implement sink and stream with tokio::spawn

11 files changed, 336 insertions, 101 deletions

diff --git a/jabber/src/client.rs b/jabber/src/client.rs
index c6cab07..32b8f6e 100644
--- a/jabber/src/client.rs
+++ b/jabber/src/client.rs
@@ -1,6 +1,12 @@
-use std::{pin::pin, sync::Arc, task::Poll};
+use std::{
+    borrow::Borrow,
+    future::Future,
+    pin::pin,
+    sync::Arc,
+    task::{ready, Poll},
+};
 
-use futures::{Sink, Stream, StreamExt};
+use futures::{FutureExt, Sink, SinkExt, Stream, StreamExt};
 use jid::ParseError;
 use rsasl::config::SASLConfig;
 use stanza::{
@@ -8,9 +14,11 @@ use stanza::{
     sasl::Mechanisms,
     stream::{Feature, Features},
 };
+use tokio::sync::Mutex;
 
 use crate::{
     connection::{Tls, Unencrypted},
+    jabber_stream::bound_stream::BoundJabberStream,
     Connection, Error, JabberStream, Result, JID,
 };
 
@@ -56,7 +64,7 @@ impl JabberClient {
         }
     }
 
-    pub(crate) fn inner(self) -> Result<JabberStream<Tls>> {
+    pub(crate) fn inner(self) -> Result<BoundJabberStream<Tls>> {
         match self.connection {
             ConnectionState::Disconnected => return Err(Error::Disconnected),
             ConnectionState::Connecting(_connecting) => return Err(Error::Connecting),
@@ -64,21 +72,137 @@ impl JabberClient {
         }
     }
 
-    pub async fn send_stanza(&mut self, stanza: &Stanza) -> Result<()> {
-        match &mut self.connection {
-            ConnectionState::Disconnected => return Err(Error::Disconnected),
-            ConnectionState::Connecting(_connecting) => return Err(Error::Connecting),
-            ConnectionState::Connected(jabber_stream) => {
-                Ok(jabber_stream.send_stanza(stanza).await?)
-            }
-        }
+    // pub async fn send_stanza(&mut self, stanza: &Stanza) -> Result<()> {
+    //     match &mut self.connection {
+    //         ConnectionState::Disconnected => return Err(Error::Disconnected),
+    //         ConnectionState::Connecting(_connecting) => return Err(Error::Connecting),
+    //         ConnectionState::Connected(jabber_stream) => {
+    //             Ok(jabber_stream.send_stanza(stanza).await?)
+    //         }
+    //     }
+    // }
+}
+
+impl Sink<Stanza> for JabberClient {
+    type Error = Error;
+
+    fn poll_ready(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> Poll<std::result::Result<(), Self::Error>> {
+        self.get_mut().connection.poll_ready_unpin(cx)
+    }
+
+    fn start_send(
+        self: std::pin::Pin<&mut Self>,
+        item: Stanza,
+    ) -> std::result::Result<(), Self::Error> {
+        self.get_mut().connection.start_send_unpin(item)
+    }
+
+    fn poll_flush(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> Poll<std::result::Result<(), Self::Error>> {
+        self.get_mut().connection.poll_flush_unpin(cx)
+    }
+
+    fn poll_close(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> Poll<std::result::Result<(), Self::Error>> {
+        self.get_mut().connection.poll_flush_unpin(cx)
+    }
+}
+
+impl Stream for JabberClient {
+    type Item = Result<Stanza>;
+
+    fn poll_next(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> Poll<Option<Self::Item>> {
+        self.get_mut().connection.poll_next_unpin(cx)
     }
 }
 
 pub enum ConnectionState {
     Disconnected,
     Connecting(Connecting),
-    Connected(JabberStream<Tls>),
+    Connected(BoundJabberStream<Tls>),
+}
+
+impl Sink<Stanza> for ConnectionState {
+    type Error = Error;
+
+    fn poll_ready(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> Poll<std::result::Result<(), Self::Error>> {
+        match self.get_mut() {
+            ConnectionState::Disconnected => Poll::Ready(Err(Error::Disconnected)),
+            ConnectionState::Connecting(_connecting) => Poll::Pending,
+            ConnectionState::Connected(bound_jabber_stream) => {
+                bound_jabber_stream.poll_ready_unpin(cx)
+            }
+        }
+    }
+
+    fn start_send(
+        self: std::pin::Pin<&mut Self>,
+        item: Stanza,
+    ) -> std::result::Result<(), Self::Error> {
+        match self.get_mut() {
+            ConnectionState::Disconnected => Err(Error::Disconnected),
+            ConnectionState::Connecting(_connecting) => Err(Error::Connecting),
+            ConnectionState::Connected(bound_jabber_stream) => {
+                bound_jabber_stream.start_send_unpin(item)
+            }
+        }
+    }
+
+    fn poll_flush(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> Poll<std::result::Result<(), Self::Error>> {
+        match self.get_mut() {
+            ConnectionState::Disconnected => Poll::Ready(Err(Error::Disconnected)),
+            ConnectionState::Connecting(_connecting) => Poll::Pending,
+            ConnectionState::Connected(bound_jabber_stream) => {
+                bound_jabber_stream.poll_flush_unpin(cx)
+            }
+        }
+    }
+
+    fn poll_close(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> Poll<std::result::Result<(), Self::Error>> {
+        match self.get_mut() {
+            ConnectionState::Disconnected => Poll::Ready(Err(Error::Disconnected)),
+            ConnectionState::Connecting(_connecting) => Poll::Pending,
+            ConnectionState::Connected(bound_jabber_stream) => {
+                bound_jabber_stream.poll_close_unpin(cx)
+            }
+        }
+    }
+}
+
+impl Stream for ConnectionState {
+    type Item = Result<Stanza>;
+
+    fn poll_next(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> Poll<Option<Self::Item>> {
+        match self.get_mut() {
+            ConnectionState::Disconnected => Poll::Ready(Some(Err(Error::Disconnected))),
+            ConnectionState::Connecting(_connecting) => Poll::Pending,
+            ConnectionState::Connected(bound_jabber_stream) => {
+                bound_jabber_stream.poll_next_unpin(cx)
+            }
+        }
+    }
 }
 
 impl ConnectionState {
@@ -150,7 +274,9 @@ impl ConnectionState {
                         ))
                     }
                     Connecting::Bind(jabber_stream) => {
-                        self = ConnectionState::Connected(jabber_stream.bind(jid).await?)
+                        self = ConnectionState::Connected(
+                            jabber_stream.bind(jid).await?.to_bound_jabber(),
+                        )
                     }
                 },
                 connected => return Ok(connected),
@@ -194,11 +320,20 @@ pub enum InsecureConnecting {
 
 #[cfg(test)]
 mod tests {
-    use std::time::Duration;
+    use std::{sync::Arc, time::Duration};
 
     use super::JabberClient;
+    use futures::{SinkExt, StreamExt};
+    use stanza::{
+        client::{
+            iq::{Iq, IqType, Query},
+            Stanza,
+        },
+        xep_0199::Ping,
+    };
     use test_log::test;
-    use tokio::time::sleep;
+    use tokio::{sync::Mutex, time::sleep};
+    use tracing::info;
 
     #[test(tokio::test)]
     async fn login() {
@@ -206,4 +341,50 @@ mod tests {
         client.connect().await.unwrap();
         sleep(Duration::from_secs(5)).await
     }
+
+    #[test(tokio::test)]
+    async fn ping_parallel() {
+        let mut client = JabberClient::new("test@blos.sm", "slayed").unwrap();
+        client.connect().await.unwrap();
+        sleep(Duration::from_secs(5)).await;
+        let jid = client.jid.clone();
+        let server = client.server.clone();
+        let mut client = Arc::new(Mutex::new(client));
+
+        tokio::join!(
+            async {
+                let mut client = client.lock().await;
+                client
+                    .send(Stanza::Iq(Iq {
+                        from: Some(jid.clone()),
+                        id: "c2s1".to_string(),
+                        to: Some(server.clone().try_into().unwrap()),
+                        r#type: IqType::Get,
+                        lang: None,
+                        query: Some(Query::Ping(Ping)),
+                        errors: Vec::new(),
+                    }))
+                    .await;
+            },
+            async {
+                let mut client = client.lock().await;
+                client
+                    .send(Stanza::Iq(Iq {
+                        from: Some(jid.clone()),
+                        id: "c2s2".to_string(),
+                        to: Some(server.clone().try_into().unwrap()),
+                        r#type: IqType::Get,
+                        lang: None,
+                        query: Some(Query::Ping(Ping)),
+                        errors: Vec::new(),
+                    }))
+                    .await;
+            },
+            async {
+                while let Some(stanza) = client.lock().await.next().await {
+                    info!("{:#?}", stanza);
+                }
+            }
+        );
+    }
 }
diff --git a/jabber/src/error.rs b/jabber/src/error.rs
index 6671fe6..902061e 100644
--- a/jabber/src/error.rs
+++ b/jabber/src/error.rs
@@ -5,6 +5,7 @@ use rsasl::mechname::MechanismNameError;
 use stanza::client::error::Error as ClientError;
 use stanza::sasl::Failure;
 use stanza::stream::Error as StreamError;
+use tokio::task::JoinError;
 
 #[derive(Debug)]
 pub enum Error {
@@ -28,6 +29,7 @@ pub enum Error {
     MissingError,
     Disconnected,
     Connecting,
+    JoinError(JoinError),
 }
 
 #[derive(Debug)]
@@ -42,6 +44,12 @@ impl From<rsasl::prelude::SASLError> for Error {
     }
 }
 
+impl From<JoinError> for Error {
+    fn from(e: JoinError) -> Self {
+        Self::JoinError(e)
+    }
+}
+
 impl From<peanuts::DeserializeError> for Error {
     fn from(e: peanuts::DeserializeError) -> Self {
         Error::Deserialization(e)
diff --git a/jabber/src/jabber_stream.rs b/jabber/src/jabber_stream.rs
index d981f8f..89890a8 100644
--- a/jabber/src/jabber_stream.rs
+++ b/jabber/src/jabber_stream.rs
@@ -27,7 +27,7 @@ pub mod bound_stream;
 // open stream (streams started)
 pub struct JabberStream<S> {
     reader: Reader<ReadHalf<S>>,
-    writer: Writer<WriteHalf<S>>,
+    pub(crate) writer: Writer<WriteHalf<S>>,
 }
 
 impl<S> JabberStream<S>
@@ -368,12 +368,12 @@ mod tests {
     async fn sink() {
         let mut client = JabberClient::new("test@blos.sm", "slayed").unwrap();
         client.connect().await.unwrap();
-        let stream = client.inner().unwrap();
-        let sink = sink::unfold(stream, |mut stream, stanza: Stanza| async move {
-            stream.writer.write(&stanza).await?;
-            Ok::<JabberStream<Tls>, Error>(stream)
-        });
-        todo!()
+        // let stream = client.inner().unwrap();
+        // let sink = sink::unfold(stream, |mut stream, stanza: Stanza| async move {
+        //     stream.writer.write(&stanza).await?;
+        //     Ok::<JabberStream<Tls>, Error>(stream)
+        // });
+        // todo!()
         // let _jabber = Connection::connect_user("test@blos.sm", "slayed".to_string())
         //     .await
         //     .unwrap()
diff --git a/jabber/src/jabber_stream/bound_stream.rs b/jabber/src/jabber_stream/bound_stream.rs
index ca93421..c0d67b0 100644
--- a/jabber/src/jabber_stream/bound_stream.rs
+++ b/jabber/src/jabber_stream/bound_stream.rs
@@ -1,70 +1,71 @@
+use std::future::ready;
 use std::pin::pin;
 use std::pin::Pin;
 use std::sync::Arc;
+use std::task::Poll;
 
+use futures::ready;
+use futures::FutureExt;
 use futures::{sink, stream, Sink, Stream};
 use peanuts::{Reader, Writer};
 use pin_project::pin_project;
 use stanza::client::Stanza;
 use tokio::io::{AsyncRead, AsyncWrite, ReadHalf, WriteHalf};
 use tokio::sync::Mutex;
+use tokio::task::JoinHandle;
 
 use crate::Error;
 
 use super::JabberStream;
 
 #[pin_project]
-pub struct BoundJabberStream<R, W, S>
+pub struct BoundJabberStream<S>
 where
-    R: Stream,
-    W: Sink<Stanza>,
     S: AsyncWrite + AsyncRead + Unpin + Send,
 {
-    reader: Arc<Mutex<Option<Reader<ReadHalf<S>>>>>,
-    writer: Arc<Mutex<Option<Writer<WriteHalf<S>>>>>,
-    stream: R,
-    sink: W,
+    reader: Arc<Mutex<Reader<ReadHalf<S>>>>,
+    writer: Arc<Mutex<Writer<WriteHalf<S>>>>,
+    write_handle: Option<JoinHandle<Result<(), Error>>>,
+    read_handle: Option<JoinHandle<Result<Stanza, Error>>>,
 }
 
-impl<R, W, S> BoundJabberStream<R, W, S>
+impl<S> BoundJabberStream<S>
 where
-    R: Stream,
-    W: Sink<Stanza>,
     S: AsyncWrite + AsyncRead + Unpin + Send,
 {
     // TODO: look into biased mutex, to close stream ASAP
-    pub async fn close_stream(self) -> Result<JabberStream<S>, Error> {
-        if let Some(reader) = self.reader.lock().await.take() {
-            if let Some(writer) = self.writer.lock().await.take() {
-                // TODO: writer </stream:stream>
-                return Ok(JabberStream { reader, writer });
-            }
-        }
-        return Err(Error::StreamClosed);
-    }
+    // TODO: put into connection
+    // pub async fn close_stream(self) -> Result<JabberStream<S>, Error> {
+    //     let reader = self.reader.lock().await.into_self();
+    //     let writer = self.writer.lock().await.into_self();
+    //     // TODO: writer </stream:stream>
+    //     return Ok(JabberStream { reader, writer });
+    // }
 }
 
 pub trait JabberStreamTrait: AsyncWrite + AsyncRead + Unpin + Send {}
 
-impl<R, W, S> Sink<Stanza> for BoundJabberStream<R, W, S>
+impl<S> Sink<Stanza> for BoundJabberStream<S>
 where
-    R: Stream,
-    W: Sink<Stanza> + Unpin,
-    S: AsyncWrite + AsyncRead + Unpin + Send,
+    S: AsyncWrite + AsyncRead + Unpin + Send + 'static,
 {
-    type Error = <W as Sink<Stanza>>::Error;
+    type Error = Error;
 
     fn poll_ready(
         self: std::pin::Pin<&mut Self>,
         cx: &mut std::task::Context<'_>,
     ) -> std::task::Poll<Result<(), Self::Error>> {
-        let this = self.project();
-        pin!(this.sink).poll_ready(cx)
+        self.poll_flush(cx)
     }
 
     fn start_send(self: std::pin::Pin<&mut Self>, item: Stanza) -> Result<(), Self::Error> {
         let this = self.project();
-        pin!(this.sink).start_send(item)
+        if let Some(_write_handle) = this.write_handle {
+            panic!("start_send called without poll_ready")
+        } else {
+            *this.write_handle = Some(tokio::spawn(write(this.writer.clone(), item)));
+            Ok(())
+        }
     }
 
     fn poll_flush(
@@ -72,32 +73,55 @@ where
         cx: &mut std::task::Context<'_>,
     ) -> std::task::Poll<Result<(), Self::Error>> {
         let this = self.project();
-        pin!(this.sink).poll_flush(cx)
+        Poll::Ready(if let Some(join_handle) = this.write_handle.as_mut() {
+            match ready!(join_handle.poll_unpin(cx)) {
+                Ok(state) => {
+                    *this.write_handle = None;
+                    state
+                }
+                Err(err) => {
+                    *this.write_handle = None;
+                    Err(err.into())
+                }
+            }
+        } else {
+            Ok(())
+        })
     }
 
     fn poll_close(
         self: std::pin::Pin<&mut Self>,
         cx: &mut std::task::Context<'_>,
     ) -> std::task::Poll<Result<(), Self::Error>> {
-        let this = self.project();
-        pin!(this.sink).poll_close(cx)
+        self.poll_flush(cx)
     }
 }
 
-impl<R, W, S> Stream for BoundJabberStream<R, W, S>
+impl<S> Stream for BoundJabberStream<S>
 where
-    R: Stream + Unpin,
-    W: Sink<Stanza>,
-    S: AsyncWrite + AsyncRead + Unpin + Send,
+    S: AsyncWrite + AsyncRead + Unpin + Send + 'static,
 {
-    type Item = <R as Stream>::Item;
+    type Item = Result<Stanza, Error>;
 
     fn poll_next(
         self: Pin<&mut Self>,
         cx: &mut std::task::Context<'_>,
     ) -> std::task::Poll<Option<Self::Item>> {
         let this = self.project();
-        pin!(this.stream).poll_next(cx)
+
+        loop {
+            if let Some(join_handle) = this.read_handle.as_mut() {
+                let stanza = ready!(join_handle.poll_unpin(cx));
+                if let Ok(item) = stanza {
+                    *this.read_handle = None;
+                    return Poll::Ready(Some(item));
+                } else if let Err(err) = stanza {
+                    return Poll::Ready(Some(Err(err.into())));
+                }
+            } else {
+                *this.read_handle = Some(tokio::spawn(read(this.reader.clone())))
+            }
+        }
     }
 }
 
@@ -105,49 +129,36 @@ impl<S> JabberStream<S>
 where
     S: AsyncWrite + AsyncRead + Unpin + Send,
 {
-    pub fn to_bound_jabber(self) -> BoundJabberStream<impl Stream, impl Sink<Stanza>, S> {
-        let reader = Arc::new(Mutex::new(Some(self.reader)));
-        let writer = Arc::new(Mutex::new(Some(self.writer)));
-        let sink = sink::unfold(writer.clone(), |writer, s: Stanza| async move {
-            write(writer, s).await
-        });
-        let stream = stream::unfold(reader.clone(), |reader| async { read(reader).await });
+    pub fn to_bound_jabber(self) -> BoundJabberStream<S> {
+        let reader = Arc::new(Mutex::new(self.reader));
+        let writer = Arc::new(Mutex::new(self.writer));
         BoundJabberStream {
-            sink,
-            stream,
             writer,
             reader,
+            write_handle: None,
+            read_handle: None,
         }
     }
 }
 
 pub async fn write<W: AsyncWrite + Unpin + Send>(
-    writer: Arc<Mutex<Option<Writer<WriteHalf<W>>>>>,
+    writer: Arc<Mutex<Writer<WriteHalf<W>>>>,
     stanza: Stanza,
-) -> Result<Arc<Mutex<Option<Writer<WriteHalf<W>>>>>, Error> {
+) -> Result<(), Error> {
     {
-        if let Some(writer) = writer.lock().await.as_mut() {
-            writer.write(&stanza).await?;
-        } else {
-            return Err(Error::StreamClosed);
-        }
+        let mut writer = writer.lock().await;
+        writer.write(&stanza).await?;
     }
-    Ok(writer)
+    Ok(())
 }
 
 pub async fn read<R: AsyncRead + Unpin + Send>(
-    reader: Arc<Mutex<Option<Reader<ReadHalf<R>>>>>,
-) -> Option<(
-    Result<Stanza, Error>,
-    Arc<Mutex<Option<Reader<ReadHalf<R>>>>>,
-)> {
+    reader: Arc<Mutex<Reader<ReadHalf<R>>>>,
+) -> Result<Stanza, Error> {
     let stanza: Result<Stanza, Error>;
     {
-        if let Some(reader) = reader.lock().await.as_mut() {
-            stanza = reader.read().await.map_err(|e| e.into());
-        } else {
-            stanza = Err(Error::StreamClosed)
-        };
+        let mut reader = reader.lock().await;
+        stanza = reader.read().await.map_err(|e| e.into());
     }
-    Some((stanza, reader))
+    stanza
 }
diff --git a/stanza/src/bind.rs b/stanza/src/bind.rs
index 155fd1b..63644b1 100644
--- a/stanza/src/bind.rs
+++ b/stanza/src/bind.rs
@@ -6,7 +6,7 @@ use peanuts::{
 
 pub const XMLNS: &str = "urn:ietf:params:xml:ns:xmpp-bind";
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct Bind {
     pub r#type: Option<BindType>,
 }
@@ -28,7 +28,7 @@ impl IntoElement for Bind {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub enum BindType {
     Resource(ResourceType),
     Jid(FullJidType),
@@ -56,7 +56,7 @@ impl IntoElement for BindType {
 }
 
 // minLength 8 maxLength 3071
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct FullJidType(pub JID);
 
 impl FromElement for FullJidType {
@@ -77,7 +77,7 @@ impl IntoElement for FullJidType {
 }
 
 // minLength 1 maxLength 1023
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct ResourceType(pub String);
 
 impl FromElement for ResourceType {
diff --git a/stanza/src/client/iq.rs b/stanza/src/client/iq.rs
index 388979e..6ee80ea 100644
--- a/stanza/src/client/iq.rs
+++ b/stanza/src/client/iq.rs
@@ -9,10 +9,12 @@ use peanuts::{
 use crate::{
     bind::{self, Bind},
     client::error::Error,
+    xep_0199::{self, Ping},
 };
 
 use super::XMLNS;
 
+#[derive(Debug)]
 pub struct Iq {
     pub from: Option<JID>,
     pub id: String,
@@ -25,9 +27,10 @@ pub struct Iq {
     pub errors: Vec<Error>,
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub enum Query {
     Bind(Bind),
+    Ping(Ping),
     Unsupported,
 }
 
@@ -35,6 +38,7 @@ impl FromElement for Query {
     fn from_element(element: peanuts::Element) -> peanuts::element::DeserializeResult<Self> {
         match element.identify() {
             (Some(bind::XMLNS), "bind") => Ok(Query::Bind(Bind::from_element(element)?)),
+            (Some(xep_0199::XMLNS), "ping") => Ok(Query::Ping(Ping::from_element(element)?)),
             _ => Ok(Query::Unsupported),
         }
     }
@@ -44,6 +48,7 @@ impl IntoElement for Query {
     fn builder(&self) -> peanuts::element::ElementBuilder {
         match self {
             Query::Bind(bind) => bind.builder(),
+            Query::Ping(ping) => ping.builder(),
             // TODO: consider what to do if attempt to serialize unsupported
             Query::Unsupported => todo!(),
         }
@@ -88,7 +93,7 @@ impl IntoElement for Iq {
     }
 }
 
-#[derive(Copy, Clone, PartialEq, Eq)]
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
 pub enum IqType {
     Error,
     Get,
diff --git a/stanza/src/client/message.rs b/stanza/src/client/message.rs
index b9d995f..2337d7b 100644
--- a/stanza/src/client/message.rs
+++ b/stanza/src/client/message.rs
@@ -8,6 +8,7 @@ use peanuts::{
 
 use super::XMLNS;
 
+#[derive(Debug)]
 pub struct Message {
     from: Option<JID>,
     id: Option<String>,
@@ -69,7 +70,7 @@ impl IntoElement for Message {
     }
 }
 
-#[derive(Default, PartialEq, Eq, Copy, Clone)]
+#[derive(Default, PartialEq, Eq, Copy, Clone, Debug)]
 pub enum MessageType {
     Chat,
     Error,
@@ -106,7 +107,7 @@ impl ToString for MessageType {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct Body {
     lang: Option<String>,
     body: Option<String>,
@@ -132,7 +133,7 @@ impl IntoElement for Body {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct Subject {
     lang: Option<String>,
     subject: Option<String>,
@@ -158,7 +159,7 @@ impl IntoElement for Subject {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct Thread {
     parent: Option<String>,
     thread: Option<String>,
diff --git a/stanza/src/client/mod.rs b/stanza/src/client/mod.rs
index 2b063d6..e9c336e 100644
--- a/stanza/src/client/mod.rs
+++ b/stanza/src/client/mod.rs
@@ -15,6 +15,7 @@ pub mod presence;
 
 pub const XMLNS: &str = "jabber:client";
 
+#[derive(Debug)]
 pub enum Stanza {
     Message(Message),
     Presence(Presence),
diff --git a/stanza/src/client/presence.rs b/stanza/src/client/presence.rs
index dd14bff..5354966 100644
--- a/stanza/src/client/presence.rs
+++ b/stanza/src/client/presence.rs
@@ -8,6 +8,7 @@ use peanuts::{
 
 use super::{error::Error, XMLNS};
 
+#[derive(Debug)]
 pub struct Presence {
     from: Option<JID>,
     id: Option<String>,
@@ -70,7 +71,7 @@ impl IntoElement for Presence {
 
 pub enum Other {}
 
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Debug)]
 pub enum PresenceType {
     Error,
     Probe,
@@ -112,7 +113,7 @@ impl ToString for PresenceType {
     }
 }
 
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Debug)]
 pub enum Show {
     Away,
     Chat,
@@ -160,7 +161,7 @@ impl ToString for Show {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct Status {
     lang: Option<String>,
     status: String1024,
@@ -188,7 +189,7 @@ impl IntoElement for Status {
 
 // TODO: enforce?
 /// minLength 1 maxLength 1024
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct String1024(pub String);
 
 impl FromStr for String1024 {
@@ -206,7 +207,7 @@ impl ToString for String1024 {
 }
 
 // xs:byte
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Debug)]
 pub struct Priority(pub i8);
 
 impl FromElement for Priority {
diff --git a/stanza/src/lib.rs b/stanza/src/lib.rs
index 32716d3..f3b0dca 100644
--- a/stanza/src/lib.rs
+++ b/stanza/src/lib.rs
@@ -7,5 +7,6 @@ pub mod stanza_error;
 pub mod starttls;
 pub mod stream;
 pub mod stream_error;
+pub mod xep_0199;
 
 pub static XML_VERSION: VersionInfo = VersionInfo::One;
diff --git a/stanza/src/xep_0199.rs b/stanza/src/xep_0199.rs
new file mode 100644
index 0000000..9605721
--- /dev/null
+++ b/stanza/src/xep_0199.rs
@@ -0,0 +1,26 @@
+use peanuts::{
+    element::{FromElement, IntoElement},
+    Element,
+};
+
+pub const XMLNS: &str = "urn:xmpp:ping";
+
+#[derive(Clone, Copy, Debug)]
+pub struct Ping;
+
+impl FromElement for Ping {
+    fn from_element(element: peanuts::Element) -> peanuts::element::DeserializeResult<Self> {
+        element.check_name("ping")?;
+        element.check_namespace(XMLNS)?;
+
+        element.no_more_content()?;
+
+        Ok(Ping)
+    }
+}
+
+impl IntoElement for Ping {
+    fn builder(&self) -> peanuts::element::ElementBuilder {
+        Element::builder("ping", Some(XMLNS))
+    }
+}