inter-instance!

webui/src/lib/interInstanceTransfer.js

@@ -0,0 +1,48 @@
+// Inter-Instance Transfer Helpers
+// Purpose: Builds cross-server links and moves the local settings cookie only when the user opts in before leaving.
+// Scope: Keeps URL encoding and settings-transfer behavior out of the rover queue rendering code.
+import { loadSettings } from '../settings/persistence.js';
+
+function base64UrlEncodeJson(value) {
+  const json = JSON.stringify(value ?? {});
+  const bytes = new TextEncoder().encode(json);
+  let binary = '';
+  bytes.forEach((byte) => {
+    binary += String.fromCharCode(byte);
+  });
+  return btoa(binary).replace(/\+/g, '-').replace(/\//g, '_').replace(/=+$/g, '');
+}
+
+export function base64UrlDecodeJson(value) {
+  const raw = String(value || '').replace(/-/g, '+').replace(/_/g, '/');
+  const padded = raw.padEnd(Math.ceil(raw.length / 4) * 4, '=');
+  const binary = atob(padded);
+  const bytes = Uint8Array.from(binary, (char) => char.charCodeAt(0));
+  return JSON.parse(new TextDecoder().decode(bytes));
+}
+
+export function buildExternalRoverUrl(instance, roverId, { includeSettings = false } = {}) {
+  const publicUrl = String(instance?.instance?.publicUrl || instance?.publicUrl || instance?.url || '').trim();
+  if (!publicUrl) return '';
+  const url = new URL(publicUrl);
+  if (roverId) url.searchParams.set('rover', String(roverId));
+  /*
+    The destination always applies settingsTransfer if present, so this helper
+    only adds it after the current page has already asked for consent.
+  */
+  if (includeSettings) {
+    url.searchParams.set('settingsTransfer', base64UrlEncodeJson(loadSettings()));
+  }
+  return url.toString();
+}
+
+export function openExternalRoverWithPrompt(instance, roverId) {
+  const withoutTransfer = buildExternalRoverUrl(instance, roverId);
+  if (!withoutTransfer) return;
+  const instanceName = String(instance?.instance?.name || instance?.url || 'that server');
+  const includeSettings = window.confirm(
+    `Transfer your identity and settings to ${instanceName}? Press Cancel to open without transferring them.`,
+  );
+  const targetUrl = buildExternalRoverUrl(instance, roverId, { includeSettings });
+  window.location.href = targetUrl || withoutTransfer;
+}