#!/usr/bin/perl
use warnings;
use Algorithm::NaiveBayes;
local $/ = "\015";

my $pos_file = '/Users/Agnes/Documents/positive.TXT';
my $neg_file = '/Users/Agnes/Documents/negative.txt';
my $neu_file = '/Users/Agnes/Documents/neutral.txt';

my $categorizer = Algorithm::NaiveBayes->new;
my $fh;

open($fh,"<",$pos_file) or die "Could not open $pos_file: $!";
while (my $sentence = <$fh>) {
    chomp $sentence;
    my @words = split(' ',$sentence);
    my %positive;
    $positive{$_}++ for @words;
    $categorizer->add_instance(
    attributes => \%positive,
    label => 'positive');
}
close($fh);

open($fh,"<",$neg_file) or die "Could not open $neg_file: $!";
while (my $sentence = <$fh>) {
    chomp $sentence;
    my @words = split(' ',$sentence);
    my %negative;
    $negative{$_}++ for @words;
    $categorizer->add_instance(
    attributes => \%negative,
    label => 'negative');
}
close($fh);

open($fh,"<",$neu_file) or die "Could not open $neg_file: $!";
while (my $sentence = <$fh>) {
    chomp $sentence;
    my @words = split(' ',$sentence);
    my %neutral;
    $neutral{$_}++ for @words;
    $categorizer->add_instance(
    attributes => \%neutral,
    label => 'neutral');
}
close($fh);

$categorizer->train;

my $sentence_file = '/Users/Agnes/Documents/2012_10_18stem.txt';

open($fh,"<",$sentence_file) or die "Could not open $sentence_file: $!
+";
while (my $sentence = <$fh>) {
    chomp $sentence;
    my @words = split(' ',$sentence);
    my %test;
    $test{$_}++ for @words;
    my $probability = $categorizer->predict(attributes => \%test);
    if ($probability->{positive} > $probability->{negative} and
    $probability->{positive} > $probability->{neutral}) {
        print "positive: $sentence\n";
    }
    elsif ($probability->{negative} > $probability->{positive} and
    $probability->{negative} > $probability->{neutral}) {
        print "negative: $sentence\n";
    }
    elsif ($probability->{neutral} > $probability->{positive} and
    $probability->{neutral} > $probability->{negative}) {
        print "neutral: $sentence\n";
    }
}

close ($fh);