implement demo mode

server/demo/index.js

@@ -0,0 +1,94 @@
+// Demo mode entrypoint.
+//
+// Each visitor gets an isolated session with up to N session-prefixed vaults, cleaned up after inactivity.
+// The proxy is allowlisted, Obsidian account login is blocked to discourage inputing credentials in a demo environment.
+
+const config = require("../config");
+
+const { cleanupExpired } = require("./demo-cleanup");
+const {
+  activityHeartbeat,
+  captureOriginalVaultName,
+  inboundTranslator,
+  outboundTranslator,
+  vaultsPerSessionEnforcer,
+  quotaEnforcer,
+  proxyAllowlist,
+  trackVaultLifecycle,
+  pluginsBlocker,
+  pageLoadHandler,
+  provisionEndpoint,
+} = require("./demo-middleware");
+const { wireWebSocket } = require("./demo-ws");
+
+// Mount HTTP middleware.
+// Call before the API routes mount so this middleware intercepts first.
+function setupDemo(app) {
+  if (!config.demoMode) {
+    return;
+  }
+
+  console.log("[demo] Demo mode enabled");
+  console.log(`[demo] Max sessions: ${config.demoMaxSessions}`);
+  console.log(`[demo] Vaults per session: ${config.demoVaultsPerSession}`);
+  console.log(
+    `[demo] Quota per session: ${config.demoSessionQuotaBytes} bytes`,
+  );
+  console.log(`[demo] Inactivity timeout: ${config.demoTimeoutMs} ms`);
+
+  // Page-load capacity gate (before static html)
+  app.use(pageLoadHandler);
+
+  // Heartbeat on every request so /api/ext/*, /vault-files/*, etc. keep the session alive too.
+  app.use(activityHeartbeat);
+
+  // Provisioning endpoint for the client to call when no vault is selected
+  app.get("/api/demo/provision", provisionEndpoint);
+
+  // Snapshot the user-visible name before inbound translation rewrites it.
+  app.use(
+    ["/api/vault", "/api/fs", "/api/bootstrap"],
+    captureOriginalVaultName,
+  );
+
+  // Inbound: rewrite ?vault= and bodies to prefixed storage names
+  app.use(["/api/vault", "/api/fs", "/api/bootstrap"], inboundTranslator);
+
+  // Outbound: filter vault lists and strip prefixes from responses
+  app.use(["/api/vault", "/api/fs", "/api/bootstrap"], outboundTranslator);
+
+  // quota enforcement
+  app.use("/api/vault", vaultsPerSessionEnforcer);
+  app.use("/api/fs", quotaEnforcer);
+
+  // Track vault create/rename/delete in session.vaults
+  app.use("/api/vault", trackVaultLifecycle);
+
+  // Restrict the CORS proxy
+  app.use("/api/proxy", proxyAllowlist);
+
+  // Hide server-side plugins (headless-sync) from the demo UI
+  app.use("/api/plugins", pluginsBlocker);
+
+  // Cleanup timer
+  const interval = setInterval(() => {
+    cleanupExpired().catch((e) =>
+      console.warn("[demo] Cleanup error:", e.message),
+    );
+  }, 60 * 1000);
+
+  if (interval.unref) {
+    interval.unref();
+  }
+}
+
+// Wire WebSocket-level vault translation. Called after setupWebSocket.
+function wireDemoWebSocket(server) {
+  if (!config.demoMode) {
+    return;
+  }
+
+  wireWebSocket(server);
+}
+
+module.exports = { setupDemo, wireDemoWebSocket };