#!/usr/bin/perl -w

my %freq_spam = ();
my %freq_nonspam = ();

my $num_spam;
my $num_nonspam;

while (<>) {
  /^\s+(\d+)\s+(\d+)\s+(\d+)\s+(.+)\s*$/ or next;

  my $overall = $1+0;
  my $spam = $2+0;
  my $nonspam = $3+0;
  my $test = $4;

  if ($test eq '(all messages)') {
    $num_spam = $spam;
    $num_nonspam = $nonspam;
    next;
  }

  $freq{$test} = $overall;
  $freq_spam{$test} = $spam;
  $freq_nonspam{$test} = $nonspam;

  $mutatable{$test} = 1;
  if ($spam + $nonspam < 5) {
    $mutatable{$test} = 0;
    $ratio{$test} = 0;

  } else {
    if ($nonspam == 0) {
      $nonspam = 1;	# avoid / by 0
      $spam *= 20;	# give the spam score a bonus to make up
    }
    my $ratio = $spam / $nonspam;
    $ratio{$test} = $ratio;
  }
}

system ("mkdir tmp >/dev/null 2>&1");
open (OUT, ">tmp/ranges.data");
foreach my $test (sort { $ratio{$b} <=> $ratio{$a} } keys %freq) {
  my $overall = $freq{$test};
  my $spam = $freq_spam{$test};
  my $nonspam = $freq_nonspam{$test};
  my $ratio = $ratio{$test};
  my $mutatable = $mutatable{$test};

  if (!$mutatable) {
    printf OUT ("%3.1f %3.1f 0 $test\n", 0, 0);
    next;
  }

  if ($ratio > 200.0) { $ratio = 200.0; }	# set a ceiling
  if ($ratio < 1.0) { $ratio = 1.0; }		# and floor

  # now we have a number between 1.0 and 200.0 indicating how
  # effective the test is. Come up with a reasonable range
  # for scores based on this.
  my ($lo, $hi) = ratio_in_200_to_range($ratio);

  printf OUT ("%3.1f %3.1f 1 $test\n", $lo, $hi);
  #printf "range: %3.1f %3.1f $test ($spam / $nonspam = $ratio)\n",
  #$lo, $hi;
}
close OUT;
exit;

sub ratio_in_200_to_range {
  my $ratio = shift;

  # the current algo maps 200.0 to a range between 1.0 and 5.0,
  # and 1.0 to a range between 0.1 and 1.0.

  my $hi_lo = 200 / 1.0;
  my $hi_hi = 200 / 5.0;
  my $lo_lo =   1 / 0.1;
  my $lo_hi =   1 / 1.0;

  my $lo_diff = abs($lo_lo - $hi_lo);
  my $hi_diff = abs($lo_hi - $hi_hi);

  my $lo = ($ratio / (($ratio/200) * $lo_diff + $lo_lo));
  my $hi = ($ratio / (($ratio/200) * $hi_diff + $lo_hi));
  ($lo, $hi);
}