Harden LA publishers and add multi-relay guide

deploy/cloudflare-worker/src/index.ts

@@ -212,10 +212,17 @@ type PublicStreamEntry = {
   relay_url: string;
   broadcast_name: string;
   track_name: string;
+  relays: PublicStreamRelay[];
   updated_ms: number;
   expires_ms: number;
 };
 
+type PublicStreamRelay = {
+  relay_url: string;
+  broadcast_name: string;
+  track_name: string;
+};
+
 type PublicStreamList = {
   now_ms: number;
   entries: PublicStreamEntry[];
@@ -323,9 +330,41 @@ type StreamUpsertReq = {
   relay_url: string;
   broadcast_name: string;
   track_name?: string;
+  relays?: PublicStreamRelay[];
   expires_ms?: number;
 };
 
+function publicStreamRelayKey(relay: PublicStreamRelay): string {
+  return `${relay.relay_url}\n${relay.broadcast_name}\n${relay.track_name}`;
+}
+
+function normalizePublicStreamRelays(body: StreamUpsertReq): PublicStreamRelay[] {
+  const relays: PublicStreamRelay[] = [];
+
+  const addRelay = (candidate?: Partial<PublicStreamRelay>) => {
+    if (!candidate?.relay_url || !candidate.broadcast_name) return;
+    const relay: PublicStreamRelay = {
+      relay_url: clampStr(candidate.relay_url, 512),
+      broadcast_name: clampStr(candidate.broadcast_name, 256),
+      track_name: clampStr(candidate.track_name || "video0.m4s", 256),
+    };
+    if (!relays.some((existing) => publicStreamRelayKey(existing) === publicStreamRelayKey(relay))) {
+      relays.push(relay);
+    }
+  };
+
+  addRelay({
+    relay_url: body.relay_url,
+    broadcast_name: body.broadcast_name,
+    track_name: body.track_name,
+  });
+  if (Array.isArray(body.relays)) {
+    for (const relay of body.relays) addRelay(relay);
+  }
+
+  return relays.slice(0, 16);
+}
+
 function authBearerToken(request: Request): string | null {
   const auth = request.headers.get("authorization");
   if (!auth) return null;
@@ -392,17 +431,20 @@ export class EcApiContainer implements DurableObject {
           { status: 400 },
         );
       }
+      const relays = normalizePublicStreamRelays(body);
 
       const requestedExpires = body.expires_ms ?? now + 20_000;
       const requestedTtl = Math.max(0, requestedExpires - now);
       const ttlMs = Math.min(60_000, Math.max(5_000, requestedTtl));
 
+      const primaryRelay = relays[0];
       const entry: PublicStreamEntry = {
         stream_id: clampStr(body.stream_id, 256),
         title: clampStr(body.title, 128),
-        relay_url: clampStr(body.relay_url, 512),
-        broadcast_name: clampStr(body.broadcast_name, 256),
-        track_name: clampStr(body.track_name || "video0.m4s", 256),
+        relay_url: primaryRelay.relay_url,
+        broadcast_name: primaryRelay.broadcast_name,
+        track_name: primaryRelay.track_name,
+        relays,
         updated_ms: now,
         expires_ms: now + ttlMs,
       };