Restructure modules

Modules are now separated into a fashion where the library can be used
for most use cases, without needing to compile the rest.

The core of serenity, with no features enabled, contains only the
struct (model) definitions, constants, and prelude. Models do not have
most functions compiled in, as that is separated into the `model`
feature.

The `client` module has been split into 3 modules: `client`, `gateway`,
and `http`.

`http` contains functions to interact with the REST API. `gateway`
contains the Shard to interact with the gateway, requiring `http` for
retrieving the gateway URL. `client` requires both of the other features
and acts as an abstracted interface over both the gateway and REST APIs,
handling the event loop.

The `builder` module has been separated from `utils`, and can now be
optionally compiled in. It and the `http` feature are required by the
`model` feature due to a large number of methods requiring access to
them.

`utils` now contains a number of utilities, such as the Colour struct, the
`MessageBuilder`, and mention parsing functions.

Each of the original `ext` modules are still featured, with `cache` not
requiring any feature to be enabled, `framework` requiring the `client`,
`model`, and `utils`, and `voice` requiring `gateway`.

In total the features and their requirements are:

- `builder`: none
- `cache`: none
- `client`: `gateway`, `http`
- `framework`: `client`, `model`, `utils`
- `gateway`: `http`
- `http`: none
- `model`: `builder`, `http`
- `utils`: none
- `voice`: `gateway`

The default features are `builder`, `cache`, `client`, `framework`,
`gateway`, `model`, `http`, and `utils`.

To help with forwards compatibility, modules have been re-exported from
their original locations.

1 files changed, 126 insertions, 0 deletions

diff --git a/src/voice/manager.rs b/src/voice/manager.rs
new file mode 100644
index 0000000..fe1b489
--- /dev/null
+++ b/src/voice/manager.rs
@@ -0,0 +1,126 @@
+use std::collections::HashMap;
+use std::sync::mpsc::Sender as MpscSender;
+use super::Handler;
+use ::gateway::GatewayStatus;
+use ::model::{ChannelId, GuildId, UserId};
+
+/// A manager is a struct responsible for managing [`Handler`]s which belong to
+/// a single [`Shard`]. This is a fairly complex key-value store,
+/// with a bit of extra utility for easily joining a "target".
+///
+/// The "target" used by the Manager is determined based on the `guild_id` and
+/// `channel_id` provided. If a `guild_id` is _not_ provided to methods that
+/// optionally require it, then the target is a group or 1-on-1 call with a
+/// user. The `channel_id` is then used as the target.
+///
+/// If a `guild_id` is provided, then the target is the guild, as a user
+/// can not be connected to two channels within one guild simultaneously.
+///
+/// [`Group`]: ../../model/struct.Group.html
+/// [`Handler`]: struct.Handler.html
+/// [guild's channel]: ../../model/enum.ChannelType.html#variant.Voice
+/// [`Shard`]: ../gateway/struct.Shard.html
+#[derive(Clone, Debug)]
+pub struct Manager {
+    handlers: HashMap<GuildId, Handler>,
+    user_id: UserId,
+    ws: MpscSender<GatewayStatus>,
+}
+
+impl Manager {
+    #[doc(hidden)]
+    pub fn new(ws: MpscSender<GatewayStatus>, user_id: UserId) -> Manager {
+        Manager {
+            handlers: HashMap::new(),
+            user_id: user_id,
+            ws: ws,
+        }
+    }
+
+    /// Retrieves a mutable handler for the given target, if one exists.
+    pub fn get<G: Into<GuildId>>(&mut self, guild_id: G) -> Option<&mut Handler> {
+        self.handlers.get_mut(&guild_id.into())
+    }
+
+    /// Connects to a target by retrieving its relevant [`Handler`] and
+    /// connecting, or creating the handler if required.
+    ///
+    /// This can also switch to the given channel, if a handler already exists
+    /// for the target and the current connected channel is not equal to the
+    /// given channel.
+    ///
+    /// In the case of channel targets, the same channel is used to connect to.
+    ///
+    /// In the case of guilds, the provided channel is used to connect to. The
+    /// channel _must_ be in the provided guild. This is _not_ checked by the
+    /// library, and will result in an error. If there is already a connected
+    /// handler for the guild, _and_ the provided channel is different from the
+    /// channel that the connection is already connected to, then the handler
+    /// will switch the connection to the provided channel.
+    ///
+    /// If you _only_ need to retrieve the handler for a target, then use
+    /// [`get`].
+    ///
+    /// [`Handler`]: struct.Handler.html
+    /// [`get`]: #method.get
+    #[allow(map_entry)]
+    pub fn join<C, G>(&mut self, guild_id: G, channel_id: C) -> &mut Handler
+        where C: Into<ChannelId>, G: Into<GuildId> {
+        let channel_id = channel_id.into();
+        let guild_id = guild_id.into();
+
+        {
+            let mut found = false;
+
+            if let Some(handler) = self.handlers.get_mut(&guild_id) {
+                handler.switch_to(channel_id);
+
+                found = true;
+            }
+
+            if found {
+                // Actually safe, as the key has already been found above.
+                return self.handlers.get_mut(&guild_id).unwrap();
+            }
+        }
+
+        let mut handler = Handler::new(guild_id, self.ws.clone(), self.user_id);
+        handler.join(channel_id);
+
+        self.handlers.insert(guild_id, handler);
+
+        // Actually safe, as the key would have been inserted above.
+        self.handlers.get_mut(&guild_id).unwrap()
+    }
+
+    /// Retrieves the [handler][`Handler`] for the given target and leaves the
+    /// associated voice channel, if connected.
+    ///
+    /// This will _not_ drop the handler, and will preserve it and its settings.
+    ///
+    /// This is a wrapper around [getting][`get`] a handler and calling
+    /// [`leave`] on it.
+    ///
+    /// [`Handler`]: struct.Handler.html
+    /// [`get`]: #method.get
+    /// [`leave`]: struct.Handler.html#method.leave
+    pub fn leave<G: Into<GuildId>>(&mut self, guild_id: G) {
+        if let Some(handler) = self.handlers.get_mut(&guild_id.into()) {
+            handler.leave();
+        }
+    }
+
+    /// Retrieves the [`Handler`] for the given target and leaves the associated
+    /// voice channel, if connected.
+    ///
+    /// The handler is then dropped, removing settings for the target.
+    ///
+    /// [`Handler`]: struct.Handler.html
+    pub fn remove<G: Into<GuildId>>(&mut self, guild_id: G) {
+        let guild_id = guild_id.into();
+
+        self.leave(guild_id);
+
+        self.handlers.remove(&guild_id);
+    }
+}