);
            }
        }
        if ($entries{$fields{'allowedsections'}}) {
            $entries{$fields{'allowedsections'}} =~ s/^\s+//;
            $entries{$fields{'allowedsections'}} =~ s/\s+$//;
            my @allowedsections;
            foreach my $poss (split(/\s*,\s*/,$entries{$fields{'allowedsections'}})) {
                if (($poss !~ /\W/) && ($poss ne 'none')) {
                    unless (grep(/^\Q$poss\E$/,@allowedsections)) {
                        push(@allowedsections,$poss);
                    }
                }
            }
            if (@allowedsections > 0) {
                $slot{'allowedsections'} = join(',',@allowedsections);
            }
        }
	if ($entries{$fields{'uniqueperiod'}}) {
            my ($start,$end)= map { &UnixDate($_,"%s"); } split(',',$entries{$fields{'uniqueperiod'}});
            if (($start ne '') && ($end ne '')) {
                $slot{'uniqueperiod'}=[$start,$end];
            } else {
                push(@errors,"$name -- Slot's unique period ignored -- one or both of the comma separated values for start and end had an invalid format");
            }
	}
	if (ref($slot{'uniqueperiod'}) eq 'ARRAY' 
	    && $slot{'uniqueperiod'}[0] > $slot{'uniqueperiod'}[1]) {
	    push(@errors,"$name not created -- Slot's unique period start time is later than the unique period's end time.");
	    next;
	}

	&Apache::lonnet::cput('slots',{$name=>\%slot},$cdom,$cname);
	$r->print('.');
	$r->rflush();
	$countdone++;
    }
    if ($countdone) {
        &Apache::lonnet::devalidate_slots_cache($cname,$cdom); 
    }
    $r->print('<p>'.&mt('Created [quant,_1,slot]',$countdone)."\n".'</p>');
    foreach my $error (@errors) {
	$r->print('<p><span class="LC_warning">'.$error.'</span></p>'."\n");
    }
    &show_table($r,$mgr);
    return '';
}

sub slot_command_titles {
    my %titles = (
                 slotlog            => 'Reservation Logs',
                 showslots          => 'Manage Slots',
                 showresv           => 'Reservation History',
                 manageresv         => 'Manage Reservations',
                 uploadstart        => 'Upload Slots File',
                 csvuploadmap       => 'Upload Slots File',
                 csvuploadassign    => 'Upload Slots File',
                 delete             => 'Slot Deletion',
                 release            => 'Reservation Result',
                 remove_reservation => 'Remove Registration',
                 get_reservation    => 'Request Reservation',
              );
    return %titles;
}

sub slot_reservationmsg_options {
    my %options = &Apache::lonlocal::texthash (
                        only_student  => 'Sent to student',
        student_and_user_notes_screen => 'Sent to student and added to user notes',
                                 none => 'None sent and no record in user notes',
    );
    return %options;
}

sub handler {
    my $r=shift;

    &Apache::loncommon::content_type($r,'text/html');
    &Apache::loncommon::no_cache($r);
    if ($r->header_only()) {
	$r->send_http_header();
	return OK;
    }

    &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'});

    my %crumb_titles = &slot_command_titles();
    my ($brcrum,$bread_crumbs_component);

    my $vgr=&Apache::lonnet::allowed('vgr',$env{'request.course.id'});
    my $mgr=&Apache::lonnet::allowed('mgr',$env{'request.course.id'});
    my (%slots,$consumed_uniqueperiods);
    if ($env{'form.command'} eq 'showslots') {
        if (($vgr ne 'F') && ($mgr ne 'F')) {
            $env{'form.command'} = 'manageresv'; 
        }
    } elsif ($env{'form.command'} eq 'manageresv') {
        if (($vgr eq 'F') || ($mgr eq 'F')) {
            $env{'form.command'} = 'showslots';
        }
    }
    my $title='Requesting Another Worktime';
    if ($env{'form.command'} eq 'showresv') {
        $title = 'Reservation History';
        if ($env{'form.origin'} eq 'aboutme') {
            $brcrum =[{href=>"/adm/$env{'form.udom'}/$env{'form.uname'}/aboutme",text=>'Personal Information Page'}];
        } else {
            $brcrum =[{href=>"/adm/slotrequest?command=manageresv",text=>'Manage Reservations'}];
        }
        if (ref($brcrum) eq 'ARRAY') {
            push(@{$brcrum},{href=>"/adm/slotrequest?command=showresv",text=>$title});
        }
    } elsif (($env{'form.requestattempt'}) || ($env{'form.command'} eq 'manageresv')) {  
        if ($env{'form.command'} eq 'manageresv') {
            $title = 'Manage Reservations';
            $brcrum =[{href=>"/adm/slotrequest?command=manageresv",text=>$title}];
        }
        my ($cnum,$cdom)=&get_course();
        %slots = &Apache::lonnet::get_course_slots($cnum,$cdom);
        $consumed_uniqueperiods = &get_consumed_uniqueperiods(\%slots);
    } elsif ($vgr eq 'F') {
        if ($env{'form.command'} =~ /^(slotlog|showslots|uploadstart|csvuploadmap|csvuploadassign|delete|release|remove_registration)$/) {
            $brcrum =[{href=>"/adm/slotrequest?command=showslots",
                       text=>$crumb_titles{'showslots'},
                       help=>'Slot_Use'}];
	    $title = 'Managing Slots';
            $bread_crumbs_component = 'Slots';
            unless ($env{'form.command'} eq 'showslots') {
                if (ref($brcrum) eq 'ARRAY') {
                    push(@{$brcrum},{href=>"/adm/slotrequest?command=$env{'form.command'}",text=>$crumb_titles{$env{'form.command'}}});
                }
            }
        }
    } elsif ($env{'form.command'} eq 'release') {
        if ($env{'form.context'} eq 'usermanage') {
            $brcrum =[{href=>"/adm/slotrequest?command=manageresv",
                       text=>$crumb_titles{'showslots'}}];
            $title = 'Manage Reservations';
            if (ref($brcrum) eq 'ARRAY') {
                push(@{$brcrum},{href=>"/adm/slotrequest?command=$env{'form.command'}",text=>$crumb_titles{$env{'form.command'}}});
            }
        }
    } else {
        $brcrum =[];
    }
    my ($symb,$js,$available,$allavailable,$got_slots);
    $available = [];
    if ($env{'form.requestattempt'}) {
        $symb=&unescape($env{'form.symb'});
        @{$got_slots}=&check_for_reservation($symb,'allslots');
    }
    if (($env{'form.requestattempt'}) || ($env{'form.command'} eq 'manageresv')) {
        $js = &reservation_js(\%slots,$consumed_uniqueperiods,$available,$got_slots,$symb);
    }
    &start_page($r,$title,$brcrum,$bread_crumbs_component,$js,$mgr);

    if ($env{'form.command'} eq 'manageresv') {
        $allavailable = $available;
        undef($available);
        undef($got_slots);
        my $crstype = &Apache::loncommon::course_type();
        &manage_reservations($r,$crstype,\%slots,$consumed_uniqueperiods,$allavailable);
    } elsif ($env{'form.command'} eq 'showresv') {
        &show_reservations($r,$env{'form.uname'},$env{'form.udom'});
    } elsif ($env{'form.command'} eq 'showslots' && $vgr eq 'F') {
	&show_table($r,$mgr);
    } elsif ($env{'form.command'} eq 'remove_registration' && $mgr eq 'F') {
	&remove_registration($r);
    } elsif ($env{'form.command'} eq 'release' && $mgr eq 'F') {
	if ($env{'form.entry'} eq 'remove all') {
	    &release_all_slot($r,$mgr);
	} else {
	    &release_slot($r,undef,undef,undef,$mgr);
	}
    } elsif ($env{'form.command'} eq 'delete' && $mgr eq 'F') {
	&delete_slot($r);
    } elsif ($env{'form.command'} eq 'uploadstart' && $mgr eq 'F') {
	&upload_start($r);
    } elsif ($env{'form.command'} eq 'csvuploadmap' && $mgr eq 'F') {
	&csv_upload_map($r);
    } elsif ($env{'form.command'} eq 'csvuploadassign' && $mgr eq 'F') {
	if ($env{'form.associate'} ne 'Reverse Association') {
	    &csv_upload_assign($r,$mgr);
	} else {
	    if ( $env{'form.upfile_associate'} ne 'reverse' ) {
		$env{'form.upfile_associate'} = 'reverse';
	    } else {
		$env{'form.upfile_associate'} = 'forward';
	    }
	    &csv_upload_map($r);
	}
    } elsif (($env{'form.command'} eq 'slotlog') && ($vgr eq 'F')) {
        &show_reservations_log($r);
    } else {
	my $symb=&unescape($env{'form.symb'});
	if (!defined($symb)) {
	    &fail($r,'not_valid');
	    return OK;
	}
	my (undef,undef,$res)=&Apache::lonnet::decode_symb($symb);
	my $useslots = &Apache::lonnet::EXT("resource.0.useslots",$symb);
	if ($useslots ne 'resource' 
	    && $useslots ne 'map' 
	    && $useslots ne 'map_map') {
	    &fail($r,'not_available');
	    return OK;
	}
	$env{'request.symb'}=$symb;
	my $type = ($res =~ /\.task$/) ? 'Task'
	                               : 'problem';
	my ($status) = &Apache::lonhomework::check_slot_access('0',$type);
	if ($status eq 'CAN_ANSWER' ||
	    $status eq 'NEEDS_CHECKIN' ||
	    $status eq 'WAITING_FOR_GRADE') {
	    &fail($r,'not_allowed');
	    return OK;
	}
	if ($env{'form.requestattempt'}) {
            $r->print('<div class="LC_left_float">'); 
	    &show_choices($r,$symb,undef,undef,\%slots,$consumed_uniqueperiods,$available,$got_slots);
            $r->print('</div><div style="padding:0;clear:both;margin:0;border:0"></div>');
	} elsif ($env{'form.command'} eq 'release') {
	    &release_slot($r,$symb);
	} elsif ($env{'form.command'} eq 'get') {
	    &get_slot($r,$symb);
	} elsif ($env{'form.command'} eq 'change') {
            if ($env{'form.nochange'}) {
                my $slot_name = $env{'form.releaseslot'};
                my @slots = &check_for_reservation($symb,'allslots');
                my $msg;
                if (($slot_name ne '') && (grep(/^\Q$slot_name\E/,@slots))) { 
                     my %slot=&Apache::lonnet::get_slot($env{'form.releaseslot'});
                     my $description=&get_description($slot_name,\%slot);
                     $msg = '<span style="font-weight: bold;">'.
                            &mt('Unchanged reservation: [_1]',$description).'</span><br /><br />';
                     my $person = 
                         &Apache::loncommon::plainname($env{'user.name'},$env{'user.domain'});
                     my $subject = &mt('Reservation unchanged: [_1]',$description);
                     my $msgbody = &mt('No change to existing registration by [_1] for [_2].',$person,$description);
                     $msg .= &slot_change_messaging($slot{'reservationmsg'},$subject,$msgbody,'nochange');
                } else {
                    $msg = '<span class="LC_warning">'.&mt('Reservation no longer reported as available.').'</span>';
                }
                $r->print($msg);
                &return_link($r);
	    } elsif (&get_slot($r,$symb,$env{'form.releaseslot'},1)) {
		&release_slot($r,$symb,$env{'form.releaseslot'});
	    }
	} else {
	    $r->print('<p>'.&mt('Unknown command: [_1]',$env{'form.command'}).'</p>');
	}
    }
    &end_page($r);
    return OK;
}

1;
__END__