#!/usr/bin/perl

#  keymaster.pl
##::: Author		stradust, wheakory
##::: Hostname		ux5.isu.edu (development), ux7.isu.edu (production)
##::: Language		Perl
##::: Libs/Deps		perl libraries => DBI, CGI, Time::Local, CGI::Session
##:::				in-house config library => PHQConf.pm
##:::
##::: Path/Filename	/cwis/apache/cgi-bin/keymaster.pl
##::: Path/Exe		
##:::
##::: Project		PH Web Throttling
##::: SubProject	 
##::: Keywords		queuing, PHWeb Throttling
##:::
##::: DateCreated	03/15/2003
##:::
##::: ExeByWho		HTTP as a cgi script
##::: ExeByWhat		
##::: 
##::: Description:  This script handles the "client side" of the PHWeb queuing process.  When the user 
##:::				requests a web portal via a link, they are first directed through hp-redirect.pl 
##:::				which tests the current status of HP1.  If HP1 is up, the request is then passed to
##:::				this script, keymaster.pl
##:::
##:::				Keymaster.pl handles session management and database record insertion for a new
##:::				request being added to the queue, and reports the current queue position for requests
##:::				still passing through the queue.
##:::
##:::				Refer to its partner script, gatekeeper.pl, for the "server side" of this process.
##:::               
##:::
##:::
##:::
##::: ModDate   WhoBy     Tag  Description
##::: ========  ========  ==== ===============================================
##::: 00/00/02  NameAcct  NA01 template
##:::
##::: END   

use DBI;	
use CGI;						# Enables perl database abstraction layer - interface to MySQL database
use Time::Local;				# Enables date and time manipulation functions
use CGI::Session qw/-api3/;		# Use sessions	
use PHQConf;					# Configuration parameters stored here
#use Env qw(HTTP_REFERER CONTENT_LENGTH QUERY_STRING);
$CGI::POST_MAX=1024 * 100;		# max 100K posts - Set to avoid Denial of Service attacks
$CGI::DISABLE_UPLOADS = 1;		# no uploads - Set to avoid Denial of Service attacks
$CGI::Session::IP_MATCH=1;		# IP address must match to access session
#use strict;

use vars qw(%PHQConf $targetApp $tableName $AR_FLAG);	# Declaring global variables
do "$PHQConf{AR_FILE}";			# Populate $AR_FLAG with the current available resource state

#print "Content-type: text/html\n\n";
#foreach $var (keys(%ENV)) {
#	print "$var = ".$ENV{$var}."<BR>\n";
#}

#print $ENV{'HTTP_REFERER'}.":".$ENV{'CONTENT_LENGTH'}.":".$ENV{'QUERY_STRING'}."\n";
#exit;

$debug = "";
%custData = ();					# Initializing container for customer database info.

($targetApp, $referrer) = &getParms;			# Retrieve current targetApp

print "$targetApp, $referrer<BR>\n";
exit;

# Determine that the page is being called either from hp-redirect or as a refresh of itself, otherwise die.
if (!($ENV{'HTTP_REFERER'} =~ /hp-redirect.pl/)) {
	if ($referrer ne "keymaster") {
		$error = "Keymaster was called from an unaccepted referring location.";
		&generateError($error);
	}
}

if ($targetApp eq "myISU") {	# Set the working database table name.
	$tableName = "myISU_queue";
}
elsif ($targetApp eq "fsTools") {
	$tableName = "fsTools_queue";
}
else {
	&genLinkErrorPage($debug);
	exit;
}
$debug .= "My referring page is: ".$ENV{'HTTP_REFERER'}."<br>";

my $sessHandle = &getCookie();		# Retrieve cookie data from client machine
$debug .= "Call to getCookie on line 47 returned: \$sessHandle = $sessHandle<BR>";
if ($sessHandle) {
	$debug .= "\$sessHandle name is ".$sessHandle->name.".  \$sessHandle id is ".$sessHandle->id."<BR>";
}


if (! $sessHandle) {
	$token = 0;
}
else {
	$token = $sessHandle->id;
}
$debug .= "\$token is set to $token<BR>";

$cID = &queConnect();				# Connect to database
if (! $cID) {
	$error = "Unable to establish a connection with the MySQL Database: ".$DBI::errstr."\n";
	PHQConf::generateError($error);
	exit;
}

$check = &queueCheck($targetApp, $token, \%custData);
$debug .= "queueCheck() returned $check<BR>";

if ($check == -1) { # the queue is currently not empty or resources are unavailable and
					# the customer is not in the queue.
	
	# Customer needs to be added to the queue.  Start by creating the cookie.
	my $sessionObject = &bakeCookie();
	$debug .= "\$sessionObject is $sessionObject.  \$sessionObject's session id is $sessionObject->id<BR>";

	if ($sessionObject) {
		# Cookie was created correctly.  Proceed with updating the database.
		my $rv = &addCust($tableName, $targetApp, $sessionObject, \%custData);
		if (! $rv) {
			$error = "Unable to add customer to queue database: ".$DBI::errstr."\n";
			PHQConf::generateError($error);

			# Something else should happen here. . . if the user isn't added to the database
			# this whole process fails.  Determine what should happen in the error state.
		}

		# Customer is added to the queue.  Populate the custData hash for the queue position.
		#my $rc = &getCustData2($sessionObject->id, \%custData);		
		#if (! $rc) {
		#	$error = "Unable to retrieve customer data: ".$DBI::errstr."\n";
		#	PHQConf::generateError($error);
		#}
		
		# Push out the refresh page.
		&genRefreshPage($sessionObject);
	}
	else {
		# Error setting cookie
		$error = "Unable to create cookie on client machine: $!\n";
		PHQConf::generateError($error);
	}
}
elsif ($check == 0) {
	# Send customer to login page
	if ($targetApp eq "myISU") {
		$target = $PHQConf{MYISU};
	}
	elsif ($targetApp eq "fsTools") {
		$target = $PHQConf{FSTOOLS};
	}

	if ($sessHandle) {
		my $cookieHandle = &eatCookie($sessHandle);
		if (! $cookieHandle) {
			PHQConf::generateError($DBI::errstr);
		}
	}
	
	my $cgi = new CGI();
	print $cgi->redirect(-uri=>$target, -cookie=>$cookieHandle); 
}
elsif ($check == 1) {
	# Customer is in queue.  
	
	if (! $sessHandle) {
		$error = "No session exists <BR>";
		PHQConf::generateError($error);
	}
	
	# Calculate last refresh and generate errors if refresh is happening before specified period
	if (time - $custData{'lastRefresh'} < $PHQConf{REFRESH_PERIOD}) {
		$refreshWarning = "This page will automatically refresh.  Forcing a refresh will not affect your";
		$refreshWarning .= " place in the queue.  Please do not refresh this page.";
	}

	# Update expire times on cookie & session
#	$sessHandle->param("expires", $PHQConf{EXPIRE_TIME});
	$sessHandle->expires($PHQConf{EXPIRE_TIME});
	my $cgi = new CGI();
	$cookieHandle = $cgi->cookie(-name=>$PHQConf{COOKIE_NAME}, -value=>$sessHandle->id, -expires=>$PHQConf{EXPIRE_TIME});
	print $cgi->header(-cookie=>$cookieHandle);

	# Update last refresh time in database table
	my $query = "UPDATE ".$tableName." SET lastRefresh=NOW() WHERE custID=".$custData{'custID'};
	my $sth = $cID->prepare($query);
	my $rv = $sth->execute;
	if (! $rv) {
		PHQConf::generateError("Failed to update the last refresh time in the MySQL databases: ".$DBI::errstr.":<BR>".$debug);
	}

	# Generate refresh page
	&genRefreshPage($sessHandle,$refreshWarning);
}

exit;



#************************************ SUBROUTINE DEFINITIONS *************************************
sub getParms() {
	# This subroutine gathers the parameter data - the application the customer is tring to access,
	# specified as targetApp.  The targetApp will be passed from hp-redirect.pl or as POST data from the
	# refresh form.

	my %form = ();
	
	# No arguments were passed, so check for POST data
	if ($ENV{'REQUEST_METHOD'} eq "GET") {
		return $ENV{'QUERY_STRING'};
	}
	else {
		read(STDIN, $buffer, $ENV{'CONTENT_LENGTH'});
	}

	# Split out the name-value pairs by & seperator, and load into array
	my @pairs = split(/&/, $buffer);
	$debug .= "\$buffer is $buffer<BR>";

	foreach $pair (@pairs)
	{
		# split name-value pairs by = sign
		my ($name, $value) = split(/=/, $pair);

		# Un-Webify plus signs and %-encoding
		$value =~ tr/+/ /;
		$value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
		$name =~ tr/+/ /;
		$name =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;

		# load name-value pairs into associative arrays, indexed by name
		$form{$name} = $value;
	}
	return $form{'targetApp'},$form{'referrer'};

} # end getParms()

sub queConnect() {
	# This subroutine defines the login parameters for the queue database and establishes a connection

	my $db = "queue";
	my $dbUsername = "keymaster";
	my $dbPasswd = "k3yzplz";

	my $connectionID = &mysqlConnect($db, $dbUsername, $dbPasswd);
	return $connectionID;
} # end queConnect()

sub mysqlConnect($$$) {
	# This subroutine establishes a connection to a mysql database
	
	my ($database_name, $database_user, $database_passwd) = @_;

	my $dbh = DBI->connect("DBI:mysql:database=$database_name", $database_user, $database_passwd, { RaiseError => 0, AutoCommit => 0 });
	return $dbh;
} # End dbconnect

sub getCookie() {
# This subroutine determines if a queue cookie is set in the client's browser
	
	my $cgi = new CGI();
	my $cookieHandle = $cgi->cookie($PHQConf{COOKIE_NAME}) || "undef";

	$debug .= "getCookie checked for a cookie.  \$cookieHandle is $cookieHandle<BR>";

	if ($cookieHandle eq "undef") {
		return 0;
	}
	else {
	    my $session = new CGI::Session(undef, $cookieHandle, {Directory=>$PHQConf{SESSIONDIR}});
		# Return the session handle
		return $session;
	}
} # End checkCookie()

sub bakeCookie() {

	# Create a new session and cookie
	my $cgi = new CGI();
	my $session = new CGI::Session(undef, $cgi, {Directory=>$PHQConf{SESSIONDIR}});
	$session->expire($PHQConf{EXPIRE_TIME});
    #$session->param(expire,$STALE_PERIOD);
	my $cookieHandle = $cgi->cookie(-name=>$PHQConf{COOKIE_NAME}, -value=>$session->id, -expires=>$PHQConf{EXPIRE_TIME});
	print $cgi->header(-cookie=>$cookieHandle);

	$debug .= "bakeCookie() set cookie $cookieHandle<BR>";
	return $session;
} # End bakeCookie()

sub queueCheck($$$) {
	# Accepts the targetApp, client cookie token, and an array reference for hash to store customer data in

	# This subroutine checks the current state of the queue.  It returns -1 if the queue is currently 
	# not empty or resources are unavailable but the customer is not in the queue.  It returns 0 if the 
	# queue is empty and resources are available (indicating the client should be sent straight to the
	# login page).  And last it returns 1 if the customer was found in the database.  In this case, it
	# stores the customer's data in the hash indicated by the passed array reference

	my ($targetApp, $clientCookieTok, $custData_ref) = @_;
		
	# Check the current queue state for the targetApp
	my $query = "SELECT COUNT(*) FROM ".$tableName;
	my $sth = $cID->prepare($query);
	$sth->execute;
	my $queueCount = "";
	my $row = "";
	$row = $sth->fetchrow_array;
	$queueCount = $row;
	$debug .= "\$queueCount is $queueCount.<BR>";
	if (! $queueCount) {
		# The queue table is empty.  Check for available resources.
		  
		$debug .= "Resource status is set to ".$PHQConf{AR_FLAG}."<br>";
		if ($AR_FLAG) {
			# Resources are available - Direct user to login page
			return 0;
		}
		else {
			# Resources are not available - Add user to queue
			return -1;
		}
	}
	else {
		# The queue table is not empty.  
		if ($clientCookieTok) {
			# Check to see if this customer is already in the queue.
			my $rc = &getCustData2($clientCookieTok, $custData_ref);
			$debug .= "getCustData2 returned $rc<BR>";
			if ($rc) {
			# Determine the user's current accessState.  If access has been granted and resources are available,
			# send the user to the portal login page
				if ($$custData_ref{'accessState'} eq "Y") {
					return 0;
				}
				else {
					return 1;
				}
			}
			else {
				# Customer data was not found in the queue.
				return -1;
			}
		}
		else {
			# This client doesn't have a cookie set. Add them to the queue.
			return -1;
		}
	}
} # End queueCheck()

sub addCust($$$$) {
	# Adds a customer entry to the database.
	# Accepts the targetApp and tableName and treats %cookieData as a global variable
	my ($tableName, $targetApp, $sessionHandle, $custData_ref) = @_;

	# Get the next available customer ID.
	my $query = "SELECT MAX(custID) FROM ".$tableName;
	my $sth = $cID->prepare($query);
	$sth->execute;
	my @row	= $sth->fetchrow_array;
	my $maxID = $row[0];

	$query = "INSERT INTO ".$tableName." VALUES('".++$maxID."','".$sessionHandle->param("_SESSION_REMOTE_ADDR")."','";
	$query .= $sessionHandle->id."','N',NOW(),NOW(),NULL)";
	$sth = $cID->prepare($query);
	my $rv = $sth->execute;
	if (! $rv) {
		PHQConf::generateError("Failed to return a \"true\" return code: ".$DBI::errstr);
		return 0;
	}
	else {
		#### Testing
		$query = "INSERT INTO ".$tableName."_order VALUES(NULL,'".$maxID."')";
		$sth = $cID->prepare($query);
		$rv = $sth->execute;
		
		if ($rv) {
			# Add data to custData hash
			$$custData_ref{'custID'} = $maxID;
			$$custData_ref{'IP'} = $sessionHandle->param("_SESSION_REMOTE_ADDR");
			$$custData_ref{'token'} = $sessionHandle->id;
			$$custData_ref{'accessState'} = "N";
			$$custData_ref{'quePos'} = $cID->{'mysql_insertid'} || undef;
		}
		return $rv;
	}
} # end addCust()

sub genRefreshPage($$) {
	# This subroutine generates the refresh page the customer sees while in the queue.  It accepts any error
	# messages that have been generated when the script checks refresh times.  It builds a page that informs
	# the customer of their current position in the queue.
	
	my ($session, $refreshErrors) = @_;
	my $refTime = $PHQConf{REFRESH_PERIOD} * 1000;
	
	#print "Content-type: text/html\n\n";
	
	print "<!doctype html public \"-//w3c//dtd html 4.0 transitional//en\">\n";
	print "<html>\n";
	print "<head><title>ISU Portal Applications - Queue Refresh Page</title>\n";
	#print "<meta http-equiv=\"refresh\" CONTENT=\"".$PHQConf{REFRESH_PERIOD}.";URL=".$PHQConf{KEYMASTER}."?".$targetApp."\">\n";
	print "<link rel=\"stylesheet\" type=\"text/css\" href=\"".$PHQConf{STYLESHEET}."\">\n";

	print "<script language=\"javascript\">\n";
	print "timerID = setTimeout(\"document.refresher.submit()\",".$refTime.");\n";
	print "</script>\n";	
	
	print "</head>\n";

	print "<body>\n";
	my $banner = &includeFile($PHQConf{ISU_BANNER});
	print $banner."\n";

	print "<form name=\"refresher\" method=\"POST\" action=\"".$PHQConf{KEYMASTER}."\">\n";
	print "<input type=\"hidden\" name=\"referrer\" value=\"keymaster\">\n";
	print "<input type=\"hidden\" name=\"targetApp\" value=\"$targetApp\">\n";

	print "<table width=\"100%\" cellspacing=0 cellpadding=0 border=0>\n";
	print "<tr><td width=\"".$PHQConf{LEFT_CELL_SIZE}."\" valign=top><table width=\"100%\" cellspacing=0 cellpadding=0 border=0>\n";
	print "<tr><td>";
	require ($PHQConf{REFRESH_LEFT_CELL});
	print "</td></tr></table></td>\n";
	print "<td>";
	
	if ($refreshErrors) {
		print "<div align=\"center\" style=\"margin-top: 5em; font-weight: bold; color: red;\">".$refreshErrors."</div>\n";
	}
	#print "<div align=\"center\" style=\"margin-top: 15em; font-weight: bold;\">Your session name is ".$session->name.".</div><BR>\n";
	print "<div align=\"center\" style=\"margin-top: 15em; font-weight: bold;\">Your current queue position is: ".$custData{'quePos'}."</div><BR>\n";
	#print "Your session id is ".$session->id."<BR>";
	print "<p>$debug\n";

	print "</td>\n";
	print "<td><table width=\"100%\" cellspacing=0 cellpadding=0 border=0>\n";
	print "<tr><td width=\"".$PHQConf{RIGHT_CELL_SIZE}."\" valign=top>".&includeFile($PHQConf{REFRESH_RIGHT_CELL})."</td></tr></table></td>\n";
	print "</tr></table>\n";
	print "</body>\n";
	print "</html>\n";
}

sub genLinkErrorPage() {
	print "Content-type: text/html\n\n";

	print "<!doctype html public \"-//w3c//dtd html 4.0 transitional//en\">\n";
	print "<html>\n";
	print "<head><title>ISU Portal Applications - Unspecified Target Application</title>\n";
	##print "<meta http-equiv=\"Content-Type\" content=\"text/html; charset=iso-8859-1\">\n";
	print "</head>\n";

	print "<body>\n";
	print "<div align=center>The link you followed seems broken.  Please select the portal application you wish to use:";
	print "<p><ul>\n";
	print "<li><a href=\"".$PHQConf{KEYMASTER}."?myISU\">MyISU Student Portal</a></li>\n";
	print "<li><a href=\"".$PHQConf{FSTOOLS}."?fsTools\">Faculty/Staff Tools</a></li>\n";
	print "</ul></div>\n";
	print "</body></html>\n";
} # End genLinkErrorPage

sub getCustData($$) {
	my ($clientCookieTok, $custData_ref) = @_;

	my $query = "SELECT custID, IP, token, enteredQue, UNIX_TIMESTAMP(lastRefresh), accessState";
	$query .= " FROM ".$tableName." ORDER BY enteredQue";
	my $sth = $cID->prepare($query);
	$sth->execute;
	my $quePos = 0;
	while (my($custID,$IP,$token,$enteredQue,$lastRefresh,$accessState) = $sth->fetchrow_array) {
		$quePos++;
		if ($token eq $clientCookieTok) {
			
			# Update custData hash with values from $row and return 1
			$$custData_ref{'custID'} = $custID;
			$$custData_ref{'IP'} = $IP;
			$$custData_ref{'token'} = $token;
			$$custData_ref{'enteredQue'} = $enteredQue;
			$$custData_ref{'lastRefresh'} = $lastRefresh;
			$$custData_ref{'accessState'} = $accessState;
			$$custData_ref{'quePos'} = $quePos;
			return 1;
		}
	}
	return 0;
} # end getCustData()

sub getCustData2($$) {
	my ($clientCookieTok, $custData_ref) = @_;

	my $query = "SELECT $tableName.custID, $tableName.IP, $tableName.token, UNIX_TIMESTAMP($tableName.enteredQue),";
	$query .= " UNIX_TIMESTAMP($tableName.lastRefresh), $tableName.accessState, ".$tableName."_order.row_num";
	$query .= " FROM $tableName LEFT JOIN ".$tableName."_order ON $tableName.custID=".$tableName."_order.custID";
	$query .= " WHERE $tableName.token='".$clientCookieTok."'";
	$debug .= $query."<BR>";
	my $sth = $cID->prepare($query);
	my $rc = $sth->execute;
	if (! $rc) {
		return 0;
	}

	my($custID,$IP,$token,$enteredQue,$lastRefresh,$accessState,$quePos) = $sth->fetchrow_array;
	if ($quePos eq "NULL") {
		$quePos = "";
	}
			
	# Update custData hash with values from $row and return 1
	$$custData_ref{'custID'} = $custID;
	$$custData_ref{'IP'} = $IP;
	$$custData_ref{'token'} = $token;
	$$custData_ref{'enteredQue'} = $enteredQue;
	$$custData_ref{'lastRefresh'} = $lastRefresh;
	$$custData_ref{'accessState'} = $accessState;
	$$custData_ref{'quePos'} = $quePos;

	return 1;
} # end getCustData()

sub eatCookie($) {
	my ($sessionObj) = @_;

	my $sql = "DELETE FROM ".$tableName." WHERE token='".$sessionObj->id."'";
	my $sth = $cID->prepare($sql);
	my $rv = $sth->execute;
	if (! $rv) {
		return 0;
	}
	
	my $cgi = new CGI();
	my $cookieHandle = $cgi->cookie(-name=>$PHQConf{COOKIE_NAME}, -value=>$sessionObj->id, -expires=>$PHQConf{DELETE_COOKIE});
	$sessionObj->delete();
	return $cookieHandle;
}

sub includeFile($) {
	my ($filePath) = @_;
	
	if (! $filePath) {
		return undef;
	}
	
	open (FILEHANDLE, "< $filePath") || return "Unable to open file $filePath.<BR>\n";
	my $text = "";
	while (<FILEHANDLE>) {
		$text .= $_;
	}
	close (FILEHANDLE);

	return $text;
} # end includeFile