helper.patch

diff --git a/AudioSwitchPrefs/HelperAppManager.swift b/AudioSwitchPrefs/HelperAppManager.swift
index 041d7b5..1bdfd4d 100644
--- a/AudioSwitchPrefs/HelperAppManager.swift
+++ b/AudioSwitchPrefs/HelperAppManager.swift
@@ -1,11 +1,36 @@
-// Copyright 2018 Vincent Duvert.
+// Copyright 2018-2022 Vincent Duvert.
 // Distributed under the terms of the MIT License.
 
 import AppKit
 import ServiceManagement
 
 /// Manages the helper application installation as a service
-final class HelperAppManager {
+protocol HelperAppManager: AnyObject {
+    /// Indicates if the helper app is currently running
+    var helperAppRunning: Bool { get }
+
+    /// Indicates if the helper app is enabled; returns nil if an error occurred trying to get the information
+    var helperAppEnabled: Bool? { get }
+
+    /// Enable or disable the helper auto-start property. May show modal UI for progress, using the passed parent window.
+    /// Once the operation is done, returns the new enable status in the completion handler (true if enabled, false if disabled,
+    /// nil if not sure).
+    /// - Returns: true if change was successful, false if an error occurred
+    func setHelperAutoStart(enabled: Bool, parentWindow: NSWindow, completionHandler: @escaping (Bool?) -> ())
+}
+
+/// Returns an instance of helper application manager for the running OS.
+func getHelperAppManager() -> HelperAppManager {
+    if #available(macOS 13.0, *) {
+        return HelperAppManagerNewSM()
+    } else {
+        return HelperAppManagerOldSM()
+    }
+}
+
+/// Manages the helper application installation as a service (macOS 12 and previous)
+@available(macOS, obsoleted: 13)
+fileprivate final class HelperAppManagerOldSM: HelperAppManager {
     /// Bundle ID of the helper application
     private let helperAppId: String
     
@@ -36,7 +61,88 @@ final class HelperAppManager {
     
     /// Enable or disable the helper auto-start property
     /// - Returns: true if change was successful, false if an error occurred
-    func setHelperAutoStart(enabled: Bool) -> Bool {
-        return SMLoginItemSetEnabled(helperAppId as CFString, enabled)
+    func setHelperAutoStart(enabled: Bool, parentWindow: NSWindow, completionHandler: @escaping (Bool?) -> ()) {
+        if (SMLoginItemSetEnabled(helperAppId as CFString, enabled)) {
+            completionHandler(enabled)
+        } else {
+            let alert = NSAlert()
+            alert.messageText = NSLocalizedString("An error occurred enabling or disabling AudioSwitch.", comment:"Alert message")
+            alert.addButton(withTitle: NSLocalizedString("Cancel", comment: "Alert button"))
+            alert.beginSheetModal(for: parentWindow) { _ in
+                completionHandler(nil)
+            }
+        }
+    }
+}
+
+/// Manages the helper application installation as a service (macOS 13+)
+@available(macOS 13.0, *)
+fileprivate final class HelperAppManagerNewSM: HelperAppManager {
+    /// Bundle ID of the helper application
+    private let helperAppId: String
+
+    /// Service manager handle of the helper application
+    private let helperAppService: SMAppService
+
+    init() {
+        guard let appId = Bundle.main.object(forInfoDictionaryKey: "HelperApp") as? String else {
+            fatalError("HelperApp missing in info plist")
+        }
+
+        helperAppId = appId
+        helperAppService = .loginItem(identifier: appId)
+        /*if helperAppService.status == .notFound {
+            fatalError("HelperApp ID \(appId) not found by service manager")
+        }*/
+    }
+
+    var helperAppRunning: Bool {
+        return NSWorkspace.shared.runningApplications.contains { $0.bundleIdentifier == self.helperAppId }
+    }
+
+    var helperAppEnabled: Bool? {
+        return helperAppService.status == .enabled
+    }
+
+    func setHelperAutoStart(enabled: Bool, parentWindow: NSWindow, completionHandler: @escaping (Bool?) -> ()) {
+        do {
+            if (enabled) {
+                switch (helperAppService.status) {
+                case .enabled:
+                    completionHandler(true)
+                    return
+
+                case .notRegistered:
+                    try helperAppService.register()
+                    completionHandler(true)
+                    return
+
+                default:
+                    let alert = NSAlert()
+                    alert.messageText = NSLocalizedString("AudioSwitch needs to be allowed to start.", comment:"Alert message")
+                    alert.informativeText = NSLocalizedString("Allow AudioSwitch in the Login Items System Preferences.", comment:"Alert message")
+                    alert.addButton(withTitle: NSLocalizedString("Open System Preferences", comment: "Alert button"))
+                    alert.addButton(withTitle: NSLocalizedString("Cancel", comment: "Alert button"))
+
+                    alert.beginSheetModal(for: parentWindow) { retCode in
+                        if retCode == .alertFirstButtonReturn {
+                            SMAppService.openSystemSettingsLoginItems()
+                        }
+                        completionHandler(false)
+                    }
+                }
+            } else {
+                try helperAppService.unregister()
+                completionHandler(false)
+                return
+            }
+
+        } catch {
+            let alert = NSAlert(error: error)
+            alert.addButton(withTitle: NSLocalizedString("Cancel", comment: "Alert button"))
+            alert.beginSheetModal(for: parentWindow) { _ in
+                completionHandler(nil)
+            }
+        }
     }
 }