feat(dictionary): add Hachidori backend support (#266)

src/main/runtime/subtitle-prefetch-init.ts

@@ -4,6 +4,7 @@ import type {
 } from '../../core/services/subtitle-prefetch';
 import type { SubtitleData } from '../../types';
 import type { SubtitleCue } from '../../types';
+import { buildOverlapPrefetchCues } from './subtitle-prefetch-overlaps';
 
 export interface SubtitlePrefetchInitControllerDeps {
   getCurrentService: () => SubtitlePrefetchService | null;
@@ -14,6 +15,7 @@ export interface SubtitlePrefetchInitControllerDeps {
   tokenizeSubtitle: (text: string) => Promise<SubtitleData | null>;
   preCacheTokenization: (text: string, data: SubtitleData) => void;
   hasCachedTokenization?: (text: string) => boolean;
+  getCacheGeneration?: () => number;
   logInfo: (message: string) => void;
   logWarn: (message: string) => void;
   onParsedSubtitleCuesChanged?: (cues: SubtitleCue[] | null, sourceKey: string | null) => void;
@@ -32,11 +34,20 @@ export function createSubtitlePrefetchInitController(
   deps: SubtitlePrefetchInitControllerDeps,
 ): SubtitlePrefetchInitController {
   let initRevision = 0;
+  // What the running service was built from. Startup fires several inits for one source
+  // (Jellyfin preload seed, sid change, each track-list update); restarting on each would
+  // discard the in-flight tokenization and re-queue the priority window behind it.
+  let activeSource: { key: string; content: string; cues: SubtitleCue[] } | null = null;
+
+  const stopCurrentService = (): void => {
+    deps.getCurrentService()?.stop();
+    deps.setCurrentService(null);
+    activeSource = null;
+  };
 
   const cancelPendingInit = (): void => {
     initRevision += 1;
-    deps.getCurrentService()?.stop();
-    deps.setCurrentService(null);
+    stopCurrentService();
     deps.onParsedSubtitleCuesChanged?.(null, null);
   };
 
@@ -46,14 +57,26 @@ export function createSubtitlePrefetchInitController(
     sourceKey = sourcePath,
   ): Promise<void> => {
     const revision = ++initRevision;
-    deps.getCurrentService()?.stop();
-    deps.setCurrentService(null);
+    // The same source may still be current once loaded; keep its service running until then.
+    if (activeSource?.key !== sourceKey) {
+      stopCurrentService();
+    }
 
     try {
       const content = await deps.loadSubtitleSourceText(sourcePath);
       if (revision !== initRevision) {
         return;
       }
+      if (
+        activeSource?.key === sourceKey &&
+        activeSource.content === content &&
+        deps.getCurrentService()
+      ) {
+        // A track change clears the published cues synchronously, so republish them.
+        deps.onParsedSubtitleCuesChanged?.(activeSource.cues, sourceKey);
+        return;
+      }
+      stopCurrentService();
 
       const cues = deps.parseSubtitleCues(content, sourcePath);
       if (revision !== initRevision || cues.length === 0) {
@@ -66,11 +89,16 @@ export function createSubtitlePrefetchInitController(
         return;
       }
 
+      // Overlap cues only feed the cache; the published cue list stays as authored.
+      const prefetchCues = [...cues, ...buildOverlapPrefetchCues(cues)].sort(
+        (a, b) => a.startTime - b.startTime,
+      );
       const nextService = deps.createSubtitlePrefetchService({
-        cues,
+        cues: prefetchCues,
         tokenizeSubtitle: (text) => deps.tokenizeSubtitle(text),
         preCacheTokenization: (text, data) => deps.preCacheTokenization(text, data),
         hasCachedTokenization: (text) => deps.hasCachedTokenization?.(text) ?? false,
+        getCacheGeneration: deps.getCacheGeneration,
       });
 
       if (revision !== initRevision) {
@@ -78,6 +106,7 @@ export function createSubtitlePrefetchInitController(
       }
 
       deps.setCurrentService(nextService);
+      activeSource = { key: sourceKey, content, cues };
       deps.onParsedSubtitleCuesChanged?.(cues, sourceKey);
       nextService.start(currentTimePos);
       deps.logInfo(
@@ -85,6 +114,7 @@ export function createSubtitlePrefetchInitController(
       );
     } catch (error) {
       if (revision === initRevision) {
+        stopCurrentService();
         deps.onParsedSubtitleCuesChanged?.(null, null);
         deps.logWarn(`[subtitle-prefetch] failed to initialize: ${(error as Error).message}`);
       }