Properly transfer a node if another one gets removed

Fixes #29

Author: duncte123

src/main/kotlin/dev/arbjerg/lavalink/client/LavalinkClient.kt

@@ -148,7 +148,10 @@ class LavalinkClient(val userId: Long) : Closeable, Disposable {
             return
         }
 
-        if (nodes.size == 1) {
+        // In case a node was removed and we have a single node left.
+        // we should always check if the node is the same
+        // NEVER assume that the disconnected node is still in the nodes list.
+        if (nodes.size == 1 && nodes.first() == node) {
             linkMap.forEach { (_, link) ->
                 link.state = LinkState.DISCONNECTED
             }

src/main/kotlin/dev/arbjerg/lavalink/internal/LavalinkSocket.kt

@@ -129,6 +129,15 @@ class LavalinkSocket(private val node: LavalinkNode) : WebSocketListener(), Clos
     }
 
     override fun onFailure(webSocket: WebSocket, t: Throwable, response: Response?) {
+        handleFailureTrhowable(t)
+
+        node.available = false
+        open = false
+
+        node.lavalink.onNodeDisconnected(node)
+    }
+
+    private fun handleFailureTrhowable(t: Throwable) {
         when(t) {
             is EOFException -> {
                 logger.debug("Got disconnected from ${node.name}, trying to reconnect", t)
@@ -156,11 +165,6 @@ class LavalinkSocket(private val node: LavalinkNode) : WebSocketListener(), Clos
                 logger.error("Unknown error on ${node.name}", t)
             }
         }
-
-        node.available = false
-        open = false
-
-        node.lavalink.onNodeDisconnected(node)
     }
 
     override fun onClosing(webSocket: WebSocket, code: Int, reason: String) {

testbot/src/main/java/me/duncte123/testbot/JDAListener.java

@@ -37,6 +37,14 @@ public void onReady(@NotNull ReadyEvent event) {
         event.getJDA().updateCommands()
             .addCommands(
                 Commands.slash("lyrics", "Testing custom requests"),
+                Commands.slash("node", "What node am I on?"),
+                Commands.slash("del-node", "test")
+                    .addOption(
+                        OptionType.STRING,
+                        "node-name",
+                        "Name of the node",
+                        true
+                    ),
                 Commands.slash("join", "Join the voice channel you are in."),
                 Commands.slash("leave", "Leaves the vc"),
                 Commands.slash("stop", "Stops the current track"),
@@ -67,6 +75,23 @@ public void onSlashCommandInteraction(@NotNull SlashCommandInteractionEvent even
         }
 
         switch (event.getFullCommandName()) {
+            case "node": {
+                final var link = this.client.getLinkIfCached(guild.getIdLong());
+
+                if (link == null) {
+                    event.reply("No link for this guild").queue();
+                    break;
+                }
+
+                event.reply("Connected to: " + link.getNode().getName()).queue();
+
+                break;
+            }
+            case "del-node": {
+                this.client.removeNode(event.getOption("node-name").getAsString());
+                event.reply("Ok").queue();
+                break;
+            }
             case "join":
                 joinHelper(event);
                 break;

testbot/src/main/java/me/duncte123/testbot/Main.java

@@ -66,16 +66,16 @@ private static void registerLavalinkNodes(LavalinkClient client) {
                     .setServerUri("ws://optiplex.local.duncte123.lgbt")
                     .setPassword("youshallnotpass")
                     .build()
-            )
+            ),
 
-//            client.addNode(
-//                new NodeOptions.Builder()
-//                    .setName("pi")
-//                    .setServerUri("ws://pi.local.duncte123.lgbt:2333/bepis")
-//                    .setPassword("youshallnotpass")
-//                    .setRegionFilter(RegionGroup.US)
-//                    .build()
-//            )
+            client.addNode(
+                new NodeOptions.Builder()
+                    .setName("pi")
+                    .setServerUri("ws://pi.local.duncte123.lgbt:2333")
+                    .setPassword("youshallnotpass")
+                    .setRegionFilter(RegionGroup.US)
+                    .build()
+            )
         ).forEach((node) -> {
             node.on(TrackStartEvent.class).subscribe((event) -> {
                 final LavalinkNode node1 = event.getNode();