Selection of the ideal Lavalink node according to the location of the Discord server

src/structures/Manager.ts

@@ -228,8 +228,49 @@ export class Manager extends EventEmitter {
       });
   }
 
-  /**
-   * Initiates the Manager class.
+    /**
+     * Returns the Node in same region as server.
+     * @param region
+     */
+    public nearestNode(region: string): Node {
+        const nodes = this.nodes
+            .filter((node) => {
+                if (!node.options.region)
+                    return node.connected
+                else if (Array.isArray(node.options.region))
+                    return node.connected && node.options.region.includes(region)
+                else
+                    return node.connected && node.options.region.toLowerCase() == region.toLowerCase()
+            });
+
+        if (!nodes)
+            return null;
+        else if (nodes.size === 1)
+            return nodes.first();
+        else if (nodes.size > 1)
+            return this.leastLoadNodesByRegion(nodes).first();
+    }
+
+    /**
+     * Returns the least system load Nodes from provided Nodes.
+     * @param nodes
+     */
+    public leastLoadNodesByRegion(nodes: Collection<string, Node>): Collection<string, Node> {
+        return nodes
+            .filter((node) => node.connected)
+            .sort((a, b) => {
+                const aload = a.stats.cpu
+                    ? (a.stats.cpu.systemLoad / a.stats.cpu.cores) * 100
+                    : 0;
+                const bload = b.stats.cpu
+                    ? (b.stats.cpu.systemLoad / b.stats.cpu.cores) * 100
+                    : 0;
+                return aload - bload;
+            });
+    }
+
+    /**
+     * Initiates the Manager class.
    * @param options
    */
   constructor(options: ManagerOptions) {

src/structures/Node.ts

@@ -58,6 +58,11 @@ function check(options: NodeOptions) {
     typeof options.retryDelay !== "number"
   )
     throw new TypeError('Node option "retryDelay" must be a number.');
+
+  if (typeof options.region !== "undefined" && 
+      ((typeof options.region !== "string" || 
+        !/.+/.test(options.region)) && (!Array.isArray(options.region) || options.region.length === 0 || !/.+/.test(options.region[0]))))
+    throw new TypeError('Node option "region" must be a non-empty string or array.');
 }
 
 export class Node {
@@ -390,6 +395,8 @@ export interface NodeOptions {
   retryAmount?: number;
   /** The retryDelay for the node. */
   retryDelay?: number;
+  /** Regions for which the node can be used */
+  region?: string | string[];
 }
 
 export interface NodeStats {

src/structures/Player.ts

@@ -10,6 +10,9 @@ function check(options: PlayerOptions) {
     throw new TypeError(
       'Player option "guild" must be present and be a non-empty string.'
     );
+
+  if (options.region && !/^\d+$/.test(options.region))
+    throw new TypeError('Player option "region" must be a non-empty string.');
 
   if (options.textChannel && !/^\d+$/.test(options.textChannel))
     throw new TypeError(
@@ -62,6 +65,8 @@ export class Player {
   public node: Node;
   /** The guild the player. */
   public guild: string;
+  /** The region of Discord server. */
+  public region: string | null = null;
   /** The voice channel for the player. */
   public voiceChannel: string | null = null;
   /** The text channel for the player. */
@@ -119,7 +124,9 @@ export class Player {
     if (options.textChannel) this.textChannel = options.textChannel;
 
     const node = this.manager.nodes.get(options.node);
-    this.node = node || this.manager.leastLoadNodes.first();
+    if (node) this.node = node
+    else if (options.region) this.node = this.manager.nearestNode(options.region);
+    if (!this.node) this.node = this.manager.leastLoadNodes.first()
 
     if (!this.node) throw new RangeError("No available nodes.");
 
@@ -448,6 +455,8 @@ export class Player {
 export interface PlayerOptions {
   /** The guild the Player belongs to. */
   guild: string;
+  /** The region of Discord server. */
+  region?: string;
   /** The text channel the Player belongs to. */
   textChannel: string;
   /** The voice channel the Player belongs to. */

src/structures/Utils.ts

@@ -397,4 +397,4 @@ export interface PlayerUpdate {
     time: number;
   };
   guildId: string;
-}
+}