make it work with minidom

src/xmpp_codec.rs

@@ -9,8 +9,9 @@ use std::io::{Error, ErrorKind};
 use std::collections::HashMap;
 use std::collections::vec_deque::VecDeque;
 use tokio_io::codec::{Encoder, Decoder};
-use minidom::Element;
+use minidom::{Element, Node};
 use xml5ever::tokenizer::{XmlTokenizer, TokenSink, Token, Tag, TagKind};
+use xml5ever::interface::Attribute;
 use bytes::*;
 
 // const NS_XMLNS: &'static str = "http://www.w3.org/2000/xmlns/";
@@ -25,10 +26,11 @@ pub enum Packet {
 }
 
 struct ParserSink {
-    // Ready stanzas
+    // Ready stanzas, shared with XMPPCodec
     queue: Rc<RefCell<VecDeque<Packet>>>,
     // Parsing stack
     stack: Vec<Element>,
+    ns_stack: Vec<HashMap<Option<String>, String>>,
 }
 
 impl ParserSink {
@@ -36,21 +38,79 @@ impl ParserSink {
         ParserSink {
             queue,
             stack: vec![],
+            ns_stack: vec![],
         }
     }
 
     fn push_queue(&self, pkt: Packet) {
-        println!("push: {:?}", pkt);
         self.queue.borrow_mut().push_back(pkt);
     }
 
+    fn lookup_ns(&self, prefix: &Option<String>) -> Option<&str> {
+        for nss in self.ns_stack.iter().rev() {
+            match nss.get(prefix) {
+                Some(ns) => return Some(ns),
+                None => (),
+            }
+        }
+
+        None
+    }
+
     fn handle_start_tag(&mut self, tag: Tag) {
-        let el = tag_to_element(&tag);
+        let mut nss = HashMap::new();
+        let is_prefix_xmlns = |attr: &Attribute| attr.name.prefix.as_ref()
+            .map(|prefix| prefix.eq_str_ignore_ascii_case("xmlns"))
+            .unwrap_or(false);
+        for attr in &tag.attrs {
+            match attr.name.local.as_ref() {
+                "xmlns" => {
+                    nss.insert(None, attr.value.as_ref().to_owned());
+                },
+                prefix if is_prefix_xmlns(attr) => {
+                        nss.insert(Some(prefix.to_owned()), attr.value.as_ref().to_owned());
+                    },
+                _ => (),
+            }
+        }
+        self.ns_stack.push(nss);
+
+        let el = {
+            let mut el_builder = Element::builder(tag.name.local.as_ref());
+            match self.lookup_ns(&tag.name.prefix.map(|prefix| prefix.as_ref().to_owned())) {
+                Some(el_ns) => el_builder = el_builder.ns(el_ns),
+                None => (),
+            }
+            for attr in &tag.attrs {
+                match attr.name.local.as_ref() {
+                    "xmlns" => (),
+                    _ if is_prefix_xmlns(attr) => (),
+                    _ => {
+                        el_builder = el_builder.attr(
+                            attr.name.local.as_ref(),
+                            attr.value.as_ref()
+                        );
+                    },
+                }
+            }
+            el_builder.build()
+        };
+
+        if self.stack.is_empty() {
+            let attrs = HashMap::from_iter(
+                el.attrs()
+                    .map(|(name, value)| (name.to_owned(), value.to_owned()))
+            );
+            self.push_queue(Packet::StreamStart(attrs));
+        }
+
         self.stack.push(el);
     }
 
     fn handle_end_tag(&mut self) {
         let el = self.stack.pop().unwrap();
+        self.ns_stack.pop();
+
         match self.stack.len() {
             // </stream:stream>
             0 =>
@@ -66,22 +126,8 @@ impl ParserSink {
     }
 }
 
-fn tag_to_element(tag: &Tag) -> Element {
-    let el_builder = Element::builder(tag.name.local.as_ref())
-        .ns(tag.name.ns.as_ref());
-    let el_builder = tag.attrs.iter().fold(
-        el_builder,
-        |el_builder, attr| el_builder.attr(
-            attr.name.local.as_ref(),
-            attr.value.as_ref()
-        )
-    );
-    el_builder.build()
-}
-
 impl TokenSink for ParserSink {
     fn process_token(&mut self, token: Token) {
-        println!("Token: {:?}", token);
         match token {
             Token::TagToken(tag) => match tag.kind {
                 TagKind::StartTag =>
@@ -119,9 +165,14 @@ impl TokenSink for ParserSink {
 }
 
 pub struct XMPPCodec {
+    /// Outgoing
+    ns: Option<String>,
+    /// Incoming
     parser: XmlTokenizer<ParserSink>,
-    // For handling truncated utf8
+    /// For handling incoming truncated utf8
+    // TODO: optimize using  tendrils?
     buf: Vec<u8>,
+    /// Shared with ParserSink
     queue: Rc<RefCell<VecDeque<Packet>>>,
 }
 
@@ -132,6 +183,7 @@ impl XMPPCodec {
         // TODO: configure parser?
         let parser = XmlTokenizer::new(sink, Default::default());
         XMPPCodec {
+            ns: None,
             parser,
             queue,
             buf: vec![],
@@ -144,7 +196,6 @@ impl Decoder for XMPPCodec {
     type Error = Error;
 
     fn decode(&mut self, buf: &mut BytesMut) -> Result<Option<Self::Item>, Self::Error> {
-        println!("decode {} bytes", buf.len());
         let buf1: Box<AsRef<[u8]>> =
             if self.buf.len() > 0 && buf.len() > 0 {
                 let mut prefix = std::mem::replace(&mut self.buf, vec![]);
@@ -196,32 +247,39 @@ impl Encoder for XMPPCodec {
     type Error = Error;
 
     fn encode(&mut self, item: Self::Item, dst: &mut BytesMut) -> Result<(), Self::Error> {
-        println!("encode {:?}", item);
         match item {
             Packet::StreamStart(start_attrs) => {
                 let mut buf = String::new();
                 write!(buf, "<stream:stream").unwrap();
-                for (ref name, ref value) in &start_attrs {
+                for (name, value) in start_attrs.into_iter() {
                     write!(buf, " {}=\"{}\"", escape(&name), escape(&value))
                         .unwrap();
+                    if name == "xmlns" {
+                        self.ns = Some(value);
+                    }
                 }
                 write!(buf, ">\n").unwrap();
 
                 print!(">> {}", buf);
                 write!(dst, "{}", buf)
-                    .map_err(|_| Error::from(ErrorKind::InvalidInput))
+                    .map_err(|e| Error::new(ErrorKind::InvalidInput, e))
             },
             Packet::Stanza(stanza) => {
-                println!(">> {:?}", stanza);
-                let mut root_ns = None;  // TODO
-                stanza.write_to_inner(&mut dst.clone().writer(), &mut root_ns)
-                    .map_err(|_| Error::from(ErrorKind::InvalidInput))
+                let root_ns = self.ns.as_ref().map(|s| s.as_ref());
+                write_element(&stanza, dst, root_ns)
+                    .and_then(|_| {
+                        println!(">> {:?}", dst);
+                        Ok(())
+                    })
+                    .map_err(|e| Error::new(ErrorKind::InvalidInput, format!("{}", e)))
             },
             Packet::Text(text) => {
-                let escaped = escape(&text);
-                println!(">> {}", escaped);
-                write!(dst, "{}", escaped)
-                    .map_err(|_| Error::from(ErrorKind::InvalidInput))
+                write_text(&text, dst)
+                    .and_then(|_| {
+                        println!(">> {:?}", dst);
+                        Ok(())
+                    })
+                    .map_err(|e| Error::new(ErrorKind::InvalidInput, format!("{}", e)))
             },
             // TODO: Implement all
             _ => Ok(())
@@ -229,6 +287,45 @@ impl Encoder for XMPPCodec {
     }
 }
 
+pub fn write_text<W: Write>(text: &str, writer: &mut W) -> Result<(), std::fmt::Error> {
+    write!(writer, "{}", text)
+}
+
+// TODO: escape everything?
+pub fn write_element<W: Write>(el: &Element, writer: &mut W, parent_ns: Option<&str>) -> Result<(), std::fmt::Error> {
+    write!(writer, "<")?;
+    write!(writer, "{}", el.name())?;
+
+    if let Some(ref ns) = el.ns() {
+        if parent_ns.map(|s| s.as_ref()) != el.ns() {
+            write!(writer, " xmlns=\"{}\"", ns)?;
+        }
+    }
+
+    for (key, value) in el.attrs() {
+        write!(writer, " {}=\"{}\"", key, value)?;
+    }
+
+    if ! el.nodes().any(|_| true) {
+        write!(writer, " />")?;
+        return Ok(())
+    }
+
+    write!(writer, ">")?;
+
+    for node in el.nodes() {
+        match node {
+            &Node::Element(ref child) =>
+                write_element(child, writer, el.ns())?,
+            &Node::Text(ref text) =>
+                write_text(text, writer)?,
+        }
+    }
+
+    write!(writer, "</{}>", el.name())?;
+    Ok(())
+}
+
 /// Copied from RustyXML for now
 pub fn escape(input: &str) -> String {
     let mut result = String::with_capacity(input.len());