package My::XML::Generator;

use strict;
use warnings;

use Exporter    qw( import );
use XML::LibXML qw( );

our @EXPORT_OK = qw(
    gen_document
    gen_root_element
    gen_element
    gen_data_element
);

our %EXPORT_TAGS = ( 'all' => \@EXPORT_OK );


# --------------------
# Public Functions


sub gen_document {
    my $doc = XML::LibXML::Document->new('1.0', 'UTF-8');
    $doc->setDocumentElement(gen_root_element(@_));
    return $doc->toString();
}


# Can't use objects passed as children after calling this.
sub gen_root_element {
    my $name      = shift;
    my $children  = pop;
    my $root = XML::LibXML::Element->new($name);
    while (@_) {
        my $key = shift;
        my $val = shift;
        if ($key eq '__NAMESPACE') {
            $root->setNamespace($val);
        } else {
            $root->setAttribute($key, $val);
        }
    }
    foreach (@$children) {
        $root->addChild($_);
    }
    return $root;
}


# Can't use objects passed as children after calling this.
sub gen_element {
    my $name     = shift;
    my $children = @_ % 2 == 1 ? pop : [];
    my $ele = XML::LibXML::Element->new($name);
    while (@_) {
        $ele->setAttribute(shift, shift);
    }
    foreach (@$children) {
        $ele->addChild($_);
    }
    return $ele;
}


sub gen_data_element {
    my $name = shift;
    my $text = shift;
    my $ele = XML::LibXML::Element->new($name);
    while (@_) {
        $ele->setAttribute(shift, shift);
    }
    $ele->appendTextNode($text);
    return $ele;
}


1;


__END__

=head1 NAME

My::XML::Generator - A fast XML generator.


=head1 SYNOPSIS

    use My::XML::Generator qw( gen_document gen_element gen_data_element );

    sub gen_breakdown {
        ...
        return gen_element('PTC_Farebreakdown', [
            gen_element('PassengerTypeQuantity',
                'Code'     => format_pax_type($pax_type),
                'Quantity' => $pax_qty,
            ),
            gen_element('PassengerFare', [
                gen_element('BaseFare', 'Amount' => $base_fare),
                gen_element('Taxes', [
                    gen_data_element('Tax', 'Taxes and Surcharges', 'Amount' => $tax_and_surch),
                ]),
                gen_element('TotalFare', 'Amount' => $total),
            ]),
        ]);
    }