feat: conversation state machine, mic meter, history, wake lock (Phase 3)

Sources/LiveKit/VoiceSession.swift

@@ -1,3 +1,4 @@
+import UIKit
 import Foundation
 import LiveKit
 import os
@@ -24,10 +25,12 @@ final class VoiceSession: ObservableObject {
     @Published private(set) var state: VoiceSessionState = .idle
     @Published private(set) var agent: AgentInfo?
     @Published private(set) var isMuted = false
+    @Published private(set) var micError: String?
 
     private(set) var room = Room()
     let controlChannel = ControlChannel()
     let transcriptHandler = TranscriptHandler()
+    let stateModel = ConversationStateModel()
     private let config: ServerConfig
     private let tokenClient: TokenClient
     private var reconnectAttempted = false
@@ -78,6 +81,7 @@ final class VoiceSession: ObservableObject {
         switch result {
         case .success:
             logger.log("room connected")
+            UIApplication.shared.isIdleTimerDisabled = true
             scanForAgent()
             startAgentWait()
         case .failure(let error):
@@ -137,6 +141,7 @@ final class VoiceSession: ObservableObject {
         }
         agentWaitTask?.cancel()
         state = .ready
+        stateModel.start()
         logger.log("state=ready, enabling mic")
         Task { await enableMicrophone() }
     }
@@ -163,6 +168,7 @@ final class VoiceSession: ObservableObject {
             do {
                 try await room.localParticipant.setMicrophone(enabled: true)
                 isMuted = false
+                micError = nil
                 logger.log("mic enabled")
                 return
             } catch {
@@ -172,8 +178,9 @@ final class VoiceSession: ObservableObject {
                     try? await Task.sleep(for: .seconds(1))
                     continue
                 }
+                // Non-fatal: keep the session usable (text mode still works).
                 logger.error("mic enable failed after retries: \(message, privacy: .public)")
-                state = .failed("Microphone error: \(error.localizedDescription)")
+                micError = "Microphone unavailable (\(error.localizedDescription)). Text mode still works."
             }
         }
     }
@@ -184,11 +191,22 @@ final class VoiceSession: ObservableObject {
             try await room.localParticipant.setMicrophone(enabled: !muted)
             isMuted = muted
         } catch {
-            state = .failed("Microphone error: \(error.localizedDescription)")
+            micError = "Microphone error: \(error.localizedDescription)"
+        }
+    }
+
+    func setMode(_ mode: String) async {
+        guard isReady else { return }
+        do {
+            try await controlChannel.setMode(mode, room: room)
+            logger.log("set_mode sent: \(mode, privacy: .public)")
+        } catch {
+            logger.error("set_mode failed: \(String(describing: error), privacy: .public)")
         }
     }
 
     func sendText(_ text: String) async throws {
+        logger.log("sendText lk.chat chars=\(text.count)")
         try await room.localParticipant.sendText(text, for: "lk.chat")
     }
 
@@ -197,10 +215,17 @@ final class VoiceSession: ObservableObject {
         state = .idle
         agent = nil
         isMuted = false
+        micError = nil
         reconnectAttempted = false
+        stateModel.stop()
+        UIApplication.shared.isIdleTimerDisabled = false
         await teardownRoom()
     }
 
+    func tickAudioLevels(local: Float, remote: Float) {
+        stateModel.tick(localAudioLevel: local, remoteAudioLevel: remote)
+    }
+
 }
 
 extension VoiceSession: RoomDelegate {
@@ -211,6 +236,22 @@ extension VoiceSession: RoomDelegate {
         }
     }
 
+    nonisolated func room(_ room: Room, didUpdateSpeakingParticipants participants: [Participant]) {
+        Task { @MainActor [weak self] in
+            guard let self, self.state == .ready else { return }
+            var local = Float(0)
+            var remote = Float(0)
+            for participant in participants {
+                if participant.identity?.stringValue == room.localParticipant.identity?.stringValue {
+                    local = max(local, participant.audioLevel)
+                } else {
+                    remote = max(remote, participant.audioLevel)
+                }
+            }
+            self.tickAudioLevels(local: local, remote: remote)
+        }
+    }
+
     nonisolated func room(_ room: Room, participant: RemoteParticipant?, didReceiveData data: Data, forTopic topic: String, encryptionType: EncryptionType) {
         logger.log("data topic=\(topic, privacy: .public) bytes=\(data.count) payload=\(String(data: data.prefix(300), encoding: .utf8) ?? "<binary>", privacy: .public)")
         Task { @MainActor [weak self] in