android/app/src/main/java/com/fabledsword/minstrel/player/PlayerController.kt

@@ -166,17 +166,51 @@ class PlayerController @Inject constructor(
     }
 
     /**
-     * Seed a fresh radio queue from [trackId] and start playback.
-     * Replaces the existing queue. The `source` tag is "radio:<id>"
-     * so the server-side rotation reporter can distinguish radio
-     * plays from album / playlist plays. No-op on an empty server
-     * response; throws on transport / non-2xx for the caller to
-     * surface in a snackbar.
+     * Seed a fresh radio queue from [trackId]. The `source` tag is
+     * "radio:<id>" so the server-side rotation reporter can
+     * distinguish radio plays from album / playlist plays.
+     *
+     * Two modes:
+     *  - Nothing in the queue: start the radio cold from track 0
+     *    (the seed plays first, recommendations follow).
+     *  - Queue already populated: do NOT interrupt — keep the current
+     *    track playing as-is, trim every upcoming track, and append
+     *    the radio results after the current item. If the seed is the
+     *    currently playing track (the common "tap Start Radio on the
+     *    song I'm listening to" case), drop it from the appended list
+     *    so it doesn't immediately repeat. This is an intentional
+     *    divergence from Flutter's `playerActions.startRadio`, which
+     *    always calls `playTracks` and restarts playback from 0.
+     *
+     * No-op on an empty server response; throws on transport / non-2xx
+     * for the caller to surface in a snackbar.
      */
     suspend fun startRadio(trackId: String) {
+        val controller = mediaController ?: return
         val tracks = radio.seed(trackId)
         if (tracks.isEmpty()) return
-        setQueue(tracks, initialIndex = 0, source = "radio:$trackId")
+        val source = "radio:$trackId"
+
+        if (controller.mediaItemCount == 0) {
+            setQueue(tracks, initialIndex = 0, source = source)
+            return
+        }
+
+        val currentIdx = controller.currentMediaItemIndex
+        val currentTrack = queueRefs.getOrNull(currentIdx)
+        // Server returns seed at index 0. Drop the duplicate when the
+        // seed is the currently playing track — otherwise append the
+        // full list so the current track is followed by the seed +
+        // recommendations.
+        val toAppend = if (currentTrack?.id == trackId) tracks.drop(1) else tracks
+        if (toAppend.isEmpty()) return
+
+        val nextIdx = currentIdx + 1
+        if (nextIdx < controller.mediaItemCount) {
+            controller.removeMediaItems(nextIdx, controller.mediaItemCount)
+        }
+        queueRefs = queueRefs.take(nextIdx) + toAppend
+        controller.addMediaItems(toAppend.map { it.toMediaItem(source) })
     }
 
     // ── Internal: async connect + Listener-driven UI state sync ──────────