Exporting: Refactor out zip exporting into a separate class

Signed-off-by: Roopesh Chander <roop@roopc.net>

WireGuard/WireGuard/UI/iOS/ErrorPresenter.swift

@@ -32,6 +32,12 @@ class ErrorPresenter {
         case ZipImporterError.noTunnelsInZipArchive:
             return ("No tunnels in zip archive", "No .conf tunnel files were found inside the zip archive.")
 
+        // Exporting a zip file
+        case ZipArchiveError.cantOpenOutputZipFileForWriting:
+            return ("Unable to create zip archive", "Could not create a zip file in the app's document directory.")
+        case ZipExporterError.noTunnelsToExport:
+            return ("Nothing to export", "There are no tunnels to export")
+
         default:
             os_log("ErrorPresenter: Error not presented: %{public}@", log: OSLog.default, type: .error, "\(error)")
             return nil

WireGuard/WireGuard/UI/iOS/SettingsTableViewController.swift

@@ -63,20 +63,7 @@ class SettingsTableViewController: UITableViewController {
     }
 
     func exportConfigurationsAsZipFile(sourceView: UIView) {
-        guard let tunnelsManager = tunnelsManager, tunnelsManager.numberOfTunnels() > 0 else {
-            showErrorAlert(title: "Nothing to export", message: "There are no tunnels to export")
-            return
-        }
-        var inputsToArchiver: [(fileName: String, contents: Data)] = []
-        for i in 0 ..< tunnelsManager.numberOfTunnels() {
-            guard let tunnelConfiguration = tunnelsManager.tunnel(at: i).tunnelConfiguration() else { continue }
-            if let contents = WgQuickConfigFileWriter.writeConfigFile(from: tunnelConfiguration) {
-                let name = tunnelConfiguration.interface.name
-                assert(name != tunnelsManager.tunnel(at: i - 1).name)
-                inputsToArchiver.append((fileName: "\(name).conf", contents: contents))
-            }
-        }
-
+        guard let tunnelsManager = tunnelsManager else { return }
         guard let destinationDir = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else {
             return
         }
@@ -87,16 +74,19 @@ class SettingsTableViewController: UITableViewController {
             os_log("Failed to delete file: %{public}@ : %{public}@", log: OSLog.default, type: .error, destinationURL.absoluteString, error.localizedDescription)
         }
 
+        let count = tunnelsManager.numberOfTunnels()
+        let tunnelConfigurations = (0 ..< count).compactMap { tunnelsManager.tunnel(at: $0).tunnelConfiguration() }
         do {
-            try ZipArchive.archive(inputs: inputsToArchiver, to: destinationURL)
-            let activityVC = UIActivityViewController(activityItems: [destinationURL], applicationActivities: nil)
-            // popoverPresentationController shall be non-nil on the iPad
-            activityVC.popoverPresentationController?.sourceView = sourceView
-            activityVC.popoverPresentationController?.sourceRect = sourceView.bounds
-            present(activityVC, animated: true)
+            try ZipExporter.exportConfigFiles(tunnelConfigurations: tunnelConfigurations, to: destinationURL)
         } catch (let error) {
-            showErrorAlert(title: "Unable to export", message: "There was an error exporting the tunnel configuration archive: \(String(describing: error))")
+            ErrorPresenter.showErrorAlert(error: error, from: self)
         }
+
+        let activityVC = UIActivityViewController(activityItems: [destinationURL], applicationActivities: nil)
+        // popoverPresentationController shall be non-nil on the iPad
+        activityVC.popoverPresentationController?.sourceView = sourceView
+        activityVC.popoverPresentationController?.sourceRect = sourceView.bounds
+        present(activityVC, animated: true)
     }
 
     func showErrorAlert(title: String, message: String) {

WireGuard/WireGuard/ZipArchive/ZipExporter.swift

@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: MIT
+// Copyright © 2018 WireGuard LLC. All Rights Reserved.
+
+import UIKit
+
+enum ZipExporterError: Error {
+    case noTunnelsToExport
+}
+
+class ZipExporter {
+    static func exportConfigFiles(tunnelConfigurations: [TunnelConfiguration], to destinationURL: URL) throws {
+
+        guard (!tunnelConfigurations.isEmpty) else { throw ZipExporterError.noTunnelsToExport }
+
+        var inputsToArchiver: [(fileName: String, contents: Data)] = []
+
+        var lastTunnelName: String = ""
+        for tunnelConfiguration in tunnelConfigurations {
+            if let contents = WgQuickConfigFileWriter.writeConfigFile(from: tunnelConfiguration) {
+                let name = tunnelConfiguration.interface.name
+                if (name.isEmpty || name == lastTunnelName) { continue }
+                inputsToArchiver.append((fileName: "\(name).conf", contents: contents))
+                lastTunnelName = name
+            }
+        }
+        try ZipArchive.archive(inputs: inputsToArchiver, to: destinationURL)
+    }
+}