fix(plugin): keep loading OSD off on warm playlist advance (#317)

* fix(plugin): keep loading OSD off on warm playlist advance

- Track overlay_content_ready_seen when the app sends subminer-overlay-loading-ready
- Skip restarting the "Overlay loading" spinner for an overlay that already reported ready, so it no longer times out into "Overlay did not become ready" (#315)
- Reset the flag on stop, restart, start failure and shutdown
- Add start-gate tests for warm and not-yet-ready playlist advances

* fix(plugin): only report overlay ready once content has loaded

Hide paths dismissed the loading OSD with subminer-overlay-loading-ready,
which the plugin now remembers to skip the spinner on later playlist files.
A hide before the overlay had content would wrongly mark it ready. The app
now sends ready only when the overlay window content is ready, and a new
stop-only subminer-overlay-loading-dismissed message otherwise.

* fix(plugin): resync overlay readiness on dismissal and mpv connect

A dismissal now clears the plugin's readiness flag, since the app sends it
only while its overlay window has no content (e.g. a replaced window).
On mpv (re)connect the app resends subminer-overlay-loading-ready when the
overlay already has content, so a ready signal lost while mpv was away, or
sent before this mpv's plugin existed, still reaches the plugin.

* refactor(main): pass overlay readiness handler directly

src/main/runtime/overlay-notifications-runtime.test.ts

@@ -0,0 +1,60 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import type { BrowserWindow } from 'electron';
+
+import { OVERLAY_WINDOW_CONTENT_READY_FLAG } from '../../core/services/overlay-window-flags';
+import type { MpvIpcClient } from '../../core/services';
+import type { ResolvedConfig } from '../../types';
+import { createOverlayNotificationsRuntime } from './overlay-notifications-runtime';
+
+function createRuntimeHarness(contentReady: boolean) {
+  const sent: unknown[][] = [];
+  const overlayWindow = {
+    isDestroyed: () => false,
+    [OVERLAY_WINDOW_CONTENT_READY_FLAG]: contentReady,
+  } as unknown as BrowserWindow;
+  const mpvClient = {
+    send: ({ command }: { command: unknown[] }) => {
+      sent.push(command);
+    },
+  } as unknown as MpvIpcClient;
+  const runtime = createOverlayNotificationsRuntime({
+    getResolvedConfig: () => ({}) as ResolvedConfig,
+    getMainOverlayWindow: () => overlayWindow,
+    getVisibleOverlayVisible: () => false,
+    broadcastToOverlayWindows: () => {},
+    showMpvOsd: () => {},
+    getMpvClient: () => mpvClient,
+    getAnkiIntegration: () => null,
+    getRuntimeOptionsManager: () => null,
+  });
+  const scriptMessages = () =>
+    sent.filter((command) => command[0] === 'script-message').map((command) => command[1]);
+  return { runtime, scriptMessages };
+}
+
+test('dismissing the loading OSD before overlay content is ready only stops the plugin spinner', () => {
+  const { runtime, scriptMessages } = createRuntimeHarness(false);
+
+  runtime.dismissOverlayLoadingStatusNotification();
+
+  assert.deepEqual(scriptMessages(), ['subminer-overlay-loading-dismissed']);
+});
+
+test('dismissing the loading OSD once overlay content is ready reports readiness to the plugin', () => {
+  const { runtime, scriptMessages } = createRuntimeHarness(true);
+
+  runtime.dismissOverlayLoadingStatusNotification();
+
+  assert.deepEqual(scriptMessages(), ['subminer-overlay-loading-ready']);
+});
+
+test('reporting overlay readiness after an mpv connect resends ready only for loaded content', () => {
+  const ready = createRuntimeHarness(true);
+  ready.runtime.reportOverlayContentReadyToPlugin();
+  assert.deepEqual(ready.scriptMessages(), ['subminer-overlay-loading-ready']);
+
+  const loading = createRuntimeHarness(false);
+  loading.runtime.reportOverlayContentReadyToPlugin();
+  assert.deepEqual(loading.scriptMessages(), []);
+});

src/main/runtime/overlay-notifications-runtime.ts

@@ -61,6 +61,7 @@ export function createOverlayNotificationsRuntime(deps: OverlayNotificationsRunt
   showYoutubeFlowStatusNotification: (message: string) => void;
   showOverlayLoadingStatusNotification: () => void;
   dismissOverlayLoadingStatusNotification: () => void;
+  reportOverlayContentReadyToPlugin: () => void;
   maybeStartOverlayLoadingOsd: (mediaPath?: string | null) => void;
 } {
   function isVisibleOverlayContentReady(): boolean {
@@ -229,15 +230,39 @@ export function createOverlayNotificationsRuntime(deps: OverlayNotificationsRunt
     getOverlayLoadingOsdController().start();
   }
 
+  function isMainOverlayContentReady(): boolean {
+    const overlayWindow = deps.getMainOverlayWindow();
+    return Boolean(overlayWindow && isOverlayWindowContentReady(overlayWindow));
+  }
+
+  function sendPluginOverlayLoadingMessage(
+    message: 'subminer-overlay-loading-ready' | 'subminer-overlay-loading-dismissed',
+  ): void {
+    sendMpvCommandRuntime(deps.getMpvClient(), ['script-message', message]);
+  }
+
+  // Hide paths also dismiss, often before the overlay has content. Only a content-ready window
+  // reports `subminer-overlay-loading-ready`: the plugin remembers it and skips the spinner on
+  // later playlist files, so other dismissals send the stop-only message, which also makes the
+  // plugin forget readiness from a replaced window.
   function dismissOverlayLoadingStatusNotification(): void {
     getOverlayLoadingOsdController().stop();
-    sendMpvCommandRuntime(deps.getMpvClient(), [
-      'script-message',
-      'subminer-overlay-loading-ready',
-    ]);
+    sendPluginOverlayLoadingMessage(
+      isMainOverlayContentReady()
+        ? 'subminer-overlay-loading-ready'
+        : 'subminer-overlay-loading-dismissed',
+    );
     dismissOverlayNotification('overlay-loading-status');
   }
 
+  // Called when mpv (re)connects: a ready message sent while mpv was away, or before this mpv's
+  // plugin existed, was lost. Never sends the dismissal, since nothing is being hidden.
+  function reportOverlayContentReadyToPlugin(): void {
+    if (isMainOverlayContentReady()) {
+      sendPluginOverlayLoadingMessage('subminer-overlay-loading-ready');
+    }
+  }
+
   const maybeStartOverlayLoadingOsd = createMaybeStartOverlayLoadingOsdHandler({
     getVisibleOverlayRequested: () => deps.getVisibleOverlayVisible(),
     isOverlayContentReady: () => isVisibleOverlayContentReady(),
@@ -261,6 +286,7 @@ export function createOverlayNotificationsRuntime(deps: OverlayNotificationsRunt
     showYoutubeFlowStatusNotification,
     showOverlayLoadingStatusNotification,
     dismissOverlayLoadingStatusNotification,
+    reportOverlayContentReadyToPlugin,
     maybeStartOverlayLoadingOsd,
   };
 }