inter-instance!

webui/src/hooks/useIncomingInterInstanceTransfer.js

@@ -0,0 +1,60 @@
+// Hook: useIncomingInterInstanceTransfer
+// Purpose: Applies settings transferred through an inter-instance URL before the normal identity heartbeat runs.
+// Scope: Owns only inbound URL parameters; requesting the target rover is handled after socket/session state is ready.
+import { useEffect, useRef } from 'react';
+import { useSettings } from '../settings/index.js';
+import { base64UrlDecodeJson } from '../lib/interInstanceTransfer.js';
+import { useSessionActions, useSessionSelector } from '../context/SessionContext.jsx';
+
+export default function useIncomingInterInstanceTransfer() {
+  const settings = useSettings();
+  const { requestControl } = useSessionActions();
+  const connected = useSessionSelector((state) => state.connected);
+  const appliedRef = useRef(false);
+  const requestedRef = useRef(false);
+  const roverIdRef = useRef('');
+
+  useEffect(() => {
+    if (appliedRef.current || typeof window === 'undefined') return;
+    const url = new URL(window.location.href);
+    const transfer = url.searchParams.get('settingsTransfer');
+    roverIdRef.current = String(url.searchParams.get('rover') || '').trim();
+    if (!transfer) {
+      appliedRef.current = true;
+      return;
+    }
+    try {
+      /*
+        The source page already asked before adding settingsTransfer. A present
+        transfer param is therefore an explicit instruction to replace the local
+        settings cookie without asking again on the destination server.
+      */
+      const nextSettings = base64UrlDecodeJson(transfer);
+      settings.saveAll(nextSettings && typeof nextSettings === 'object' ? nextSettings : {});
+      url.searchParams.delete('settingsTransfer');
+      window.history.replaceState({}, '', `${url.pathname}${url.search}${url.hash}`);
+    } catch (error) {
+      // A bad transfer payload should not block the page or the rover request.
+      console.warn('Failed to apply transferred inter-instance settings', error);
+    } finally {
+      appliedRef.current = true;
+    }
+  }, [settings]);
+
+  useEffect(() => {
+    if (!appliedRef.current || requestedRef.current || !connected) return;
+    const roverId = roverIdRef.current;
+    if (!roverId) return;
+    requestedRef.current = true;
+    /*
+      The identity heartbeat reacts to the settings overwrite through the shared
+      settings context. Waiting for a connected socket here keeps this hook from
+      racing the initial Socket.IO connection while still using the existing
+      request-control path.
+    */
+    requestControl(roverId).catch((error) => {
+      requestedRef.current = false;
+      console.warn('Failed to request transferred inter-instance rover', error);
+    });
+  }, [connected, requestControl]);
+}