Save last used profile (#1036)

Especially useful on macOS and tvOS where Network Extension does not
retain this information when the profile is disabled. On these
platforms, there's no native way to tell the last used profile, so save
it to UserDefaults and fall back to it when tunnel.currentProfile is
nil.

Library/Sources/CommonLibrary/Business/ExtendedTunnel.swift

@@ -29,6 +29,8 @@ import PassepartoutKit
 
 @MainActor
 public final class ExtendedTunnel: ObservableObject {
+    private let defaults: UserDefaults?
+
     private let tunnel: Tunnel
 
     private let environment: TunnelEnvironment
@@ -54,11 +56,13 @@ public final class ExtendedTunnel: ObservableObject {
     private var subscriptions: Set<AnyCancellable>
 
     public init(
+        defaults: UserDefaults? = nil,
         tunnel: Tunnel,
         environment: TunnelEnvironment,
         processor: AppTunnelProcessor? = nil,
         interval: TimeInterval
     ) {
+        self.defaults = defaults
         self.tunnel = tunnel
         self.environment = environment
         self.processor = processor
@@ -83,12 +87,15 @@ extension ExtendedTunnel {
 
 extension ExtendedTunnel {
     public var currentProfile: TunnelCurrentProfile? {
-        tunnel.currentProfile
+        tunnel.currentProfile ?? lastUsedProfile
     }
 
     public var currentProfilePublisher: AnyPublisher<TunnelCurrentProfile?, Never> {
         tunnel
             .$currentProfile
+            .map {
+                $0 ?? self.lastUsedProfile
+            }
             .eraseToAnyPublisher()
     }
 
@@ -154,7 +161,10 @@ private extension ExtendedTunnel {
         tunnel
             .$currentProfile
             .receive(on: DispatchQueue.main)
-            .sink { [weak self] _ in
+            .sink { [weak self] in
+                if let id = $0?.id {
+                    self?.defaults?.set(id.uuidString, forKey: AppPreference.lastUsedProfileId.key)
+                }
                 self?.objectWillChange.send()
             }
             .store(in: &subscriptions)
@@ -195,8 +205,18 @@ private extension ExtendedTunnel {
 
 // MARK: - Helpers
 
+private extension ExtendedTunnel {
+    var lastUsedProfile: TunnelCurrentProfile? {
+        guard let uuidString = defaults?.object(forKey: AppPreference.lastUsedProfileId.key) as? String,
+              let uuid = UUID(uuidString: uuidString) else {
+            return nil
+        }
+        return TunnelCurrentProfile(id: uuid, onDemand: false)
+    }
+}
+
 extension TunnelStatus {
-    public func withEnvironment(_ environment: TunnelEnvironment) -> TunnelStatus {
+    func withEnvironment(_ environment: TunnelEnvironment) -> TunnelStatus {
         var status = self
         if status == .active, let connectionStatus = environment.environmentValue(forKey: TunnelEnvironmentKeys.connectionStatus) {
             if connectionStatus == .connected {

Library/Sources/CommonLibrary/Domain/AppPreference.swift

@@ -26,6 +26,8 @@
 import Foundation
 
 public enum AppPreference: String, PreferenceProtocol {
+    case lastUsedProfileId
+
     case logsPrivateData
 
     public var key: String {

Passepartout/App/Context/AppContext+Shared.swift

@@ -113,6 +113,7 @@ extension AppContext {
         )
 
         let tunnel = ExtendedTunnel(
+            defaults: .standard,
             tunnel: Tunnel(strategy: tunnelStrategy),
             environment: tunnelEnvironment,
             processor: processor,