# The LearningOnline Network
# Re-launch guidance for deep linked access with username mismatch
#
# $Id: lonrelaunch.pm,v 1.4 2022/08/24 20:58:50 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::lonrelaunch;

use strict;
use lib '/home/httpd/lib/perl/';
use Apache::Constants qw(:common :http REDIRECT);
use Apache::lonnet;
use Apache::loncommon();
use Apache::lonlocal;
use LONCAPA qw(:DEFAULT :match);
use CGI::Cookie();

sub handler {
    my $r = shift;

    my %data;
    if ($r->args) {
        &Apache::loncommon::get_unprocessed_cgi($r->args,['rtoken']);
        if (exists($env{'form.rtoken'})) {
            %data = &Apache::lonnet::tmpget($env{'form.rtoken'});
        }
    }
    my $handle = &Apache::lonnet::check_for_valid_session($r);
    if ($handle ne '') {
        my $lonidsdir=$r->dir_config('lonIDsDir');
        &Apache::lonnet::transfer_profile_to_env($lonidsdir,$handle);
        if (unlink("$lonidsdir/$handle.id")) {
            if (($env{'user.linkedenv'} =~ /^[a-f0-9]+_linked$/) &&
                (-l "$lonidsdir/$env{'user.linkedenv'}.id") &&
                (readlink("$lonidsdir/$env{'user.linkedenv'}.id") eq "$lonidsdir/$handle.id")) {
                unlink("$lonidsdir/$env{'user.linkedenv'}.id");
            }
        }
        my %temp=('logout' => time);
        my $ip = &Apache::lonnet::get_requestor_ip();
        &Apache::lonnet::put('email_status',\%temp);
        &Apache::lonnet::log($env{'user.domain'},
                             $env{'user.name'},
                             $env{'user.home'},
                             "Logout $ip");
        #expire the cookies
        my %cookies=CGI::Cookie->parse($r->header_in('Cookie'));
        foreach my $name (keys(%cookies)) {
            next unless ($name =~ /^lon(|S|Link|Pub)ID$/);
            my $c = new CGI::Cookie(-name    => $name,
                                    -value   => '',
                                    -expires => '-10y',);
            $r->headers_out->add('Set-cookie' => $c);
        }
    }
    if (!$Apache::lonlocal::lh) {
        &Apache::lonlocal::get_language_handle($r);
    }
    &Apache::loncommon::content_type($r,'text/html');
    $r->send_http_header;
    return OK if $r->header_only;

    if ((keys(%data)) && ($data{'origurl'} =~ m{^/tiny/$match_domain/\w+$})) {
        my $url = $data{'origurl'};
        if ($data{'linkprot'} =~ m{^\w+(c|d):\Q$url\E$}) {
            if ((!exists($data{'linkprotuser'})) ||
                (($data{'linkprotuser'}) &&
                 ($data{'linkprotuser'} =~ m{^($match_username):($match_domain)$}))) {
                $url .= '?ltoken='.$env{'form.rtoken'};
                $r->print(&Apache::loncommon::start_page('Updating session',undef,
                                                         {'only_body'    => 1,
                                                          'redirect'     => [1,$url,'',$data{'lcssowin'}]}).
                          '<p>'.&mt('Updating old session information').'</p>'.
                          &Apache::loncommon::end_page());
                return OK;
            }
        }
    }
    my $args = {'only_body' => 1};
    if ($data{'lcssowin'}) {
        $args->{'redirect'} = [1,$data{'origurl'},'',$data{'lcssowin'}];
    }
    if ($data{'linkprot'}) {
        $r->print(&Apache::loncommon::start_page('Updating session',undef,$args));
        if ($data{'linkprotuser'} ne '') {
            $r->print(&mt('Although your credentials were authenticated, the username you entered did not match what was expected [_1] from the link you followed',"($data{'linkprotuser'})"));
        } else {
            $r->print(&mt('Expired any existing session'));
        }
    } else {
        $r->print(&Apache::loncommon::start_page('Session removed',undef,$args));
        $r->print(&mt('Expired any existing session'));
    }
    $r->print(&Apache::loncommon::end_page());
    if (exists($env{'form.rtoken'})) {
        &Apache::lonnet::tmpdel($env{'form.rtoken'});       
    }
    return OK;
}

1;