fix(anki): snapshot mining media clip timing (#197)

src/core/services/index.ts

@@ -16,6 +16,7 @@ export {
 export { createOverlayShortcutRuntimeHandlers } from './overlay-shortcut-handler';
 export { createCliCommandDepsRuntime, handleCliCommand } from './cli-command';
 export {
+  captureLiveSubtitleMiningContext,
   copyCurrentSubtitle,
   handleMineSentenceDigit,
   handleMultiCopyDigit,

src/core/services/mining.test.ts

@@ -1,6 +1,7 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
 import {
+  captureLiveSubtitleMiningContext,
   copyCurrentSubtitle,
   handleMineSentenceDigit,
   handleMultiCopyDigit,
@@ -345,3 +346,46 @@ test('handleMineSentenceDigit joins per-entry secondary subtitles when available
     tracker.destroy();
   }
 });
+
+test('captureLiveSubtitleMiningContext snapshots the current line and timings', () => {
+  const context = captureLiveSubtitleMiningContext(
+    { currentSubText: ' 食べる ', currentSubStart: 12.5, currentSubEnd: 15.25 },
+    () => 1234,
+  );
+
+  assert.deepEqual(context, {
+    source: 'overlay',
+    text: '食べる',
+    startTime: 12.5,
+    endTime: 15.25,
+    capturedAtMs: 1234,
+  });
+});
+
+test('captureLiveSubtitleMiningContext rejects missing client, empty text and bad timings', () => {
+  assert.equal(captureLiveSubtitleMiningContext(null), null);
+  assert.equal(
+    captureLiveSubtitleMiningContext({
+      currentSubText: '  ',
+      currentSubStart: 1,
+      currentSubEnd: 2,
+    }),
+    null,
+  );
+  assert.equal(
+    captureLiveSubtitleMiningContext({
+      currentSubText: 'line',
+      currentSubStart: 5,
+      currentSubEnd: 5,
+    }),
+    null,
+  );
+  assert.equal(
+    captureLiveSubtitleMiningContext({
+      currentSubText: 'line',
+      currentSubStart: NaN,
+      currentSubEnd: 2,
+    }),
+    null,
+  );
+});

src/core/services/mining.ts

@@ -1,4 +1,5 @@
 import type { SubtitleTimingBlock } from '../../subtitle-timing-tracker';
+import type { SubtitleMiningContext } from '../../types/subtitle';
 
 interface SubtitleTimingTrackerLike {
   getRecentBlocks: (count: number) => string[];
@@ -54,6 +55,27 @@ export function handleMultiCopyDigit(
   }
 }
 
+/**
+ * Snapshot the live mpv subtitle line and its timings as a mining context. Media
+ * generation can run tens of seconds after the user mines (slow audio extraction),
+ * so anything that reads `currentSubStart`/`currentSubEnd` lazily clips whichever
+ * line is on screen by then; callers capture here at mining time instead.
+ */
+export function captureLiveSubtitleMiningContext(
+  client: Pick<MpvClientLike, 'currentSubText' | 'currentSubStart' | 'currentSubEnd'> | null,
+  now: () => number = Date.now,
+): SubtitleMiningContext | null {
+  if (!client) {
+    return null;
+  }
+  const text = client.currentSubText?.trim();
+  const { currentSubStart: startTime, currentSubEnd: endTime } = client;
+  if (!text || !Number.isFinite(startTime) || !Number.isFinite(endTime) || endTime <= startTime) {
+    return null;
+  }
+  return { source: 'overlay', text, startTime, endTime, capturedAtMs: now() };
+}
+
 export function copyCurrentSubtitle(deps: {
   subtitleTimingTracker: SubtitleTimingTrackerLike | null;
   writeClipboardText: (text: string) => void;