From c245b1ef0b9fc1790c54552068322d8461b7cb02 Mon Sep 17 00:00:00 2001
From: Bryan Van Deusen <bryan.vandeusen@fabledsword.com>
Date: Thu, 4 Jun 2026 00:37:34 -0400
Subject: [PATCH] fix(android): hold UI patch until cursor sync lands; reanchor
 on track flip

---
 .../minstrel/player/PlayerController.kt       | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/android/app/src/main/java/com/fabledsword/minstrel/player/PlayerController.kt b/android/app/src/main/java/com/fabledsword/minstrel/player/PlayerController.kt
index e0760987..3f7ae5a8 100644
--- a/android/app/src/main/java/com/fabledsword/minstrel/player/PlayerController.kt
+++ b/android/app/src/main/java/com/fabledsword/minstrel/player/PlayerController.kt
@@ -411,6 +411,11 @@ class PlayerController @Inject constructor(
                     // Reset the per-item evaluation guard so the new
                     // item's STATE_READY transition gets a fresh check.
                     lastEvaluatedItemIndex = -1
+                    // The track flipped -- re-anchor the position interpolator
+                    // so the next polling tick treats the new track's
+                    // remoteState.positionMs as fresh rather than carrying the
+                    // old anchor + elapsed forward.
+                    lastSeenRemotePositionMs = -1L
                 }
 
                 override fun onPlaybackStateChanged(playbackState: Int) {
@@ -493,6 +498,14 @@ class PlayerController @Inject constructor(
             while (isActive) {
                 delay(POSITION_POLL_INTERVAL_MS)
                 val upnpActive = activeUpnpHolder.active.value != null
+                // Track-alignment gate: if Sonos's reported Track is past the
+                // wrapped player's currentMediaItemIndex, a forward cursor sync
+                // is in flight (pollOnce wrote new remoteState, handler.post'd
+                // delegate.seekTo; the seek hasn't run yet). Skipping the tick
+                // here lets onMediaItemTransition rebuild the full uiState
+                // atomically rather than patching position+duration while
+                // currentTrack/queueIndex still point at the old track.
+                if (upnpActive && isForwardCursorSyncPending(controller)) continue
                 val effectiveIsPlaying =
                     if (upnpActive) remoteState.isPlaying else controller.isPlaying
                 val effectivePosition = if (upnpActive) {
@@ -533,6 +546,12 @@ class PlayerController @Inject constructor(
     @Volatile private var positionAnchorMs: Long = 0L
     @Volatile private var positionAnchorAtRealtimeMs: Long = 0L
 
+    private fun isForwardCursorSyncPending(controller: MediaController): Boolean {
+        val sonosTrack = remoteState.trackNumber
+        if (sonosTrack <= 0) return false
+        return (sonosTrack - 1) > controller.currentMediaItemIndex
+    }
+
     private fun interpolatedRemotePosition(isPlaying: Boolean): Long {
         val raw = remoteState.positionMs
         val now = SystemClock.elapsedRealtime()