fix(overlay): Linux X11/XWayland stacking, stale pause state, multi-copy selector (#101)

src/main/runtime/current-subtitle-snapshot.ts

@@ -1,5 +1,10 @@
 import type { SubtitleData } from '../../types';
 
+type CurrentSubtitleMpvClient = {
+  connected?: boolean;
+  requestProperty: (name: string) => Promise<unknown>;
+};
+
 export async function resolveCurrentSubtitleForRenderer(deps: {
   currentSubText: string;
   currentSubtitleData: SubtitleData | null;
@@ -27,3 +32,81 @@ export async function resolveCurrentSubtitleForRenderer(deps: {
     tokens: null,
   });
 }
+
+export async function primeVisibleOverlaySubtitleFromMpv(deps: {
+  getMpvClient: () => CurrentSubtitleMpvClient | null;
+  setCurrentSubText: (text: string) => void;
+  getCurrentSubtitleData: () => SubtitleData | null;
+  consumeCachedSubtitle: (text: string) => SubtitleData | null;
+  onSubtitleChange: (text: string) => void;
+  refreshCurrentSubtitle: (text: string) => void;
+  emitSubtitle: (payload: SubtitleData) => void;
+  setCurrentSecondarySubText?: (text: string) => void;
+  emitSecondarySubtitle?: (text: string) => void;
+  logDebug?: (message: string) => void;
+}): Promise<void> {
+  const client = deps.getMpvClient();
+  if (!client?.connected) {
+    return;
+  }
+
+  let subTextRaw: unknown;
+  try {
+    subTextRaw = await client.requestProperty('sub-text');
+  } catch (error) {
+    deps.logDebug?.(
+      `[visible-overlay-subtitle-prime] failed to read sub-text: ${
+        error instanceof Error ? error.message : String(error)
+      }`,
+    );
+    return;
+  }
+
+  const text = typeof subTextRaw === 'string' ? subTextRaw : '';
+  deps.setCurrentSubText(text);
+
+  const primeSecondarySubtitle = async (): Promise<void> => {
+    if (!deps.setCurrentSecondarySubText && !deps.emitSecondarySubtitle) {
+      return;
+    }
+
+    try {
+      const secondarySubTextRaw = await client.requestProperty('secondary-sub-text');
+      const secondaryText = typeof secondarySubTextRaw === 'string' ? secondarySubTextRaw : '';
+      deps.setCurrentSecondarySubText?.(secondaryText);
+      deps.emitSecondarySubtitle?.(secondaryText);
+    } catch (error) {
+      deps.logDebug?.(
+        `[visible-overlay-subtitle-prime] failed to read secondary-sub-text: ${
+          error instanceof Error ? error.message : String(error)
+        }`,
+      );
+    }
+  };
+
+  if (!text.trim()) {
+    deps.onSubtitleChange(text);
+    deps.emitSubtitle({ text, tokens: null });
+    await primeSecondarySubtitle();
+    return;
+  }
+
+  const currentPayload = deps.getCurrentSubtitleData();
+  if (currentPayload?.text === text) {
+    deps.emitSubtitle(currentPayload);
+    deps.refreshCurrentSubtitle(text);
+    await primeSecondarySubtitle();
+    return;
+  }
+
+  const cachedPayload = deps.consumeCachedSubtitle(text);
+  if (cachedPayload) {
+    deps.onSubtitleChange(text);
+    deps.emitSubtitle(cachedPayload);
+    await primeSecondarySubtitle();
+    return;
+  }
+
+  deps.refreshCurrentSubtitle(text);
+  await primeSecondarySubtitle();
+}