From caa83ce78909fd423966f46b4e2c17d17a365ff9 Mon Sep 17 00:00:00 2001
From: Emmanuel Gil Peyrot <emmanuel.peyrot@collabora.com>
Date: Sat, 1 Apr 2017 17:15:37 +0100
Subject: [PATCH] add a component builder

---
 src/component.rs | 168 +++++++++++++++++++++++++++++++++++++++++++++++
 src/lib.rs       |   1 +
 2 files changed, 169 insertions(+)
 create mode 100644 src/component.rs

diff --git a/src/component.rs b/src/component.rs
new file mode 100644
index 00000000..530a2e30
--- /dev/null
+++ b/src/component.rs
@@ -0,0 +1,168 @@
+use jid::Jid;
+use transport::{Transport, PlainTransport};
+use error::Error;
+use ns;
+use plugin::{Plugin, PluginProxyBinding};
+use event::AbstractEvent;
+use connection::{Connection, Component2S};
+use openssl::hash::{hash, MessageDigest};
+
+use minidom::Element;
+
+use xml::reader::XmlEvent as ReaderEvent;
+
+use std::sync::mpsc::{Receiver, channel};
+
+/// A builder for `Component`s.
+pub struct ComponentBuilder {
+    jid: Jid,
+    secret: String,
+    host: Option<String>,
+    port: u16,
+}
+
+impl ComponentBuilder {
+    /// Creates a new builder for an XMPP component that will connect to `jid` with default parameters.
+    pub fn new(jid: Jid) -> ComponentBuilder {
+        ComponentBuilder {
+            jid: jid,
+            secret: "".to_owned(),
+            host: None,
+            port: 5347,
+        }
+    }
+
+    /// Sets the host to connect to.
+    pub fn host(mut self, host: String) -> ComponentBuilder {
+        self.host = Some(host);
+        self
+    }
+
+    /// Sets the port to connect to.
+    pub fn port(mut self, port: u16) -> ComponentBuilder {
+        self.port = port;
+        self
+    }
+
+    /// Sets the password to use.
+    pub fn password<P: Into<String>>(mut self, password: P) -> ComponentBuilder {
+        self.secret = password.into();
+        self
+    }
+
+    /// Connects to the server and returns a `Component` when succesful.
+    pub fn connect(self) -> Result<Component, Error> {
+        let host = &self.host.unwrap_or(self.jid.domain.clone());
+        let mut transport = PlainTransport::connect(host, self.port)?;
+        Component2S::init(&mut transport, &self.jid.domain, "stream_opening")?;
+        let (sender_out, sender_in) = channel();
+        let (dispatcher_out, dispatcher_in) = channel();
+        let mut component = Component {
+            jid: self.jid,
+            transport: transport,
+            plugins: Vec::new(),
+            binding: PluginProxyBinding::new(sender_out, dispatcher_out),
+            sender_in: sender_in,
+            dispatcher_in: dispatcher_in,
+        };
+        component.connect(self.secret)?;
+        Ok(component)
+    }
+}
+
+/// An XMPP component.
+pub struct Component {
+    jid: Jid,
+    transport: PlainTransport,
+    plugins: Vec<Box<Plugin>>,
+    binding: PluginProxyBinding,
+    sender_in: Receiver<Element>,
+    dispatcher_in: Receiver<AbstractEvent>,
+}
+
+impl Component {
+    /// Returns a reference to the `Jid` associated with this `Component`.
+    pub fn jid(&self) -> &Jid {
+        &self.jid
+    }
+
+    /// Registers a plugin.
+    pub fn register_plugin<P: Plugin + 'static>(&mut self, mut plugin: P) {
+        plugin.bind(self.binding.clone());
+        self.plugins.push(Box::new(plugin));
+    }
+
+    /// Returns the plugin given by the type parameter, if it exists, else panics.
+    pub fn plugin<P: Plugin>(&self) -> &P {
+        for plugin in &self.plugins {
+            let any = plugin.as_any();
+            if let Some(ret) = any.downcast_ref::<P>() {
+                return ret;
+            }
+        }
+        panic!("plugin does not exist!");
+    }
+
+    /// Returns the next event and flush the send queue.
+    pub fn next_event(&mut self) -> Result<AbstractEvent, Error> {
+        self.flush_send_queue()?;
+        loop {
+            if let Ok(evt) = self.dispatcher_in.try_recv() {
+                return Ok(evt);
+            }
+            let elem = self.transport.read_element()?;
+            for plugin in self.plugins.iter_mut() {
+                plugin.handle(&elem);
+                // TODO: handle plugin return
+            }
+            self.flush_send_queue()?;
+        }
+    }
+
+    /// Flushes the send queue, sending all queued up stanzas.
+    pub fn flush_send_queue(&mut self) -> Result<(), Error> { // TODO: not sure how great of an
+                                                              //       idea it is to flush in this
+                                                              //       manner…
+        while let Ok(elem) = self.sender_in.try_recv() {
+            self.transport.write_element(&elem)?;
+        }
+        Ok(())
+    }
+
+    fn connect(&mut self, secret: String) -> Result<(), Error> {
+        // TODO: this is very ugly
+        let mut sid = String::new();
+        loop {
+            let e = self.transport.read_event()?;
+            match e {
+                ReaderEvent::StartElement { attributes, .. } => {
+                    for attribute in attributes {
+                        if attribute.name.namespace == None && attribute.name.local_name == "id" {
+                            sid = attribute.value;
+                        }
+                    }
+                    break;
+                },
+                _ => (),
+            }
+        }
+        let concatenated = format!("{}{}", sid, secret);
+        let hash = hash(MessageDigest::sha1(), concatenated.as_bytes())?;
+        let mut handshake = String::new();
+        for byte in hash {
+            // TODO: probably terrible perfs!
+            handshake = format!("{}{:x}", handshake, byte);
+        }
+        let mut elem = Element::builder("handshake")
+                               .ns(ns::COMPONENT_ACCEPT)
+                               .build();
+        elem.append_text_node(handshake);
+        self.transport.write_element(&elem)?;
+        loop {
+            let n = self.transport.read_element()?;
+            if n.is("handshake", ns::COMPONENT_ACCEPT) {
+                return Ok(());
+            }
+        }
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index d9f54698..9f96d034 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -9,6 +9,7 @@ pub mod ns;
 pub mod transport;
 pub mod error;
 pub mod client;
+pub mod component;
 pub mod plugin;
 pub mod event;
 pub mod plugins;