Fix libass relay renderer never activating for HTTP streams

Pre-extraction is skipped for non-local streams so embeddedNativeAssTracks
is always empty, which meant embeddedSubtitle was always null, which meant
the relay renderer was never assigned as the active renderer. Relay renderer
should win whenever there is no external subtitle selected.

app/src/main/java/com/fluxa/app/ui/catalog/NativeLibassSubtitleOverlay.kt

@@ -4,6 +4,7 @@ import android.content.Context
 import android.graphics.Bitmap
 import android.graphics.Canvas
 import android.net.Uri
+import android.os.SystemClock
 import android.util.Log
 import android.view.View
 import androidx.compose.runtime.Composable
@@ -19,6 +20,7 @@ import androidx.media3.common.Player
 import androidx.media3.exoplayer.ExoPlayer
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.fluxa.app.player.ExternalSubtitleTrack
+import com.fluxa.app.player.LibassDebugLog
 import com.fluxa.app.player.MediaPlayerController
 import com.fluxa.app.player.MediaTrack
 import com.fluxa.app.player.MkvNativeAssExtractor
@@ -72,6 +74,10 @@ internal fun NativeLibassSubtitleOverlay(
     var localRenderer by remember { mutableStateOf<NativeLibassRenderer?>(null) }
 
     LaunchedEffect(externalSubtitle?.url, embeddedSubtitle?.id) {
+        LibassDebugLog.d(
+            "overlay selection external=${externalSubtitle?.let { "${LibassDebugLog.urlSummary(it.url)} label=${it.label} lang=${it.language}" } ?: "<none>"} " +
+                "embedded=${embeddedSubtitle?.let { "id=${it.id} label=${it.label} lang=${it.language} bytes=${it.assData.size} fonts=${it.fonts.size}" } ?: "<none>"}"
+        )
         val previous = localRenderer
         localRenderer = null
         previous?.close()
@@ -83,19 +89,29 @@ internal fun NativeLibassSubtitleOverlay(
                     fonts = embedded.fonts,
                     fontsDir = context.filesDir.resolve("fonts").absolutePath
                 )
-            }.onFailure { e -> Log.w("NativeLibassOverlay", "Embedded renderer failed", e) }.getOrNull()
+            }.onFailure { e ->
+                Log.w("NativeLibassOverlay", "Embedded renderer failed", e)
+                LibassDebugLog.w("overlay embedded renderer failed id=${embedded.id}", e)
+            }.getOrNull()
+            LibassDebugLog.d("overlay embedded renderer ${if (localRenderer != null) "ready" else "not ready"} id=${embedded.id}")
             return@LaunchedEffect
         }
         val url = externalSubtitle?.url ?: return@LaunchedEffect
         localRenderer = runCatching {
             val data = fetchSubtitleBytes(context, url)
+            LibassDebugLog.d("overlay fetched external ASS bytes=${data.size} url=${LibassDebugLog.urlSummary(url)}")
             val fonts = MkvNativeAssExtractor.extractExternalFontHints(url)
+            LibassDebugLog.d("overlay external font hints fonts=${fonts.size} url=${LibassDebugLog.urlSummary(url)}")
             NativeLibassRenderer.create(
                 assData = data,
                 fonts = fonts,
                 fontsDir = context.filesDir.resolve("fonts").absolutePath
             )
-        }.onFailure { e -> Log.w("NativeLibassOverlay", "External renderer failed", e) }.getOrNull()
+        }.onFailure { e ->
+            Log.w("NativeLibassOverlay", "External renderer failed", e)
+            LibassDebugLog.w("overlay external renderer failed url=${LibassDebugLog.urlSummary(url)}", e)
+        }.getOrNull()
+        LibassDebugLog.d("overlay external renderer ${if (localRenderer != null) "ready" else "not ready"} url=${LibassDebugLog.urlSummary(url)}")
     }
 
     DisposableEffect(Unit) {
@@ -106,9 +122,14 @@ internal fun NativeLibassSubtitleOverlay(
     }
 
     val activeRenderer = when {
-        embeddedSubtitle != null -> relayRenderer ?: localRenderer
         externalSubtitle != null -> localRenderer
-        else -> null
+        else -> relayRenderer ?: localRenderer
+    }
+    LaunchedEffect(activeRenderer, relayRenderer, localRenderer, externalSubtitle?.url, embeddedSubtitle?.id) {
+        LibassDebugLog.d(
+            "overlay activeRenderer=${activeRenderer != null} relayRenderer=${relayRenderer != null} localRenderer=${localRenderer != null} " +
+                "external=${externalSubtitle != null} embedded=${embeddedSubtitle != null}"
+        )
     }
 
     AndroidView(
@@ -133,6 +154,9 @@ private class NativeLibassSubtitleView(context: Context) : View(context) {
 
     var renderer: NativeLibassRenderer? = null
         set(value) {
+            if (field !== value) {
+                LibassDebugLog.d("overlay view renderer changed active=${value != null} view=${width}x$height attached=$isAttachedToWindow")
+            }
             field = value
             if (isAttachedToWindow) postInvalidateOnAnimation()
         }
@@ -144,6 +168,8 @@ private class NativeLibassSubtitleView(context: Context) : View(context) {
         }
 
     private var bitmap: Bitmap? = null
+    private var lastDrawLogMs = 0L
+    private var lastDrawHadPixels: Boolean? = null
 
     private val playerListener = object : Player.Listener {
         override fun onIsPlayingChanged(isPlaying: Boolean) {
@@ -161,12 +187,14 @@ private class NativeLibassSubtitleView(context: Context) : View(context) {
 
     override fun onAttachedToWindow() {
         super.onAttachedToWindow()
+        LibassDebugLog.d("overlay view attached size=${width}x$height")
         player?.addListener(playerListener)
         postInvalidateOnAnimation()
     }
 
     override fun onDetachedFromWindow() {
         super.onDetachedFromWindow()
+        LibassDebugLog.d("overlay view detached")
         player?.removeListener(playerListener)
         bitmap?.recycle()
         bitmap = null
@@ -186,6 +214,15 @@ private class NativeLibassSubtitleView(context: Context) : View(context) {
 
         val result = activeRenderer.render(activePlayer.currentPosition + subtitleDelayMs, targetBitmap)
         if (result > 0) canvas.drawBitmap(targetBitmap, 0f, 0f, null)
+        val hasPixels = result > 0
+        val now = SystemClock.elapsedRealtime()
+        if (lastDrawHadPixels != hasPixels || now - lastDrawLogMs > 1_500L) {
+            LibassDebugLog.d(
+                "overlay draw positionMs=${activePlayer.currentPosition} delayMs=$subtitleDelayMs size=${width}x$height result=$result hasPixels=$hasPixels playing=${activePlayer.isPlaying} playWhenReady=${activePlayer.playWhenReady}"
+            )
+            lastDrawHadPixels = hasPixels
+            lastDrawLogMs = now
+        }
 
         if (activePlayer.isPlaying || activePlayer.playWhenReady) {
             if (result == 0) postInvalidateDelayed(100) else postInvalidateOnAnimation()