properly implement discord channels, dry up code

src/modules/discord.rs

@@ -67,6 +67,40 @@ impl Debug for DiscordMessageSender {
     }
 }
 
+fn make_channel_object (discord: Arc<Discord>, channel: discord::model::Channel) -> Option<Channel> {
+    match channel {
+        discord::model::Channel::Group(group) => {
+            Some(Channel {
+                name: group.name.unwrap_or_else(|| String::from("Group channel")),
+                description: String::from(""),
+                topic: String::from(""),
+                sender: Box::new(DiscordMessageSender {
+                    discord: discord,
+                    channel_id: group.channel_id
+                })
+            })
+        },
+        discord::model::Channel::Private(private_channel) => {
+            None
+        },
+        discord::model::Channel::Public(public_channel) => {
+            Some(channel_from_public_channel(discord, public_channel))
+        }
+    }
+}
+
+fn channel_from_public_channel (discord: Arc<Discord>, channel: discord::model::PublicChannel) -> Channel {
+    Channel {
+        name: channel.name,
+        description: String::from(""),
+        topic: channel.topic.unwrap_or_else(|| String::new()),
+        sender: Box::new(DiscordMessageSender {
+            discord: discord,
+            channel_id: channel.id
+        })
+    }
+}
+
 impl EventLoop for DiscordModule {
     fn run (&self, sender: Box<ExtSender<event::Envelope>>, _: Receiver<Arc<event::Envelope>>) {
         let discord = Arc::new(Discord::from_bot_token(&self.token[..]).expect("Discord module: Login failed"));
@@ -88,15 +122,7 @@ impl EventLoop for DiscordModule {
                                 info!(" - Joined channel: {}", channel.name);
 
                                 match sender.send(Envelope::new(event::Event::SelfJoin {
-                                    channel: Channel {
+                                    channel: channel_from_public_channel(discord.clone(), channel)
-                                        name: channel.name,
-                                        description: String::from(""),
-                                        topic: channel.topic.unwrap_or_else(|| String::from("")),
-                                        sender: Box::new(DiscordMessageSender {
-                                            discord: discord.clone(),
-                                            channel_id: channel.id
-                                        })
-                                    }
                                 })) {
                                     Err(err) => error!("Error sending selfjoin event: {:?}", err),
                                     Ok(_) => {}
@@ -115,20 +141,10 @@ impl EventLoop for DiscordModule {
                         })
                     };
 
-                    let channel = Channel {
-                        name: String::from("channel"),
-                        description: String::from(""),
-                        topic: String::from(""),
-                        sender: Box::new(DiscordMessageSender {
-                            discord: discord.clone(),
-                            channel_id: message.channel_id
-                        })
-                    };
-
                     let message = Message {
                         author: author,
                         content: message.content,
-                        channel: Some(channel)
+                        channel: discord.get_channel(message.channel_id).ok().and_then(|channel| make_channel_object(discord.clone(), channel))
                     };
 
                     match sender.send(Envelope::new(event::Event::Message { message: message })) {