namespace Xmpp {

public class Stanza : Object {

    public const string ATTRIBUTE_FROM = "from";
    public const string ATTRIBUTE_ID = "id";
    public const string ATTRIBUTE_TO = "to";
    public const string ATTRIBUTE_TYPE = "type";

    public const string TYPE_ERROR = "error";

    private Jid? my_jid;
    private Jid? from_;
    private Jid? to_;

    public virtual Jid? from {
        owned get {
            string? from_attribute = stanza.get_attribute(ATTRIBUTE_FROM);
            // "when a client receives a stanza that does not include a 'from' attribute, it MUST assume that the stanza
            // is from the user's account on the server." (RFC6120 8.1.2.1)
            if (from_attribute != null) {
                try {
                    return from_ = new Jid(from_attribute);
                } catch (InvalidJidError e) {
                    warning("Ignoring invalid from Jid: %s", e.message);
                }
            }
            if (my_jid != null) {
                return my_jid.bare_jid;
            }
            return null;
        }
        set { stanza.set_attribute(ATTRIBUTE_FROM, value.to_string()); }
    }

    public virtual string? id {
        get { return stanza.get_attribute(ATTRIBUTE_ID); }
        set { stanza.set_attribute(ATTRIBUTE_ID, value); }
    }

    public virtual Jid? to {
        owned get {
            string? to_attribute = stanza.get_attribute(ATTRIBUTE_TO);
            // "if the stanza does not include a 'to' address then the client MUST treat it as if the 'to' address were
            // included with a value of the client's full JID." (RFC6120 8.1.1.1)
            try {
                return to_attribute == null ? my_jid : to_ = new Jid(to_attribute);
            } catch (InvalidJidError e) {
                warning("Ignoring invalid to Jid: %s", e.message);
            }
            return my_jid;
        }
        set { stanza.set_attribute(ATTRIBUTE_TO, value.to_string()); }
    }

    public virtual string? type_ {
        get { return stanza.get_attribute(ATTRIBUTE_TYPE); }
        set { stanza.set_attribute(ATTRIBUTE_TYPE, value); }
    }

    public StanzaNode stanza;

    public Stanza.incoming(StanzaNode stanza, Jid? my_jid) {
        this.stanza = stanza;
        this.my_jid = my_jid;
    }

    public Stanza.outgoing(StanzaNode stanza) {
        this.stanza = stanza;
    }

    public bool is_error() {
        return type_ == TYPE_ERROR;
    }

    public ErrorStanza? get_error() {
        return new ErrorStanza.from_stanza(this.stanza);
    }
}

}