#!/usr/bin/perl
# http://www.jmbsoft.com/license.php


$DDIR = './data';


require "$DDIR/variables";


## Parse the request
_ParseRequest($ENV{'REQUEST_METHOD'});

if( $ENV{'REQUEST_METHOD'} eq 'GET' )
{
    if( $O_GATEWAY )
    {
        DisplayGateway();
    }
    else
    {
        GiveHit();
    }
}
elsif( $ENV{'REQUEST_METHOD'} eq 'POST' )
{
    GiveHit();
}



sub GiveHit
{
    my $forward_url = $FORWARD_URL;

    ## If using the gateway, and requiring cookie enabled browser, check to make sure the cookie is set
    if( $O_GATEWAY && $O_REQ_COOKIES && $ENV{'HTTP_COOKIE'} !~ /arp_gateway=true/ )
    {
        HandleCheat('No Cookie Support');
    }


    ## If using cookies to track hits, check the arp_id cookie
    if( $O_COOKIES && index($ENV{'HTTP_COOKIE'}, "arp_$F{'id'}=") != -1 )
    {
         HandleCheat('Multiple Click - Cookie');
    }


    ## If not allowing proxies, check for proxy server
    if( $O_PROXY && ($ENV{'HTTP_VIA'} || $ENV{'HTTP_X_FORWARDED_FOR'}) )
    {
        HandleCheat('Proxy Detected');
    }


    ## Check for a valid browser
    if( !$ENV{'HTTP_ACCEPT'} || !$ENV{'HTTP_USER_AGENT'} )
    {
        HandleCheat('Unsupported Browser');
    }


    ## If using the gateway, check for valid referer
    if( $O_GATEWAY && index($ENV{'HTTP_REFERER'}, $IN_URL) == -1 )
    {
        HandleCheat('Bad Referring URL');
    }


    ## If using the gateway, check the session
    if( $O_GATEWAY && time - $F{'s'} > $GATEWAY_EXPIRE )
    {
        HandleCheat('Expired Gateway Session');
    }


    ## Check the IP address if using IP logging
    if( $O_IPS )
    {
        CheckIP();
    }

    ## Set a cookie to mark that this browser has been used to register a hit
    if( $O_COOKIES )
    {
        SetCookie("arp_$F{'id'}", time, $COOKIE_EXPIRE);
    }

    my @member = ();

    $F{'id'} =~ s/\||;//gi;

    ## Give the member a hit
    if( -f "./data/members/$F{'id'}" )
    {
        open(FILE, "+<./data/members/$F{'id'}") || _Error("$!", "./data/members/$F{'id'}");
        flock(FILE, 2);
        @member = split(/\|/, <FILE>, 31);

        $member[0]++;
        $member[2]++;
        $member[20] = 0;

        seek(FILE, 0, 0);
        print FILE join('|', @member);
        my $tell = tell(FILE);
        if( $tell != -1 )
        {
            truncate(FILE, $tell);
        }
        flock(FILE, 8);
        close(FILE);
    }


    ## See if it is time for a rebuild or reset
    CheckTime() if( !$O_CRON );

    
    if( $O_FORWARD_CAT && $member[14] )
    {
        $forward_url = "$MAIN_URL/" . _PlainString($member[14]) . ".$FILE_EXT";
    }


    ## Forward surfer to the correct page
    print "Location: $forward_url\n\n";
}



sub DisplayGateway
{
    if( !$F{'id'} )
    {
        print "Location: $FORWARD_URL\n\n";
        exit;
    }

    if( $O_REQ_COOKIES )
    {
        SetCookie('arp_gateway', 'true', 86400);
    }

    $T{'In_URL'}  = $IN_URL;
    $T{'Session'} = time;
    $T{'ID'}      = $F{'id'};

    print "Content-type: text/html\n\n";

    open(FILE, "./templates/in_gateway.tpl");
    read(FILE, $gateway, 65536);
    close(FILE);

    $gateway =~ s/##(.*?)##/$T{$1}/gise;

    print $gateway;
}



sub HandleCheat
{
    my $type      = shift;
    my $message   = "[%s] %s [%s] [%s]\n";
    my $ip_string = "$ENV{'REMOTE_ADDR'}" . ($ENV{'HTTP_X_FORWARDED_FOR'} ? " Proxy: $ENV{'HTTP_X_FORWARDED_FOR'}" : '');

    if( $O_CHEAT_LOG )
    {
        open(CHEAT, ">>$DDIR/cheatlog");
        printf CHEAT ($message, scalar(gmtime(time+3600*$TIME_ZONE)), $type, $F{'id'}, $ip_string);
        close(CHEAT);
    }

    ## See if it is time for a rebuild or reset
    CheckTime() if( !$O_CRON );

    print "Location: $FORWARD_URL\n\n";

    exit;
}



sub CheckIP
{
    my $a = (split(/\./, $ENV{'REMOTE_ADDR'}))[0];

    open(IP, "+<$DDIR/ips/$a") || _Error("$!", "$DDIR/ips/$a");
    flock(IP, 2);
    for( <IP> )
    {
        if( $_ eq "$ENV{'REMOTE_ADDR'}|$F{'id'}\n" )
        {
            flock(IP, 8);
            close(IP);
            HandleCheat("Multiple Click - IP Address");
        }
    }
    print IP "$ENV{'REMOTE_ADDR'}|$F{'id'}\n";
    flock(IP, 8);
    close(IP);
}



sub SetCookie
{
    my $name    = shift;
    my $value   = shift;
    my $expires = shift;
    my @months  = ("Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec");
    my @days    = ("Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat");
    my @date    = gmtime(time + $expires);

    printf("Set-Cookie: %s=%s; expires=%s, %02d-%s-%02d %02d:%02d:%02d GMT\n", $name, 
                                                                               $value, 
                                                                               $days[$date[6]], 
                                                                               $date[3], 
                                                                               $months[$date[4]], 
                                                                               $date[5] + 1900, 
                                                                               $date[2],
                                                                               $date[1], 
                                                                               $date[0]);
}



sub CheckTime
{
    my $line  = undef;
    my $key   = undef;
    my $time  = time;

    $TIMES = {};

    open(TIMES, "+<$DDIR/times") || _Error("$!", "$DDIR/times");
    
    if( flock(TIMES, 2|4) )
    {
        my $required = 0;
        my $update   = 0;

        for( <TIMES> )
        {
            $line = $_;

            if( $line =~ /^=>\[(.*?)\]\n/ )
            {
                $key = $1;
            }
            else
            {
                $TIMES->{$key} .= $line;
            }
        }


        if( $time - $TIMES->{'Rebuild'} >= $REBUILD )
        {
            require 'common.pl';
            require 'arp.pl';

            $required = 1;
            $update   = 1;

            $TIMES->{'Rebuild'}    = "$time\n";
            $TIMES->{'Rebuild_By'} = "in.cgi\n";

            BuildPages();
        }

        if( $time - $TIMES->{'Reset'} >= $RESET )
        {
            if( !$required )
            {
                require 'common.pl';
                require 'arp.pl';
            }

            $update = 1;

            $TIMES->{'Reset'}    = "$time\n";
            $TIMES->{'Reset_By'} = "in.cgi\n";
            
            ResetCurrentHits();
        }

        if( $O_IPS && $time - $TIMES->{'IP_Clean'} >= $IP_EXPIRE )
        {
            $TIMES->{'IP_Clean'} = "$time\n";

            $update = 1;

            for( 1..255 )
            {
                open(IPFILE, ">$DDIR/ips/$_");
                close(IPFILE);
            }
        }

        
        if( $update )
        {
            seek(TIMES, 0, 0);

            for( keys %$TIMES )
            {
                print TIMES "=>[$_]\n$TIMES->{$_}";
            }

            my $tell = tell(TIMES);

            if( $tell != -1 )
            {
                truncate(TIMES, $tell);
            }
        }

        flock(TIMES, 8);
    }

    close(TIMES);
}



sub _PlainString
{
    my $string = shift;

    $string =~ s/[^a-z0-9]//gi;

    return lc($string);
}



sub _Error
{
    my $error = shift;
    my $file  = shift;

    print "Content-type: text/html\n\n";
    print "Error: $error<br />";
    print "File: $file<br />";

    exit;
}



sub _ParseRequest
{
    my $type   = shift;
    my $buffer = undef;
    my $name   = undef;
    my $value  = undef;
    my @pairs  = ();

    if( $type eq 'POST' )
    {
        read(STDIN, $buffer, $ENV{'CONTENT_LENGTH'});
    }
    else
    {
        $buffer = $ENV{'QUERY_STRING'};
    }

    @pairs = split(/&/, $buffer);
	
    for (@pairs)
    {
        ($name, $value) = split(/=/, $_);
        $value =~ tr/+/ /;
        $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
        $F{$name} = $value;
    }
}