package DJabberd::XMLElement;
use strict;
use fields (
            'ns',        # namespace name
            'element',   # element name
            'attrs',     # hashref of {namespace}attr => value
            'children',  # arrayref of child elements of this same type, or scalars for text nodes
            );

use DJabberd::Util;

sub new {
    my $class = shift;
    if (ref $_[0]) {
        # the down-classer that subclasses can inherit
        return bless $_[0], $class;
    }

    # constructing a new XMLElement:
    my ($ns, $elementname, $attrs, $children) = @_;

    Carp::confess("children isn't an arrayref, is: $children") unless ref $children eq "ARRAY";

    my $self = fields::new($class);
    $self->{ns}       = $ns;
    $self->{element}  = $elementname;
    $self->{attrs}    = $attrs;
    $self->{children} = $children;

    return $self;
}

sub children {
    my DJabberd::XMLElement $self = shift;
    return @{ $self->{children} };
}

sub first_child {
    my $self = shift;
    return @{ $self->{children} } ? $self->{children}[0] : undef;
}

sub first_element {
    my $self = shift;
    foreach my $c (@{ $self->{children} }) {
        return $c if ref $c;
    }
    return undef;
}

sub attr {
    return $_[0]->{attrs}{$_[1]};
}

sub set_attr {
    $_[0]->{attrs}{$_[1]} = $_[2];
}

sub attrs {
    return $_[0]->{attrs};
}

sub element {
    my $self = shift;
    return ($self->{ns}, $self->{element}) if wantarray;
    return "{$self->{ns}}$self->{element}";
}

sub element_name {
    my $self = shift;
    return $self->{element};
}

sub namespace {
    my $self = shift;
    return $self->{ns};
}

sub as_xml {
    my $self = shift;
    my $nsmap = shift || {};  # localname -> uri, uri -> localname
    my $def_ns = shift;

    my ($ns, $el) = $self->element;

    # FIXME: escaping
    my $attr_str = "";
    my $attr = $self->attrs;
    foreach my $k (keys %$attr) {
        my $value = $attr->{$k};
        $k =~ s!^\{(.+)\}!!;
        my $ns = $1;
        $attr_str .= " $k='" . DJabberd::Util::exml($value) . "'";
    }

    my $xmlns = $ns eq $def_ns ? "" : " xmlns='$ns'";
    my $innards = $self->innards_as_xml($nsmap, $ns);
    return length $innards ?
        "<$el$xmlns$attr_str>$innards</$el>" :
        "<$el$xmlns$attr_str/>";
}

sub innards_as_xml {
    my $self = shift;
    my $nsmap = shift || {};
    my $def_ns = shift;

    my $ret = "";
    foreach my $c ($self->children) {
        if (ref $c) {
            $ret .= $c->as_xml($nsmap, $def_ns);
        } else {
            $ret .= DJabberd::Util::exml($c);
        }
    }
    return $ret;
}

1;