Add support for fusing/unfusing JellyLMS zones into synchronized

multi-room groups, addressed by MAC (derived from the `lms-{mac}` device id).

src-tauri/src/commands/playback_mode.rs

@@ -51,6 +51,22 @@ pub async fn playback_mode_transfer_to_remote(
     manager.0.transfer_to_remote(session_id, position).await
 }
 
+/// Set the transferring flag on the playback mode manager.
+///
+/// Used by the frontend remote->local flow to mark the whole two-step sequence
+/// as a transfer, so `player_play_tracks` starts LOCAL playback instead of
+/// casting back to the remote session it's leaving. Always pair `true` with a
+/// later `false` (including on error) so the flag can't stick.
+#[tauri::command]
+#[specta::specta]
+pub async fn playback_mode_set_transferring(
+    manager: State<'_, PlaybackModeManagerWrapper>,
+    transferring: bool,
+) -> Result<(), String> {
+    manager.0.set_transferring(transferring);
+    Ok(())
+}
+
 /// Transfer playback from remote session back to local device
 ///
 /// Parameters:

src-tauri/src/commands/player/remote.rs

@@ -6,6 +6,7 @@
 use tauri::State;
 
 use super::PlayerStateWrapper;
+use crate::jellyfin::client::LmsSyncGroup;
 
 /// Play items on a remote Jellyfin session (casting)
 #[tauri::command]
@@ -129,3 +130,92 @@ pub async fn remote_session_toggle_mute(
         Err("Jellyfin client not configured".to_string())
     }
 }
+
+// --- JellyLMS multi-room sync groups (fuse / unfuse LMS zones) --------------
+//
+// The frontend addresses LMS players by MAC address, which it derives from a
+// session's device id (`lms-{mac}`). These commands forward to the JellyLMS
+// plugin REST API via the configured JellyfinClient.
+
+/// List current LMS sync groups.
+#[tauri::command]
+#[specta::specta]
+pub async fn lms_get_sync_groups(
+    player: State<'_, PlayerStateWrapper>,
+) -> Result<Vec<LmsSyncGroup>, String> {
+    let client_opt = {
+        let controller = player.0.lock().await;
+        controller.jellyfin_client().lock().map_err(|e| e.to_string())?.clone()
+    };
+
+    if let Some(client) = client_opt {
+        client.lms_get_sync_groups().await
+    } else {
+        Err("Jellyfin client not configured".to_string())
+    }
+}
+
+/// Fuse LMS zones into a sync group. `master_mac` keeps playing and the
+/// `slave_macs` zones join it in sync.
+#[tauri::command]
+#[specta::specta]
+pub async fn lms_create_sync_group(
+    player: State<'_, PlayerStateWrapper>,
+    master_mac: String,
+    slave_macs: Vec<String>,
+) -> Result<(), String> {
+    log::info!("[LmsSync] Fusing zones: master={}, slaves={:?}", master_mac, slave_macs);
+
+    let client_opt = {
+        let controller = player.0.lock().await;
+        controller.jellyfin_client().lock().map_err(|e| e.to_string())?.clone()
+    };
+
+    if let Some(client) = client_opt {
+        client.lms_create_sync_group(&master_mac, slave_macs).await
+    } else {
+        Err("Jellyfin client not configured".to_string())
+    }
+}
+
+/// Remove a single LMS zone from its sync group (decouple one player).
+#[tauri::command]
+#[specta::specta]
+pub async fn lms_unsync_player(
+    player: State<'_, PlayerStateWrapper>,
+    mac: String,
+) -> Result<(), String> {
+    log::info!("[LmsSync] Decoupling zone {}", mac);
+
+    let client_opt = {
+        let controller = player.0.lock().await;
+        controller.jellyfin_client().lock().map_err(|e| e.to_string())?.clone()
+    };
+
+    if let Some(client) = client_opt {
+        client.lms_unsync_player(&mac).await
+    } else {
+        Err("Jellyfin client not configured".to_string())
+    }
+}
+
+/// Dissolve an entire LMS sync group, identified by its master's MAC.
+#[tauri::command]
+#[specta::specta]
+pub async fn lms_dissolve_sync_group(
+    player: State<'_, PlayerStateWrapper>,
+    master_mac: String,
+) -> Result<(), String> {
+    log::info!("[LmsSync] Dissolving group with master {}", master_mac);
+
+    let client_opt = {
+        let controller = player.0.lock().await;
+        controller.jellyfin_client().lock().map_err(|e| e.to_string())?.clone()
+    };
+
+    if let Some(client) = client_opt {
+        client.lms_dissolve_sync_group(&master_mac).await
+    } else {
+        Err("Jellyfin client not configured".to_string())
+    }
+}

src-tauri/src/jellyfin/client.rs

@@ -384,6 +384,82 @@ impl JellyfinClient {
         let sessions = self.get_sessions().await?;
         Ok(sessions.into_iter().find(|s| s.id.as_deref() == Some(session_id)))
     }
+
+    // --- JellyLMS multi-room sync groups -----------------------------------
+    //
+    // The JellyLMS plugin exposes a REST API under `/JellyLms` for grouping LMS
+    // players ("zones") into synchronized multi-room sync groups. Players are
+    // addressed by MAC address; JellyTau maps a Jellyfin session to a MAC by
+    // stripping the `lms-` prefix off the session's device id (see
+    // LmsDeviceDiscoveryService in the jellyLMS repo, which registers each player
+    // with deviceId = "lms-{MacAddress}").
+
+    /// List current LMS sync groups.
+    pub async fn lms_get_sync_groups(&self) -> Result<Vec<LmsSyncGroup>, String> {
+        self.get("/JellyLms/SyncGroups").await
+    }
+
+    /// Fuse LMS zones: create a sync group with `master_mac` as the sync master
+    /// and `slave_macs` joining it. The master keeps playing; slaves follow.
+    pub async fn lms_create_sync_group(
+        &self,
+        master_mac: &str,
+        slave_macs: Vec<String>,
+    ) -> Result<(), String> {
+        let payload = serde_json::json!({
+            "MasterMac": master_mac,
+            "SlaveMacs": slave_macs,
+        });
+        self.post("/JellyLms/SyncGroups", &payload).await
+    }
+
+    /// Remove a single LMS player from whatever sync group it's in.
+    pub async fn lms_unsync_player(&self, mac: &str) -> Result<(), String> {
+        self.delete(&format!("/JellyLms/SyncGroups/Players/{}", mac)).await
+    }
+
+    /// Dissolve an entire LMS sync group, identified by its master's MAC.
+    pub async fn lms_dissolve_sync_group(&self, master_mac: &str) -> Result<(), String> {
+        self.delete(&format!("/JellyLms/SyncGroups/{}", master_mac)).await
+    }
+
+    /// Make a DELETE request to the Jellyfin API (used by the JellyLMS endpoints).
+    async fn delete(&self, endpoint: &str) -> Result<(), String> {
+        let url = format!("{}{}", self.config.server_url, endpoint);
+
+        log::debug!("[JellyfinClient] DELETE {}", endpoint);
+
+        let response = self.http_client
+            .delete(&url)
+            .header("X-Emby-Authorization", self.get_auth_header())
+            .send()
+            .await
+            .map_err(|e| format!("Network request failed: {}", e))?;
+
+        let status = response.status();
+        if !status.is_success() {
+            let error_text = response.text().await.unwrap_or_else(|_| "Unknown error".to_string());
+            return Err(format!("Jellyfin API error {}: {}", status.as_u16(), error_text));
+        }
+        Ok(())
+    }
+}
+
+/// An LMS multi-room sync group, as returned by JellyLMS `/JellyLms/SyncGroups`.
+///
+/// Mirrors the plugin's `SyncGroup` model. The master is the sync source; slaves
+/// follow it in lockstep.
+#[derive(specta::Type, Debug, Clone, Deserialize, serde::Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct LmsSyncGroup {
+    #[serde(alias = "MasterMac")]
+    pub master_mac: String,
+    #[serde(default, alias = "MasterName")]
+    pub master_name: String,
+    #[serde(default, alias = "SlaveMacs")]
+    pub slave_macs: Vec<String>,
+    #[serde(default, alias = "SlaveNames")]
+    pub slave_names: Vec<String>,
 }
 
 /// Default value for supports_remote_control when missing from API

src-tauri/src/lib.rs

@@ -52,11 +52,13 @@ use commands::{
     // Remote session control commands
     remote_play_on_session, remote_send_command, remote_session_seek, remote_session_set_volume,
     remote_session_toggle_mute,
+    // LMS multi-room sync group commands
+    lms_get_sync_groups, lms_create_sync_group, lms_unsync_player, lms_dissolve_sync_group,
     // Session polling commands
     sessions_set_polling_hint, sessions_poll_now, SessionPollerWrapper,
     // Playback mode commands
     playback_mode_get_current, playback_mode_set, playback_mode_is_transferring,
-    playback_mode_transfer_to_remote, playback_mode_transfer_to_local,
+    playback_mode_transfer_to_remote, playback_mode_transfer_to_local, playback_mode_set_transferring,
     playback_mode_get_remote_status,
     // Playback reporting commands
     playback_reporter_init, playback_reporter_destroy,
@@ -417,6 +419,11 @@ fn specta_builder() -> Builder<tauri::Wry> {
             remote_session_seek,
             remote_session_set_volume,
             remote_session_toggle_mute,
+            // LMS multi-room sync group commands
+            lms_get_sync_groups,
+            lms_create_sync_group,
+            lms_unsync_player,
+            lms_dissolve_sync_group,
             // Session polling commands
             sessions_set_polling_hint,
             sessions_poll_now,
@@ -427,6 +434,7 @@ fn specta_builder() -> Builder<tauri::Wry> {
             playback_mode_transfer_to_remote,
             playback_mode_get_remote_status,
             playback_mode_transfer_to_local,
+            playback_mode_set_transferring,
             // Playback reporting commands
             playback_reporter_init,
             playback_reporter_destroy,

src-tauri/src/playback_mode/mod.rs

@@ -81,6 +81,19 @@ impl PlaybackModeManager {
         self.is_transferring.load(Ordering::Relaxed)
     }
 
+    /// Set the transferring flag directly.
+    ///
+    /// The remote->local transfer is driven from the frontend in two steps
+    /// (`player_play_tracks` to start local playback, then
+    /// `playback_mode_transfer_to_local` to stop the remote). The first step's
+    /// routing depends on this flag: while it's set, `player_play_tracks` plays
+    /// locally instead of casting back to the remote session. The frontend must
+    /// raise the flag *before* that first call and lower it when the sequence is
+    /// done (or aborts), so it can't be left stuck on.
+    pub fn set_transferring(&self, transferring: bool) {
+        self.is_transferring.store(transferring, Ordering::Relaxed);
+    }
+
     /// Send volume command to remote session
     /// Commands: "SetVolume", "VolumeUp", "VolumeDown"
     #[allow(dead_code)] // Called from Android JNI callback