Squash Odysseus development history

static/js/appConfig.js

@@ -0,0 +1,86 @@
+// static/js/appConfig.js
+//
+// One shared, invalidatable cache for the two config endpoints that every
+// module wants at startup.
+//
+// Before this, /api/auth/settings was fetched independently by six modules and
+// /api/tools by three, none of them aware of the others — 4 and 3 requests on a
+// single cold load. Worse than the requests: each caller could observe a
+// different snapshot of the same object, and chatRenderer.js is imported under
+// three different ?v= query strings, so it is three separate module instances
+// each issuing its own /api/tools fetch. Caching here fixes both, because the
+// cache lives in one module every instance imports by the same specifier.
+//
+// URLs are bare paths on purpose. The callers that used `${API_BASE}/api/...`
+// resolved to the identical URL — API_BASE is `window.location.origin`
+// (app.js) — so nothing about the request changes for them.
+//
+// WRITERS MUST INVALIDATE. Anything that POSTs /api/auth/settings calls
+// invalidateSettings(); anything that POSTs /api/tools calls invalidateTools()
+// *and* invalidateSettings(), because that route persists `disabled_tools`
+// into the same settings store (routes/model_routes.py). Miss one and the UI
+// serves a stale settings object for the rest of the session, which is worse
+// than the duplicate fetches this replaces.
+//
+// The resolved object is shared by reference, so treat it as read-only: copy
+// before mutating (`{ ...await getSettings() }`).
+
+// Written by login.html immediately before it redirects to '/', so the first
+// load after a login can skip the request entirely. Consumed once per page
+// load, by whichever module asks for settings first.
+const PREFETCH_KEY = 'ody-prefetch-settings';
+
+const _URLS = { settings: '/api/auth/settings', tools: '/api/tools' };
+const _cache = { settings: null, tools: null };
+
+function _readPrefetchedSettings() {
+  try {
+    const raw = sessionStorage.getItem(PREFETCH_KEY);
+    if (!raw) return null;
+    sessionStorage.removeItem(PREFETCH_KEY);
+    return JSON.parse(raw);
+  } catch (_) {
+    return null;
+  }
+}
+
+// A rejected promise must not stay in the slot. Plain `??=` memoisation would
+// keep it, so one transient blip during boot would leave keybinds, TTS and the
+// search provider on their defaults for the whole session with no retry. Clear
+// the slot on failure — unless a later invalidate/refetch already replaced it —
+// and rethrow, so every caller's existing .catch() still runs exactly as before.
+function _get(key) {
+  if (_cache[key]) return _cache[key];
+  const pending = fetch(_URLS[key], { credentials: 'same-origin' })
+    .then(r => r.json())
+    .catch(err => {
+      if (_cache[key] === pending) _cache[key] = null;
+      throw err;
+    });
+  _cache[key] = pending;
+  return pending;
+}
+
+/** GET /api/auth/settings, once per page load (or once per invalidation). */
+export function getSettings() {
+  if (!_cache.settings) {
+    const prefetched = _readPrefetchedSettings();
+    if (prefetched) _cache.settings = Promise.resolve(prefetched);
+  }
+  return _get('settings');
+}
+
+/** GET /api/tools, once per page load (or once per invalidation). */
+export function getTools() {
+  return _get('tools');
+}
+
+/** Call after any write that can change settings. */
+export function invalidateSettings() {
+  _cache.settings = null;
+}
+
+/** Call after any write that can change the tool enable/disable state. */
+export function invalidateTools() {
+  _cache.tools = null;
+}