Tunnel errors: Consolidate tunnel activation errors into ErrorPresenter

WireGuard/WireGuard/UI/iOS/ErrorPresenter.swift

@@ -7,6 +7,8 @@ import os.log
 class ErrorPresenter {
     static func errorMessage(for error: Error) -> (String, String)? {
         switch (error) {
+
+        // TunnelManagementError
         case TunnelManagementError.tunnelAlreadyExistsWithThatName:
             return ("Name already in use", "A tunnel with that name already exists. Please pick a different name.")
         case TunnelManagementError.vpnSystemErrorOnAddTunnel:
@@ -15,6 +17,32 @@ class ErrorPresenter {
             return ("Could not modify tunnel", "Internal error")
         case TunnelManagementError.vpnSystemErrorOnRemoveTunnel:
             return ("Could not remove tunnel", "Internal error")
+
+        // TunnelActivationError
+        case TunnelActivationError.noEndpoint:
+            return ("Endpoint missing", "There must be at least one peer with an endpoint")
+        case TunnelActivationError.dnsResolutionFailed:
+            return ("DNS Failure", "One or more endpoint domains could not be resolved")
+        case TunnelActivationError.tunnelActivationFailed:
+            return ("Activation failed", "The tunnel could not be activated because of an internal error")
+        case TunnelActivationError.attemptingActivationWhenAnotherTunnelIsBusy(let otherTunnelStatus):
+            let statusString: String = {
+                switch (otherTunnelStatus) {
+                case .active: fallthrough
+                case .reasserting: fallthrough
+                case .restarting:
+                    return "active"
+                case .activating: fallthrough
+                case .resolvingEndpointDomains:
+                    return "being activated"
+                case .deactivating:
+                    return "being deactivated"
+                case .inactive:
+                    fatalError()
+                }
+            }()
+            return ("Activation failed", "Another tunnel is currently \(statusString). Only one tunnel can be in operation at a time.")
+
         default:
             os_log("ErrorPresenter: Error not presented: %{public}@", log: OSLog.default, type: .error, "\(error)")
             return nil

WireGuard/WireGuard/UI/iOS/TunnelDetailTableViewController.swift

@@ -149,15 +149,11 @@ extension TunnelDetailTableViewController {
             cell.onSwitchToggled = { [weak self] isOn in
                 guard let s = self else { return }
                 if (isOn) {
-                    s.tunnelsManager.startActivation(of: s.tunnel) { [weak self] error in
+                    s.tunnelsManager.startActivation(of: s.tunnel) { [weak s] error in
                         if let error = error {
-                            switch (error) {
+                            ErrorPresenter.showErrorAlert(error: error, from: s)
-                            case TunnelActivationError.noEndpoint:
+                            DispatchQueue.main.async {
-                                self?.showErrorAlert(title: "Endpoint missing", message: "There must be at least one peer with an endpoint")
+                                cell.statusSwitch.isOn = false
-                            case TunnelActivationError.dnsResolutionFailed:
-                                self?.showErrorAlert(title: "DNS Failure", message: "One or more endpoint domains could not be resolved")
-                            default:
-                                self?.showErrorAlert(title: "Internal error", message: "The tunnel could not be activated")
                             }
                         }
                     }

WireGuard/WireGuard/UI/iOS/TunnelsListTableViewController.swift

@@ -245,15 +245,11 @@ extension TunnelsListTableViewController {
             cell.onSwitchToggled = { [weak self] isOn in
                 guard let s = self, let tunnelsManager = s.tunnelsManager else { return }
                 if (isOn) {
-                    tunnelsManager.startActivation(of: tunnel) { error in
+                    tunnelsManager.startActivation(of: tunnel) { [weak s] error in
                         if let error = error {
-                            switch (error) {
+                            ErrorPresenter.showErrorAlert(error: error, from: s)
-                            case TunnelActivationError.noEndpoint:
+                            DispatchQueue.main.async {
-                                self?.showErrorAlert(title: "Endpoint missing", message: "There must be at least one peer with an endpoint")
+                                cell.statusSwitch.isOn = false
-                            case TunnelActivationError.dnsResolutionFailed:
-                                self?.showErrorAlert(title: "DNS Failure", message: "One or more endpoint domains could not be resolved")
-                            default:
-                                self?.showErrorAlert(title: "Internal error", message: "The tunnel could not be activated")
                             }
                         }
                     }