Implement biometrics module

Riot/Modules/SetPinCode/SetupBiometrics/SetupBiometricsViewModel.swift

@@ -0,0 +1,135 @@
+// File created from ScreenTemplate
+// $ createScreen.sh SetPinCode/SetupBiometrics SetupBiometrics
+/*
+ Copyright 2020 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 LocalAuthentication
+
+final class SetupBiometricsViewModel: SetupBiometricsViewModelType {
+    
+    // MARK: - Properties
+    
+    // MARK: Private
+
+    private let session: MXSession?
+    private let viewMode: SetPinCoordinatorViewMode
+    private let pinCodePreferences: PinCodePreferences
+    
+    // MARK: Public
+
+    weak var viewDelegate: SetupBiometricsViewModelViewDelegate?
+    weak var coordinatorDelegate: SetupBiometricsViewModelCoordinatorDelegate?
+    
+    // MARK: - Setup
+    
+    init(session: MXSession?, viewMode: SetPinCoordinatorViewMode, pinCodePreferences: PinCodePreferences) {
+        self.session = session
+        self.viewMode = viewMode
+        self.pinCodePreferences = pinCodePreferences
+    }
+    
+    deinit {
+        
+    }
+    
+    // MARK: - Public
+    
+    func localizedBiometricsName() -> String? {
+        return pinCodePreferences.localizedBiometricsName()
+    }
+    
+    func biometricsIcon() -> UIImage? {
+        return pinCodePreferences.biometricsIcon()
+    }
+    
+    func process(viewAction: SetupBiometricsViewAction) {
+        switch viewAction {
+        case .loadData:
+            loadData()
+        case .enableDisableTapped:
+            enableDisableBiometrics()
+        case .skipOrCancel:
+            coordinatorDelegate?.setupBiometricsViewModelDidCancel(self)
+        case .unlock:
+            unlockWithBiometrics()
+        case .cantUnlockedAlertResetAction:
+            coordinatorDelegate?.setupBiometricsViewModelDidCompleteWithReset(self)
+        }
+    }
+    
+    // MARK: - Private
+    
+    private func enableDisableBiometrics() {
+        LAContext().evaluatePolicy(.deviceOwnerAuthentication, localizedReason: VectorL10n.biometricsUsageReason) { (success, error) in
+            if success {
+                //  complete after a little delay
+                DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
+                    self.coordinatorDelegate?.setupBiometricsViewModelDidComplete(self)
+                }
+            }
+        }
+    }
+    
+    private func unlockWithBiometrics() {
+        LAContext().evaluatePolicy(.deviceOwnerAuthentication, localizedReason: VectorL10n.biometricsUsageReason) { (success, error) in
+            if success {
+                //  complete after a little delay
+                DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
+                    self.coordinatorDelegate?.setupBiometricsViewModelDidComplete(self)
+                }
+            } else {
+                if let error = error as NSError?, error.code == LAError.Code.userCancel.rawValue || error.code == LAError.Code.userFallback.rawValue {
+                    self.userCancelledUnlockWithBiometrics()
+                }
+            }
+        }
+    }
+    
+    private func userCancelledUnlockWithBiometrics() {
+        if pinCodePreferences.isPinSet {
+            //  cascade this cancellation, coordinator should take care of it
+            DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
+                self.coordinatorDelegate?.setupBiometricsViewModelDidCancel(self)
+            }
+        } else {
+            //  show an alert to nowhere to go from here
+            DispatchQueue.main.async {
+                self.update(viewState: .cantUnlocked)
+            }
+        }
+    }
+    
+    private func loadData() {
+        switch viewMode {
+        case .setupBiometricsAfterLogin:
+            self.update(viewState: .setupAfterLogin)
+        case .setupBiometricsFromSettings:
+            self.update(viewState: .setupFromSettings)
+        case .unlock:
+            self.update(viewState: .unlock)
+        case .confirmBiometricsToDeactivate:
+            self.update(viewState: .confirmToDisable)
+        default:
+            break
+        }
+    }
+    
+    private func update(viewState: SetupBiometricsViewState) {
+        self.viewDelegate?.setupBiometricsViewModel(self, didUpdateViewState: viewState)
+    }
+    
+}