fix: report login flow completion and errors

iOCNotes/Store.swift

@@ -19,6 +19,9 @@ final class Store: Logging, Storing {
     ///
     var pollingTask: Task<Void, any Error>?
 
+    /// A terminal error reported by the active login flow.
+    var loginErrorMessage: String?
+
     ///
     /// This singleton is necessary to conveniently expose the same environment object used in SwiftUI to the already existing UIKit code.
     ///
@@ -289,31 +292,45 @@ final class Store: Logging, Storing {
         }
     }
 
-    private func getResponse(endpoint: URL, token: String, options: NKRequestOptions) async -> (url: String, user: String, appPassword: String)? {
+    private func getResponse(endpoint: URL, token: String, options: NKRequestOptions) async throws -> (url: String, user: String, appPassword: String)? {
         logger.debug("Getting login flow status...")
 
-        return await withCheckedContinuation { continuation in
-            NextcloudKit.shared.getLoginFlowV2Poll(token: token, endpoint: endpoint.absoluteString, options: options) { [self] server, loginName, appPassword, _, error in
+        return try await withCheckedThrowingContinuation { continuation in
+            NextcloudKit.shared.getLoginFlowV2Poll(token: token, endpoint: endpoint.absoluteString, options: options) { [self] server, loginName, appPassword, response, error in
                 if error == .success, let urlBase = server, let user = loginName, let appPassword {
                     logger.debug("Successfully got login flow status (server: \(urlBase), user: \(user), password: \(appPassword)).")
                     continuation.resume(returning: (urlBase, user, appPassword))
-                } else {
-                    logger.debug("Failed to get login flow status.")
+                } else if response?.response?.statusCode == 404 {
+                    logger.debug("Login flow is pending.")
                     continuation.resume(returning: nil)
+                } else {
+                    logger.error("Failed to get login flow status: \(error.localizedDescription, privacy: .public)")
+                    continuation.resume(throwing: error.error)
                 }
             }
         }
     }
 
-    func beginPolling(at url: URL) async throws -> URL {
+    private func getLoginFlow(for url: URL) async throws -> (endpoint: URL, login: URL, token: String) {
+        let options = NKRequestOptions(customUserAgent: userAgent)
+
+        do {
+            return try await NextcloudKit.shared.getLoginFlowV2(serverUrl: url.absoluteString, options: options)
+        } catch {
+            logger.error("Failed to start login flow: \(error.localizedDescription, privacy: .public)")
+            throw error
+        }
+    }
+
+    func beginPolling(at url: URL, dismiss: @MainActor @Sendable @escaping () -> Void) async throws -> URL {
         logger.debug("Beginning polling at \(url.absoluteString)")
+        loginErrorMessage = nil
 
         let (_, serverInfoResult) = await NextcloudKit.shared.getServerStatusAsync(serverUrl: url.absoluteString)
 
         switch serverInfoResult {
             case .success:
-                let loginOptions = NKRequestOptions(customUserAgent: userAgent)
-                let (endpoint, loginAddress, token) = try await NextcloudKit.shared.getLoginFlowV2(serverUrl: url.absoluteString, options: loginOptions)
+                let (endpoint, loginAddress, token) = try await getLoginFlow(for: url)
                 let options = NKRequestOptions(customUserAgent: userAgent)
                 var grantValues: (url: String, user: String, appPassword: String)?
 
@@ -330,21 +347,33 @@ final class Store: Logging, Storing {
                         self.pollingTask = nil
                     }
 
-                    repeat {
-                        try Task.checkCancellation()
-                        grantValues = await getResponse(endpoint: endpoint, token: token, options: options)
-                        try await Task.sleep(for: .seconds(1))
-                    } while grantValues == nil
-
-                    guard let grantValues else {
-                        return
+                    do {
+                        repeat {
+                            try Task.checkCancellation()
+                            grantValues = try await getResponse(endpoint: endpoint, token: token, options: options)
+
+                            if grantValues == nil {
+                                try await Task.sleep(for: .seconds(1))
+                            }
+                        } while grantValues == nil
+
+                        guard let grantValues else {
+                            return
+                        }
+
+                        guard let host = URL(string: grantValues.url) else {
+                            throw NKError.urlError.error
+                        }
+
+                        addAccount(host: host, name: grantValues.user, password: grantValues.appPassword)
+                        dismiss()
+                    } catch is CancellationError {
+                        logger.debug("Login flow polling was cancelled.")
+                    } catch {
+                        logger.error("Login flow polling failed: \(error.localizedDescription, privacy: .public)")
+                        loginErrorMessage = error.localizedDescription
+                        dismiss()
                     }
-
-                    guard let host = URL(string: grantValues.url) else {
-                        return
-                    }
-
-                    addAccount(host: host, name: grantValues.user, password: grantValues.appPassword)
                 }
 
                 return loginAddress
@@ -358,7 +387,7 @@ final class Store: Logging, Storing {
         logger.debug("Cancelling polling task.")
 
         guard let pollingTask else {
-            logger.error("Attempt to cancel polling task but no task is active!")
+            logger.debug("No active polling task to cancel.")
             return
         }
 

iOCNotes/Views/ContentView.swift

@@ -37,15 +37,29 @@ struct ContentView: View {
         if store.accounts.isEmpty {
             ServerAddressView(backgroundColor: .constant(Color.accent), brandImage: Image("BrandLogo"), sharedAccounts: sharedAccounts, userAgent: userAgent) { host, name, password in
                 store.addAccount(host: host, name: name, password: password)
-            } beginPolling: { url, _ in
-               try await store.beginPolling(at: url)
+            } beginPolling: { url, dismiss in
+                try await store.beginPolling(at: url, dismiss: dismiss)
             } cancelPolling: {
                 store.cancelPolling()
             }
             .onAppear {
                 // The store must update its list of shared accounts when the login user interface is about to appear.
                 store.readSharedAccounts()
             }
+            .alert("Login Failed", isPresented: Binding(
+                get: { store.loginErrorMessage != nil },
+                set: { isPresented in
+                    if isPresented == false {
+                        store.loginErrorMessage = nil
+                    }
+                }
+            )) {
+                Button("OK", role: .cancel) {
+                    store.loginErrorMessage = nil
+                }
+            } message: {
+                Text(store.loginErrorMessage ?? "Unknown login error.")
+            }
 
         } else {
             TabView(selection: $selection) {