#---------------------------------------------------------------
# ____                   _ _         ____  _
#|  _ \ ___  _   _  __ _| | |_ _   _/ ___|| |__   __ _ _ __ ___
#| |_) / _ \| | | |/ _` | | __| | | \___ \| '_ \ / _` | '__/ _ \
#|  _ < (_) | |_| | (_| | | |_| |_| |___) | | | | (_| | | |  __/
#|_| \_\___/ \__, |\__,_|_|\__|\__, |____/|_| |_|\__,_|_|  \___|
#            |___/             |___/
#
# Copyright (C) 2008 RoyaltyShare, Inc.      All Rights Reserved
#---------------------------------------------------------------

package Common::File::UTF16;
use strict;

use lib '/app/tools/common/lib';
use Common::Assert;
use Common::UTF8;
use Common::Log;

use constant kEncodingUTF16BE => 'UTF-16BE';
use constant kEncodingUTF16LE => 'UTF-16LE';

use base 'Common::File::Base';

# This will read in UTF16 files and return utf-8 by default.  May need
# to extend it to also return ASCII.

sub open {
    my $self = shift;

    my $res = $self->SUPER::open(@_);

    unless ( $self->_isBigEndian() || $self->_isLittleEndian() ) {
        $self->{_error} = "Not UTF-16 encoded";
        return;
    }

    return $res;

}

sub _isBigEndian {
    my $self = shift;
    my ( $byte0, $byte1 ) = $self->_getHeaderBytes();

    return unless ( $byte0 && $byte1 );
    return ( ord($byte0) eq 0xfe && ord($byte1) eq 0xff );
}

sub _isLittleEndian {
    my $self = shift;
    my ( $byte0, $byte1 ) = $self->_getHeaderBytes();

    #Log->alert("byte0: ", ord($byte0));
    #Log->alert("byte1: ", ord($byte1));
    return unless ( $byte0 && $byte1 );
    return ( ord($byte0) eq 0xff && ord($byte1) eq 0xfe );
}

sub _getHeaderBytes {
    my $self = shift;

    if ( !$self->{_fileheader} ) {
        my @header;
        seek( $self->filehandle, 0, 0 );
        read( $self->filehandle, $header[0], 1 );
        read( $self->filehandle, $header[1], 1 );
        $self->{_fileheader} = \@header;
    }

    #    $self->_openFile() || die "Failed to open file";

    #    return $self->fileheader ? @{$self->fileheader} : ();
    #Log->alert("header byte 0: " . ord($self->{_fileheader}->[0]));
    #Log->alert("header byte 1: " . ord($self->{_fileheader}->[1]));
    return @{ $self->fileheader };
}

sub _encoding {
    my $self = shift;

    my $encoding;

    if ( $self->_isBigEndian() ) {
        $encoding = kEncodingUTF16BE;
    } elsif ( $self->_isLittleEndian ) {
        $encoding = kEncodingUTF16LE;
    }

    return $encoding;
}

sub isValid {
    my $self = shift;
    return ( $self->_isBigEndian() || $self->_isLittleEndian() );
}

###
1;    # Play nicely.
###