#!/usr/bin/perl -w
use strict;

use NetServer::Generic;
use Proc::Daemon;

my $listen_port = 8080;
my $logfile = '/tmp/proxy_log';
my $pageview_range = 20;          # seconds
my $per_page_time = 2;            # minutes

my $server_cb = sub  {
  my ($s) = shift ;   
  
  my $line1 = <STDIN>;
  
  unless($line1 =~ m[(\w+)\s+http://([^/:]+)(:(\d+))?(\S*)\s+(\S+)]) {
    print STDOUT "HTTP/1.0 400 Bad Request\nConnection: close\n\n";
    print STDOUT "HTTP/1.0 400 Bad Request\n";
    return;
  }
  my ($method, $serv, $port, $path, $version) = ($1, $2, $4, $5, $6);
  
  if($serv !~ /stats/) {    
    my $sock = IO::Socket::INET->new(PeerAddr => $serv,
				     PeerPort => $port || 80,
				     Proto    => 'tcp');
    
    print $sock "$method $path $version\n";
    print $sock "Connection: close\n";
    
    $SIG{CHLD} = 'IGNORE';
    if(my $pid = fork) {
      while(<STDIN>) {
	print $sock $_;
      }
    } else {
      while(<$sock>){
	print STDOUT $_;
      }    
    }
  } else {    
    my $stats = &getStats();
    print STDOUT "HTTP/1.1 200 OK\nContent-type: text/plain\n";
    print STDOUT "Connection: close\n\n";
    print STDOUT "Your Browsing Stats!\n\n";
    print STDOUT "$stats->{DAY} page views in the last day\n";
    print STDOUT "$stats->{WEEK} page views in the last week\n";
    print STDOUT "$stats->{MONTH} page views in the last month\n";
    print STDOUT "$stats->{YEAR} page views in the last year\n\n";
    my $avg_time = ($stats->{MONTH} / 30) * $per_page_time;

    print STDOUT "At $per_page_time minutes per page that's $avg_time minutes per day in the last month.\n\n";
      
    print STDOUT "Your favorite sites:\n\n";

    foreach(map {$_->[0]}     
	    sort{$b->[1] <=> $a->[1]} 
	    map{[$_, $stats->{BY_SERVER}{$_}{TOTAL}]}
	    (keys %{$stats->{BY_SERVER}})) {
      print STDOUT "$_\n";
      print STDOUT "--------------------------------------------\n";
      print STDOUT $stats->{BY_SERVER}{$_}{DAY} || 0, 
                   " page views in the last day\n";
      print STDOUT $stats->{BY_SERVER}{$_}{WEEK} || 0, 
                   " page views in the last week\n";
      print STDOUT $stats->{BY_SERVER}{$_}{MONTH} || 0, 
                   " page views in the last month\n";
      print STDOUT $stats->{BY_SERVER}{$_}{YEAR} || 0, 
                   " page views in the last year\n\n";
    }        
  }
  open LOG, ">>$logfile" or die "could not open $logfile";
  print LOG $serv, ' ', time, "\n";
  close LOG;  
};

my ($foo) = new NetServer::Generic;

$foo->port($listen_port);    
$foo->callback($server_cb);
$foo->mode('forking');
print "Starting server\n";
&Proc::Daemon::Init();
$foo->run();


sub getStats {
  my $day_ago = time - 60 * 60 * 24;
  my $week_ago = time - 60 * 60 * 24 * 7;
  my $month_ago = time - 60 * 60 * 24 * 7 * 30;
  my $year_ago = time - 60 * 60 * 24 * 7 * 30 * 12;
  my($serv, $time, %hits);

  open LOG, "$logfile" or die "could not open $logfile";  

  while(<LOG>) {
    ($serv, $time) = split;
    if($time - $hits{BY_SERVER}{$serv}{LAST} > $pageview_range) {
      $hits{BY_SERVER}{$serv}{HITS}{$time} = 1;
      $hits{BY_SERVER}{$serv}{LAST} = $time;	
      $hits{BY_SERVER}{$serv}{TOTAL}++;	
      if($day_ago < $time) {
	$hits{BY_SERVER}{$serv}{DAY}++;	
	$hits{BY_SERVER}{$serv}{WEEK}++;	
	$hits{BY_SERVER}{$serv}{MONTH}++;	
	$hits{BY_SERVER}{$serv}{YEAR}++;	
	$hits{DAY}++;	
	$hits{WEEK}++;	
	$hits{MONTH}++;	
	$hits{YEAR}++;	
      } elsif ($week_ago < $time) {
	$hits{BY_SERVER}{$serv}{WEEK}++;	
	$hits{BY_SERVER}{$serv}{MONTH}++;	
	$hits{BY_SERVER}{$serv}{YEAR}++;	
	$hits{WEEK}++;	
	$hits{MONTH}++;	
	$hits{YEAR}++;	
      } elsif ($month_ago < $time) {
	$hits{BY_SERVER}{$serv}{MONTH}++;	
	$hits{BY_SERVER}{$serv}{YEAR}++;	
	$hits{MONTH}++;	
	$hits{YEAR}++;		  
      } elsif ($year_ago < $time) {
	$hits{BY_SERVER}{$serv}{YEAR}++;	
	$hits{YEAR}++;       
      }
    } 
  }
  close LOG;    
  \%hits;
}