# Lib siren package
package lib::siren;

# Best practice
use strict;
use warnings;

# Use carp
my $debug = 0;
if ($debug) {
	use Carp qw(carp);
}

# Constructor
sub new {
	# Extract params
	my ($class) = @_;

	# Create self hash
	my $self = {
		sirens => {},
		unique => 0,
		duplicate => 0
	};

	# Link self to package
	bless($self, $class);

	# Return self object
	return $self;
}

# Parse file
sub parse {
	my ($self, $file) = @_;

	# Open file
	open(my $fh, '<', $file) or die $!;

	# Load file in hash
	map {
		# Trim line
		chomp;
		# Skip invalid siren
		if (! /^[0-9]{9}$/) {
			if ($debug) {
				carp $_.' do not seems to be a valid siren'."\n";
			}
		# Treat valid siren
		} else {
			# First meeting
			if (! defined($self->{sirens}{$_})) {
				# Add siren to hash
				$self->{sirens}{$_} = 1;
				# Grow unique number
				$self->{unique}++;
			# Second encounter
			} else {
				# Grow siren occurence number
				$self->{sirens}{$_}++;
				# Move siren from unique to duplicate category
				if ($self->{sirens}{$_} eq 2) {
					$self->{unique}--;
					$self->{duplicate}++;
				}
			}
		}
	} <$fh>;

	# Close file
	close($fh) or die $!;

	# Return self
	return $self;
}

# Show result
sub show {
	my ($self) = @_;

	# Print result
	return 'Unique'.($self->{unique} gt 1?'s':'').': '.$self->{unique}.', duplicate'.($self->{duplicate} gt 1?'s':'').': '.$self->{duplicate}."\n";
}

1;