#!/usr/bin/perl -Tw
use strict;
use CGI qw(:all);

my $CGI = new CGI;
my $file;
my $countfile="downloadcounts.txt";
my $OS_Type=$CGI->param("OS");
my %OS_Count=();
my $OS_Name;
my $count;

open(COUNT,"$countfile")||die"Can't open: $!\n";
while(<COUNT>){
  ($OS_Name,$count)=split /=/;
  chomp($OS_Name);
  chomp($count);
  $OS_Count{$OS_Name}=$count;
}
close COUNT;

if($OS_Type=~/Linux/ || $OS_Type=~/Windows/){
  if(exists $OS_Count{$OS_Type}){
    $OS_Count{$OS_Type}++;
  }
  &write(\%OS_Count);
  if($OS_Type=~/Windows/){
    $file="http://tstanley.perlmonk.org/QuizTaker32-V108.zip";
    $CGI->redirect($file);
  }elsif($OS_Type=~/Linux/){
    $file="http://tstanley.perlmonk.org/QuizTaker-V1.08.tar.gz";
    $CGI->redirect($file);
  }else{
    print $CGI->header();
    print $CGI->start_html('Try Again!');
    print $CGI->h1(-align=>'center','Incorrect OS!!');
    print $CGI->end_html();
  }
}elsif($OS_Type=~/Show/){
  print $CGI->header();
  print $CGI->start_html('Number of Downloads');
  
  foreach my $key(keys %OS_Count){
    print $CGI->h3("$key = $OS_Count{$key} downloads");
  }

  print $CGI->end_html();
}

sub write{
  my $Hash=shift;

  open(COUNT,">$countfile")||die"Can't open: $!\n";
  
  foreach my $key (keys %$Hash){
    print COUNT "$key=$$Hash{$key}\n";
  }

  close COUNT;
}