#!/usr/bin/perl -w
#
# <@LICENSE>
# Copyright 2004 Apache Software Foundation
# 
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# 
#     http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# </@LICENSE>

use FindBin;
use Getopt::Std;
getopts("fm:M:X:l:L:pxhc:at:s:i");

use vars qw {
  $opt_f $opt_m $opt_M $opt_X $opt_p $opt_x $opt_h $opt_l $opt_L $opt_c
  $opt_a $opt_t $opt_s $opt_i $sorting
};

sub usage {
  die "hit-frequencies [-c rules dir] [-f] [-m RE] [-M RE] [-X RE] [-l LC]
                [-s SC] [-a] [-p] [-x] [-i] [spam log] [ham log]

    -c p   use p as the rules directory
    -f     falses. count only false-negative or false-positive matches
    -m RE  print rules matching regular expression
    -t RE  print rules with tflags matching regular expression
    -M RE  only consider log entries matching regular expression
    -X RE  don't consider log entries matching regular expression
    -l LC  also print language specific rules for lang code LC (or 'all')
    -L LC  only print language specific rules for lang code LC (or 'all')
    -a     display all tests
    -p     percentages. implies -x
    -x     extended output, with S/O ratio and scores
    -s SC  which scoreset to use
    -i     use IG (information gain) for ranking

    options -l and -L are mutually exclusive.

    options -M and -X are *not* mutually exclusive.

    if either the spam or and ham logs are unspecified, the defaults
    are \"spam.log\" and \"ham.log\" in the cwd.

";
}

usage() if($opt_h || ($opt_l && $opt_L));

if ($opt_p) {
  $opt_x = 1;
}

$opt_s = 0 if ( !defined $opt_s );

my $cffile = $opt_c || "$FindBin::Bin/../rules";

my %freq_spam = ();
my %freq_ham = ();
my $num_spam = 0;
my $num_ham = 0;
my %ranking = ();
my $ok_lang = '';

readscores($cffile);

$ok_lang = lc ($opt_l || $opt_L || '');
if ($ok_lang eq 'all') { $ok_lang = '.'; }

foreach my $key (keys %rules) {

  if ( ($opt_L && !$rules{$key}->{lang}) ||
       ($rules{$key}->{lang} &&
         (!$ok_lang || $rules{$key}->{lang} !~ /^$ok_lang/i)
     ) ) {
    delete $rules{$key} ; next;
  }

  $freq_spam{$key} = 0;
  $freq_ham{$key} = 0;
}

readlogs();

my $hdr_all = $num_spam + $num_ham;
my $hdr_spam = $num_spam;
my $hdr_ham = $num_ham;

if ($opt_p) {
  my $sorting = $opt_i ? "IG" : "RANK";
  if ($opt_f) {
    printf "%7s %7s %7s  %6s  %6s  %6s  %s\n",
  	"OVERALL%", "FNEG%", "FPOS%", "S/O", $sorting, "SCORE", "NAME";
  } else {
    printf "%7s %7s  %7s  %6s  %6s  %6s  %s\n",
  	"OVERALL%", "SPAM%", "HAM%", "S/O", $sorting, "SCORE", "NAME";
  }
  printf "%7d  %7d  %7d  %7.3f %6.2f  %6.2f  (all messages)\n",
  	$hdr_all, $hdr_spam, $hdr_ham,
        soratio ($num_spam,$num_ham), 0, 0;

  $hdr_spam = ($num_spam / $hdr_all) * 100.0;
  $hdr_ham = ($num_ham / $hdr_all) * 100.0;
  $hdr_all = 100.0;             # this is obvious
  printf "%7.3f  %7.4f  %7.4f  %7.3f %6.2f  %6.2f  (all messages as %%)\n",
  	$hdr_all, $hdr_spam, $hdr_ham,
        soratio ($num_spam,$num_ham), 0, 0;

} elsif ($opt_x) {
  printf "%7s %7s  %7s  %6s  %6s %6s  %s\n",
  	"OVERALL%", "SPAM%", "HAM%", "S/O", $sorting, "SCORE", "NAME";
  printf "%7d  %7d  %7d  %7.3f %6.2f %6.2f  (all messages)\n",
  	$hdr_all, $hdr_spam, $hdr_ham,
        soratio ($num_spam,$num_ham), 0, 0;

} else {
  printf "%10s  %10s  %10s  %s\n",
  	"OVERALL", "SPAM", "HAM", "NAME";
  printf "%10d  %10d  %10d  (all messages)\n",
  	$hdr_all, $hdr_spam, $hdr_ham;
}

my %done = ();
my @tests = ();
my $rank_hi = 0;
my $rank_lo = 9999999;

# variables for wanted/unwanted RANK
my %wanted;
my %unwanted;
my %wranks;
my %uranks;

foreach my $test (keys %freq_spam, keys %freq_ham) {
  next unless (exists $rules{$test});           # only valid tests
  next if (!$opt_a && $rules{$test}->{issubrule});

  next if $done{$test}; $done{$test} = 1;
  push (@tests, $test);

  my $isnice = 0;
  if ($rules{$test}->{tflags} =~ /nice/) { $isnice = 1; }

  my $fs = $freq_spam{$test}; $fs ||= 0;
  my $fn = $freq_ham{$test}; $fn ||= 0;
  my $fsadj = $num_spam == 0 ? 0 : ($fs / ($num_spam)) * 100.0;
  my $fnadj = $num_ham == 0 ? 0 : ($fn / ($num_ham)) * 100.0;

  my $soratio = $soratio{$test} = soratio ($fsadj, $fnadj);

  if ($isnice) {
    $soratio = 1.0 - $soratio;
    my $tmp = $fsadj; $fsadj = $fnadj; $fnadj = $tmp;
  }

  if ($opt_i) {
    # come up with a ranking
    my $rank;

    # New new system: from "Learning to Filter Unsolicited Commercial E-Mail",
    # Ion Androutsopoulos et al: determine the information gain IG(X, C) of the
    # Boolean attributes (ie. the rules). Measures "the average reduction in
    # the entropy of C (classification) given the value of X (the rule)". Makes
    # a good ranking measure with a proper statistical basis. ;)
    #
    # Still would like to get an entropy measure in, too.
    #
    #             sum                                    P(X = x ^ C = c)
    # IG(X,C) = x in [0, 1]    P(X = x ^ C = c) . log2( ------------------- )
    #           c in [Ch, Cs]                           P(X = x) . P(C = c)
    #
    my $safe_nspam = $num_spam || 0.0000001;
    my $safe_nham = $num_ham || 0.0000001;

    my $num_all = ($num_spam + $num_ham);
    my $safe_all = $num_all || 0.0000001;
    my $f_all = $fs+$fn;

    my $px0 = (($num_all - $f_all) / $safe_all);         # P(X = 0)
    my $px1 = ($f_all / $safe_all);                      # P(X = 1)
    my $pccs = ($num_spam / $safe_all);                  # P(C = Cs)
    my $pcch = ($num_ham / $safe_all);                   # P(C = Ch)
    my $px1ccs = ($fs / $safe_nspam);                   # P(X = 1 ^ C = Cs)
    my $px1cch = ($fn / $safe_nham);                    # P(X = 1 ^ C = Ch)
    my $px0ccs = (($num_spam - $fs) / $safe_nspam);     # P(X = 0 ^ C = Cs)
    my $px0cch = (($num_ham - $fn) / $safe_nham);       # P(X = 0 ^ C = Ch)
    my $safe_px0_dot_pccs = ($px0 * $pccs) || 0.00000001;
    my $safe_px0_dot_pcch = ($px0 * $pcch) || 0.00000001;
    my $safe_px1_dot_pccs = ($px1 * $pccs) || 0.00000001;
    my $safe_px1_dot_pcch = ($px1 * $pcch) || 0.00000001;

    sub log2 { return log($_[0]) / 0.693147180559945; } # log(2) = 0.6931...

    my $safe_px0ccs = ($px0ccs || 0.0000001);
    my $safe_px0cch = ($px0cch || 0.0000001);
    my $safe_px1ccs = ($px1ccs || 0.0000001);
    my $safe_px1cch = ($px1cch || 0.0000001);
    $rank = ( $px0ccs * log2($safe_px0ccs / $safe_px0_dot_pccs) ) +
                    ( $px0cch * log2($safe_px0cch / $safe_px0_dot_pcch) ) +
                    ( $px1ccs * log2($safe_px1ccs / $safe_px1_dot_pccs) ) +
                    ( $px1cch * log2($safe_px1cch / $safe_px1_dot_pcch) );

    $ranking{$test} = $rank;
    $rank_hi = $rank if ($rank > $rank_hi);
    $rank_lo = $rank if ($rank < $rank_lo);
  }
  else {
    # basic wanted/unwanted ranking
    $wanted{$test} = $isnice ? $fn : $fs;
    $unwanted{$test} = $isnice ? $fs : $fn;
    # count number of ranks of each type
    $wranks{$wanted{$test}} = 1;
    $uranks{$unwanted{$test}} = 1;
  }
}

# finish basic wanted/unwanted ranking
if (! $opt_i) {
  my @wanted = sort { $wanted{$a} <=> $wanted{$b} } keys %wanted;
  my @unwanted = sort { $unwanted{$b} <=> $unwanted{$a} } keys %unwanted;

  # first half of ranking is the wanted rank
  my $position = 0;
  my $last = undef;
  for my $test (@wanted) {
    $position++ if defined $last && $last != $wanted{$test};
    $ranking{$test} += $position;
    $last = $wanted{$test}
  }

  # second half of ranking is the unwanted rank
  my $normalize = (scalar keys %wranks) / (scalar keys %uranks);
  $position = 0;
  $last = undef;
  for my $test (@unwanted) {
    $position++ if defined $last && $last != $unwanted{$test};
    $ranking{$test} += ($position * $normalize);
    $last = $unwanted{$test};
    $rank_hi = $ranking{$test} if ($ranking{$test} > $rank_hi);
    $rank_lo = $ranking{$test} if ($ranking{$test} < $rank_lo);
  }
}

{
  # now normalise the rankings to [0, 1]
  $rank_hi -= $rank_lo;
  foreach $test (@tests) {
    $ranking{$test} = $rank_hi == 0 ? 0.001 : ($ranking{$test} - $rank_lo) / ($rank_hi);
  }
}

foreach $test (sort { $ranking{$b} <=> $ranking{$a} } @tests) {
  next unless (exists $rules{$test});           # only valid tests
  next if (!$opt_a && $rules{$test}->{issubrule});

  my $fs = $freq_spam{$test}; $fs ||= 0;
  my $fn = $freq_ham{$test}; $fn ||= 0;
  my $fa = $fs+$fn;

  next if ($opt_m && $test !~ m/$opt_m/);	# match certain tests
  next if ($opt_t && $rules{$test}->{tflags} !~ /$opt_t/); # match tflags

  if (!$opt_a && !$opt_t) {
    next if ($rules{$test}->{tflags} =~ /net/ && ($opt_s % 2 == 0));   # not net tests
    next if ($rules{$test}->{tflags} =~ /userconf/); # or userconf
  }

  # adjust based on corpora sizes (and cvt to % while we're at it)
  my $fsadj = $num_spam == 0 ? 0 : ($fs / ($num_spam)) * 100.0;
  my $fnadj = $num_ham == 0 ? 0 : ($fn / ($num_ham)) * 100.0;

  if ($opt_f && $fsadj == 0 && $fnadj == 0) { next; }

  if ($opt_p) {
    $fa = ($fa / ($num_spam + $num_ham)) * 100.0;
    $fs = $fsadj;
    $fn = $fnadj;
  }

  my $soratio = $soratio{$test};
  if (!defined $soratio) {
    $soratio{$test} = soratio ($fsadj, $fnadj);
  }

  if ($opt_p) {
    printf "%7.3f  %7.4f  %7.4f  %7.3f %6.2f  %6.2f  %s\n",
  	$fa, $fs, $fn, $soratio, $ranking{$test}, $scores{$test}, $test;

  } elsif ($opt_x) {
    printf "%7d  %7d  %7d  %7.3f %6.2f %6.2f  %s\n",
  	$fa, $fs, $fn, $soratio, $ranking{$test}, $scores{$test}, $test;

  } else {
    printf "%10d  %10d  %10d  %s\n", $fa, $fs, $fn, $test;
  }
}
exit;



sub readlogs {
  my $spam = $ARGV[0] || "spam.log";
  my $ham = $ARGV[1] || (-f "good.log" ? "good.log" : "ham.log");

  foreach my $file ($spam, $ham) {
    open (IN, "<$file") || die "Could not open file '$file': $!";

    my $isspam = 0; ($file eq $spam) and $isspam = 1;

    while (<IN>) {
      next if (/^#/);
      next unless (!$opt_M || /$opt_M/o);
      next if ($opt_X && /$opt_X/o);

      /^(.)\s+(-?\d+)\s+(\S+)\s*(\S*)/ or next;
      my $caught = ($1 eq 'Y');
      my $hits = $2;
      $_ = $4; s/,,+/,/g;

      if ($isspam) {
        if ($opt_f) {
          if (!$caught) { $num_spam++; }
        } else {
          $num_spam++;
        }
      } else {
        if ($opt_f) {
          if ($caught) { $num_ham++; }
        } else {
          $num_ham++;
        }
      }

      my @tests = split (/,/, $_);
      foreach my $t (@tests) {
	next if ($t eq '');
	if ($isspam) {
          if ($opt_f) {
            if (!$caught) { $freq_spam{$t}++; }
          } else {
            $freq_spam{$t}++;
          }
	} else {
          if ($opt_f) {
            if ($caught) { $freq_ham{$t}++; }
          } else {
            $freq_ham{$t}++;
          }
	}
      }
    }
    close IN;
  }
}


sub readscores {
  my($cffile) = @_;
  system ("$FindBin::Bin/parse-rules-for-masses -d \"$cffile\" -s $opt_s") and die;
  require "./tmp/rules.pl";
}

sub soratio {
  my ($s, $n) = @_;

  $s ||= 0;
  $n ||= 0;

  if ($s + $n > 0) {
      return $s / ($s + $n);
  } else {
      return 0.5;		# no results -> not effective
  }
}

sub tcr {
  my ($nspam, $nlegit, $nspamspam, $nlegitspam) = @_;
  my $nspamlegit = $nspam - $nspamspam;
  my $nlegitlegit = $nlegit - $nlegitspam;

  my $lambda = 50;

  my $werr = ($lambda * $nlegitspam + $nspamlegit)
                  / ($lambda * $nlegit + $nspam);

  my $werr_base = $nspam
                  / ($lambda * $nlegit + $nspam);

  $werr ||= 0.000001;     # avoid / by 0
  my $tcr = $werr_base / $werr;
  return $tcr;
}
