# The LearningOnline Network with CAPA
# Navigate Maps Handler
#
# $Id: lonnavdisplay.pm,v 1.10 2009/05/06 16:19:34 bisitz 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::lonnavdisplay;

use strict;
use Apache::Constants qw(:common :http);
use Apache::lonmenu();
use Apache::loncommon();
use Apache::lonnavmaps();
use Apache::lonhtmlcommon();
use Apache::lonnet;
use Apache::lonlocal;
use Time::HiRes qw( gettimeofday tv_interval );

sub handler {
    my $r = shift;
    real_handler($r);
}

sub real_handler {
    my $r = shift;
    #my $t0=[&gettimeofday()];
    # Handle header-only request
    if ($r->header_only) {
        if ($env{'browser.mathml'}) {
            &Apache::loncommon::content_type($r,'text/xml');
        } else {
            &Apache::loncommon::content_type($r,'text/html');
        }
        $r->send_http_header;
        return OK;
    }

    # Send header, don't cache this page
    if ($env{'browser.mathml'}) {
        &Apache::loncommon::content_type($r,'text/xml');
    } else {
        &Apache::loncommon::content_type($r,'text/html');
    }
    &Apache::loncommon::no_cache($r);

    my %toplinkitems=();
    &Apache::lonnavmaps::add_linkitem(\%toplinkitems,'blank','',
				      "Select Action");
    if ($ENV{QUERY_STRING} eq 'collapseExternal') {
	&Apache::lonnet::put('environment',{'remotenavmap' => 'off'});
	&Apache::lonnet::appenv({'environment.remotenavmap' => 'off'});
	my $menu=&Apache::lonmenu::reopenmenu();
	my $navstatus=&Apache::lonmenu::get_nav_status();
	if ($menu) {
	    $menu=(<<MENU)
             swmenu=$menu
             swmenu.clearTimeout(swmenu.menucltim);
	     $navstatus
MENU
        } else {
	    my $nothing = &Apache::lonhtmlcommon::javascript_nothing();
	    my $mainwindow='window.open('.$nothing.',"loncapaclient","",false);';
	    $menu=(<<MENU)
             swmenu=$mainwindow
	     $navstatus
MENU
	}
        $r->send_http_header;
	my $js =<<"ENDSUBM";
	  <script type="text/javascript">
 	    function submitthis() {
		    $menu
		    self.close();
	    }
	
  	  </script>
ENDSUBM
        $r->print(&Apache::loncommon::start_page(undef,$js,
						 {'only_body' => 1,
						  'bgcolor'   => '#FFFFFF',
						  'add_entries' => 
						      {'onload' =>
							   "submitthis()"}}).
		  &Apache::loncommon::end_page());

        return OK;
    }
    if ($ENV{QUERY_STRING} =~ /^launchExternal/) {
	&Apache::lonnet::put('environment',{'remotenavmap' => 'on'});
	&Apache::lonnet::appenv({'environment.remotenavmap' => 'on'});
 	my $menu=&Apache::lonmenu::reopenmenu();
	my $navstatus=&Apache::lonmenu::get_nav_status();
	if ($menu) {
	    $r->print(<<MENU);
             <script type="text/javascript">
             swmenu=$menu
             swmenu.clearTimeout(swmenu.menucltim);
	     $navstatus
             </script>
MENU
        }
   }
    if ($ENV{QUERY_STRING} eq 'turningOffExternal') {
	$env{'environment.remotenavmap'}='off';
    }

    # Create the nav map
    my $navmap = Apache::lonnavmaps::navmap->new();

    if (!defined($navmap)) {
        my $requrl = $r->uri;
        $env{'user.error.msg'} = "$requrl:bre:0:0:Course not initialized";
        $env{'user.reinit'} = 1;
        return HTTP_NOT_ACCEPTABLE;
    }
    $r->send_http_header;

# ------------------------------------------------------------ Get query string
    &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},['register','sort','showOnlyHomework','postsymb']);
    
# ----------------------------------------------------- Force menu registration
    my $body_only='';
    my $js;
    if ($env{'environment.remotenavmap'} eq 'on') {
	$js='<script type="text/javascript">
                function collapse() {
                   this.document.location="/adm/navmaps?collapseExternal";
                }
             </script>';
	$body_only=1;
    }

    # Header
    my $course_type = &Apache::loncommon::course_type();
    $r->print(&Apache::loncommon::start_page(#'Navigate '.$course_type.
					     'Course Contents',
					     $js,
					     {'only_body'       => $body_only,
					      'force_register'  =>
						  $env{'form.register'},}));
    $r->print('<script type="text/javascript">window.focus();</script>');
     
    $r->rflush();

    # Check that it's defined
    if (!($navmap->courseMapDefined())) {
	$r->print(&Apache::loncommon::help_open_menu('Navigation Screen','Navigation_Screen',undef,'RAT'));
        $r->print('<span class="LC_error">'.&mt('Coursemap undefined.').
		  '</span>' .
                  &Apache::loncommon::end_page());
        return OK;
    }

    # See if there's only one map in the top-level, if we don't
    # already have a filter... if so, automatically display it
    # (older code; should use retrieveResources)
    if ($ENV{QUERY_STRING} !~ /filter/) {
        my $iterator = $navmap->getIterator(undef, undef, undef, 0);
        my $curRes;
        my $sequenceCount = 0;
        my $sequenceId;
        while ($curRes = $iterator->next()) {
            if (ref($curRes) && $curRes->is_sequence()) {
                $sequenceCount++;
                $sequenceId = $curRes->map_pc();
            }
        }
        
        if ($sequenceCount == 1) {
            # The automatic iterator creation in the render call 
            # will pick this up. We know the condition because
            # the defined($env{'form.filter'}) also ensures this
            # is a fresh call.
            $env{'form.filter'} = "$sequenceId";
        }
    }

    if ($ENV{QUERY_STRING} eq 'launchExternal') {
	$r->print('
          <form name="returnwin" action="/adm/flip?postdata=navlaunch%3a" 
                method="post" target="loncapaclient">
          </form>');
	$r->print('
          <script type="text/javascript">
              this.document.returnwin.submit();
          </script>');
    }

    if ($env{'environment.remotenavmap'} ne 'on') {
	$r->print(&launch_win('link','yes',\%toplinkitems));
    } 
    if ($env{'environment.remotenavmap'} eq 'on') {
	&Apache::lonnavmaps::add_linkitem(\%toplinkitems,'closenav',
					  'collapse()',
					  "Close navigation window");
    } 


    # Check to see if the student is jumping to next open, do-able problem
    if ($ENV{QUERY_STRING} =~ /^jumpToFirstHomework/) {
        # Find the next homework problem that they can do.
        my $iterator = $navmap->getIterator(undef, undef, undef, 1);
        my $curRes;
        my $foundDoableProblem = 0;
        my $minimumduedate;
        my $now = time();
	
        while ($curRes = $iterator->next()) {
            if (ref($curRes) && $curRes->is_problem()) {
                my $status = $curRes->status();
		my $thisduedate=$curRes->duedate();
                if ($thisduedate > $now 
		    && $curRes->completable()) {
                        
                    $foundDoableProblem = 1;

                    if (!defined($minimumduedate)
                        || $thisduedate<$minimumduedate) {
			# Pop open all previous maps
			my $stack = $iterator->getStack();
			pop @$stack; # last resource in the stack is the problem
			# itself, which we don't need in the map stack
			my @mapPcs = map {$_->map_pc()} @$stack;
			$env{'form.filter'} = join(',', @mapPcs);
			
			# Mark as both "here" and "jump"
			$env{'form.postsymb'} = $curRes->symb();
                        $minimumduedate=$thisduedate;
		    }
                }
            }
        }

        # If we found no problems, print a note to that effect.
        if (!$foundDoableProblem) {
            $r->print("<span class=\"LC_info\">"
                     .&mt("All homework assignments have been completed.")
                     ."</span>");
        }
    } else {
	&Apache::lonnavmaps::add_linkitem(\%toplinkitems,'firsthomework',
					  'location.href="navmaps?jumpToFirstHomework"',
					  "Show my first due problem");
    }

    my $suppressEmptySequences = 0;
    my $filterFunc = undef;
    my $resource_no_folder_link = 0;

    # Display only due homework.
    my $showOnlyHomework = 0;
    if ($env{'form.showOnlyHomework'} eq "1") {
        $showOnlyHomework = 1;
        $suppressEmptySequences = 1;
        $filterFunc = sub { my $res = shift; 
                            return $res->completable() || $res->is_map();
                        };
	&Apache::lonnavmaps::add_linkitem(\%toplinkitems,'everything',
					  'location.href="navmaps?sort='.$env{'form.sort'}.'"',
					  "Show everything");
        $r->print("<span class=\"LC_info\">".&mt("Uncompleted Problems")."</span>");
        $env{'form.filter'} = '';
        $env{'form.condition'} = 1;
	$resource_no_folder_link = 1;
    } else {
	&Apache::lonnavmaps::add_linkitem(\%toplinkitems,'uncompleted',
					  'location.href="navmaps?sort='.$env{'form.sort'}.
					  '&showOnlyHomework=1"',
					  "Show only uncompleted problems");
    }

    my %selected=($env{'form.sort'} => ' selected="selected"');
    my $sort_html=("<form name=\"sortForm\">
                 <span class=\"LC_nobreak\">
                    <input type=\"hidden\" name=\"showOnlyHomework\" value=\"".$env{'form.showOnlyHomework'}."\" />
                    ".&mt('Sort by:')."
                    <select name=\"sort\" onChange=\"document.sortForm.submit()\">
                       <option value=\"default\"$selected{'default'}>".&mt('Default')."</option>
                       <option value=\"title\"$selected{'title'}  >".&mt('Title')."</option>
                       <option value=\"duedate\"$selected{'duedate'}>".&mt('Duedate')."</option>
                       <option value=\"discussion\"$selected{'discussion'}>".&mt('Has New Discussion')."</option>
                    </select>
                 </span>
               </form>");
    # renderer call
    my $renderArgs = { 'cols' => [0,1,2,3],
		       'sort' => $env{'form.sort'},
                       'url' => '/adm/navmaps',
                       'navmap' => $navmap,
                       'suppressNavmap' => 1,
                       'suppressEmptySequences' => $suppressEmptySequences,
                       'filterFunc' => $filterFunc,
		       'resource_no_folder_link' => $resource_no_folder_link,
		       'sort_html'=> $sort_html,
                       'r' => $r,
                       'caller' => 'navmapsdisplay',
                       'linkitems' => \%toplinkitems};
    my $render = &Apache::lonnavmaps::render($renderArgs);

    # If no resources were printed, print a reassuring message so the
    # user knows there was no error.
    if ($renderArgs->{'counter'} == 0) {
        if ($showOnlyHomework) {
            $r->print("<p><span class=\"LC_info\">".&mt("All homework is currently completed.")."</span></p>");
        } else { # both jumpToFirstHomework and normal use the same: course must be empty
            $r->print("<p><span class=\"LC_info\">".&mt("This course is empty.")."</span></p>");
        }
    }
    #my $td=&tv_interval($t0);
    #$r->print("<br />$td");

    $r->print(&Apache::loncommon::end_page());
    $r->rflush();

    return OK;
}

sub launch_win {
    my ($mode,$script,$toplinkitems,$firsttime)=@_;
    my $result;
    if ($script ne 'no') {
	$result.='<script type="text/javascript">';
    }
    if ($firsttime) {
	$result.='function launch_navmapwin() {
                 newWindow=open(\'/adm/navmaps?launchExternalRoles\',\'loncapanav\',\'width=400,height=600,scrollbars=1\');
               }';
    } else {
	$result.='function launch_navmapwin() {
                 newWindow=open(\'/adm/navmaps?launchExternal\',\'loncapanav\',\'width=400,height=600,scrollbars=1\');
               }';
    }
    if ($mode eq 'now') {
	$result.="\nlaunch_navmapwin();\n";
    }
    if ($script ne 'no') {
	$result.='</script>';
    }
    if ($mode eq 'link') {
	&Apache::lonnavmaps::add_linkitem($toplinkitems,'launchnav',
					  'launch_navmapwin()',
					  "Launch navigation window");
    }
    return $result;
}

1;
__END__