--- loncom/localize/lonlocal.pm	2008/11/24 16:53:16	1.51
+++ loncom/localize/lonlocal.pm	2009/10/02 16:59:29	1.60.2.1
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Localization routines
 #
-# $Id: lonlocal.pm,v 1.51 2008/11/24 16:53:16 jms Exp $
+# $Id: lonlocal.pm,v 1.60.2.1 2009/10/02 16:59:29 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -173,9 +173,11 @@ require Exporter;
 our @ISA = qw (Exporter);
 our @EXPORT = qw(mt mtn ns mt_user);
 
+my %mtcache=();
+
 # ========================================================= The language handle
 
-use vars qw($lh);
+use vars qw($lh $current_language);
 
 # ===================================================== The "MakeText" function
 
@@ -191,7 +193,13 @@ sub mt (@) {
                 return $_[0];
             }
         } else {
-            return $lh->maketext(@_);
+            if ($#_>0) { return $lh->maketext(@_); }
+            if ($mtcache{$current_language.':'.$_[0]}) {
+               return $mtcache{$current_language.':'.$_[0]};
+            }
+            my $translation=$lh->maketext(@_);
+            $mtcache{$current_language.':'.$_[0]}=$translation;
+            return $translation; 
         }
     } else {
 	if (wantarray) {
@@ -233,14 +241,77 @@ sub current_language {
     return 'en';
 }
 
+sub preferred_languages {
+    my $defdom = &Apache::lonnet::default_login_domain();
+    foreach my $domtype ($Apache::lonnet::env{'user.domain'},$Apache::lonnet::env{'request.role.domain'},$defdom) {
+        next if ($domtype eq '');
+        if ($domtype eq 'gci') {
+            return ('gci');
+        } elsif ($domtype eq 'gcitest') {
+            return ('gct');
+        } else {
+            return ('gci');
+        }
+    }
+    my @languages=();
+    if (($Apache::lonnet::env{'request.role.adv'}) && ($Apache::lonnet::env{'form.languages'})) {
+        @languages=(@languages,split(/\s*(\,|\;|\:)\s*/,$Apache::lonnet::env{'form.languages'}));
+    }
+    if ($Apache::lonnet::env{'course.'.$Apache::lonnet::env{'request.course.id'}.'.languages'}) {
+        @languages=(@languages,split(/\s*(\,|\;|\:)\s*/,
+                 $Apache::lonnet::env{'course.'.$Apache::lonnet::env{'request.course.id'}.'.languages'}));
+    }
+
+    if ($Apache::lonnet::env{'environment.languages'}) {
+        @languages=(@languages,
+                    split(/\s*(\,|\;|\:)\s*/,$Apache::lonnet::env{'environment.languages'}));
+    }
+    my $browser=$ENV{'HTTP_ACCEPT_LANGUAGE'};
+    if ($browser) {
+        my @browser =
+            map { (split(/\s*;\s*/,$_))[0] } (split(/\s*,\s*/,$browser));
+        push(@languages,@browser);
+    }
+
+    foreach my $domtype ($Apache::lonnet::env{'user.domain'},$Apache::lonnet::env{'request.role.domain'},$defdom) {
+        if ($domtype ne '') {
+            my %domdefs = &Apache::lonnet::get_domain_defaults($domtype);
+            if ($domdefs{'lang_def'} ne '') {
+                push(@languages,$domdefs{'lang_def'});
+            }
+        }
+    }
+    return &get_genlanguages(@languages);
+}
+
+sub get_genlanguages {
+    my (@languages) = @_;
+# turn "en-ca" into "en-ca,en"
+    my @genlanguages;
+    foreach my $lang (@languages) {
+        unless ($lang=~/\w/) { next; }
+        push(@genlanguages,$lang);
+        if ($lang=~/(\-|\_)/) {
+            push(@genlanguages,(split(/(\-|\_)/,$lang))[0]);
+        }
+    }
+    #uniqueify the languages list
+    my %count;
+    @genlanguages = map { $count{$_}++ == 0 ? $_ : () } @genlanguages;
+    return @genlanguages;
+}
+
 # ============================================================== What encoding?
 
 sub current_encoding {
     my $default='UTF-8';
-    if ($Apache::lonnet::env{'browser.os'} eq 'win' && 
-	$Apache::lonnet::env{'browser.type'} eq 'explorer') {
-        $default='ISO-8859-1';
-    }
+# UTF-8 character encoding needed for the whole LON-CAPA system
+# (interface language and homework problem content)
+# See Bugzilla 5702 vs. 2189 and 4067
+#    if ($Apache::lonnet::env{'browser.os'} eq 'win' && 
+#	$Apache::lonnet::env{'browser.type'} eq 'explorer') {
+#        $default='ISO-8859-1';
+#    }
     if ($lh) {
 	my $enc=$lh->maketext('char_encoding');
 	return ($enc eq 'char_encoding'?$default:$enc);
@@ -279,9 +350,10 @@ sub get_language_handle {
 	my $headers=$r->headers_in;
 	$ENV{'HTTP_ACCEPT_LANGUAGE'}=$headers->{'Accept-language'};
     }
-    my @languages=&Apache::loncommon::preferred_languages;
+    my @languages=&preferred_languages();
     $ENV{'HTTP_ACCEPT_LANGUAGE'}='';
     $lh=Apache::localize->get_handle(@languages);
+    $current_language=&current_language();
     if ($r) {
 	$r->content_languages([&current_language()]);
     }
@@ -290,15 +362,24 @@ sub get_language_handle {
 
 # ========================================================== Localize localtime
 sub gettimezone {
-    my $timezone; 
-    if ($Apache::lonnet::env{'course.'.$Apache::lonnet::env{'request.course.id'}.'.timezone'}) {
-        $timezone = $Apache::lonnet::env{'course.'.$Apache::lonnet::env{'request.course.id'}.'.timezone'};    
-    } elsif ($Apache::lonnet::env{'request.course.id'} ne '') {
-        my $cdom = $Apache::lonnet::env{'course.'.$Apache::lonnet::env{'request.course.id'}.'.domain'};
-        if ($cdom ne '') {
-            my %domdefaults = &Apache::lonnet::get_domain_defaults($cdom);
-            if ($domdefaults{'timezone_def'} ne '') {
-                $timezone = $domdefaults{'timezone_def'};
+    my ($timezone) = @_;
+    if ($timezone ne '') {
+        if (!DateTime::TimeZone->is_valid_name($timezone)) {
+            $timezone = 'local';
+        }
+        return $timezone;
+    }
+    my $cid = $Apache::lonnet::env{'request.course.id'};  
+    if ($cid ne '') {
+        if ($Apache::lonnet::env{'course.'.$cid.'.timezone'}) {
+            $timezone = $Apache::lonnet::env{'course.'.$cid.'.timezone'};    
+        } else {
+            my $cdom = $Apache::lonnet::env{'course.'.$cid.'.domain'};
+            if ($cdom ne '') {
+                my %domdefaults = &Apache::lonnet::get_domain_defaults($cdom);
+                if ($domdefaults{'timezone_def'} ne '') {
+                    $timezone = $domdefaults{'timezone_def'};
+                }
             }
         }
     } elsif ($Apache::lonnet::env{'request.role.domain'} ne '') {
@@ -323,7 +404,8 @@ sub gettimezone {
 }
 
 sub locallocaltime {
-    my $thistime=shift;
+    my ($thistime,$timezone) = @_;
+
     if (!defined($thistime) || $thistime eq '') {
 	return &mt('Never');
     }
@@ -337,7 +419,16 @@ sub locallocaltime {
     }
 
     my $dt = DateTime->from_epoch(epoch => $thistime)
-                     ->set_time_zone(&gettimezone());
+                     ->set_time_zone(gettimezone($timezone));
+
+    # TimeZone tries to determine the 'local' timezone from $ENV{TZ} if this
+    # fails it searches through various system files. Under certain
+    # circumstances this is an extremly expensive operation.
+    # So after the first run we store the timezone in $ENV{TZ} to significantly
+    # speed up future lookups. 
+    $ENV{TZ} = $dt->time_zone()->name() 
+        if (! $ENV{TZ} && gettimezone($timezone) eq 'local');
+
     if ((&current_language=~/^en/) || (!$lh)) {
 
 	return $dt->strftime("%a %b %e %I:%M:%S %P %Y (%Z)");