#!/usr/mesh/bin/perl
#
# program name : showldc.cgi (Show Link Destination Counts)
#
# function     : Show Link-Destination-Counts on Web page. 
#
# note         : This counter is made for web site where cgi written by perl
#                is available.
#
# programmer   : makoto takenaka : takesoft@mxs.meshnet.or.jp
#
# copyright     : (c) 1996 by Takesoft
#
# version(date): 
#    1.0(Nov  5, 1996)
#    1.1(Nov  6, 1996) Add URL numbering column to table.
#    1.2(Nov  9, 1996) Add knum, first and last parameters.
#    1.3(Nov 10, 1996) Add tail parameter.
#    1.4(Nov 15, 1996) Add bdir, ldc1 and s_count parameters.
#                      Change die to "exit 1" in sub error_message.
#                      Table is centered. sub error_message does not 
#                      mail, but print out error message.
#    1.5(Dec 20, 1996) Show total hit counts $total.
#
# parameters   :
#    order=1 (original URL order)
#          2 (descending order)
#          3 (ascendting order)
#          4 (URL-alphabetic order)
#    knum=0  (no numbering)
#         1  (normal numbering)
#         2  (reverse numbering)
#    first=n (first URL data to be shown, def is 1)
#    last=n  (lase URL data to be shown, def is 1000000)
#    tail=n  (show last n URL)
#
# Form Button (1): 
#<FORM ACTION="showldc.cgi" METHOD="GET">
#<INPUT TYPE=hidden NAME="order" VALUE="2">
#<INPUT TYPE=hidden NAME="knum" VALUE="1">
#<INPUT TYPE=hidden NAME="last" VALUE="10">
#<INPUT TYPE=submit VALUE="TOP 10">
#</FORM>
#
# Form Button (2): 
#<FORM ACTION="showldc.cgi" METHOD="GET">
#<INPUT TYPE=hidden NAME="order" VALUE="3">
#<INPUT TYPE=hidden NAME="knum" VALUE="2">
#<INPUT TYPE=hidden NAME="tail" VALUE="10">
#<INPUT TYPE=submit VALUE="COUNT DOWN TOP 10">
#</FORM>
#
# Anchor tag : 
#    <A HREF="showldc.cgi?order=2&knum=1&first=1&last=20">[TOP 20]</A>
#    shows top 20 URL with numbering.
#
#(1) Send Content-type to browser.
#
   print "Content-type: text/html\n\n";
#
#(2) set constants and initial value.
#
   $limit    = 1000000; # size limit of ldc1.txt file for sorting(byte)
   $def_bdir    = "./";               # default name of directory
   $def_ldc1    = "ldc1";             # default ldc1 file(.txt)
   $def_s_count = "s_count";          # default s_count file(.txt)
   $showldc_cgi = "showldc.cgi";      # URL of showldc.cgi
   $link_page   = "link.html";        # URL of link page
   $home_page   = "../index.html";    # URL of home page
#
   $url_number = 0;                        # URL number
#
#  If absolute directory name is required, change $def_bdir such as 
#  "/home*/user_id/public_html/link/" or 
#  "/home/usr*/user_id/public_html/link/",
#  where * is a number, "link" is an example of directory of link page.
#
#(3) get parameters from string.
#
   $buffer = $ENV{'QUERY_STRING'};
#
   @pairs = split(/&/, $buffer);
#

   foreach $pair (@pairs)
      {
      ($name, $value) = split(/=/, $pair);
      $parameters{$name}    = $value;
      }
#
   $order = $parameters{'order'};
   unless($order) {$order = 1;} # Default for $order is 1.
   $knum  = $parameters{'knum'};
   $first = $parameters{'first'};
   unless($first) {$first = 1;}   # Default for $first is 1.
   $last  = $parameters{'last'};
   unless($last)  {$last = 1000000;} # Default for $last is a big number.
   $tail    = $parameters{'tail'};
   $bdir    = $parameters{'bdir'};
   unless($bdir)
      {$bdir = $def_bdir;}           # name of base directory
   $ldc1    = $parameters{'ldc1'};
   unless($ldc1)
      {$ldc1     = $def_ldc1;}
   $s_count = $parameters{'s_count'};
   unless($s_count)
      {$s_count = $def_s_count;}
#
   $ldc1_file    = "$bdir$ldc1.txt";    # file of link destination count
   $s_count_file = "$bdir$s_count.txt"; #number of guests to showldc.cgi
#
   if(-e $ldc1_file)
      {
      $ldc1_size = (-s $ldc1_file);    # Get size of ldc1_file.
      if($ldc1_size > $limit)
         {
         print "ldc1.txt file size ($ldc1_size bytes) is lager than $limit.\n";
         print "Sorting is not available, show as present order.\n";
         $order = 1;
         }
      }
   else
      {&error_message("(3): File $ldc1_file is not found.");}
#
#(4) Print first part of Web page.
#
#(4.1) Set counter.
#
   open(COUNTFILE, "+< $s_count_file")
      || &error_message("(4.1): Unable to open $s_count_file");
   flock(COUNTFILE, 2);
   $scount = <COUNTFILE>;
   $scount = $scount + 1;
   seek(COUNTFILE, 0, 0);
   print COUNTFILE $scount;
   flock(COUNTFILE, 8);
   close(COUNTFILE);
#
#(4.2) Print tags.
#
   print <<EOF;
<HTML>
<HEAD>
<TITLE>Link Destination Counts</TITLE>
</HEAD>
<BODY BGCOLOR=\"#CCFFCC\">
<P ALIGN=right>[ACCESS #$scount]</P>
<H1 ALIGN=center>Link Destination Counts</H1>
<HR>
<CENTER>
<TABLE BORDER>
EOF
   print "<CAPTION>TABLE 1   Hit Counts of URL ";
   if($order == 1)   {print "(Original Order)";}
   elsif($order == 2){print "(Descending Order)";}
   elsif($order == 3){print "(Ascending Order)";}
   elsif($order == 4){print "(URL-Alphabetic Order)";}
   else                {print "(\$order is wrong.)";}
   print "</CAPTION>\n<TR>";
   if($knum){print "<TH>Number</TH>";}
   print "<TH>Count</TH><TH>URL</TH><TH>Comments</TH></TR>";
#
#(5) Original order($order = 1)
#
#(5.1) Open $ldc1_file.
#
   if($order == 1)
      {
      open(LDC1, "$ldc1_file") 
         || &error_message("(5): Unable to open $ldc1_file as read only file");
#
#(5.2) Get number of lines $nlines if $knum=2 or $tail>0.
#
      if(($knum > 1) || ($tail > 0))
         {
         $nlines = 0;
         while(<LDC1>){$nlines++;}
         seek(LDC1, 0, 0);
         if($tail)
            {
            $first = $nlines - $tail + 1;
            $last  = $nlines
            }
         }
#
#(5.3) Show each URL line.
#
      $total = 0;
#
      while(<LDC1>)
         {
         $url_number = $url_number + 1;
         chop;
         ($count, $url, $comment) = (/^(\S+)\s+(\S+)\s*(.*)/);
         $total = $total + $count;
         next if($url_number < $first);
         if($url_number <= $last)
            {
            print "<TR>";
            if($knum == 1){print "<TD ALIGN=center>$url_number</TD>";}
            elsif($knum == 2)
               {
               $reverse = $nlines - $url_number + 1;
               print "<TD ALIGN=center>$reverse</TD>";
               }
            print "<TD ALIGN=center>$count</TD><TD>$url</TD>";
            if($comment) {print "<TD>$comment</TD>";}
            else         {print "<TD><BR></TD>";}
            print "</TR>\n";
            }
         }
      close(LDC1);
#     go to (9);
      }
#
#(6) Read ldc1.txt for $order > 1.
#
   else
      {
      open(LDC1, "$ldc1_file") 
      || &error_message("(4): Unable to open $ldc1_file as read only file");
#
      @ldc_data = <LDC1>;
      close(LDC1);
#
      $nlines   = @ldc_data;
#
      if($tail)
         {
         $first = $nlines - $tail + 1;
         $last  = $nlines
         }
#
#(7) Sort @ldc_data for $order > 1. 
#
#(7.1) Set key data.
#
      $total = 0;
#
      foreach(@ldc_data)
         {
         ($count, $url) = split;
         push(@datakeys, $count);
         push(@urlname,  $url);
         $total = $total + $count;
         }
#
#(7.2) Descending order
#
      if($order == 2)
         {
         sub descending_order{($datakeys[$b] <=> $datakeys[$a]) 
                        || ($urlname[$a]  cmp $urlname[$b]);}
         @ldc_data = @ldc_data[sort descending_order $[..$#ldc_data];
         }
#
#(7.3) Ascending order
#
      elsif($order == 3)
         {
         sub ascending_order{($datakeys[$a] <=> $datakeys[$b]) 
                       || ($urlname[$a]  cmp $urlname[$b]);}
         @ldc_data = @ldc_data[sort ascending_order $[..$#ldc_data];
         }
#
#(7.4) Alphabetic order of url
#
      elsif($order == 4)
         {
         sub alphabetic_order{$urlname[$a] cmp $urlname[$b];}
         @ldc_data = @ldc_data[sort alphabetic_order $[..$#ldc_data];
         }
      else
         {&error_message("(7.4): \$order is wrong. \$order = $order");}
#
#(8) Print count data for $order > 1.
#
      foreach(@ldc_data)
         {
         $url_number = $url_number + 1;
         last if($url_number > $last);
         next if($url_number < $first);
         chop;
         ($count, $url, $comment) = (/^(\S+)\s+(\S+)\s*(.*)/);
         print "<TR>";
         if($knum == 1){print "<TD ALIGN=center>$url_number</TD>";}
         elsif($knum == 2)
            {
            $reverse = $nlines - $url_number + 1;
            print "<TD ALIGN=center>$reverse</TD>";
            }
         print "<TD ALIGN=center>$count</TD><TD>$url</TD>";
         if($comment) {print "<TD>$comment</TD>";}
         else         {print "<TD><BR></TD>";}
         print "</TR>\n";
         }
   }
#
#(9) Print last tags.
#
   $parms="";
   if($bdir ne $def_bdir)
      {$parms = "bdir=${bdir}&";}
   if($ldc1 ne $def_ldc1)
      {$parms = "${parms}ldc1=${ldc1}&";}
   if($s_count ne $def_s_count)
      {$parms = "${parms}s_count=${s_count}&";}
#
   print "<TR>";
   if($knum > 0)
      {print "<TD><BR></TD>";}
   print "<TD ALIGN=center>$total</TD><TD>Total URL hit counts</TD><TD><BR></TD></TR>\n";
   print "</TABLE><HR>\n";
   print "<A HREF=\"${showldc_cgi}?${parms}order=1&knum=1\">[Original Order]</A>\n";
   print "<A HREF=\"${showldc_cgi}?${parms}order=2&knum=1\">[Descending Order]</A>\n";
   print "<A HREF=\"${showldc_cgi}?${parms}order=3&knum=2\">[Ascending Order]</A>\n";
   print "<A HREF=\"${showldc_cgi}?${parms}order=4\">[URL-Alphabetic Order]</A><HR>\n";
   print "<A HREF=\"$link_page\">[Back to Link Page]</A>\n";
   print "<A HREF=\"$home_page\">[Back to Home Page]</A>\n";
   print "</CENTER></BODY></HTML>\n";
#
#(10) Normal end of main program
#
   exit 0;
#
sub error_message
   {
   local($message) = @_;
#
#(sub routine) Print error message and stop.
#
   print "Error Message from showldc.cgi of Web page: \n";
   print "$message\n";
#
#  stop this perl program.
#
   exit 1;
   }