#!/home/wziemer/ww/perl/bin/perl
#
# W.K. Ziemer 2002 for webwork 1.7, wziemer@csulb.edu
# extract answers from the access log.
#
# these lines should be all one needs to modify for other systems.
#
use lib "/var/www/webwork/system/lib";
use Global;
require "${Global::scriptDirectory}$Global::DBglue_pl";
$webwork_system_path = "/var/www/webwork/system";
$tmpDir = "/var/www/webwork/courses";

#
#input desired information
# assembling a system fgrep call to the access log
#
if(@ARGV == 0){
	print "Course ID? ";
	chomp( $courseID = <STDIN>);
	$logfile = "$webwork_system_path/logs/access_log";
	print "Student's user name: ";
	chomp($user = <STDIN>);
	$shellstr = "fgrep $user $logfile | fgrep course=$courseID";
	print "Problem number: ";
	chomp( $prob = <STDIN>);
	if($prob){
		$shellstr = $shellstr."|fgrep Num=$prob "
	};	
	print "Set name (e.g. setWeek1 is Week1): ";
	chomp( $set = <STDIN>); 
	if($set){
		$psvn = getPsvnFromDB($courseID, $user, $set);
		exit(1) unless($psvn); # trap error from subroutine
		$shellstr = $shellstr."|fgrep probSetKey=$psvn "
	}else{
		$psvn = ''
	};
	$shellstr = $shellstr.">${tmpDir}/tmpfile";
}elsif(@ARGV==2){
        $logfile = "$webwork_system_path/logs/access_log";
	$courseID = $ARGV[0];
	$user = $ARGV[1];
	$psvn = '';
	$shellstr = "fgrep $courseID $logfile | fgrep $user > ${tmpDir}/tmpfile";
}elsif(@ARGV==4){
	$courseID = $ARGV[0];
	$logfile = "$webwork_system_path/logs/access_log";
	$user = $ARGV[1];
	$prob = $ARGV[2];
	$set = $ARGV[3];
	$psvn = getPsvnFromDB($courseID, $user, $set);
	exit(1) unless($psvn); # make sure $psvn exists
	$shellstr = "fgrep $courseID $logfile | fgrep $user |fgrep Num=$prob | fgrep $psvn > ${tmpDir}/tmpfile";
}else{
	print "syntax: getAnswersFromLog.pl courseID user problem set";
	print "example: getAnswersFromLog.pl demoCourse jdoe 6 Week1";
};
print "performing the command\n${shellstr}\n ... this may take a minute.\n\n";
system "$shellstr";

open(IN,"${tmpDir}/tmpfile")||die "can't open tmpfile: $!";
print "-------------------------------------------------------------\n";
print "The answers of $user in $courseID:\n\n";
# Typical entry is of the form
#INFO () Thu Oct  4 20:43:57 2001: AnSwEr1=4;doNotRecordAns=0;ShowAns=0;ShowSol=0;probNum=1;probSetKey=35268;answer_form_submitted=1;course=ma112_Simpson;user=jennychahal;key=DZUI5FINKXWHMK7g6hSABpjIcpZ0D9ktDsHm6YDU;action=Submit%20Answer;Mode=Latex2HTML at /var/www/webwork/system/cgi/cgi-scripts/processProblem8.pl line 153
#
while(<IN>){
	chomp;
	next unless /answer_form_submitted=1/i;
	@ans = ();
	foreach $logitem ( split /;/ ){
		if( $logitem =~ /(.*?:[0-9]{2}:[0-9]{2}.*?):/i ){
			$date = $1;
			$date =~ s/INFO.*?\)//;
		};
		if( $logitem =~ /Num=(.*)/ ){
			$prob2 = $1;
		};
		if( $logitem =~ /answer(.*?)=(.*)/i ){
			$ans[$1] = $2;
			# translate URI-escaped strings into ascii 
			$ans[$1] =~ s/%([0-9A-Fa-f]{2})/chr(hex($1))/eg;
		};
		if( $logitem =~ /SetKey=(.*)/ ){
			$psvn2 = $1;
			if($psvn ne $psvn2){
				$set = getSetFromPsvn($courseID,$psvn2);
				print "Problem Set $set:\n";
			}else{
				$psvn = $psvn2;
			}
		};
#		print "$logitem\n";
	};
	for($i=1;$i<@ans;$i++){
		print "  Problem $prob2 \t Answer$i = $ans[$i]\t on $date\n";
	};
};

close(IN)||die "close tmpfile failed: $!";
unlink "${tmpDir}/tmpfile";
print " Done.\n";

################# subroutines ####################
sub getSetFromPsvn {
	use lib "$webwork_system_path/lib";
	use Global;
	require "${Global::scriptDirectory}$Global::DBglue_pl";

	my ($courseID, $psvn) =@_ ;
	my $flag = 'R';
	my %PROBSET;
	my @probSetRecord;
	my %probSetRecord;

	&Global::getCourseEnvironment($courseID);

#get the database into %PROBSET
	&read_psvn_record(\$wwDbOj, \%PROBSET, "${Global::databaseDirectory}$Global::database", $flag, $Global::standard_tie_permission);

unless(defined($PROBSET{$psvn})){
	print "Error, the psvn $psvn is not in the database\n";
	exit(1);
}

	@probSetRecord = split(/[\&=]/, $PROBSET{$psvn});
# Hack: append a blank entry if odd number of elements.
	push(@probSetRecord, " ") unless @probSetRecord % 2 == 0;
	%probSetRecord = @probSetRecord;
	my $setNum = $probSetRecord{'stnm'};
#	print "$setNum is the set\n";
	return $setNum;
}

sub getPsvnFromDB {
	use lib "$webwork_system_path/lib";
	use Global;
	require "${Global::scriptDirectory}$Global::DBglue_pl";
	my ($courseID, $user, $set) = @_;

	my $psvn;
	my $flag = 'R';
	my %PROBSET;
	my @probSetRecord;
	my %probSetRecord;

	&Global::getCourseEnvironment($courseID);

#get the database into %PROBSET
	&read_psvn_record(\$wwDbOj, \%PROBSET, "${Global::databaseDirectory}$Global::database", $flag, $Global::standard_tie_permission);

if(defined($PROBSET{"set<>$set"})){
	@probSetRecord = split(/[\&=]/, $PROBSET{"set<>$set"});
# Hack: append a blank entry if odd number of elements.
	push(@probSetRecord, " ") unless @probSetRecord % 2 == 0;
	%probSetRecord = @probSetRecord;
#print "$probSetRecord{$user}\n";
	$psvn = $probSetRecord{$user};
}else{
	print "No problem set of name set$set\n";
	$psvn = 0;
};
return $psvn;
}