extern crate futures;
extern crate tokio_core;
extern crate tokio_xmpp;
extern crate jid;
extern crate xml;

use tokio_core::reactor::Core;
use futures::{Future, Stream, Sink, future};
use tokio_xmpp::Client;

fn main() {
    // Tokio_core context
    let mut core = Core::new().unwrap();
    // Client instance
    let client = Client::new("astrobot@example.org", "", &core.handle()).unwrap();

    // Make the two interfaces for sending and receiving independent
    // of each other so we can move one into a closure.
    let (sink, stream) = client.split();
    // Wrap sink in Option so that we can take() it for the send(self)
    // to consume and return it back when ready.
    let mut sink = Some(sink);
    let mut send = move |stanza| {
        sink = Some(
            sink.take().
                expect("sink")
                .send(stanza)
                .wait()
                .expect("sink.send")
        );
    };
    // Main loop, processes events
    let done = stream.for_each(|event| {
        if event.is_online() {
            println!("Online!");

            let presence = make_presence();
            send(presence);
        } else if let Some(stanza) = event.as_stanza() {
            if stanza.name == "message" &&
                stanza.get_attribute("type", None) != Some("error") {
                    // This is a message we'll echo
                    let from = stanza.get_attribute("from", None);
                    let body = stanza.get_child("body", Some("jabber:client"))
                        .map(|el| el.content_str());

                    match (from.as_ref(), body) {
                        (Some(from), Some(body)) => {
                            let reply = make_reply(from, body);
                            send(reply);
                        },
                        _ => (),
                    };
                }
        }

        Box::new(future::ok(()))
    });

    // Start polling `done`
    match core.run(done) {
        Ok(_) => (),
        Err(e) => {
            println!("Fatal: {}", e);
            ()
        }
    }
}

// Construct a <presence/>
fn make_presence() -> xml::Element {
    let mut presence = xml::Element::new("presence".to_owned(), None, vec![]);
    presence.tag(xml::Element::new("status".to_owned(), None, vec![]))
        .text("chat".to_owned());
    presence.tag(xml::Element::new("show".to_owned(), None, vec![]))
        .text("Echoing messages".to_owned());
    presence
}

// Construct a chat <message/>
fn make_reply(to: &str, body: String) -> xml::Element {
    let mut message = xml::Element::new(
        "message".to_owned(),
        None,
        vec![("type".to_owned(), None, "chat".to_owned()),
             ("to".to_owned(), None, to.to_owned())]
    );
    message.tag(xml::Element::new("body".to_owned(), None, vec![]))
        .text(body);
    message
}