fix: preserve vod mode across format changes

Author: Priveetee

src/main/kotlin/dev/typetype/server/services/SabrPlaybackSessionService.kt

@@ -80,7 +80,7 @@ internal class SabrPlaybackSessionService(private val sessionStore: SabrSessionS
             video = video,
             startTimeMs = playerTimeMs,
             audioOnly = audioOnly,
-            isLive = source.expectsLive() || prepared.isLive || prepared.isLiveContent,
+            isLive = source.expectsLive() || prepared.isLive,
             initialGeneration = source.nextReplacementGeneration(),
         )
     }

src/test/kotlin/dev/typetype/server/services/SabrLivePlaybackSessionServiceTest.kt

@@ -99,9 +99,11 @@ class SabrLivePlaybackSessionServiceTest {
     fun `historical live content prepares as vod`() = runTest {
         val audio = format(140, isAudio = true)
         val video = format(137, isAudio = false)
+        val replacementVideo = format(248, isAudio = false)
         val info = mockk<YoutubeSabrInfo>()
         val prepared = SabrPreparedInfo(info, token(), isLive = false, isLiveContent = true)
         val holder = holder(audio, video)
+        val replacement = holder(audio, replacementVideo, initialGeneration = 1L)
         val state = holder.session.streamState
         val store = mockk<SabrSessionStore>()
         every {
@@ -119,19 +121,43 @@ class SabrLivePlaybackSessionServiceTest {
                 0L,
             )
         } returns holder
+        every {
+            store.getOrCreate(
+                "video",
+                "user",
+                info,
+                audio,
+                replacementVideo,
+                prepared.initialToken,
+                30_000L,
+                false,
+                SabrSessionPurpose.PLAYBACK,
+                false,
+                1L,
+            )
+        } returns replacement
         coEvery { store.fetchInitializationData(holder, video) } returns byteArrayOf(1)
         coEvery { store.fetchInitializationData(holder, audio) } returns byteArrayOf(2)
+        coEvery { store.fetchInitializationData(replacement, replacementVideo) } returns byteArrayOf(3)
+        coEvery { store.fetchInitializationData(replacement, audio) } returns byteArrayOf(4)
         every { store.startPump(holder) } returns Unit
+        every { store.startPump(replacement) } returns Unit
 
-        val result = SabrPlaybackSessionService(store).prepare("video", "user", prepared, audio, video, 0L)
+        val service = SabrPlaybackSessionService(store)
+        val result = service.prepare("video", "user", prepared, audio, video, 0L)
+        service.seek(holder, prepared, audio, replacementVideo, 30_000L)
 
         assertEquals(0L, result.startTimeMs)
         assertFalse(holder.expectsLive())
+        assertFalse(replacement.expectsLive())
         verify(exactly = 0) { state.setPlayerTimeMs(9_007_199_254_740_991L) }
         coVerify(exactly = 0) { store.ensureWarmed(any(), any()) }
         coVerify(exactly = 1) { store.fetchInitializationData(holder, video) }
         coVerify(exactly = 1) { store.fetchInitializationData(holder, audio) }
+        coVerify(exactly = 1) { store.fetchInitializationData(replacement, replacementVideo) }
+        coVerify(exactly = 1) { store.fetchInitializationData(replacement, audio) }
         verify(exactly = 1) { store.startPump(holder) }
+        verify(exactly = 1) { store.startPump(replacement) }
     }
 
     @Test