feat: add voice ducking

src/ts-protocol/voice-endpoint.ts

@@ -0,0 +1,104 @@
+import { lookup } from "node:dns/promises";
+import { isIP } from "node:net";
+import { Resolver } from "@honeybbq/teamspeak-client/discovery";
+import type {
+  AddrResolver,
+  ResolvedAddr,
+} from "@honeybbq/teamspeak-client";
+
+export interface ResolvedVoiceEndpoint {
+  host: string;
+  port: number;
+}
+
+type ResolveIpv4 = (host: string) => Promise<string>;
+
+function parseVoiceAddress(address: string): ResolvedVoiceEndpoint | null {
+  let host: string;
+  let rawPort: string;
+
+  if (address.startsWith("[")) {
+    const closingBracket = address.indexOf("]");
+    if (closingBracket < 0 || address[closingBracket + 1] !== ":") return null;
+    host = address.slice(1, closingBracket);
+    rawPort = address.slice(closingBracket + 2);
+  } else {
+    const separator = address.lastIndexOf(":");
+    if (separator <= 0) return null;
+    host = address.slice(0, separator);
+    rawPort = address.slice(separator + 1);
+  }
+
+  const port = Number(rawPort);
+  if (
+    host.length === 0 ||
+    !Number.isInteger(port) ||
+    port < 1 ||
+    port > 65_535
+  ) {
+    return null;
+  }
+  return { host, port };
+}
+
+function formatVoiceAddress(endpoint: ResolvedVoiceEndpoint): string {
+  return endpoint.host.includes(":")
+    ? `[${endpoint.host}]:${endpoint.port}`
+    : `${endpoint.host}:${endpoint.port}`;
+}
+
+async function resolveIpv4(host: string): Promise<string> {
+  if (isIP(host) === 4) return host;
+  return (await lookup(host, { family: 4 })).address;
+}
+
+/**
+ * Uses the SDK's normal SRV/TSDNS discovery, then pins its selected hostname
+ * to the IPv4 address that the UDP connection will use. Besides making the
+ * connection target observable, this gives all bots a common registry scope
+ * when one is configured with a DNS alias and another with the underlying IP.
+ */
+export class TrackingVoiceEndpointResolver implements AddrResolver {
+  private endpoint: ResolvedVoiceEndpoint | null = null;
+
+  constructor(
+    private readonly delegate: AddrResolver = new Resolver(),
+    private readonly resolveHost: ResolveIpv4 = resolveIpv4,
+  ) {}
+
+  async resolve(input: string, signal?: AbortSignal): Promise<ResolvedAddr[]> {
+    this.endpoint = null;
+    const candidates = await this.delegate.resolve(input, signal);
+    const selected = candidates[0];
+    if (!selected) return candidates;
+
+    const parsed = parseVoiceAddress(selected.addr);
+    if (!parsed) return candidates;
+
+    try {
+      const pinned = {
+        host: await this.resolveHost(parsed.host),
+        port: parsed.port,
+      };
+      this.endpoint = pinned;
+      return [
+        { ...selected, addr: formatVoiceAddress(pinned) },
+        ...candidates.slice(1),
+      ];
+    } catch {
+      // Preserve the SDK's original target if local A-record resolution fails.
+      // The connection may still succeed through platform-specific resolution;
+      // the registry then falls back to the logical host + resolved port.
+      this.endpoint = parsed;
+      return candidates;
+    }
+  }
+
+  reset(): void {
+    this.endpoint = null;
+  }
+
+  getEndpoint(): ResolvedVoiceEndpoint | null {
+    return this.endpoint ? { ...this.endpoint } : null;
+  }
+}