feat(config): add configuration window (#70)

src/main/runtime/autoplay-subtitle-primer.ts

@@ -0,0 +1,31 @@
+import type { SubtitleCue } from '../../types';
+
+export function selectAutoplayStartupCue(
+  cues: SubtitleCue[],
+  currentTimeSeconds: number,
+  lookaheadSeconds: number,
+): SubtitleCue | null {
+  const currentTime = Math.max(0, Number.isFinite(currentTimeSeconds) ? currentTimeSeconds : 0);
+  const lookahead = Math.max(0, Number.isFinite(lookaheadSeconds) ? lookaheadSeconds : 0);
+  const latestStartTime = currentTime + lookahead;
+
+  for (const cue of cues) {
+    if (!cue.text.trim()) {
+      continue;
+    }
+    if (cue.startTime <= currentTime && cue.endTime > currentTime) {
+      return cue;
+    }
+  }
+
+  for (const cue of cues) {
+    if (!cue.text.trim()) {
+      continue;
+    }
+    if (cue.startTime >= currentTime && cue.startTime <= latestStartTime) {
+      return cue;
+    }
+  }
+
+  return null;
+}