package Armadito::Agent::Tools::Hostname;

use strict;
use warnings;
use base 'Exporter';

use UNIVERSAL::require();
use Encode;
use English qw(-no_match_vars);

our @EXPORT_OK = qw(
	getHostname
);

BEGIN {
	if ( $OSNAME eq 'MSWin32' ) {
		no warnings 'redefine';    ## no critic (ProhibitNoWarnings)
		Win32::API->require();

		# Kernel32.dll is used more or less everywhere.
		# Without this, Win32::API will release the DLL even
		# if it's a very bad idea
		*Win32::API::DESTROY = sub { };
	}
}

sub getHostname {
	my (%params) = @_;

	my $hostname
		= $OSNAME eq 'MSWin32'
		? _getHostnameWindows()
		: _getHostnameUnix();

	if ( $params{short} ) {
		$hostname =~ s/\..*$//;
	}

	return $hostname;
}

sub _getHostnameUnix {
	Sys::Hostname->require();
	return Sys::Hostname::hostname();
}

sub _getHostnameWindows {
	my $getComputerName = Win32::API->new( "kernel32", "GetComputerNameExW", [ "I", "P", "P" ], "N" );
	my $buffer = "\x00" x 1024;
	my $n = 1024;    #pack ("c4", 160,0,0,0);

	$getComputerName->Call( 3, $buffer, $n );

	# convert from UTF16 to UTF8
	my $hostname = substr( decode( "UCS-2le", $buffer ), 0, ord $n );

	return $hostname || $ENV{COMPUTERNAME};
}

1;
__END__

=head1 NAME

Armadito::Agent::Tools::Hostname - OS-independent hostname computing

=head1 DESCRIPTION

This module provides a generic function to retrieve host name

=head1 FUNCTIONS

=head2 getHostname()

Returns the host name.
