key backup: Add a dedicated section to settings

#2193

Still WIP

Riot/Modules/Settings/KeyBackup/SettingsKeyBackupViewModel.swift

@@ -0,0 +1,142 @@
+/*
+ Copyright 2019 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 UIKit
+
+class SettingsKeyBackupViewModel: SettingsKeyBackupViewModelType {
+
+    // MARK: - Properties
+    weak var viewDelegate: SettingsKeyBackupViewModelViewDelegate?
+
+    // MARK: Private
+    private let keyBackup: MXKeyBackup
+
+    init(keyBackup: MXKeyBackup) {
+        self.keyBackup = keyBackup
+        self.registerKeyBackupVersionDidChangeStateNotification()
+    }
+
+    private func registerKeyBackupVersionDidChangeStateNotification() {
+        NotificationCenter.default.addObserver(self, selector: #selector(keyBackupDidStateChange), name: NSNotification.Name.mxKeyBackupDidStateChange, object: self.keyBackup)
+    }
+
+    @objc private func keyBackupDidStateChange() {
+        self.checkKeyBackupState()
+    }
+
+    func process(viewAction: SettingsKeyBackupViewAction) {
+        guard let viewDelegate = self.viewDelegate else {
+            return
+        }
+
+        switch viewAction {
+        case .load:
+            self.viewDelegate?.settingsKeyBackupViewModel(self, didUpdateViewState: .checkingBackup)
+            self.checkKeyBackupState()
+        case .create:
+            viewDelegate.settingsKeyBackupViewModelShowKeyBackupSetup(self)
+            break
+        case .verify(let deviceId):
+            viewDelegate.settingsKeyBackup(self, showVerifyDevice: deviceId)
+            break
+        case .restore(let keyBackupVersion):
+            viewDelegate.settingsKeyBackup(self, showKeyBackupRecover: keyBackupVersion)
+            break
+        case .delete(let keyBackupVersion):
+            self.deleteKeyBackupVersion(keyBackupVersion)
+            break
+        }
+    }
+
+    // MARK: - Private
+
+    func checkKeyBackupState() {
+
+        if let keyBackupVersion = self.keyBackup.keyBackupVersion {
+
+            self.keyBackup.trust(for: keyBackupVersion, onComplete: { [weak self] (keyBackupVersionTrust) in
+
+                guard let sself = self else {
+                    return
+                }
+
+                sself.computeState(withBackupVersionTrust:keyBackupVersionTrust)
+            })
+        }
+        else {
+            computeState()
+        }
+    }
+
+    func computeState(withBackupVersionTrust keyBackupVersionTrust:MXKeyBackupVersionTrust? = nil) {
+
+        var viewState: SettingsKeyBackupViewState?
+        switch self.keyBackup.state {
+
+        case MXKeyBackupStateUnknown,
+             MXKeyBackupStateCheckingBackUpOnHomeserver:
+            viewState = .checkingBackup
+
+        case MXKeyBackupStateDisabled, MXKeyBackupStateEnabling:
+            viewState = .noBackup
+
+        case MXKeyBackupStateNotTrusted:
+            guard let keyBackupVersion = self.keyBackup.keyBackupVersion, let keyBackupVersionTrust = keyBackupVersionTrust else {
+                return
+            }
+            viewState = .backupButNotTrusted(keyBackupVersion, keyBackupVersionTrust)
+
+        case MXKeyBackupStateReadyToBackUp:
+            guard let keyBackupVersion = self.keyBackup.keyBackupVersion, let keyBackupVersionTrust = keyBackupVersionTrust else {
+                return
+            }
+            viewState = .backup(keyBackupVersion, keyBackupVersionTrust)
+
+        case MXKeyBackupStateWillBackUp, MXKeyBackupStateBackingUp:
+            guard let keyBackupVersion = self.keyBackup.keyBackupVersion, let keyBackupVersionTrust = keyBackupVersionTrust else {
+                return
+            }
+
+            // Get the backup progress before updating the state
+            self.keyBackup.backupProgress { [weak self] (progress) in
+                guard let sself = self else {
+                    return
+                }
+
+                sself.viewDelegate?.settingsKeyBackupViewModel(sself, didUpdateViewState: .backupAndRunning(keyBackupVersion, keyBackupVersionTrust, progress))
+            }
+        default:
+            break
+        }
+
+        if let vviewState = viewState {
+            self.viewDelegate?.settingsKeyBackupViewModel(self, didUpdateViewState: vviewState)
+        }
+    }
+
+    func deleteKeyBackupVersion(_ keyBackupVersion: MXKeyBackupVersion) {
+        guard let keyBackupVersionVersion = keyBackupVersion.version  else {
+            return
+        }
+
+        self.keyBackup.deleteVersion(keyBackupVersionVersion, success: {
+
+        }) { (Error) in
+
+        }
+
+    }
+}