--- loncom/homework/grades.pm	2003/04/21 18:39:43	1.86
+++ loncom/homework/grades.pm	2003/04/30 20:16:02	1.88
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # The LON-CAPA Grading handler
 #
-# $Id: grades.pm,v 1.86 2003/04/21 18:39:43 ng Exp $
+# $Id: grades.pm,v 1.88 2003/04/30 20:16:02 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -46,6 +46,9 @@ use Apache::lonhomework;
 use Apache::loncoursedata;
 use Apache::lonmsg qw(:user_normal_msg);
 use Apache::Constants qw(:common);
+use String::Similarity;
+
+my %oldessays=();
 
 # ----- These first few routines are general use routines.----
 #
@@ -221,6 +224,50 @@ sub jscriptNform {
 }
 
 #------------------ End of general use routines --------------------
+
+#
+# Find most similar essay
+#
+
+sub most_similar {
+    my ($uname,$udom,$uessay)=@_;
+
+# ignore spaces and punctuation
+
+    $uessay=~s/\W+/ /gs;
+
+# these will be returned. Do not care if not at least 50 percent similar
+    my $limit=0.6;
+    my $sname='';
+    my $sdom='';
+    my $scrsid='';
+    my $sessay='';
+# go through all essays ...
+    foreach my $tkey (keys %oldessays) {
+	my ($tname,$tdom,$tcrsid)=split(/\./,$tkey);
+# ... except the same student
+        if (($tname ne $uname) || ($tdom ne $udom)) {
+	    my $tessay=$oldessays{$tkey};
+            $tessay=~s/\W+/ /gs;
+# String similarity gives up if not even limit
+            my $tsimilar=&String::Similarity::similarity($uessay,$tessay,$limit);
+# Found one
+            if ($tsimilar>$limit) {
+		$limit=$tsimilar;
+                $sname=$tname;
+                $sdom=$tdom;
+                $scrsid=$tcrsid;
+                $sessay=$oldessays{$tkey};
+            }
+        } 
+    }
+    if ($limit>0.6) {
+       return ($sname,$sdom,$scrsid,$sessay,$limit);
+    } else {
+       return ('','','','',0);
+    }
+}
+
 #-------------------------------------------------------------------
 
 #------------------------------------ Receipt Verification Routines
@@ -1075,6 +1122,9 @@ sub submission {
 	$request->print($prnmsg);
 
 	if ($ENV{'form.handgrade'} eq 'yes' && $ENV{'form.showgrading'} eq 'yes') {
+#
+# Print out the keyword options line
+#
 	    $request->print(<<KEYWORDS);
 &nbsp;<b>Keyword Options:</b>&nbsp;
 <a href="javascript:keywords(document.SCORE.keywords)"; TARGET=_self>List</a>&nbsp; &nbsp;
@@ -1082,6 +1132,14 @@ sub submission {
  CLASS="page">Paste Selection to List</a>&nbsp; &nbsp;
 <a href="javascript:kwhighlight()"; TARGET=_self>Highlight Attribute</a><br /><br />
 KEYWORDS
+#
+# Load the other essays for similarity check
+#
+            my $essayurl=&Apache::lonnet::declutter($url);
+	    my ($adom,$aname,$apath)=($essayurl=~/^(\w+)\/(\w+)\/(.*)$/);
+	    $apath=&Apache::lonnet::escape($apath);
+	    $apath=~s/\W/\_/gs;
+	    %oldessays=&Apache::lonnet::dump('nohist_essay_'.$apath,$adom,$aname);
         }
     }
 
@@ -1189,6 +1247,15 @@ KEYWORDS
 			my ($partid,$respid) = /^resource\.(\d+)\.(\d+)\.submission/;
 			if ($part eq ($partid.'_'.$respid)) {
 			    my ($ressub,$subval) = split(/:/,$_,2);
+# Similarity check
+                            my $similar='';
+                            my ($oname,$odom,$ocrsid,$oessay,$osim)=&most_similar($uname,$udom,$subval);
+                            if ($osim) {
+				$osim=int($osim*100.0);
+				$similar='<hr /><h3><font color="#FF0000">Essay is '.$osim.'% similar to an essay by '.&Apache::loncommon::plainname($oname,$odom).
+                                '</font></h3><blockquote><i>'.
+                                &keywords_highlight($oessay).'</i></blockquote><hr />';
+                            }
 			    $lastsubonly.='<tr><td bgcolor="#ffffe6"><b>Part '.
 				$partid.'</b> <font color="#999999">( ID '.$respid.
 				' )</font>&nbsp; &nbsp;'.
@@ -1196,8 +1263,8 @@ KEYWORDS
                                 '<a href="'.
                                 &Apache::lonnet::tokenwrapper($record{"resource.$partid.$respid.uploadedurl"}).
    '"><img src="/adm/lonIcons/unknown.gif" border=0"> File uploaded by student</a> <font color="red" size="1">Like all files provided by users, this file may contain virusses</font><br />':'').
-                                '<b>Answer: </b>'.
-				&keywords_highlight($subval).'</td></tr>'."\n"
+                                '<b>Answer: </b><blockquote>'.
+				&keywords_highlight($subval).'</blockquote><br />&nbsp;'.$similar.'</td></tr>'."\n"
 				if ($ENV{'form.lastSub'} eq 'lastonly' || 
 				    ($ENV{'form.lastSub'} eq 'hdgrade' && 
 				     $$handgrade{$part} =~ /:yes$/));