Gateway: Twilight 0.15 support (#171)

This patch changes around quite a few things.
The main entrypoint for twilight besides process will now be the
TwilightMap which concists of command senders for each shard.

This simplifies parts of the code as there is not any difference
between shards and clusters anymore.

src/manager.rs

@@ -26,10 +26,9 @@ use serenity::{
 };
 use std::sync::Arc;
 use tokio::sync::Mutex;
+#[cfg(feature = "serenity")]
 use tracing::debug;
 #[cfg(feature = "twilight")]
-use twilight_gateway::Cluster;
-#[cfg(feature = "twilight")]
 use twilight_model::gateway::event::Event as TwilightEvent;
 
 #[derive(Clone, Copy, Debug)]
@@ -88,7 +87,7 @@ impl Songbird {
     /// [`process`].
     ///
     /// [`process`]: Songbird::process
-    pub fn twilight<U>(cluster: Arc<Cluster>, user_id: U) -> Self
+    pub fn twilight<U>(cluster: Arc<crate::shards::TwilightMap>, user_id: U) -> Self
     where
         U: Into<UserId>,
     {
@@ -103,17 +102,21 @@ impl Songbird {
     /// [`process`].
     ///
     /// [`process`]: Songbird::process
-    pub fn twilight_from_config<U>(cluster: Arc<Cluster>, user_id: U, config: Config) -> Self
+    pub fn twilight_from_config<U>(
+        sender_map: Arc<crate::shards::TwilightMap>,
+        user_id: U,
+        config: Config,
+    ) -> Self
     where
         U: Into<UserId>,
     {
         Self {
             client_data: OnceCell::with_value(ClientData {
-                shard_count: cluster.config().shard_scheme().total(),
+                shard_count: sender_map.shard_count(),
                 user_id: user_id.into(),
             }),
             calls: DashMap::new(),
-            sharder: Sharder::TwilightCluster(cluster),
+            sharder: Sharder::Twilight(sender_map),
             config: config.initialise_disposer().into(),
         }
     }
@@ -370,8 +373,8 @@ impl Songbird {
     pub async fn process(&self, event: &TwilightEvent) {
         match event {
             TwilightEvent::VoiceServerUpdate(v) => {
-                let id = GuildId::from(v.guild_id);
-                let call = self.get(id);
+                let guild_id = GuildId::from(v.guild_id);
+                let call = self.get(guild_id);
 
                 if let Some(call) = call {
                     let mut handler = call.lock().await;