Merge pull request 'Android #618 offline-mode UX + Sonos polish + server DRY' (#81) from dev into main

android/app/src/main/java/com/fabledsword/minstrel/MainActivity.kt

@@ -21,6 +21,9 @@ import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.navigation.compose.rememberNavController
 import com.fabledsword.minstrel.auth.ui.AuthGateViewModel
 import com.fabledsword.minstrel.cache.CachedTrackIds
+import com.fabledsword.minstrel.connectivity.LocalServerHealth
+import com.fabledsword.minstrel.connectivity.ServerHealth
+import com.fabledsword.minstrel.connectivity.ServerHealthController
 import com.fabledsword.minstrel.nav.DetailSeedCache
 import com.fabledsword.minstrel.nav.LocalDetailSeedCache
 import com.fabledsword.minstrel.nav.MinstrelNavGraph
@@ -38,6 +41,7 @@ import javax.inject.Inject
 class MainActivity : ComponentActivity() {
     @Inject lateinit var seedCache: DetailSeedCache
     @Inject lateinit var cachedTrackIds: CachedTrackIds
+    @Inject lateinit var serverHealth: ServerHealthController
 
     // Flipped to true when the user taps the media notification (or
     // any other entry point that asks for the full player). The App
@@ -54,6 +58,7 @@ class MainActivity : ComponentActivity() {
             App(
                 seedCache = seedCache,
                 cachedTrackIds = cachedTrackIds,
+                serverHealth = serverHealth,
                 pendingOpenNowPlaying = pendingOpenNowPlaying.asStateFlow(),
                 onOpenedNowPlaying = { pendingOpenNowPlaying.value = false },
             )
@@ -86,6 +91,7 @@ class MainActivity : ComponentActivity() {
 private fun App(
     seedCache: DetailSeedCache,
     cachedTrackIds: CachedTrackIds,
+    serverHealth: ServerHealthController,
     pendingOpenNowPlaying: StateFlow<Boolean>,
     onOpenedNowPlaying: () -> Unit,
     themeVm: ThemePreferenceViewModel = hiltViewModel(),
@@ -93,11 +99,13 @@ private fun App(
 ) {
     val theme by themeVm.themeMode.collectAsStateWithLifecycle()
     val cached by cachedTrackIds.ids.collectAsStateWithLifecycle()
+    val health: ServerHealth by serverHealth.state.collectAsStateWithLifecycle()
     val pending by pendingOpenNowPlaying.collectAsStateWithLifecycle()
     MinstrelTheme(darkOverride = theme.toDarkOverride()) {
         CompositionLocalProvider(
             LocalDetailSeedCache provides seedCache,
             LocalCachedTrackIds provides cached,
+            LocalServerHealth provides health,
         ) {
             val startDestination by gate.startDestination.collectAsStateWithLifecycle()
             val resolved = startDestination

android/app/src/main/java/com/fabledsword/minstrel/MinstrelApplication.kt

@@ -19,6 +19,7 @@ import com.fabledsword.minstrel.player.PlayEventsReporter
 import com.fabledsword.minstrel.player.PlaybackErrorReporter
 import com.fabledsword.minstrel.player.ResumeController
 import com.fabledsword.minstrel.update.data.UpdateBannerController
+import com.fabledsword.minstrel.connectivity.ServerHealthController
 import com.fabledsword.minstrel.update.data.VersionCheckController
 import dagger.hilt.android.HiltAndroidApp
 import kotlinx.coroutines.CoroutineScope
@@ -121,6 +122,15 @@ class MinstrelApplication :
      */
     @Suppress("unused") @Inject lateinit var versionCheckController: VersionCheckController
 
+    /**
+     * Same construct-the-singleton trick — ServerHealthController combines
+     * ConnectivityObserver + VersionCheckController.reachable into the
+     * tri-state ServerHealth signal. Its stateIn is `SharingStarted.Eagerly`
+     * so the StateFlow needs an active subscriber from launch onward; the
+     * @Inject keeps the singleton alive and the flow collecting.
+     */
+    @Suppress("unused") @Inject lateinit var serverHealthController: ServerHealthController
+
     /**
      * Same construct-the-singleton trick — UpdateBannerController polls
      * /api/client/version at launch + every 24h and drives the shell's

android/app/src/main/java/com/fabledsword/minstrel/cache/db/dao/CachedAlbumDao.kt

@@ -24,6 +24,14 @@ interface CachedAlbumDao {
     @Query("SELECT * FROM cached_albums WHERE id = :id")
     fun observeById(id: String): Flow<CachedAlbumEntity?>
 
+    @Query(
+        "SELECT * FROM cached_albums " +
+            "WHERE title LIKE '%' || :q || '%' COLLATE NOCASE " +
+            "ORDER BY sortTitle COLLATE NOCASE ASC " +
+            "LIMIT :limit",
+    )
+    suspend fun searchByTitle(q: String, limit: Int): List<CachedAlbumEntity>
+
     @Query("SELECT id FROM cached_albums WHERE fetchedAt < :before LIMIT :limit")
     suspend fun idsStaleBefore(before: Long, limit: Int): List<String>
 

android/app/src/main/java/com/fabledsword/minstrel/cache/db/dao/CachedArtistDao.kt

@@ -18,6 +18,14 @@ interface CachedArtistDao {
     @Query("SELECT * FROM cached_artists WHERE id = :id")
     fun observeById(id: String): Flow<CachedArtistEntity?>
 
+    @Query(
+        "SELECT * FROM cached_artists " +
+            "WHERE name LIKE '%' || :q || '%' COLLATE NOCASE " +
+            "ORDER BY sortName COLLATE NOCASE ASC " +
+            "LIMIT :limit",
+    )
+    suspend fun searchByName(q: String, limit: Int): List<CachedArtistEntity>
+
     @Query("SELECT id FROM cached_artists WHERE fetchedAt < :before LIMIT :limit")
     suspend fun idsStaleBefore(before: Long, limit: Int): List<String>
 

android/app/src/main/java/com/fabledsword/minstrel/cache/db/dao/CachedTrackDao.kt

@@ -24,6 +24,14 @@ interface CachedTrackDao {
     @Query("SELECT * FROM cached_tracks WHERE id IN (:ids)")
     suspend fun getByIds(ids: List<String>): List<CachedTrackEntity>
 
+    @Query(
+        "SELECT * FROM cached_tracks " +
+            "WHERE title LIKE '%' || :q || '%' COLLATE NOCASE " +
+            "ORDER BY title COLLATE NOCASE ASC " +
+            "LIMIT :limit",
+    )
+    suspend fun searchByTitle(q: String, limit: Int): List<CachedTrackEntity>
+
     @Query("SELECT id FROM cached_tracks WHERE fetchedAt < :before LIMIT :limit")
     suspend fun idsStaleBefore(before: Long, limit: Int): List<String>
 

android/app/src/main/java/com/fabledsword/minstrel/cache/mutations/MutationQueue.kt

@@ -2,12 +2,18 @@ package com.fabledsword.minstrel.cache.mutations
 
 import com.fabledsword.minstrel.cache.db.dao.CachedMutationDao
 import com.fabledsword.minstrel.cache.db.entities.CachedMutationEntity
+import kotlinx.coroutines.channels.BufferOverflow
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.SharedFlow
+import kotlinx.coroutines.flow.asSharedFlow
 import kotlinx.serialization.Serializable
 import kotlinx.serialization.encodeToString
 import kotlinx.serialization.json.Json
 import javax.inject.Inject
 import javax.inject.Singleton
 
+private const val QUEUED_MESSAGE = "Saved — will sync when online"
+
 /**
  * Stable mutation kinds the queue knows how to replay. Strings are
  * persisted in `cached_mutations.kind` so renaming a variant breaks
@@ -71,47 +77,59 @@ class MutationQueue @Inject constructor(
     private val dao: CachedMutationDao,
     private val json: Json,
 ) {
+    // capacity=1 DROP_OLDEST so a burst of user enqueues (e.g. liking N
+    // tracks while offline) surfaces as one snackbar rather than queueing
+    // N. replay=0 because a hint observed at enqueue time isn't useful
+    // to a screen that mounts later.
+    private val _userEnqueueHints = MutableSharedFlow<String>(
+        replay = 0,
+        extraBufferCapacity = 1,
+        onBufferOverflow = BufferOverflow.DROP_OLDEST,
+    )
+
+    /**
+     * Hint stream consumed by [com.fabledsword.minstrel.shared.widgets.ShellScaffold]
+     * to surface "Saved — will sync when online" as a snackbar whenever a
+     * user-driven write hits the offline-fallback path. Background-only
+     * enqueues (play-events, playback-error reports) do not emit — those
+     * fire from non-foreground paths where a snackbar would be either
+     * dropped (no shell mounted) or jarring (lock-screen toggle).
+     */
+    val userEnqueueHints: SharedFlow<String> = _userEnqueueHints.asSharedFlow()
+
     suspend fun enqueueLikeToggle(
         entityType: String,
         entityId: String,
         desiredState: Boolean,
-    ): Long = dao.insert(
-        CachedMutationEntity(
-            kind = MutationKind.LIKE_TOGGLE,
-            payload = json.encodeToString(
-                LikeTogglePayload.serializer(),
-                LikeTogglePayload(entityType, entityId, desiredState),
-            ),
+    ): Long = insertUserDriven(
+        MutationKind.LIKE_TOGGLE,
+        json.encodeToString(
+            LikeTogglePayload.serializer(),
+            LikeTogglePayload(entityType, entityId, desiredState),
         ),
     )
 
-    suspend fun enqueueRequestCreate(payload: RequestCreatePayload): Long = dao.insert(
-        CachedMutationEntity(
-            kind = MutationKind.REQUEST_CREATE,
-            payload = json.encodeToString(RequestCreatePayload.serializer(), payload),
-        ),
+    suspend fun enqueueRequestCreate(payload: RequestCreatePayload): Long = insertUserDriven(
+        MutationKind.REQUEST_CREATE,
+        json.encodeToString(RequestCreatePayload.serializer(), payload),
     )
 
-    suspend fun enqueueQuarantineUnflag(trackId: String): Long = dao.insert(
-        CachedMutationEntity(
-            kind = MutationKind.QUARANTINE_UNFLAG,
-            payload = json.encodeToString(
-                QuarantineUnflagPayload.serializer(),
-                QuarantineUnflagPayload(trackId),
-            ),
+    suspend fun enqueueQuarantineUnflag(trackId: String): Long = insertUserDriven(
+        MutationKind.QUARANTINE_UNFLAG,
+        json.encodeToString(
+            QuarantineUnflagPayload.serializer(),
+            QuarantineUnflagPayload(trackId),
         ),
     )
 
     suspend fun enqueuePlaylistAppend(
         playlistId: String,
         trackIds: List<String>,
-    ): Long = dao.insert(
-        CachedMutationEntity(
-            kind = MutationKind.PLAYLIST_APPEND,
-            payload = json.encodeToString(
-                PlaylistAppendPayload.serializer(),
-                PlaylistAppendPayload(playlistId, trackIds),
-            ),
+    ): Long = insertUserDriven(
+        MutationKind.PLAYLIST_APPEND,
+        json.encodeToString(
+            PlaylistAppendPayload.serializer(),
+            PlaylistAppendPayload(playlistId, trackIds),
         ),
     )
 
@@ -119,13 +137,19 @@ class MutationQueue @Inject constructor(
         trackId: String,
         reason: String,
         notes: String,
-    ): Long = dao.insert(
-        CachedMutationEntity(
-            kind = MutationKind.QUARANTINE_FLAG,
-            payload = json.encodeToString(
-                QuarantineFlagPayload.serializer(),
-                QuarantineFlagPayload(trackId, reason, notes),
-            ),
+    ): Long = insertUserDriven(
+        MutationKind.QUARANTINE_FLAG,
+        json.encodeToString(
+            QuarantineFlagPayload.serializer(),
+            QuarantineFlagPayload(trackId, reason, notes),
+        ),
+    )
+
+    suspend fun enqueueRequestCancel(requestId: String): Long = insertUserDriven(
+        MutationKind.REQUEST_CANCEL,
+        json.encodeToString(
+            RequestCancelPayload.serializer(),
+            RequestCancelPayload(requestId),
         ),
     )
 
@@ -136,22 +160,18 @@ class MutationQueue @Inject constructor(
         ),
     )
 
-    suspend fun enqueueRequestCancel(requestId: String): Long = dao.insert(
-        CachedMutationEntity(
-            kind = MutationKind.REQUEST_CANCEL,
-            payload = json.encodeToString(
-                RequestCancelPayload.serializer(),
-                RequestCancelPayload(requestId),
-            ),
-        ),
-    )
-
     suspend fun enqueuePlaybackErrorReport(payload: PlaybackErrorReportPayload): Long = dao.insert(
         CachedMutationEntity(
             kind = MutationKind.PLAYBACK_ERROR_REPORT,
             payload = json.encodeToString(PlaybackErrorReportPayload.serializer(), payload),
         ),
     )
+
+    private suspend fun insertUserDriven(kind: String, payload: String): Long {
+        val id = dao.insert(CachedMutationEntity(kind = kind, payload = payload))
+        _userEnqueueHints.tryEmit(QUEUED_MESSAGE)
+        return id
+    }
 }
 
 /**

android/app/src/main/java/com/fabledsword/minstrel/cache/mutations/OfflineWriteHintViewModel.kt

@@ -0,0 +1,20 @@
+package com.fabledsword.minstrel.cache.mutations
+
+import androidx.lifecycle.ViewModel
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.Flow
+import javax.inject.Inject
+
+/**
+ * Hilt-injectable wrapper exposing [MutationQueue.userEnqueueHints] to
+ * ShellScaffold. The queue itself is an app-scoped singleton; this VM
+ * just bridges its SharedFlow into a `hiltViewModel()`-resolvable
+ * surface so ShellScaffold can collect it without an EntryPoint
+ * accessor. Mirrors PlaybackErrorViewModel.
+ */
+@HiltViewModel
+class OfflineWriteHintViewModel @Inject constructor(
+    mutationQueue: MutationQueue,
+) : ViewModel() {
+    val messages: Flow<String> = mutationQueue.userEnqueueHints
+}

android/app/src/main/java/com/fabledsword/minstrel/connectivity/ServerHealthController.kt

@@ -0,0 +1,63 @@
+package com.fabledsword.minstrel.connectivity
+
+import androidx.compose.runtime.staticCompositionLocalOf
+import com.fabledsword.minstrel.di.ApplicationScope
+import com.fabledsword.minstrel.update.data.VersionCheckController
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.stateIn
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * Tri-state server-reachability signal that downstream consumers can branch
+ * on to decide whether to hit the network, gate writes, or fall back to
+ * cache-only behavior.
+ *
+ * Composed from two existing signals -- this controller doesn't poll its own
+ * endpoint:
+ *
+ *  - [ConnectivityObserver.online] -- system-level NetworkCallback with the
+ *    INTERNET + VALIDATED capability check (captive portals fail this).
+ *  - [VersionCheckController.reachable] -- did the last `/healthz` poll
+ *    succeed. Distinguishes "device has network but our server is down" from
+ *    "no network at all," which the connectivity-only signal can't.
+ *
+ * `version too old` is intentionally *not* folded in here -- it's a separate
+ * UX (the VersionTooOldBanner) and conflating it with offline would mask the
+ * real cause.
+ */
+enum class ServerHealth { Healthy, Offline, ServerDown }
+
+@Singleton
+class ServerHealthController @Inject constructor(
+    @ApplicationScope scope: CoroutineScope,
+    connectivity: ConnectivityObserver,
+    versionCheck: VersionCheckController,
+) {
+    val state: StateFlow<ServerHealth> = combine(
+        connectivity.online,
+        versionCheck.reachable,
+    ) { online, serverReachable ->
+        when {
+            !online -> ServerHealth.Offline
+            !serverReachable -> ServerHealth.ServerDown
+            else -> ServerHealth.Healthy
+        }
+    }.stateIn(
+        scope = scope,
+        started = SharingStarted.Eagerly,
+        initialValue = ServerHealth.Healthy,
+    )
+}
+
+/**
+ * Reactive [ServerHealth] snapshot provided once at the app root from the
+ * controller's StateFlow. Lets leaf composables (TrackRow gating, write-
+ * affordance disabling) branch on health without each ViewModel re-
+ * injecting the controller. Defaults to Healthy so unwrapped previews
+ * and tests don't crash.
+ */
+val LocalServerHealth = staticCompositionLocalOf { ServerHealth.Healthy }

android/app/src/main/java/com/fabledsword/minstrel/connectivity/ui/ConnectionErrorBanner.kt

@@ -25,45 +25,45 @@ import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewModelScope
 import com.composables.icons.lucide.CloudOff
 import com.composables.icons.lucide.Lucide
-import com.fabledsword.minstrel.connectivity.ConnectivityObserver
+import com.fabledsword.minstrel.connectivity.ServerHealth
+import com.fabledsword.minstrel.connectivity.ServerHealthController
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.stateIn
 import javax.inject.Inject
 
-private const val ONLINE_SHARE_STOP_TIMEOUT_MS = 5_000L
+private const val HEALTH_SHARE_STOP_TIMEOUT_MS = 5_000L
 
 /**
- * Tiny VM that just lifts the [ConnectivityObserver] singleton's
- * Flow into a StateFlow with the standard sharing strategy. Keeps
- * the banner composable pure-presentation.
+ * Lifts [ServerHealthController]'s tri-state into a StateFlow for the banner
+ * composable. Keeps the banner pure-presentation.
  */
 @HiltViewModel
 class ConnectivityBannerViewModel @Inject constructor(
-    observer: ConnectivityObserver,
+    health: ServerHealthController,
     @Suppress("UnusedPrivateProperty") savedStateHandle: SavedStateHandle,
 ) : ViewModel() {
-    val online: StateFlow<Boolean> = observer.online.stateIn(
+    val health: StateFlow<ServerHealth> = health.state.stateIn(
         scope = viewModelScope,
-        started = SharingStarted.WhileSubscribed(ONLINE_SHARE_STOP_TIMEOUT_MS),
-        initialValue = true,
+        started = SharingStarted.WhileSubscribed(HEALTH_SHARE_STOP_TIMEOUT_MS),
+        initialValue = ServerHealth.Healthy,
     )
 }
 
 /**
- * Banner shown at the top of the shell when the device has no usable
- * internet. Mirrors Flutter's ConnectionErrorBanner: red-tinted error
- * surface, CloudOff icon, "No connection — check Wi-Fi or mobile
- * data" copy. Auto-hides via slide+fade when connectivity returns.
+ * Banner shown at the top of the shell when the user can't reach the server.
+ * Tri-state so we tell the user *why*: no device network vs server-down.
+ * Copy choices match the Flutter analogues. Auto-hides via slide+fade when
+ * health returns to [ServerHealth.Healthy].
  */
 @Composable
 fun ConnectionErrorBanner(
     viewModel: ConnectivityBannerViewModel = hiltViewModel(),
 ) {
-    val online by viewModel.online.collectAsStateWithLifecycle()
+    val health by viewModel.health.collectAsStateWithLifecycle()
     AnimatedVisibility(
-        visible = !online,
+        visible = health != ServerHealth.Healthy,
         enter = expandVertically() + fadeIn(),
         exit = shrinkVertically() + fadeOut(),
     ) {
@@ -81,7 +81,13 @@ fun ConnectionErrorBanner(
                 tint = MaterialTheme.colorScheme.onErrorContainer,
             )
             Text(
-                text = "No connection — check Wi-Fi or mobile data.",
+                text = when (health) {
+                    ServerHealth.Offline ->
+                        "No connection — check Wi-Fi or mobile data."
+                    ServerHealth.ServerDown ->
+                        "Server unreachable — your cached content is still available."
+                    ServerHealth.Healthy -> ""
+                },
                 style = MaterialTheme.typography.bodyMedium,
                 color = MaterialTheme.colorScheme.onErrorContainer,
             )

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

@@ -81,6 +81,21 @@ class MinstrelForwardingPlayer(
     // CONFLATED so repeated trySend's between polls don't queue up.
     private val pollTrigger = Channel<Unit>(Channel.CONFLATED)
 
+    // External Player.Listener registry (separate from super.addListener which
+    // forwards to the wrapped ExoPlayer). The wrapped player is paused with
+    // no audio loaded while UPnP is active, so it never fires events for our
+    // synthesized remote state -- the MediaSession's notification card and
+    // lock-screen scrubber stay frozen on whatever state was last captured
+    // before UPnP took over. We dual-register: super.addListener keeps the
+    // listener attached to the delegate (so local-playback events still
+    // reach it), AND we hold a ref here so we can directly invoke listener
+    // callbacks on remote-state changes. The listener's read of isPlaying /
+    // duration / position then routes through our overrides to remoteState.
+    private val externalListeners = mutableListOf<Player.Listener>()
+
+    @Volatile private var lastNotifiedIsPlaying: Boolean = false
+    @Volatile private var lastNotifiedTrackIdx: Int = -1
+
     private val lifecycleObserver = object : DefaultLifecycleObserver {
         override fun onResume(owner: LifecycleOwner) {
             pollTrigger.trySend(Unit)
@@ -121,7 +136,10 @@ class MinstrelForwardingPlayer(
         } else {
             scope.launch {
                 runCatching { active.avTransport.play() }
-                    .onSuccess { remoteState.applyTransportPlaying() }
+                    .onSuccess {
+                        remoteState.applyTransportPlaying()
+                        notifyRemoteStateChanged()
+                    }
                     .onFailure { handleSoapFailure(active, it) }
             }
         }
@@ -139,7 +157,10 @@ class MinstrelForwardingPlayer(
         } else {
             scope.launch {
                 runCatching { active.avTransport.pause() }
-                    .onSuccess { remoteState.applyTransportPaused() }
+                    .onSuccess {
+                        remoteState.applyTransportPaused()
+                        notifyRemoteStateChanged()
+                    }
                     .onFailure { handleSoapFailure(active, it) }
             }
         }
@@ -269,6 +290,54 @@ class MinstrelForwardingPlayer(
     override fun getPlayWhenReady(): Boolean =
         if (isRemote()) remoteState.isPlaying else super.getPlayWhenReady()
 
+    override fun addListener(listener: Player.Listener) {
+        super.addListener(listener)
+        synchronized(externalListeners) { externalListeners.add(listener) }
+    }
+
+    override fun removeListener(listener: Player.Listener) {
+        super.removeListener(listener)
+        synchronized(externalListeners) { externalListeners.remove(listener) }
+    }
+
+    /**
+     * Direct-invoke the externally-registered Player.Listeners so the
+     * MediaSession's PlaybackState publisher (notification card, lock-screen
+     * scrubber, BT/AVRCP, Auto, Wear OS tile) re-reads our overridden state.
+     * The listeners then query isPlaying / getDuration / getCurrentPosition,
+     * all of which route through to remoteState while UPnP is active.
+     *
+     * Posted to the player's application looper because Player.Listener
+     * callbacks contract on the application thread.
+     */
+    private fun notifyRemoteStateChanged() {
+        if (!isRemote()) return
+        val playing = remoteState.isPlaying
+        val trackIdx = (remoteState.trackNumber - 1).coerceAtLeast(0)
+        val isPlayingChanged = playing != lastNotifiedIsPlaying
+        val trackChanged = trackIdx != lastNotifiedTrackIdx
+        if (!isPlayingChanged && !trackChanged) return
+        lastNotifiedIsPlaying = playing
+        lastNotifiedTrackIdx = trackIdx
+        val snapshot = synchronized(externalListeners) { externalListeners.toList() }
+        handler.post {
+            for (l in snapshot) {
+                if (isPlayingChanged) {
+                    l.onIsPlayingChanged(playing)
+                    l.onPlaybackStateChanged(Player.STATE_READY)
+                }
+                if (trackChanged) {
+                    val item = if (trackIdx < delegate.mediaItemCount) {
+                        delegate.getMediaItemAt(trackIdx)
+                    } else {
+                        null
+                    }
+                    l.onMediaItemTransition(item, Player.MEDIA_ITEM_TRANSITION_REASON_AUTO)
+                }
+            }
+        }
+    }
+
     override fun release() {
         pollJob?.cancel()
         scope.cancel()
@@ -288,6 +357,11 @@ class MinstrelForwardingPlayer(
     private fun onActiveChanged(active: ActiveUpnp?) {
         pollJob?.cancel()
         nonPlayingPollStreak = 0
+        // Reset notify cache so the first poll after a route flip republishes
+        // playing/track state to the MediaSession even if it happens to match
+        // the prior session's values numerically.
+        lastNotifiedIsPlaying = false
+        lastNotifiedTrackIdx = -1
         if (active != null) {
             Timber.w("UPnP active: %s -- pollLoop starting", active.routeName)
             // Pause the wrapped ExoPlayer so we are not playing local audio
@@ -373,6 +447,7 @@ class MinstrelForwardingPlayer(
             }
             TransportState.TRANSITIONING, TransportState.UNKNOWN -> Unit
         }
+        notifyRemoteStateChanged()
     }
 
     private fun maybeSyncLocalCursor(sonosTrack: Int) {

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

@@ -0,0 +1,65 @@
+package com.fabledsword.minstrel.player
+
+import androidx.media3.datasource.DataSource
+import androidx.media3.datasource.DataSpec
+import androidx.media3.datasource.TransferListener
+import com.fabledsword.minstrel.connectivity.ServerHealth
+import com.fabledsword.minstrel.connectivity.ServerHealthController
+import java.io.IOException
+import java.io.InterruptedIOException
+
+/**
+ * DataSource wrapper that fails the network read immediately when
+ * [ServerHealthController] reports a non-Healthy state. CacheDataSource only
+ * calls this upstream factory on cache misses, so playback of cached audio is
+ * unaffected -- only "tap a non-cached track while offline" hits this branch
+ * and gets a fast, meaningful error instead of a multi-second network timeout
+ * (which then surfaced as a silent decode failure to the user).
+ *
+ * Wrapping rather than substituting the OkHttp data source lets the cache
+ * write path remain intact for when health returns and we DO want to fetch:
+ * we keep the same upstream all the time, just gate `open()`.
+ */
+class OfflineGatedDataSource(
+    private val delegate: DataSource,
+    private val health: ServerHealthController,
+) : DataSource {
+
+    override fun open(dataSpec: DataSpec): Long {
+        when (health.state.value) {
+            ServerHealth.Offline -> throw OfflineException(
+                "Track not in the on-device cache and the device is offline.",
+            )
+            ServerHealth.ServerDown -> throw OfflineException(
+                "Track not in the on-device cache and the Minstrel server is unreachable.",
+            )
+            ServerHealth.Healthy -> Unit
+        }
+        return delegate.open(dataSpec)
+    }
+
+    override fun close() = delegate.close()
+    override fun getUri() = delegate.uri
+    override fun read(buffer: ByteArray, offset: Int, length: Int): Int =
+        delegate.read(buffer, offset, length)
+    override fun addTransferListener(transferListener: TransferListener) =
+        delegate.addTransferListener(transferListener)
+    override fun getResponseHeaders() = delegate.responseHeaders
+}
+
+class OfflineGatedDataSourceFactory(
+    private val upstream: DataSource.Factory,
+    private val health: ServerHealthController,
+) : DataSource.Factory {
+    override fun createDataSource(): DataSource =
+        OfflineGatedDataSource(upstream.createDataSource(), health)
+}
+
+/**
+ * Signals the audio-source error path that the request was denied because the
+ * device is offline / the server is unreachable. ExoPlayer's [androidx.media3
+ * .common.PlaybackException] catches it via [InterruptedIOException]'s
+ * `IOException` ancestor and surfaces it as a SOURCE error, which then flows
+ * through the existing [PlaybackErrorReporter] -> snackbar path.
+ */
+class OfflineException(message: String) : IOException(message)

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

@@ -666,6 +666,10 @@ class PlayerController @Inject constructor(
             .setArtist(artistName)
             .setAlbumTitle(albumTitle)
             .apply {
+                // Server-known duration -- gives the lock-screen / notification
+                // scrubber a real total even when the wrapped ExoPlayer is
+                // paused under UPnP (it never probes a duration in that state).
+                if (durationSec > 0) setDurationMs(durationSec.toLong() * MS_PER_SECOND)
                 if (source != null) setExtras(sourceExtras(source))
             }
             .build()

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

@@ -52,6 +52,7 @@ class PlayerFactory @Inject constructor(
     private val cacheConfig: CacheConfig,
     private val activeUpnpHolder: ActiveUpnpHolder,
     private val remoteState: RemotePlayerState,
+    private val serverHealth: com.fabledsword.minstrel.connectivity.ServerHealthController,
 ) {
     private val cacheDir: File = File(context.cacheDir, "audio_cache").apply { mkdirs() }
 
@@ -83,9 +84,14 @@ class PlayerFactory @Inject constructor(
 
     private fun buildExoPlayer(): ExoPlayer {
         val httpDataSource = OkHttpDataSource.Factory(okHttpClient)
+        // Gate network reads on ServerHealth so a cache miss while offline
+        // fails fast with an OfflineException instead of hitting an OkHttp
+        // timeout. CacheDataSource only consults the upstream factory on a
+        // cache miss, so playback of cached audio is unaffected.
+        val gatedUpstream = OfflineGatedDataSourceFactory(httpDataSource, serverHealth)
         val cacheDataSource = CacheDataSource.Factory()
             .setCache(simpleCache)
-            .setUpstreamDataSourceFactory(httpDataSource)
+            .setUpstreamDataSourceFactory(gatedUpstream)
             .setCacheWriteDataSinkFactory(
                 CacheDataSink.Factory()
                     .setCache(simpleCache)

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

@@ -19,6 +19,7 @@ import com.fabledsword.minstrel.player.output.upnp.UpnpDiscoveryController
 import com.fabledsword.minstrel.player.output.upnp.bareUdn
 import dagger.hilt.android.qualifiers.ApplicationContext
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
@@ -372,6 +373,13 @@ class OutputPickerController @Inject constructor(
                 if (outcome.isSuccess) {
                     consecutiveFailures = 0
                     succeeded += 1
+                    // Throttle the burst so we don't tickle Sonos's burst-add
+                    // rejection -- logcat 2026-06-04 showed 33 consecutive
+                    // failures clustered at ~10ms intervals once offset 39 was
+                    // reached, which looks like a rate-limit kicking in. The
+                    // delay is small enough that extending 100 tracks adds
+                    // only ~5s to background work that's already async.
+                    delay(EXTEND_THROTTLE_MS)
                 } else {
                     consecutiveFailures += 1
                     val e = outcome.exceptionOrNull()
@@ -423,5 +431,6 @@ class OutputPickerController @Inject constructor(
 
     private companion object {
         const val EXTEND_ABORT_AFTER_FAILURES = 3
+        const val EXTEND_THROTTLE_MS = 50L
     }
 }

android/app/src/main/java/com/fabledsword/minstrel/search/data/SearchRepository.kt

@@ -1,6 +1,11 @@
 package com.fabledsword.minstrel.search.data
 
 import com.fabledsword.minstrel.api.endpoints.SearchApi
+import com.fabledsword.minstrel.cache.db.dao.CachedAlbumDao
+import com.fabledsword.minstrel.cache.db.dao.CachedArtistDao
+import com.fabledsword.minstrel.cache.db.dao.CachedTrackDao
+import com.fabledsword.minstrel.connectivity.ServerHealth
+import com.fabledsword.minstrel.connectivity.ServerHealthController
 import com.fabledsword.minstrel.library.data.toDomain
 import com.fabledsword.minstrel.models.SearchResponseRef
 import retrofit2.Retrofit
@@ -8,17 +13,34 @@ import retrofit2.create
 import javax.inject.Inject
 import javax.inject.Singleton
 
+private const val LOCAL_SEARCH_LIMIT = 20
+
 /**
- * Thin Retrofit wrapper around `/api/search`. Debouncing lives in
- * the ViewModel, not here, so the repository stays trivial.
+ * Cache-first when offline. When [ServerHealthController] is Healthy the
+ * repository hits `/api/search` and returns the server's three-facet
+ * paged response. When health is Offline or ServerDown it falls back to
+ * Room LIKE queries against `cached_*` so the user can still find
+ * something to play from what's already on the device; the outcome's
+ * [SearchOutcome.localOnly] flag lets the screen draw an "offline
+ * results" hint instead of pretending the server answered.
  */
 @Singleton
 class SearchRepository @Inject constructor(
     retrofit: Retrofit,
+    private val serverHealth: ServerHealthController,
+    private val trackDao: CachedTrackDao,
+    private val albumDao: CachedAlbumDao,
+    private val artistDao: CachedArtistDao,
 ) {
     private val api: SearchApi = retrofit.create()
 
-    suspend fun search(query: String): SearchResponseRef {
+    suspend fun search(query: String): SearchOutcome = when (serverHealth.state.value) {
+        ServerHealth.Healthy -> SearchOutcome(remoteSearch(query), localOnly = false)
+        ServerHealth.Offline, ServerHealth.ServerDown ->
+            SearchOutcome(localSearch(query), localOnly = true)
+    }
+
+    private suspend fun remoteSearch(query: String): SearchResponseRef {
         val wire = api.search(query)
         return SearchResponseRef(
             artists = wire.artists.items.map { it.toDomain() },
@@ -26,4 +48,21 @@ class SearchRepository @Inject constructor(
             tracks = wire.tracks.items.map { it.toDomain() },
         )
     }
+
+    private suspend fun localSearch(query: String): SearchResponseRef = SearchResponseRef(
+        artists = artistDao.searchByName(query, LOCAL_SEARCH_LIMIT).map { it.toDomain() },
+        albums = albumDao.searchByTitle(query, LOCAL_SEARCH_LIMIT).map { it.toDomain() },
+        tracks = trackDao.searchByTitle(query, LOCAL_SEARCH_LIMIT).map { it.toDomain() },
+    )
 }
+
+/**
+ * Wraps the search response with the signal of whether the result came
+ * from the server or from the local cached entities. The screen renders
+ * the same SearchResponseRef either way; the flag drives the offline
+ * banner copy.
+ */
+data class SearchOutcome(
+    val response: SearchResponseRef,
+    val localOnly: Boolean,
+)

android/app/src/main/java/com/fabledsword/minstrel/search/ui/SearchScreen.kt

@@ -158,17 +158,28 @@ private fun ResultsPane(
         is SearchResultsState.Error -> CenteredHint("Search failed: ${state.message}")
         is SearchResultsState.Loaded -> {
             if (state.response.isEmpty) {
-                CenteredHint("No matches for that query.")
-            } else {
-                ResultsList(
-                    response = state.response,
-                    playingTrackId = playingTrackId,
-                    onArtistClick = onArtistClick,
-                    onAlbumClick = onAlbumClick,
-                    onTrackPlay = onTrackPlay,
-                    onNavigateToAlbum = onNavigateToAlbum,
-                    onNavigateToArtist = onNavigateToArtist,
+                CenteredHint(
+                    if (state.localOnly) {
+                        "No matches in your on-device library."
+                    } else {
+                        "No matches for that query."
+                    },
                 )
+            } else {
+                Column(modifier = Modifier.fillMaxSize()) {
+                    if (state.localOnly) {
+                        OfflineResultsHint()
+                    }
+                    ResultsList(
+                        response = state.response,
+                        playingTrackId = playingTrackId,
+                        onArtistClick = onArtistClick,
+                        onAlbumClick = onAlbumClick,
+                        onTrackPlay = onTrackPlay,
+                        onNavigateToAlbum = onNavigateToAlbum,
+                        onNavigateToArtist = onNavigateToArtist,
+                    )
+                }
             }
         }
     }
@@ -308,6 +319,18 @@ private fun SectionHeader(label: String, count: Int) {
     }
 }
 
+@Composable
+private fun OfflineResultsHint() {
+    Text(
+        text = "Showing on-device matches only — the server is unreachable.",
+        modifier = Modifier
+            .fillMaxWidth()
+            .padding(horizontal = 16.dp, vertical = 6.dp),
+        style = MaterialTheme.typography.bodySmall,
+        color = MaterialTheme.colorScheme.onSurfaceVariant,
+    )
+}
+
 @Composable
 private fun CenteredHint(text: String) {
     Box(modifier = Modifier.fillMaxSize().padding(24.dp), contentAlignment = Alignment.Center) {

android/app/src/main/java/com/fabledsword/minstrel/search/ui/SearchViewModel.kt

@@ -26,7 +26,10 @@ sealed interface SearchResultsState {
     /** Empty query — screen shows "type to search" hint. */
     data object Idle : SearchResultsState
     data object Loading : SearchResultsState
-    data class Loaded(val response: SearchResponseRef) : SearchResultsState
+    data class Loaded(
+        val response: SearchResponseRef,
+        val localOnly: Boolean = false,
+    ) : SearchResultsState
     data class Error(val message: String) : SearchResultsState
 }
 
@@ -98,8 +101,15 @@ class SearchViewModel @Inject constructor(
     private suspend fun runSearch(q: String) {
         internal.update { it.copy(results = SearchResultsState.Loading) }
         try {
-            val response = repository.search(q)
-            internal.update { it.copy(results = SearchResultsState.Loaded(response)) }
+            val outcome = repository.search(q)
+            internal.update {
+                it.copy(
+                    results = SearchResultsState.Loaded(
+                        response = outcome.response,
+                        localOnly = outcome.localOnly,
+                    ),
+                )
+            }
         } catch (
             @Suppress("TooGenericExceptionCaught") e: Throwable,
         ) {

android/app/src/main/java/com/fabledsword/minstrel/shared/widgets/ShellScaffold.kt

@@ -12,6 +12,7 @@ import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Modifier
 import androidx.hilt.navigation.compose.hiltViewModel
+import com.fabledsword.minstrel.cache.mutations.OfflineWriteHintViewModel
 import com.fabledsword.minstrel.connectivity.ui.ConnectionErrorBanner
 import com.fabledsword.minstrel.player.ui.MiniPlayer
 import com.fabledsword.minstrel.player.ui.PlaybackErrorViewModel
@@ -48,6 +49,7 @@ fun ShellScaffold(
     modifier: Modifier = Modifier,
     trackActionsViewModel: TrackActionsViewModel = hiltViewModel(),
     playbackErrorViewModel: PlaybackErrorViewModel = hiltViewModel(),
+    offlineWriteHintViewModel: OfflineWriteHintViewModel = hiltViewModel(),
     content: @Composable () -> Unit,
 ) {
     val snackbarHostState = remember { SnackbarHostState() }
@@ -61,6 +63,11 @@ fun ShellScaffold(
             snackbarHostState.showSnackbar(msg)
         }
     }
+    LaunchedEffect(Unit) {
+        offlineWriteHintViewModel.messages.collect { msg ->
+            snackbarHostState.showSnackbar(msg)
+        }
+    }
     // Consume the status-bar inset once here so the banner stack sits
     // below the status bar (mirrors Flutter's SafeArea(bottom:false)).
     // statusBarsPadding consumes the inset for descendants, so the in-

android/app/src/main/java/com/fabledsword/minstrel/shared/widgets/TrackRow.kt

@@ -1,5 +1,6 @@
 package com.fabledsword.minstrel.shared.widgets
 
+import android.widget.Toast
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
@@ -12,8 +13,14 @@ import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
+import com.fabledsword.minstrel.connectivity.LocalServerHealth
+import com.fabledsword.minstrel.connectivity.ServerHealth
+
+private const val OFFLINE_UNAVAILABLE_ALPHA = 0.4f
+private const val OFFLINE_TAP_MESSAGE = "Not downloaded — connect to play"
 
 /**
  * Shared track-list row. Replaces the 5 per-screen `TrackRow`s — every
@@ -30,6 +37,14 @@ import androidx.compose.ui.unit.dp
  * for applying its own alpha if it should match (the row doesn't
  * cascade because the trailing slot's content is the caller's, not
  * ours).
+ *
+ * Reads [LocalServerHealth] + [LocalCachedTrackIds] and intercepts taps
+ * on tracks that aren't downloaded when the server is unreachable —
+ * fires a Toast instead of attempting playback. The text dims so the
+ * user can see at a glance which rows in a long list will work offline.
+ * The trailing slot stays interactive so the kebab / like / playlist-
+ * add affordances can still queue mutations for offline replay (Phase
+ * 5 of #618 gates those at the action level).
  */
 @Composable
 fun TrackRow(
@@ -45,15 +60,28 @@ fun TrackRow(
     leading: @Composable () -> Unit = {},
     trailing: @Composable RowScope.() -> Unit = {},
 ) {
+    val context = LocalContext.current
+    val offlineUnavailable = LocalServerHealth.current != ServerHealth.Healthy &&
+        trackId !in LocalCachedTrackIds.current
     val titleColor = if (nowPlaying) {
         MaterialTheme.colorScheme.primary
     } else {
         MaterialTheme.colorScheme.onSurface
     }
+    val effectiveAlpha = if (offlineUnavailable) {
+        minOf(contentAlpha, OFFLINE_UNAVAILABLE_ALPHA)
+    } else {
+        contentAlpha
+    }
+    val effectiveOnClick: () -> Unit = if (offlineUnavailable) {
+        { Toast.makeText(context, OFFLINE_TAP_MESSAGE, Toast.LENGTH_SHORT).show() }
+    } else {
+        onClick
+    }
     Row(
         modifier = modifier
             .fillMaxWidth()
-            .clickable(enabled = enabled, onClick = onClick)
+            .clickable(enabled = enabled, onClick = effectiveOnClick)
             .padding(horizontal = 16.dp, vertical = 8.dp),
         verticalAlignment = Alignment.CenterVertically,
         horizontalArrangement = horizontalArrangement,
@@ -63,7 +91,7 @@ fun TrackRow(
             Text(
                 text = title,
                 style = MaterialTheme.typography.bodyLarge,
-                color = titleColor.copy(alpha = contentAlpha),
+                color = titleColor.copy(alpha = effectiveAlpha),
                 maxLines = 1,
                 overflow = TextOverflow.Ellipsis,
             )
@@ -71,7 +99,7 @@ fun TrackRow(
                 Text(
                     text = artist,
                     style = MaterialTheme.typography.bodySmall,
-                    color = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = contentAlpha),
+                    color = MaterialTheme.colorScheme.onSurfaceVariant.copy(alpha = effectiveAlpha),
                     maxLines = 1,
                     overflow = TextOverflow.Ellipsis,
                 )

android/app/src/main/java/com/fabledsword/minstrel/update/data/VersionCheckController.kt

@@ -41,6 +41,16 @@ class VersionCheckController @Inject constructor(
     private val internal = MutableStateFlow(VersionResult.SKIPPED)
     val result: StateFlow<VersionResult> = internal.asStateFlow()
 
+    // Whether the most recent /healthz poll reached the server. Separate from
+    // VersionResult because "unreachable" and "version mismatch" drive
+    // different UX (offline banner vs version-too-old banner). Optimistic
+    // initial value -- the first poll fires within seconds of app launch and
+    // we don't want a "server down" flash before we've actually tried.
+    // Consumed by ServerHealthController to compose with ConnectivityObserver
+    // for the tri-state offline / server-down / healthy signal.
+    private val internalReachable = MutableStateFlow(true)
+    val reachable: StateFlow<Boolean> = internalReachable.asStateFlow()
+
     init {
         scope.launch {
             while (true) {
@@ -56,7 +66,13 @@ class VersionCheckController @Inject constructor(
     }
 
     private suspend fun runOnce() {
-        val response = runCatching { api.check() }.getOrNull() ?: return
+        val outcome = runCatching { api.check() }
+        val response = outcome.getOrNull()
+        if (response == null) {
+            internalReachable.value = false
+            return
+        }
+        internalReachable.value = true
         val min = response.minClientVersion
         internal.value = when {
             min.isEmpty() -> VersionResult.SKIPPED