#!/usr/bin/perl

#  <IMG SRC="http://www.net.hu/cgi-bin/counterserver?identifier">
#  identifier is an alphanumeric string that identifies the counter.

# counterserver works only for homepages on a Hungary.Network server
# (hhrf.org, hrfa.org)

&initialize;
&incrementCount;      
&generateBitmap;
&writeBitmap;
exit(0);

# -----------------------------------------
sub initialize {
   $host = $ENV{"REMOTE_ADDR"};
   $referer  = $ENV{"HTTP_REFERER"};
   if ( $referer !~ m#http://([\w\.\-]+)(.*)# ) {
      &error("Not a valid referer");
   }
   $referer_host=$1;
   if( ( $referer_host !~ /(net.hu)|(hu.net)|(hungary.com)$/ ) &&
       ( $referer_host !~ /(gecse.com)|(hhrf.org)|(hrfa.org)$/ ) ) {
       &error("Not a valid referer");
   }

   $counterid = $ENV{"QUERY_STRING"};
   $counterid =~ s/\W//g;
   if($counterid eq '') {
      $counterid = "general.counter";
   }

   $minLen = 7;           # minimum number of digits in bigmap
   $isHigh = 1;           # if 1, digits are 16 pixels high, to
                          # allow room for border
   $isInverse = 1;        # If 1, digits are white on black
   # $counterFile = "/www/data/hhrf/cgi/ujcounts.$counterid";
   $counterFile = "/home/www/hhrf.org/htdocs/cgi/ujcounts.$counterid";
   # bitmap for each digit
   #  Each digit is 8 pixels wide, 10 high
   #  @invdigits are white on black, @digits black on white
   @invdigits = ("c3 99 99 99 99 99 99 99 99 c3",  # 0
                 "cf c7 cf cf cf cf cf cf cf c7",  # 1
                 "c3 99 9f 9f cf e7 f3 f9 f9 81",  # 2
                 "c3 99 9f 9f c7 9f 9f 9f 99 c3",  # 3
                 "cf cf c7 c7 cb cb cd 81 cf 87",  # 4
                 "81 f9 f9 f9 c1 9f 9f 9f 99 c3",  # 5
                 "c7 f3 f9 f9 c1 99 99 99 99 c3",  # 6
                 "81 99 9f 9f cf cf e7 e7 f3 f3",  # 7
                 "c3 99 99 99 c3 99 99 99 99 c3",  # 8
                 "c3 99 99 99 99 83 9f 9f cf e3"); # 9
   
   
      @digits = ("3c 66 66 66 66 66 66 66 66 3c",  # 0
                 "30 38 30 30 30 30 30 30 30 30",  # 1
                 "3c 66 60 60 30 18 0c 06 06 7e",  # 2
                 "3c 66 60 60 38 60 60 60 66 3c",  # 3
                 "30 30 38 38 34 34 32 7e 30 78",  # 4
                 "7e 06 06 06 3e 60 60 60 66 3c",  # 5
                 "38 0c 06 06 3e 66 66 66 66 3c",  # 6
                 "7e 66 60 60 30 30 18 18 0c 0c",  # 7
                 "3c 66 66 66 3c 66 66 66 66 3c",  # 8
                 "3c 66 66 66 66 7c 60 60 30 1c"); # 9
}

sub incrementCount 
{
   if ( -e $counterfile ) {
      open(COUNT,">$counterFile") || die "$0: can\'t open $counterFile: $!\n";
   }
   else {
      open(COUNT,">>$counterFile") || die "$0: can\'t open $counterFile: $!\n";
   }
   print COUNT "#";
   close COUNT;
   $totalReads = -s $counterFile;
}

# generateBitmap() - $count contains number to display
#                    $minLen contains minimum number of digits to display
#                    $isHigh is one for 16 bit high numbers (else 10)
#                    $isInverse is one for reverse video (white on black);
sub generateBitmap {
   $count = $totalReads;
   @bytes = ();
   $len = length($count) > $minLen ? length($count) : $minLen;
   $formattedCount = sprintf("%0${len}d",$count);
   if ( $isHigh ) {
      for ( $i = 0; $i < $len*3; $i++ ) {
         if ( $isInverse ) {
            push(@bytes,"ff");       # add three blank rows to each digit
         }
         else {
            push(@bytes,"00");
         }
      }
   }
   for ($y=0; $y < 10; $y++) {
       for ( $x=0; $x < $len; $x++ ) {
           $digit = substr($formattedCount,$x,1);
           if ( $isInverse ) {             # $inv = 1 for inverted text
               $byte = substr($invdigits[$digit],$y*3,2);
           } 
           else {
               $byte = substr($digits[$digit],$y*3,2);
           }
           push(@bytes,$byte);
       }
   }
   if ( $isHigh ) {
      for ( $i = 0; $i < $len*3; $i++ ) {
         if ( $isInverse ) {
            push(@bytes,"ff");       # add three blank rows to each digit
         }
         else {
            push(@bytes,"00");
         }
      }
   }
}

sub writeBitmap {
   print ("Content-type: image/x-xbitmap\n\n");
   if ($isHigh) {
      printf("#define count_width %d\n#define count_height 16\n", 
              $len*8);
   }
   else {
      printf("#define count_width %d\n#define count_height 10\n", 
              $len*8);
   }
   printf STDOUT "static char count_bits[] = {\n";
   for ( $i = 0; $i < ($#bytes + 1); $i++ ) {
       print("0x$bytes[$i]");
       if ( $i != $#bytes ) {
          print(",");
          if ( ($i+1) % 7 == 0) {
             print("\n");
         }
      }
   }
   print("};\n");
}

sub error
{
   local($err)=@_;
   print "Content-type: text/html\n\n";
   print $err;
   exit;
}