#40: Add UserSessionStoreProtocol.

Only log out of the specific account.
Add tests for the keychain controller.
Expand test coverage.
PR comments

ElementX/Sources/Services/UserSession/KeychainController.swift

@@ -1,53 +0,0 @@
-//
-//  KeychainController.swift
-//  ElementX
-//
-//  Created by Stefan Ceriu on 14.02.2022.
-//  Copyright © 2022 Element. All rights reserved.
-//
-
-import Foundation
-import KeychainAccess
-
-class KeychainController: KeychainControllerProtocol {
-    private let keychain: Keychain
-    
-    init(identifier: String) {
-        keychain = Keychain(service: identifier)
-    }
- 
-    func setAccessToken(_ accessToken: String, forUsername username: String) {
-        do {
-            try keychain.set(accessToken, key: username)
-        } catch {
-            MXLog.error("Failed storing user restore token with error: \(error)")
-        }
-    }
-    
-    func accessTokenForUsername(_ username: String) -> String? {
-        do {
-            return try keychain.get(username)
-        } catch {
-            MXLog.error("Failed retrieving user restore token")
-            return nil
-        }
-    }
-    
-    func accessTokens() -> [(username: String, accessToken: String)] {
-        keychain.allKeys().compactMap { username in
-            guard let accessToken = accessTokenForUsername(username) else {
-                return nil
-            }
-            
-            return (username, accessToken)
-        }
-    }
-    
-    func removeAllAccessTokens() {
-        do {
-            try keychain.removeAll()
-        } catch {
-            MXLog.error("Failed removing all tokens")
-        }
-    }
-}

ElementX/Sources/Services/UserSession/KeychainControllerProtocol.swift

@@ -1,16 +0,0 @@
-//
-//  KeychainControllerProtocol.swift
-//  ElementX
-//
-//  Created by Stefan Ceriu on 14.02.2022.
-//  Copyright © 2022 Element. All rights reserved.
-//
-
-import Foundation
-
-protocol KeychainControllerProtocol {
-    func setAccessToken(_ accessToken: String, forUsername username: String)
-    func accessTokenForUsername(_ username: String) -> String?
-    func accessTokens() -> [(username: String, accessToken: String)]
-    func removeAllAccessTokens()
-}

ElementX/Sources/Services/UserSession/UserSessionStore.swift

@@ -1,134 +0,0 @@
-//
-// Copyright 2022 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
-import MatrixRustSDK
-import Kingfisher
-
-enum UserSessionStoreError: Error {
-    case missingCredentials
-    case failedRestoringLogin
-    case failedSettingUpSession
-}
-
-@MainActor
-class UserSessionStore {
-    
-    private let keychainController: KeychainControllerProtocol
-    
-    /// Whether or not there are sessions in the store.
-    var hasSessions: Bool { !keychainController.accessTokens().isEmpty }
-    
-    init(bundleIdentifier: String) {
-        keychainController = KeychainController(identifier: bundleIdentifier)
-    }
-    
-    func restoreUserSession() async -> Result<UserSession, UserSessionStoreError> {
-        let availableAccessTokens = keychainController.accessTokens()
-        
-        guard let usernameTokenTuple = availableAccessTokens.first else {
-            return .failure(.missingCredentials)
-        }
-        
-        switch await restorePreviousLogin(usernameTokenTuple) {
-        case .success(let clientProxy):
-            return .success(UserSession(clientProxy: clientProxy,
-                                        mediaProvider: MediaProvider(clientProxy: clientProxy, imageCache: ImageCache.default)))
-        case .failure(let error):
-            MXLog.error("Failed restoring login with error: \(error)")
-            
-            // On any restoration failure reset the token and restart
-            keychainController.removeAllAccessTokens()
-            deleteBaseDirectory(for: usernameTokenTuple.username)
-            
-            return .failure(error)
-        }
-    }
-    
-    func userSession(for client: Client) async -> Result<UserSession, UserSessionStoreError> {
-        switch await setupProxyForClient(client) {
-        case .success(let clientProxy):
-            return .success(UserSession(clientProxy: clientProxy,
-                                        mediaProvider: MediaProvider(clientProxy: clientProxy, imageCache: ImageCache.default)))
-        case .failure(let error):
-            MXLog.error("Failed creating user session with error: \(error)")
-            return .failure(error)
-        }
-    }
-    
-    func logout(userSession: UserSessionProtocol) {
-        keychainController.removeAllAccessTokens()
-        deleteBaseDirectory(for: userSession.clientProxy.userIdentifier)
-    }
-    
-    private func restorePreviousLogin(_ usernameTokenTuple: (username: String, accessToken: String)) async -> Result<ClientProxyProtocol, UserSessionStoreError> {
-        Benchmark.startTrackingForIdentifier("Login", message: "Started restoring previous login")
-        
-        let basePath = baseDirectoryPath(for: usernameTokenTuple.username)
-        let loginTask = Task.detached {
-            try loginWithToken(basePath: basePath,
-                               restoreToken: usernameTokenTuple.accessToken)
-        }
-        
-        switch await loginTask.result {
-        case .success(let client):
-            return await setupProxyForClient(client)
-        case .failure(let error):
-            MXLog.error("Failed restoring login with error: \(error)")
-            return .failure(.failedRestoringLogin)
-        }
-    }
-    
-    private func setupProxyForClient(_ client: Client) async -> Result<ClientProxyProtocol, UserSessionStoreError> {
-        Benchmark.endTrackingForIdentifier("Login", message: "Finished login")
-        
-        do {
-            let accessToken = try client.restoreToken()
-            let userId = try client.userId()
-            
-            keychainController.setAccessToken(accessToken, forUsername: userId)
-        } catch {
-            MXLog.error("Failed setting up user session with error: \(error)")
-            return .failure(.failedSettingUpSession)
-        }
-        
-        let clientProxy = ClientProxy(client: client)
-        
-        return .success(clientProxy)
-    }
-    
-    func baseDirectoryPath(for username: String) -> String {
-        guard var url = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask).first else {
-            fatalError("Should always be able to retrieve the caches directory")
-        }
-        
-        url = url.appendingPathComponent(username)
-        
-        try? FileManager.default.createDirectory(at: url, withIntermediateDirectories: false, attributes: nil)
-        
-        return url.path
-    }
-    
-    private func deleteBaseDirectory(for username: String) {
-        guard var url = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask).first else {
-            fatalError("Should always be able to retrieve the caches directory")
-        }
-        
-        url = url.appendingPathComponent(username)
-
-        try? FileManager.default.removeItem(at: url)
-    }
-}