Persist audio input device by UID so selection survives reboots and replugs

Sources/OpenWisprLib/AppDelegate.swift

@@ -31,7 +31,11 @@ public class AppDelegate: NSObject, NSApplicationDelegate {
     private func setupInner() throws {
         config = Config.load()
         inserter = TextInserter()
-        recorder.preferredDeviceID = config.audioInputDeviceID
+        migrateAudioDeviceUIDIfNeeded()
+        recorder.preferredDeviceID = AudioDeviceManager.resolveConfiguredDeviceID(
+            uid: config.audioInputDeviceUID,
+            legacyID: config.audioInputDeviceID
+        )
         if Config.effectiveMaxRecordings(config.maxRecordings) == 0 {
             RecordingStore.deleteAllRecordings()
         }
@@ -153,13 +157,28 @@ public class AppDelegate: NSObject, NSApplicationDelegate {
         applyConfigChange(newConfig)
     }
 
+    /// Configs written by older versions store only the numeric AudioDeviceID,
+    /// which is not stable across reboots or device replugs. If that ID still
+    /// refers to a device, persist its UID so the selection survives.
+    private func migrateAudioDeviceUIDIfNeeded() {
+        guard config.audioInputDeviceUID == nil,
+              let legacyID = config.audioInputDeviceID,
+              let uid = AudioDeviceManager.getDeviceUID(deviceID: legacyID) else { return }
+        config.audioInputDeviceUID = uid
+        try? config.save()
+    }
+
     func applyConfigChange(_ newConfig: Config) {
         guard isReady else { return }
         let wasDownloading: Bool
         if case .downloading = statusBar.state { wasDownloading = true } else { wasDownloading = false }
-        let deviceChanged = recorder.preferredDeviceID != newConfig.audioInputDeviceID
+        let newDeviceID = AudioDeviceManager.resolveConfiguredDeviceID(
+            uid: newConfig.audioInputDeviceUID,
+            legacyID: newConfig.audioInputDeviceID
+        )
+        let deviceChanged = recorder.preferredDeviceID != newDeviceID
         config = newConfig
-        recorder.preferredDeviceID = config.audioInputDeviceID
+        recorder.preferredDeviceID = newDeviceID
         if deviceChanged {
             recorder.reload()
         }

Sources/OpenWisprLib/AudioDeviceManager.swift

@@ -3,6 +3,7 @@ import Foundation
 
 struct AudioInputDevice {
     let id: AudioDeviceID
+    let uid: String?
     let name: String
     let isDefault: Bool
 }
@@ -44,6 +45,7 @@ class AudioDeviceManager {
                   let name = getDeviceName(deviceID: deviceID) else { continue }
             result.append(AudioInputDevice(
                 id: deviceID,
+                uid: getDeviceUID(deviceID: deviceID),
                 name: name,
                 isDefault: deviceID == defaultID
             ))
@@ -69,6 +71,29 @@ class AudioDeviceManager {
         return deviceID
     }
 
+    /// Resolve the configured input device to a current AudioDeviceID.
+    /// A stored UID wins over the numeric ID, because AudioDeviceIDs are not
+    /// stable across reboots or device replugs while UIDs are. If a UID is
+    /// set but no longer present, returns nil (system default) rather than
+    /// trusting the possibly-reassigned numeric ID.
+    static func resolveConfiguredDeviceID(uid: String?, legacyID: AudioDeviceID?) -> AudioDeviceID? {
+        guard let uid = uid else { return legacyID }
+        return listInputDevices().first(where: { $0.uid == uid })?.id
+    }
+
+    static func getDeviceUID(deviceID: AudioDeviceID) -> String? {
+        var address = AudioObjectPropertyAddress(
+            mSelector: kAudioDevicePropertyDeviceUID,
+            mScope: kAudioObjectPropertyScopeGlobal,
+            mElement: kAudioObjectPropertyElementMain
+        )
+        var uid: Unmanaged<CFString>?
+        var size = UInt32(MemoryLayout<Unmanaged<CFString>?>.size)
+        let status = AudioObjectGetPropertyData(deviceID, &address, 0, nil, &size, &uid)
+        guard status == noErr, let cfUID = uid?.takeRetainedValue() else { return nil }
+        return cfUID as String
+    }
+
     private static func isVirtualDevice(deviceID: AudioDeviceID) -> Bool {
         var transportType: UInt32 = 0
         var size = UInt32(MemoryLayout<UInt32>.size)

Sources/OpenWisprLib/Config.swift

@@ -14,6 +14,7 @@ public struct Config: Codable {
     public var maxRecordings: Int?
     public var toggleMode: FlexBool?
     public var audioInputDeviceID: UInt32?
+    public var audioInputDeviceUID: String?
 
     public var hotkey: HotkeyConfig {
         get { hotkeys[0] }
@@ -44,6 +45,7 @@ public struct Config: Codable {
         case maxRecordings
         case toggleMode
         case audioInputDeviceID
+        case audioInputDeviceUID
     }
 
     public init(from decoder: Decoder) throws {
@@ -64,6 +66,7 @@ public struct Config: Codable {
         self.maxRecordings = try c.decodeIfPresent(Int.self, forKey: .maxRecordings)
         self.toggleMode = try c.decodeIfPresent(FlexBool.self, forKey: .toggleMode)
         self.audioInputDeviceID = try c.decodeIfPresent(UInt32.self, forKey: .audioInputDeviceID)
+        self.audioInputDeviceUID = try c.decodeIfPresent(String.self, forKey: .audioInputDeviceUID)
     }
 
     public func encode(to encoder: Encoder) throws {
@@ -77,6 +80,7 @@ public struct Config: Codable {
         try c.encodeIfPresent(maxRecordings, forKey: .maxRecordings)
         try c.encodeIfPresent(toggleMode, forKey: .toggleMode)
         try c.encodeIfPresent(audioInputDeviceID, forKey: .audioInputDeviceID)
+        try c.encodeIfPresent(audioInputDeviceUID, forKey: .audioInputDeviceUID)
     }
 
     public init(
@@ -87,7 +91,8 @@ public struct Config: Codable {
         spokenPunctuation: FlexBool?,
         maxRecordings: Int?,
         toggleMode: FlexBool?,
-        audioInputDeviceID: UInt32? = nil
+        audioInputDeviceID: UInt32? = nil,
+        audioInputDeviceUID: String? = nil
     ) {
         self.hotkeys = hotkeys.isEmpty
             ? [HotkeyConfig(keyCode: 63, modifiers: [])]
@@ -99,6 +104,7 @@ public struct Config: Codable {
         self.maxRecordings = maxRecordings
         self.toggleMode = toggleMode
         self.audioInputDeviceID = audioInputDeviceID
+        self.audioInputDeviceUID = audioInputDeviceUID
     }
 
     public static let supportedLanguages: [LanguageOption] = [

Sources/OpenWisprLib/StatusBarController.swift

@@ -221,28 +221,29 @@ class StatusBarController: NSObject {
         menu.addItem(modelItem)
 
         let devices = AudioDeviceManager.listInputDevices()
-        let selectedDeviceID = config.audioInputDeviceID
-        let currentDeviceName: String
-        if let selectedID = selectedDeviceID,
-           let device = devices.first(where: { $0.id == selectedID }) {
-            currentDeviceName = device.name
-        } else {
-            currentDeviceName = "System Default"
-        }
+        let selectedDevice = devices.first(where: { device in
+            if let uid = config.audioInputDeviceUID { return device.uid == uid }
+            if let id = config.audioInputDeviceID { return device.id == id }
+            return false
+        })
+        let currentDeviceName = selectedDevice?.name ?? "System Default"
         let audioItem = NSMenuItem(title: "Audio Input: \(currentDeviceName)", action: nil, keyEquivalent: "")
         let audioSubmenu = NSMenu()
         audioSubmenu.autoenablesItems = false
 
         let defaultTarget = MenuItemTarget { [weak self] in
             var cfg = Config.load()
             cfg.audioInputDeviceID = nil
+            cfg.audioInputDeviceUID = nil
             try? cfg.save()
             self?.onConfigChange?(cfg)
         }
         menuItemTargets.append(defaultTarget)
         let defaultItem = NSMenuItem(title: "System Default", action: #selector(MenuItemTarget.invoke), keyEquivalent: "")
         defaultItem.target = defaultTarget
-        if selectedDeviceID == nil { defaultItem.state = .on }
+        if config.audioInputDeviceID == nil && config.audioInputDeviceUID == nil {
+            defaultItem.state = .on
+        }
         audioSubmenu.addItem(defaultItem)
 
         if !devices.isEmpty {
@@ -253,13 +254,14 @@ class StatusBarController: NSObject {
             let target = MenuItemTarget { [weak self] in
                 var cfg = Config.load()
                 cfg.audioInputDeviceID = device.id
+                cfg.audioInputDeviceUID = device.uid
                 try? cfg.save()
                 self?.onConfigChange?(cfg)
             }
             menuItemTargets.append(target)
             let item = NSMenuItem(title: device.name, action: #selector(MenuItemTarget.invoke), keyEquivalent: "")
             item.target = target
-            if selectedDeviceID == device.id { item.state = .on }
+            if selectedDevice?.id == device.id { item.state = .on }
             audioSubmenu.addItem(item)
         }
 

Tests/OpenWisprTests/AudioDeviceManagerTests.swift

@@ -0,0 +1,27 @@
+import XCTest
+@testable import OpenWisprLib
+
+final class AudioDeviceManagerTests: XCTestCase {
+
+    func testResolveWithoutUIDFallsBackToLegacyID() {
+        XCTAssertEqual(
+            AudioDeviceManager.resolveConfiguredDeviceID(uid: nil, legacyID: 42),
+            42
+        )
+    }
+
+    func testResolveWithoutUIDAndWithoutLegacyIDReturnsNil() {
+        XCTAssertNil(AudioDeviceManager.resolveConfiguredDeviceID(uid: nil, legacyID: nil))
+    }
+
+    func testResolveWithUnknownUIDReturnsNilInsteadOfStaleID() {
+        // The stored numeric ID must not be trusted when the UID it was
+        // saved with no longer matches any present device.
+        XCTAssertNil(
+            AudioDeviceManager.resolveConfiguredDeviceID(
+                uid: "OpenWisprTests:NoSuchDevice:UID",
+                legacyID: 42
+            )
+        )
+    }
+}

Tests/OpenWisprTests/ConfigTests.swift

@@ -133,6 +133,53 @@ final class ConfigTests: XCTestCase {
         XCTAssertEqual(config.toggleMode?.value, false)
     }
 
+    // MARK: - audioInputDevice decoding
+
+    func testConfigDecodesAudioInputDeviceUID() throws {
+        let json = """
+        {
+            "hotkey": {"keyCode": 63, "modifiers": []},
+            "modelSize": "base.en",
+            "language": "en",
+            "audioInputDeviceID": 82,
+            "audioInputDeviceUID": "AppleUSBAudioEngine:Vendor:Headset:1234:1"
+        }
+        """.data(using: .utf8)!
+        let config = try Config.decode(from: json)
+        XCTAssertEqual(config.audioInputDeviceID, 82)
+        XCTAssertEqual(config.audioInputDeviceUID, "AppleUSBAudioEngine:Vendor:Headset:1234:1")
+    }
+
+    func testConfigDecodesLegacyAudioInputDeviceIDWithoutUID() throws {
+        let json = """
+        {
+            "hotkey": {"keyCode": 63, "modifiers": []},
+            "modelSize": "base.en",
+            "language": "en",
+            "audioInputDeviceID": 82
+        }
+        """.data(using: .utf8)!
+        let config = try Config.decode(from: json)
+        XCTAssertEqual(config.audioInputDeviceID, 82)
+        XCTAssertNil(config.audioInputDeviceUID)
+    }
+
+    func testConfigEncodesAudioInputDeviceUIDRoundTrip() throws {
+        var config = Config.defaultConfig
+        config.audioInputDeviceID = 82
+        config.audioInputDeviceUID = "BuiltInMicrophoneDevice"
+        let data = try JSONEncoder().encode(config)
+        let decoded = try Config.decode(from: data)
+        XCTAssertEqual(decoded.audioInputDeviceID, 82)
+        XCTAssertEqual(decoded.audioInputDeviceUID, "BuiltInMicrophoneDevice")
+    }
+
+    func testConfigOmitsAudioInputDeviceUIDWhenNil() throws {
+        let data = try JSONEncoder().encode(Config.defaultConfig)
+        let json = String(data: data, encoding: .utf8)!
+        XCTAssertFalse(json.contains("audioInputDeviceUID"))
+    }
+
     // MARK: - Language and model constants
 
     func testSupportedLanguagesContainsEnglish() {