audio forward

server/src/services/audioForwardService/policy.js

@@ -0,0 +1,81 @@
+// audio Forward Service policy
+// Purpose: Encapsulates permission checks and media path/url derivation helpers.
+// Scope: Keeps runtime behavior unchanged while isolating validation and path-construction logic.
+function createAudioForwardPolicy(deps) {
+  const {
+    isVerified,
+    roverManager,
+    turnService,
+    streamSuffix,
+    mediaConfig,
+  } = deps;
+
+  function ensureVipVerified(socket) {
+    if (!isVerified(socket)) {
+      throw new Error('VIP verification required');
+    }
+  }
+
+  function ensureAudioForwardPermission(socket, roverId) {
+    ensureVipVerified(socket);
+    if (!roverManager.isDriver(roverId, socket)) {
+      throw new Error('Audio forwarding is only allowed on your own rover');
+    }
+    if (!turnService.canDrive(roverId, socket)) {
+      throw new Error('Only the current driver can play audio');
+    }
+  }
+
+  function forcePublishStreamMode(rawUrl) {
+    const value = String(rawUrl || '').trim();
+    if (!value) return '';
+    if (!/[?&]streamid=#!::/.test(value)) return value;
+    if (/,m=publish\b/.test(value)) return value;
+    if (/,m=[a-zA-Z]+\b/.test(value)) return value.replace(/,m=[a-zA-Z]+\b/, ',m=publish');
+    return value.replace(/([?&]streamid=#!::[^&]*)/, '$1,m=publish');
+  }
+
+  function resolveForwardUrl(roverId) {
+    const record = roverManager.rovers.get(roverId);
+    const configured = record?.meta?.media?.audioForwardUrl;
+    if (configured) return forcePublishStreamMode(configured);
+    return `srt://127.0.0.1:9000?streamid=#!::r=${encodeURIComponent(
+      roverId + streamSuffix,
+    )},m=publish&latency=10&mode=caller&transtype=live&pkt_size=1316`;
+  }
+
+  function resolveForwardPathId(roverId) {
+    return `${roverId}${streamSuffix}`;
+  }
+
+  function getMediaPrefix() {
+    const base = mediaConfig.whepBaseUrl;
+    if (!base) return '';
+    try {
+      const parsed = new URL(base);
+      return `${parsed.origin}${parsed.pathname}`.replace(/\/+$/, '');
+    } catch {
+      return String(base).replace(/\/+$/, '');
+    }
+  }
+
+  function buildWhipUrl(pathId) {
+    const prefix = getMediaPrefix();
+    if (!prefix) {
+      throw new Error('Server media base URL missing');
+    }
+    return `${prefix}/${encodeURIComponent(pathId)}/whip`;
+  }
+
+  return {
+    ensureVipVerified,
+    ensureAudioForwardPermission,
+    resolveForwardUrl,
+    resolveForwardPathId,
+    buildWhipUrl,
+  };
+}
+
+module.exports = {
+  createAudioForwardPolicy,
+};