--- loncom/auth/lonauth.pm	2010/03/22 20:11:08	1.104
+++ loncom/auth/lonauth.pm	2010/07/17 20:02:02	1.105
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # User Authentication Module
 #
-# $Id: lonauth.pm,v 1.104 2010/03/22 20:11:08 droeschl Exp $
+# $Id: lonauth.pm,v 1.105 2010/07/17 20:02:02 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -211,11 +211,15 @@ sub handler {
 	        &Apache::loncommon::start_page('Already logged in');
 	    my $end_page = 
 	        &Apache::loncommon::end_page();
+            my $dest = '/adm/roles';
+            if ($env{'form.firsturl'} ne '') {
+                $dest = $env{'form.firsturl'};
+            }
             $r->print(
                $start_page
               .'<h1>'.&mt('You are already logged in!').'</h1>'
               .'<p>'.&mt('Please either [_1]continue the current session[_2] or [_3]log out[_4].'
-                    ,'<a href="/adm/roles">','</a>','<a href="/adm/logout">','</a>')
+                    ,'<a href="'.$dest.'">','</a>','<a href="/adm/logout">','</a>')
               .'</p>'
               .$end_page
             );
@@ -331,8 +335,10 @@ sub handler {
     if (grep(/^login$/,@cancreate)) {
         $defaultauth = 1;
     }
+    my $clientcancheckhost = 1;
     my $authhost=Apache::lonnet::authenticate($form{'uname'},$upass,
-                                              $form{'udom'},$defaultauth);
+                                              $form{'udom'},$defaultauth,
+                                              $clientcancheckhost);
     
 # --------------------------------------------------------------------- Failed?
 
@@ -344,9 +350,10 @@ sub handler {
         my %domconfig = 
             &Apache::lonnet::get_dom('configuration',['usercreation'],$form{'udom'});
         if (grep(/^login$/,@cancreate)) {
+            my $domdesc = &Apache::lonnet::domain($form{'udom'},'description');
+            &check_can_host($r,\%form,'no_account_on_host',$domdesc);
             my $start_page = 
                 &Apache::loncommon::start_page('Create a user account in LON-CAPA');
-            my $domdesc = &Apache::lonnet::domain($form{'udom'},'description');
             my $lonhost = $r->dir_config('lonHostID');
             my $origmail = $Apache::lonnet::perlvar{'lonSupportEMail'};
             my $contacts = 
@@ -396,10 +403,13 @@ sub handler {
 	}
     }
 
+    &check_can_host($r,\%form,$authhost);
+
     if ($r->dir_config("lonBalancer") eq 'yes') {
 	&success($r,$form{'uname'},$form{'udom'},$authhost,'noredirect',undef,
 		 \%form);
-	$r->internal_redirect('/adm/switchserver');
+        my ($otherserver) = &choose_server($form{'udom'});
+	$r->internal_redirect('/adm/switchserver?otherserver='.$otherserver);
     } else {
 	&success($r,$form{'uname'},$form{'udom'},$authhost,$firsturl,undef,
 		 \%form);
@@ -407,6 +417,75 @@ sub handler {
     return OK;
 }
 
+sub check_can_host {
+    my ($r,$form,$authhost,$domdesc) = @_;
+    return unless (ref($form) eq 'HASH');
+    my $canhost = 1;
+    my @machinedoms = &Apache::lonnet::current_machine_domains();
+    my $udom = $form->{'udom'};
+    unless (grep(/^\Q$udom\E/,@machinedoms)) {
+        my $defdom = &Apache::lonnet::default_login_domain();
+        my %defdomdefaults = &Apache::lonnet::get_domain_defaults($defdom);
+        my %udomdefaults = &Apache::lonnet::get_domain_defaults($udom);
+        my $loncaparev;
+        if ($authhost eq 'no_account_on_host') {
+            $loncaparev = &Apache::lonnet::get_server_loncaparev($defdom);
+        } else {
+            $loncaparev = &Apache::lonnet::get_server_loncaparev($defdom,$authhost);
+        }
+        $canhost = &Apache::lonnet::can_host_session($udom,$defdom,$loncaparev,$udomdefaults{'remotesessions'},$defdomdefaults{'hostedsessions'});
+    }
+    unless ($canhost) {
+        if ($authhost eq 'no_account_on_host') {
+            my ($login_host,$hostname) = &choose_server($udom);
+            &Apache::loncommon::content_type($r,'text/html');
+            $r->send_http_header;
+            if ($login_host ne '') {
+                my $protocol = $Apache::lonnet::protocol{$login_host};
+                $protocol = 'http' if ($protocol ne 'https');
+                my $newurl = $protocol.'://'.$hostname.'/adm/createaccount';
+                $r->print(&Apache::loncommon::start_page('Create a user account in LON-CAPA').
+                          '<h3>'.&mt('Account creation').'</h3>'.
+                          &mt('You do not currently have a LON-CAPA account at this institution.').'<br />'.
+                          '<p>'.&mt('You will be able to create one by logging into a LON-CAPA server within the [_1] domain.',$domdesc).'</p>'.
+                          '<p>'.&mt('[_1]Log in[_2]','<a href="'.$newurl.'">','</a>').
+                          &Apache::loncommon::end_page());
+            } else {
+                $r->print(&Apache::loncommon::start_page('Access to LON-CAPA unavailable').
+                          '<h3>'.&mt('Account creation unavailable').'</h3>'.
+                          &mt('You do not currently have a LON-CAPA account at this institution.').'<br />'.
+                          '<p>'.&mt('Currently a LON-CAPA server is not available within the [_1] domain for you to log-in to, to create an account.',$domdesc).'</p>'.
+                          &Apache::loncommon::end_page());
+            }
+            return OK;
+        } else {
+            &success($r,$form->{'uname'},$udom,$authhost,'noredirect',undef,
+                     $form);
+            my ($otherserver) = &choose_server($udom);
+            $r->internal_redirect('/adm/switchserver?otherserver='.$otherserver);
+        }
+    }
+}
+
+sub choose_server {
+    my ($udom) = @_;
+    my %domconfhash = &Apache::loncommon::get_domainconf($udom);
+    my %servers = &Apache::lonnet::get_servers($udom);
+    my $lowest_load = 30000;
+    my ($login_host,$hostname);
+    foreach my $lonhost (keys(%servers)) {
+        my $loginvia = $domconfhash{$udom.'.login.loginvia_'.$lonhost};
+        if ($loginvia eq '') {
+            ($login_host, $lowest_load) =
+            &Apache::lonnet::compare_server_load($lonhost, $login_host, $lowest_load);
+        }
+    }
+    if ($login_host ne '') {
+        $hostname = $servers{$login_host};
+    }
+    return ($login_host,$hostname);
+}
+
 1;
 __END__