Added JAM feature

src/app/event.rs

@@ -166,4 +166,14 @@ pub enum AppEvent {
     DevicePlayback(crate::devices::PlaybackSnapshot),
     /// Playback command addressed to this device.
     PlaybackCommand(crate::devices::PlaybackCommand),
+    /// Current lifecycle/status of the federation Jam.
+    JamStatus(crate::jam::JamStatus),
+    /// Host playback snapshot received by a Jam participant.
+    JamPlayback(crate::devices::PlaybackSnapshot),
+    /// Participant command accepted by this Jam host.
+    JamCommand(crate::devices::PlaybackCommand),
+    /// Result of creating/regenerating a Jam capability.
+    JamInvite(Result<String, String>),
+    /// Result of joining a Jam capability.
+    JamJoined(Result<String, String>),
 }

src/app/mod.rs

@@ -38,6 +38,7 @@ pub struct Runtime {
     pub event_tx: mpsc::UnboundedSender<AppEvent>,
     pub library: Arc<Library>,
     pub devices: Arc<crate::devices::DeviceSync>,
+    pub jam: Arc<crate::jam::JamManager>,
     pub federation: Arc<crate::federation::Federation>,
     /// When the last Federation-tab status snapshot was requested.
     pub fed_status_at: Option<std::time::Instant>,
@@ -249,7 +250,12 @@ pub async fn run(
 
     let devices = crate::devices::DeviceSync::new(Arc::clone(&library))?;
     devices.set_event_tx(event_tx.clone());
-    let federation = crate::federation::Federation::new(Arc::clone(&library), Arc::clone(&devices));
+    let jam = crate::jam::JamManager::new(event_tx.clone());
+    let federation = crate::federation::Federation::new(
+        Arc::clone(&library),
+        Arc::clone(&devices),
+        Arc::clone(&jam),
+    );
     state.federation.settings = federation.settings();
     state.federation.devices = Some(devices.status());
     if let Ok((device_id, device_name)) = devices.identity_summary() {
@@ -263,6 +269,7 @@ pub async fn run(
         event_tx,
         library,
         devices,
+        jam,
         federation,
         fed_status_at: None,
         library_network_refresh_at: None,
@@ -360,7 +367,7 @@ fn sync_player_shared(state: &mut AppState, runtime: &Runtime) {
     } else {
         runtime.player.shared.audio_analysis()
     };
-    if state.device_playback.role == state::DevicePlaybackRole::Active {
+    if state.device_playback.is_audio_owner() {
         publish_playback_snapshot(state, runtime);
     }
 }
@@ -474,7 +481,7 @@ fn apply_playback_state_to_ui(
 }
 
 fn publish_playback_snapshot(state: &mut AppState, runtime: &Runtime) {
-    if state.device_playback.role != state::DevicePlaybackRole::Active {
+    if !state.device_playback.is_audio_owner() {
         return;
     }
     publish_playback_snapshot_with_active(state, runtime, true);
@@ -503,6 +510,19 @@ fn publish_playback_snapshot_with_active(state: &mut AppState, runtime: &Runtime
         state: playback_state_from_ui(state),
     };
     runtime.devices.publish_playback(snapshot);
+    if state.device_playback.role == state::DevicePlaybackRole::Jam
+        && state.device_playback.jam_host
+    {
+        runtime
+            .jam
+            .publish_host_playback(crate::devices::PlaybackSnapshot {
+                device_id: state.device_playback.self_device_id.clone(),
+                device_name: state.device_playback.self_device_name.clone(),
+                active: true,
+                updated_at_ms: unix_time_ms(),
+                state: playback_state_from_ui(state),
+            });
+    }
 }
 
 fn update_local_idle_since(state: &mut AppState) {
@@ -532,7 +552,7 @@ fn active_idle_lease_expired(snapshot: &crate::devices::PlaybackSnapshot, now: i
 }
 
 fn local_active_lease_protected(state: &mut AppState, now: i64) -> bool {
-    if state.device_playback.role != state::DevicePlaybackRole::Active || !state.player.playing {
+    if !state.device_playback.is_audio_owner() || !state.player.playing {
         return false;
     }
     if !state.player.paused {
@@ -576,7 +596,7 @@ pub(crate) fn become_control_device(
     runtime: &Runtime,
     snapshot: crate::devices::PlaybackSnapshot,
 ) {
-    if state.device_playback.role == state::DevicePlaybackRole::Active {
+    if state.device_playback.is_audio_owner() {
         runtime.player.stop();
         publish_inactive_playback_snapshot(state, runtime);
     }
@@ -596,6 +616,7 @@ pub(crate) fn become_control_device(
 pub(crate) fn become_active_device(state: &mut AppState, runtime: &mut Runtime, start_audio: bool) {
     let was_control = state.device_playback.role == state::DevicePlaybackRole::Control;
     state.device_playback.role = state::DevicePlaybackRole::Active;
+    state.device_playback.jam_host = false;
     let Ok((device_id, device_name)) = runtime.devices.identity_summary() else {
         return;
     };
@@ -617,7 +638,7 @@ pub(crate) fn become_active_device(state: &mut AppState, runtime: &mut Runtime,
 }
 
 pub(crate) fn transfer_active_to_this_device(state: &mut AppState, runtime: &mut Runtime) {
-    if state.device_playback.role == state::DevicePlaybackRole::Active {
+    if state.device_playback.is_audio_owner() {
         publish_playback_snapshot(state, runtime);
         request_urgent_device_sync(runtime);
         return;
@@ -722,6 +743,12 @@ fn record_control_playback_state(state: &mut AppState, runtime: &Runtime, seek:
         state: playback_state_from_ui(state),
         seek,
     };
+    if state.device_playback.role == state::DevicePlaybackRole::Jam {
+        if let Err(err) = runtime.jam.submit_command(command) {
+            state.status_message = Some(format!("Jam command failed: {err:#}"));
+        }
+        return;
+    }
     record_playback_command_async(runtime, target, command, "device command");
 }
 
@@ -1479,10 +1506,41 @@ fn perform_effect(state: &mut AppState, runtime: &mut Runtime, effect: Effect) {
         | Effect::DeviceSetName(_)
         | Effect::DeviceRevoke(_)
         | Effect::DeviceLeaveGroup
+        | Effect::JamCreate
+        | Effect::JamJoin(_)
             if !state.connected_devices_enabled() =>
         {
             state.status_message = Some("enable federation before using connected devices".into());
         }
+        Effect::JamCreate => {
+            let federation = Arc::clone(&runtime.federation);
+            let tx = runtime.event_tx.clone();
+            tokio::spawn(async move {
+                let result = federation
+                    .create_jam()
+                    .await
+                    .map_err(|err| format!("{err:#}"));
+                let _ = tx.send(AppEvent::JamInvite(result));
+            });
+        }
+        Effect::JamJoin(invite) => {
+            let result = runtime
+                .federation
+                .join_jam(&invite)
+                .map(|()| "joined Jam; waiting for host state".to_string())
+                .map_err(|err| format!("{err:#}"));
+            let _ = runtime.event_tx.send(AppEvent::JamJoined(result));
+            let _ = runtime
+                .event_tx
+                .send(AppEvent::JamStatus(runtime.jam.status()));
+        }
+        Effect::JamLeave => {
+            runtime.jam.leave();
+            state.jam = runtime.jam.status();
+            state.device_playback.role = state::DevicePlaybackRole::Active;
+            state.device_playback.jam_host = false;
+            state.status_message = Some("left Jam".into());
+        }
         Effect::DeviceShowInvite => {
             let fed = Arc::clone(&runtime.federation);
             let devices = Arc::clone(&runtime.devices);
@@ -1679,6 +1737,8 @@ fn is_controlled_playback_effect(effect: &Effect) -> bool {
 
 fn perform_control_playback_effect(state: &mut AppState, runtime: &mut Runtime, effect: Effect) {
     let mut seek = false;
+    let local_only_volume = state.device_playback.role == state::DevicePlaybackRole::Jam
+        && matches!(effect, Effect::SetVolume(_));
     match effect {
         Effect::PlayCurrent => {
             state.player.current = state.player.queue.get(state.player.queue_pos).cloned();
@@ -1708,6 +1768,9 @@ fn perform_control_playback_effect(state: &mut AppState, runtime: &mut Runtime,
         | Effect::LoadListenHistory => {}
         _ => {}
     }
+    if local_only_volume {
+        return;
+    }
     record_control_playback_state(state, runtime, seek);
 }
 
@@ -2753,7 +2816,7 @@ fn handle_device_playback_snapshot(
     let already_controls_this_device = state.device_playback.is_control()
         && state.device_playback.active_device_id.as_deref() == Some(snapshot.device_id.as_str());
     if !lease_expired || already_controls_this_device {
-        let was_active = state.device_playback.role == state::DevicePlaybackRole::Active;
+        let was_active = state.device_playback.is_audio_owner();
         let was_paused = state.player.playing && state.player.paused;
         become_control_device(state, runtime, snapshot.clone());
         if was_active && was_paused {
@@ -2829,7 +2892,7 @@ fn handle_playback_command(
             if active_device_id == state.device_playback.self_device_id {
                 return;
             }
-            let was_active = state.device_playback.role == state::DevicePlaybackRole::Active;
+            let was_active = state.device_playback.is_audio_owner();
             let snapshot = crate::devices::PlaybackSnapshot {
                 device_id: active_device_id,
                 device_name: active_device_name,
@@ -2962,6 +3025,83 @@ fn handle_app_event(state: &mut AppState, runtime: &mut Runtime, event: AppEvent
         AppEvent::PlaybackCommand(command) => {
             handle_playback_command(state, runtime, command);
         }
+        AppEvent::JamStatus(status) => {
+            state.jam = status.clone();
+            match status.role {
+                crate::jam::JamRole::Host => {
+                    state.device_playback.role = state::DevicePlaybackRole::Jam;
+                    state.device_playback.jam_host = true;
+                    publish_playback_snapshot(state, runtime);
+                }
+                crate::jam::JamRole::Participant => {
+                    if state.device_playback.is_audio_owner() {
+                        runtime.player.stop();
+                        runtime.player_start_pending = false;
+                    }
+                    state.device_playback.role = state::DevicePlaybackRole::Jam;
+                    state.device_playback.jam_host = false;
+                }
+                crate::jam::JamRole::None => {
+                    if state.device_playback.role == state::DevicePlaybackRole::Jam {
+                        state.device_playback.role = state::DevicePlaybackRole::Active;
+                        state.device_playback.jam_host = false;
+                    }
+                }
+            }
+        }
+        AppEvent::JamPlayback(snapshot) => {
+            let local_volume = state.player.volume;
+            become_control_device(state, runtime, snapshot);
+            state.device_playback.role = state::DevicePlaybackRole::Jam;
+            state.device_playback.jam_host = false;
+            state.player.volume = local_volume;
+            state.status_message = Some(format!(
+                "Jam · controlling {}",
+                state.device_playback.active_label()
+            ));
+        }
+        AppEvent::JamCommand(command) => {
+            let command = match command {
+                crate::devices::PlaybackCommand::SetState {
+                    state: mut wire,
+                    seek,
+                } => {
+                    wire.volume = state.player.volume;
+                    crate::devices::PlaybackCommand::SetState { state: wire, seek }
+                }
+                crate::devices::PlaybackCommand::ActiveChanged { .. } => {
+                    state.status_message =
+                        Some("Jam cannot transfer audio away from its host".into());
+                    return;
+                }
+            };
+            handle_playback_command(state, runtime, command);
+            state.device_playback.role = state::DevicePlaybackRole::Jam;
+            state.device_playback.jam_host = true;
+            publish_playback_snapshot(state, runtime);
+        }
+        AppEvent::JamInvite(result) => match result {
+            Ok(invite) => {
+                if !state.device_playback.is_audio_owner() {
+                    transfer_active_to_this_device(state, runtime);
+                }
+                state.jam = runtime.jam.status();
+                state.device_playback.role = state::DevicePlaybackRole::Jam;
+                state.device_playback.jam_host = true;
+                publish_playback_snapshot(state, runtime);
+                state.popup = Some(state::Popup::FedCopyText {
+                    title: "Jam invite".to_string(),
+                    text: invite,
+                    help: "Copied capability lets federation peers control this host player until restart or regeneration.".to_string(),
+                });
+                state.status_message = Some("Jam started".into());
+            }
+            Err(error) => state.status_message = Some(format!("Jam: {error}")),
+        },
+        AppEvent::JamJoined(result) => match result {
+            Ok(message) => state.status_message = Some(message),
+            Err(error) => state.status_message = Some(format!("Jam: {error}")),
+        },
         AppEvent::FedSearchLoaded { seq, result } => {
             if runtime.search_seq.load(std::sync::atomic::Ordering::SeqCst) != seq {
                 return;

src/app/popup.rs

@@ -82,7 +82,7 @@ pub(crate) fn connected_device_rows(state: &AppState) -> Vec<ConnectedDevicePopu
                 is_self: true,
                 online: true,
                 section: DevicePresenceSection::Online,
-                active: state.device_playback.role == crate::app::state::DevicePlaybackRole::Active,
+                active: state.device_playback.is_audio_owner(),
                 playing: state.player.playing,
                 paused: state.player.paused,
                 queue_len: state.player.queue.len(),
@@ -386,6 +386,32 @@ fn handle_connected_devices(
     let cursor = cursor.min(last);
     match key.code {
         KeyCode::Esc | KeyCode::Char('q') => {}
+        KeyCode::Char('h') => {
+            super::perform_effect(state, runtime, crate::app::update::Effect::JamCreate);
+        }
+        KeyCode::Char('J') => {
+            state.popup = Some(Popup::FedInput {
+                field: FedInputField::JamInvite,
+                input: crate::app::input::LineEdit::default(),
+            });
+        }
+        KeyCode::Char('l') if state.jam.role != crate::jam::JamRole::None => {
+            super::perform_effect(state, runtime, crate::app::update::Effect::JamLeave);
+        }
+        KeyCode::Char('c') => {
+            if let Some(invite) = state.jam.invite.as_deref() {
+                match copy_to_clipboard(invite) {
+                    Ok(()) => state.status_message = Some("Jam invite copied".into()),
+                    Err(error) => {
+                        state.status_message = Some(format!("clipboard: {error}"));
+                        state.popup = Some(Popup::ConnectedDevices { cursor });
+                    }
+                }
+            } else {
+                state.status_message = Some("only the Jam host has an invite".into());
+                state.popup = Some(Popup::ConnectedDevices { cursor });
+            }
+        }
         KeyCode::Up | KeyCode::Char('k') => {
             state.popup = Some(Popup::ConnectedDevices {
                 cursor: cursor.saturating_sub(1),
@@ -499,6 +525,17 @@ fn handle_fed_input(
                         );
                     }
                 }
+                FedInputField::JamInvite => {
+                    if value.is_empty() {
+                        state.status_message = Some("Jam invite is empty".into());
+                    } else {
+                        super::perform_effect(
+                            state,
+                            runtime,
+                            crate::app::update::Effect::JamJoin(value),
+                        );
+                    }
+                }
             }
         }
         _ => {

src/app/state.rs

@@ -805,6 +805,7 @@ pub enum FedInputField {
     ConnectTicket,
     DeviceName,
     ConnectInvite,
+    JamInvite,
 }
 
 impl FedInputField {
@@ -814,6 +815,7 @@ impl FedInputField {
             FedInputField::ConnectTicket => "Connect to peer (paste ticket)",
             FedInputField::DeviceName => "Device name",
             FedInputField::ConnectInvite => "Connect device (paste frid://i invite)",
+            FedInputField::JamInvite => "Join Jam (paste frid://j invite)",
         }
     }
 
@@ -831,6 +833,9 @@ impl FedInputField {
             FedInputField::ConnectInvite => {
                 "Paste a frid:// invite generated by another client to add this device to its sync group."
             }
+            FedInputField::JamInvite => {
+                "Paste a frid://j capability to control the host player for this Jam only."
+            }
         }
     }
 }
@@ -1210,6 +1215,7 @@ pub enum DevicePlaybackRole {
     #[default]
     Active,
     Control,
+    Jam,
 }
 
 impl DevicePlaybackRole {
@@ -1217,6 +1223,7 @@ impl DevicePlaybackRole {
         match self {
             DevicePlaybackRole::Active => "active",
             DevicePlaybackRole::Control => "control",
+            DevicePlaybackRole::Jam => "jam",
         }
     }
 }
@@ -1232,11 +1239,18 @@ pub struct DevicePlaybackState {
     pub local_idle_since_ms: Option<i64>,
     pub remote: BTreeMap<String, crate::devices::PlaybackSnapshot>,
     pub last_remote_snapshot: Option<crate::devices::PlaybackSnapshot>,
+    pub jam_host: bool,
 }
 
 impl DevicePlaybackState {
     pub fn is_control(&self) -> bool {
         self.role == DevicePlaybackRole::Control
+            || (self.role == DevicePlaybackRole::Jam && !self.jam_host)
+    }
+
+    pub fn is_audio_owner(&self) -> bool {
+        self.role == DevicePlaybackRole::Active
+            || (self.role == DevicePlaybackRole::Jam && self.jam_host)
     }
 
     pub fn active_label(&self) -> String {
@@ -1264,6 +1278,7 @@ pub struct AppState {
     pub settings_cursor: usize,
     pub player: PlayerBar,
     pub device_playback: DevicePlaybackState,
+    pub jam: crate::jam::JamStatus,
     pub visualizer: crate::visualizer::VisualizerState,
     pub global: GlobalTab,
     pub artist_views: HashMap<i64, Loadable<ArtistDetail>>,

src/app/update.rs

@@ -68,6 +68,12 @@ pub enum Effect {
     DeviceRevoke(String),
     /// Leave the current personal-device group after publishing self-revoke.
     DeviceLeaveGroup,
+    /// Create or regenerate the runtime Jam capability.
+    JamCreate,
+    /// Join a federation Jam by capability.
+    JamJoin(String),
+    /// Leave the current Jam without changing personal-device state.
+    JamLeave,
     /// Assemble the federated artist card (fan-out to the owning peers).
     FedOpenArtist(String),
     /// Download federated tracks into the local library, one by one.