Check network reachability before attempting to restart the sync service

ElementX/Sources/Application/ServiceLocator.swift

@@ -33,9 +33,9 @@ class ServiceLocator {
         settings = appSettings
     }
     
-    private(set) var networkMonitor: NetworkMonitor!
+    private(set) var networkMonitor: NetworkMonitorProtocol!
     
-    func register(networkMonitor: NetworkMonitor) {
+    func register(networkMonitor: NetworkMonitorProtocol) {
         self.networkMonitor = networkMonitor
     }
     

ElementX/Sources/Other/NetworkMonitor/NetworkMonitor.swift

@@ -18,12 +18,7 @@ import Combine
 import Foundation
 import Network
 
-enum NetworkMonitorReachability {
-    case reachable
-    case unreachable
-}
-
-class NetworkMonitor {
+class NetworkMonitor: NetworkMonitorProtocol {
     private let pathMonitor: NWPathMonitor
     private let queue: DispatchQueue
     

ElementX/Sources/Other/NetworkMonitor/NetworkMonitorProtocol.swift

@@ -0,0 +1,28 @@
+//
+// Copyright 2023 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import Foundation
+
+enum NetworkMonitorReachability {
+    case reachable
+    case unreachable
+}
+
+protocol NetworkMonitorProtocol {
+    var reachabilityPublisher: CurrentValuePublisher<NetworkMonitorReachability, Never> { get }
+    var isCurrentConnectionExpensive: Bool { get }
+    var isCurrentConnectionConstrained: Bool { get }
+}

ElementX/Sources/Services/Client/ClientProxy.swift

@@ -23,6 +23,7 @@ class ClientProxy: ClientProxyProtocol {
     private let client: ClientProtocol
     private let backgroundTaskService: BackgroundTaskServiceProtocol
     private let appSettings: AppSettings
+    private let networkMonitor: NetworkMonitorProtocol
     
     private var sessionVerificationControllerProxy: SessionVerificationControllerProxy?
     private let mediaLoader: MediaLoaderProtocol
@@ -77,10 +78,14 @@ class ClientProxy: ClientProxyProtocol {
         loadingStateSubject.asCurrentValuePublisher()
     }
     
-    init(client: ClientProtocol, backgroundTaskService: BackgroundTaskServiceProtocol, appSettings: AppSettings) async {
+    init(client: ClientProtocol,
+         backgroundTaskService: BackgroundTaskServiceProtocol,
+         appSettings: AppSettings,
+         networkMonitor: NetworkMonitorProtocol) async {
         self.client = client
         self.backgroundTaskService = backgroundTaskService
         self.appSettings = appSettings
+        self.networkMonitor = networkMonitor
         
         clientQueue = .init(label: "ClientProxyQueue", attributes: .concurrent)
         
@@ -94,6 +99,16 @@ class ClientProxy: ClientProxyProtocol {
             self?.callbacks.send(.receivedAuthError(isSoftLogout: isSoftLogout))
         })
         
+        networkMonitor.reachabilityPublisher
+            .removeDuplicates()
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] reachability in
+                if reachability == .reachable {
+                    self?.startSync()
+                }
+            }
+            .store(in: &cancellables)
+        
         await configureAppService()
 
         loadUserAvatarURLFromCache()
@@ -136,6 +151,11 @@ class ClientProxy: ClientProxyProtocol {
             return
         }
         
+        guard networkMonitor.reachabilityPublisher.value == .reachable else {
+            MXLog.warning("Ignoring request, network unreachable.")
+            return
+        }
+        
         MXLog.info("Starting sync")
         
         Task {

ElementX/Sources/Services/UserSession/UserSessionStore.swift

@@ -142,7 +142,8 @@ class UserSessionStore: UserSessionStoreProtocol {
         
         let clientProxy = await ClientProxy(client: client,
                                             backgroundTaskService: backgroundTaskService,
-                                            appSettings: ServiceLocator.shared.settings)
+                                            appSettings: ServiceLocator.shared.settings,
+                                            networkMonitor: ServiceLocator.shared.networkMonitor)
         
         return .success(clientProxy)
     }