Signal-iOS/Signal/src/ViewControllers/Registration/OnboardingController.swift

//
//  Copyright (c) 2021 Open Whisper Systems. All rights reserved.
//

import UIKit

@objc
public class OnboardingCountryState: NSObject {
    public let countryName: String
    public let callingCode: String
    public let countryCode: String

    @objc
    public init(countryName: String,
                callingCode: String,
                countryCode: String) {
        self.countryName = countryName
        self.callingCode = callingCode
        self.countryCode = countryCode
    }

    public static var defaultValue: OnboardingCountryState {
        AssertIsOnMainThread()

        var countryCode: String = PhoneNumber.defaultCountryCode()
        if let lastRegisteredCountryCode = OnboardingController.lastRegisteredCountryCode(),
            lastRegisteredCountryCode.count > 0 {
            countryCode = lastRegisteredCountryCode
        }

        let callingCodeNumber: NSNumber = phoneNumberUtil.getCountryCode(forRegion: countryCode)
        let callingCode = "\(COUNTRY_CODE_PREFIX)\(callingCodeNumber)"

        var countryName = NSLocalizedString("UNKNOWN_COUNTRY_NAME", comment: "Label for unknown countries.")
        if let countryNameDerived = PhoneNumberUtil.countryName(fromCountryCode: countryCode) {
            countryName = countryNameDerived
        }

        return OnboardingCountryState(countryName: countryName, callingCode: callingCode, countryCode: countryCode)
    }
}

// MARK: -

@objc
public class OnboardingPhoneNumber: NSObject {
    public let e164: String
    public let userInput: String

    @objc
    public init(e164: String,
                userInput: String) {
        self.e164 = e164
        self.userInput = userInput
    }
}

// MARK: -

@objc
public class OnboardingNavigationController: OWSNavigationController {
    let onboardingController: OnboardingController

    @objc
    public init(onboardingController: OnboardingController) {
        self.onboardingController = onboardingController
        super.init()
        if let nextMilestone = onboardingController.nextMilestone {
            setViewControllers([onboardingController.nextViewController(milestone: nextMilestone)], animated: false)
        }
    }

    public override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
        let superOrientations = super.supportedInterfaceOrientations
        let onboardingOrientations: UIInterfaceOrientationMask = UIDevice.current.isIPad ? .all : .portrait

        return superOrientations.intersection(onboardingOrientations)
    }
}

@objc
public class OnboardingController: NSObject {

    public enum OnboardingMode {
        case provisioning
        case registering
    }

    public static let defaultOnboardingMode: OnboardingMode = UIDevice.current.isIPad ? .provisioning : .registering
    public var onboardingMode: OnboardingMode
    public var isOnboardingModeOverriden: Bool {
        return onboardingMode != OnboardingController.defaultOnboardingMode
    }

    public class func ascertainOnboardingMode() -> OnboardingMode {
        if tsAccountManager.isRegisteredPrimaryDevice {
            return .registering
        } else if tsAccountManager.isRegistered {
            return .provisioning
        } else {
            return defaultOnboardingMode
        }
    }

    convenience override init() {
        let onboardingMode = OnboardingController.ascertainOnboardingMode()
        self.init(onboardingMode: onboardingMode)
    }

    init(onboardingMode: OnboardingMode) {
        self.onboardingMode = onboardingMode
        super.init()
        Logger.info("onboardingMode: \(onboardingMode), requiredMilestones: \(requiredMilestones), completedMilestones: \(completedMilestones), nextMilestone: \(nextMilestone as Optional)")
    }

    // MARK: -

    enum OnboardingMilestone {
        case verifiedPhoneNumber
        case verifiedLinkedDevice
        case restorePin
        case phoneNumberDiscoverability
        case setupProfile
        case setupPin
    }

    var requiredMilestones: [OnboardingMilestone] {
        switch onboardingMode {
        case .provisioning:
            return [.verifiedLinkedDevice]
        case .registering:
            var milestones: [OnboardingMilestone] = [.verifiedPhoneNumber, .phoneNumberDiscoverability, .setupProfile]

            let hasPendingPinRestoration = databaseStorage.read {
                KeyBackupService.hasPendingRestoration(transaction: $0)
            }

            if hasPendingPinRestoration {
                milestones.insert(.restorePin, at: 0)
            }

            if FeatureFlags.pinsForNewUsers || hasPendingPinRestoration {
                let hasBackupKeyRequestFailed = databaseStorage.read {
                    KeyBackupService.hasBackupKeyRequestFailed(transaction: $0)
                }

                if hasBackupKeyRequestFailed {
                    Logger.info("skipping setupPin since a previous request failed")
                } else if hasPendingPinRestoration {
                    milestones.insert(.setupPin, at: 1)
                } else {
                    milestones.append(.setupPin)
                }
            }

            return milestones
        }
    }

    @objc
    var isComplete: Bool {
        guard !tsAccountManager.isOnboarded() else {
            Logger.debug("previously completed onboarding")
            return true
        }

        guard nextMilestone != nil else {
            Logger.debug("no remaining milestones")
            return true
        }

        return false
    }

    var nextMilestone: OnboardingMilestone? {
        requiredMilestones.first { !completedMilestones.contains($0) }
    }

    var completedMilestones: [OnboardingMilestone] {
        var milestones: [OnboardingMilestone] = []

        if tsAccountManager.isRegisteredPrimaryDevice {
            milestones.append(.verifiedPhoneNumber)
        } else if tsAccountManager.isRegistered {
            milestones.append(.verifiedLinkedDevice)
        }

        if !FeatureFlags.phoneNumberDiscoverability || tsAccountManager.hasDefinedIsDiscoverableByPhoneNumber() {
            milestones.append(.phoneNumberDiscoverability)
        }

        if profileManager.hasProfileName {
            milestones.append(.setupProfile)
        }

        if KeyBackupService.hasMasterKey {
            milestones.append(.restorePin)
            milestones.append(.setupPin)
        }

        return milestones
    }

    @objc
    public func markAsOnboarded() {
        guard !tsAccountManager.isOnboarded() else { return }
        self.databaseStorage.asyncWrite {
            Logger.info("completed onboarding")
            self.tsAccountManager.setIsOnboarded(true, transaction: $0)
        }
    }

    func showNextMilestone(navigationController: UINavigationController) {
        guard let nextMilestone = nextMilestone else {
            SignalApp.shared().showConversationSplitView()
            markAsOnboarded()
            return
        }

        let viewController = nextViewController(milestone: nextMilestone)

        // *replace* the existing VC's. There's no going back once you've passed a milestone.
        navigationController.setViewControllers([viewController], animated: true)
    }

    fileprivate func nextViewController(milestone: OnboardingMilestone) -> UIViewController {
        Logger.info("milestone: \(milestone)")
        switch milestone {
        case .verifiedPhoneNumber, .verifiedLinkedDevice:
            if SSKPreferences.didDropYdb() {
                return OnboardingDroppedYdbViewController(onboardingController: self)
            } else {
                return OnboardingSplashViewController(onboardingController: self)
            }
        case .setupProfile:
            return OnboardingProfileCreationViewController(onboardingController: self)
        case .restorePin:
            return Onboarding2FAViewController(onboardingController: self, isUsingKBS: true)
        case .setupPin:
            return buildPinSetupViewController()
        case .phoneNumberDiscoverability:
            return OnboardingPhoneNumberDiscoverabilityViewController(onboardingController: self)
        }
    }

    // MARK: - Transitions

    public func onboardingSplashDidComplete(viewController: UIViewController) {
        AssertIsOnMainThread()

        Logger.info("")

        let view = OnboardingPermissionsViewController(onboardingController: self)
        viewController.navigationController?.pushViewController(view, animated: true)
    }

    public func onboardingSplashRequestedModeSwitch(viewController: UIViewController) {
        AssertIsOnMainThread()

        Logger.info("")

        let view = OnboardingModeSwitchConfirmationViewController(onboardingController: self)
        viewController.navigationController?.pushViewController(view, animated: true)
    }

    public func toggleModeSwitch(viewController: UIViewController) {
        AssertIsOnMainThread()

        Logger.info("")

        let wasOverridden = isOnboardingModeOverriden
        switch onboardingMode {
        case .provisioning:
            onboardingMode  = .registering
        case .registering:
            onboardingMode = .provisioning
        }

        if wasOverridden {
            onboardingMode = OnboardingController.defaultOnboardingMode
            viewController.navigationController?.popToRootViewController(animated: true)
        } else {
            let view = OnboardingPermissionsViewController(onboardingController: self)
            viewController.navigationController?.pushViewController(view, animated: true)
        }
    }

    public func onboardingPermissionsWasSkipped(viewController: UIViewController) {
        AssertIsOnMainThread()

        Logger.info("")

        guard let navigationController = viewController.navigationController else {
            owsFailDebug("navigationController was unexpectedly nil")
            return
        }

        pushStartDeviceRegistrationView(onto: navigationController)
    }

    public func onboardingPermissionsDidComplete(viewController: UIViewController) {
        AssertIsOnMainThread()

        Logger.info("")

        guard let navigationController = viewController.navigationController else {
            owsFailDebug("navigationController was unexpectedly nil")
            return
        }

        pushStartDeviceRegistrationView(onto: navigationController)
    }

    func pushStartDeviceRegistrationView(onto navigationController: UINavigationController) {
        AssertIsOnMainThread()

        if onboardingMode == .provisioning {
            let view = OnboardingTransferChoiceViewController(onboardingController: self)
            navigationController.pushViewController(view, animated: true)
        } else {
            let view = OnboardingPhoneNumberViewController(onboardingController: self)
            navigationController.pushViewController(view, animated: true)
        }
    }

    public func requestingVerificationDidSucceed(viewController: UIViewController) {
        AssertIsOnMainThread()

        Logger.info("")

        // TODO: Once notification work is complete, uncomment this.
        // Self.notificationPresenter.cancelIncompleteRegistrationNotification()

        let view = OnboardingVerificationViewController(onboardingController: self)
        viewController.navigationController?.pushViewController(view, animated: true)
    }

    public func onboardingDidRequireCaptcha(viewController: UIViewController) {
        AssertIsOnMainThread()

        Logger.info("")

        guard let navigationController = viewController.navigationController else {
            owsFailDebug("Missing navigationController.")
            return
        }

        // The service could demand CAPTCHA from the "phone number" view or later
        // from the "code verification" view.  The "Captcha" view should always appear
        // immediately after the "phone number" view.
        while navigationController.viewControllers.count > 1 &&
            !(navigationController.topViewController is OnboardingPhoneNumberViewController) {
                navigationController.popViewController(animated: false)
        }

        let view = OnboardingCaptchaViewController(onboardingController: self)
        navigationController.pushViewController(view, animated: true)
    }

    @objc
    public func verificationDidComplete(fromView view: UIViewController) {
        AssertIsOnMainThread()
        Logger.info("")
        guard let navigationController = view.navigationController else {
            owsFailDebug("navigationController was unexpectedly nil")
            return
        }

        // At this point, the user has been prompted for contact access
        // and has valid service credentials.
        // We start the contact fetch/intersection now so that by the time
        // they get to conversation list we can show meaningful contact in
        // the suggested contact bubble.
        contactsManagerImpl.fetchSystemContactsOnceIfAlreadyAuthorized()

        showNextMilestone(navigationController: navigationController)
    }

    public func linkingDidComplete(from viewController: UIViewController) {
        guard let navigationController = viewController.navigationController else {
            owsFailDebug("navigationController was unexpectedly nil")
            return
        }

        showNextMilestone(navigationController: navigationController)
    }

    func buildPinSetupViewController() -> PinSetupViewController {
        return PinSetupViewController.creating { [weak self] pinSetupVC, _ in
            guard let self = self else { return }

            guard let navigationController = pinSetupVC.navigationController else {
                owsFailDebug("navigationController was unexpectedly nil")
                return
            }

            self.showNextMilestone(navigationController: navigationController)
        }
    }

    public func onboardingDidRequire2FAPin(viewController: UIViewController) {
        AssertIsOnMainThread()

        Logger.info("")

        guard let navigationController = viewController.navigationController else {
            owsFailDebug("Missing navigationController")
            return
        }

        guard !(navigationController.topViewController is Onboarding2FAViewController) else {
            // 2fa view is already presented, we don't need to push it again.
            return
        }

        let view = Onboarding2FAViewController(onboardingController: self, isUsingKBS: kbsAuth != nil)
        navigationController.pushViewController(view, animated: true)
    }

    @objc
    public func profileWasSkipped(fromView view: UIViewController) {
        AssertIsOnMainThread()

        Logger.info("")

        showConversationSplitView(view: view)
    }

    @objc
    public func profileDidComplete(fromView view: UIViewController) {
        AssertIsOnMainThread()

        Logger.info("")

        showConversationSplitView(view: view)
    }

    private func showConversationSplitView(view: UIViewController) {
        AssertIsOnMainThread()

        guard let navigationController = view.navigationController else {
            owsFailDebug("Missing navigationController")
            return
        }

        // In production, this view will never be presented in a modal.
        // During testing (debug UI, etc.), it may be a modal.
        let isModal = navigationController.presentingViewController != nil
        if isModal {
            view.dismiss(animated: true, completion: {
                SignalApp.shared().showConversationSplitView()
            })
        } else {
            SignalApp.shared().showConversationSplitView()
        }
    }

    // MARK: - State

    public private(set) var countryState: OnboardingCountryState = .defaultValue

    public private(set) var phoneNumber: OnboardingPhoneNumber?

    public private(set) var captchaToken: String?

    public private(set) var verificationCode: String?

    public private(set) var twoFAPin: String?

    private var kbsAuth: RemoteAttestationAuth?

    public private(set) var verificationRequestCount: UInt = 0

    @objc
    public func update(countryState: OnboardingCountryState) {
        AssertIsOnMainThread()

        self.countryState = countryState
    }

    @objc
    public func update(phoneNumber: OnboardingPhoneNumber) {
        AssertIsOnMainThread()

        self.phoneNumber = phoneNumber
    }

    @objc
    public func update(captchaToken: String) {
        AssertIsOnMainThread()

        self.captchaToken = captchaToken
    }

    @objc
    public func update(verificationCode: String) {
        AssertIsOnMainThread()

        self.verificationCode = verificationCode
    }

    @objc
    public func update(twoFAPin: String) {
        AssertIsOnMainThread()

        self.twoFAPin = twoFAPin
    }

    // MARK: - Debug

    private static let kKeychainService_LastRegistered = "kKeychainService_LastRegistered"
    private static let kKeychainKey_LastRegisteredCountryCode = "kKeychainKey_LastRegisteredCountryCode"
    private static let kKeychainKey_LastRegisteredPhoneNumber = "kKeychainKey_LastRegisteredPhoneNumber"

    private class func debugValue(forKey key: String) -> String? {
        AssertIsOnMainThread()

        guard OWSIsDebugBuild() else {
            return nil
        }

        do {
            let value = try CurrentAppContext().keychainStorage().string(forService: kKeychainService_LastRegistered, key: key)
            return value
        } catch {
            // The value may not be present in the keychain.
            return nil
        }
    }

    private class func setDebugValue(_ value: String, forKey key: String) {
        AssertIsOnMainThread()

        guard OWSIsDebugBuild() else {
            return
        }

        do {
            try CurrentAppContext().keychainStorage().set(string: value, service: kKeychainService_LastRegistered, key: key)
        } catch {
            owsFailDebug("Error: \(error)")
        }
    }

    public class func lastRegisteredCountryCode() -> String? {
        return debugValue(forKey: kKeychainKey_LastRegisteredCountryCode)
    }

    private class func setLastRegisteredCountryCode(value: String) {
        setDebugValue(value, forKey: kKeychainKey_LastRegisteredCountryCode)
    }

    public class func lastRegisteredPhoneNumber() -> String? {
        return debugValue(forKey: kKeychainKey_LastRegisteredPhoneNumber)
    }

    private class func setLastRegisteredPhoneNumber(value: String) {
        setDebugValue(value, forKey: kKeychainKey_LastRegisteredPhoneNumber)
    }

    // MARK: - Registration

    public func presentPhoneNumberConfirmationSheet(from vc: UIViewController, number: String, completion: @escaping (_ didApprove: Bool) -> Void) {
        let titleFormat = NSLocalizedString(
            "REGISTRATION_VIEW_PHONE_NUMBER_CONFIRMATION_ALERT_TITLE_FORMAT",
            comment: "Title for confirmation alert during phone number registration. Embeds {{phone number}}.")
        let message = NSLocalizedString(
            "REGISTRATION_VIEW_PHONE_NUMBER_CONFIRMATION_ALERT_MESSAGE",
            comment: "Message for confirmation alert during phone number registration.")
        let editButtonTitle = NSLocalizedString(
            "REGISTRATION_VIEW_PHONE_NUMBER_CONFIRMATION_EDIT_BUTTON",
            comment: "A button allowing user to cancel registration and edit a phone number")

        let sheet = ActionSheetController(title: String(format: titleFormat, number), message: message)
        sheet.addAction(ActionSheetAction(title: CommonStrings.yesButton, style: .default, handler: { _ in
            completion(true)
        }))
        sheet.addAction(ActionSheetAction(title: editButtonTitle, style: .default, handler: { _ in
            completion(false)
        }))
        vc.present(sheet, animated: true, completion: nil)
    }

    public func requestVerification(
        fromViewController: UIViewController,
        isSMS: Bool,
        completion: ((_ willTransition: Bool, _ error: Error?) -> Void)?) {

        AssertIsOnMainThread()

        guard let phoneNumber = phoneNumber else {
            owsFailDebug("Missing phoneNumber.")
            return
        }

        // We eagerly update this state, regardless of whether or not the
        // registration request succeeds.
        OnboardingController.setLastRegisteredCountryCode(value: countryState.countryCode)
        OnboardingController.setLastRegisteredPhoneNumber(value: phoneNumber.userInput)

        let captchaToken = self.captchaToken
        self.verificationRequestCount += 1

        firstly { () -> Promise<Void> in
            return self.accountManager.requestAccountVerification(recipientId: phoneNumber.e164,
                                                           captchaToken: captchaToken,
                                                           isSMS: isSMS)
        }.done {
            completion?(true, nil)
            self.requestingVerificationDidSucceed(viewController: fromViewController)

        }.catch { error in
            Logger.error("Error: \(error)")

            switch error {
            case let error where error.httpStatusCode == 400:
                completion?(false, error)
                OWSActionSheets.showActionSheet(
                    title: NSLocalizedString("REGISTRATION_ERROR", comment: ""),
                    message: NSLocalizedString("REGISTRATION_NON_VALID_NUMBER", comment: ""))

            case let error where error.httpStatusCode == 413:
                completion?(false, error)
                OWSActionSheets.showActionSheet(
                    title: nil,
                    message: NSLocalizedString("REGISTER_RATE_LIMITING_BODY", comment: "action sheet body"))

            case let error where error.isNetworkFailureOrTimeout:
                completion?(false, error)
                OWSActionSheets.showActionSheet(
                    title: NSLocalizedString("REGISTRATION_ERROR_NETWORK_FAILURE_ALERT_TITLE",
                                             comment: "Alert title for network failure during registration"),
                    message: NSLocalizedString("REGISTRATION_ERROR_NETWORK_FAILURE_ALERT_BODY",
                                               comment: "Alert body for network failure during registration"))

            case AccountServiceClientError.captchaRequired:
                completion?(true, error)
                self.onboardingDidRequireCaptcha(viewController: fromViewController)

            default:
                owsFailDebug("unexpected error: \(error)")
                completion?(false, error)
                OWSActionSheets.showActionSheet(title: error.userErrorDescription,
                                                message: (error as NSError).localizedRecoverySuggestion)
            }
        }
    }

    // MARK: - Transfer

    func transferAccount(fromViewController: UIViewController) {
        AssertIsOnMainThread()

        Logger.info("")

        guard let navigationController = fromViewController.navigationController else {
            owsFailDebug("Missing navigationController")
            return
        }

        guard !(navigationController.topViewController is OnboardingTransferQRCodeViewController) else {
            // qr code view is already presented, we don't need to push it again.
            return
        }

        let view = OnboardingTransferQRCodeViewController(onboardingController: self)
        navigationController.pushViewController(view, animated: true)
    }

    func accountTransferInProgress(fromViewController: UIViewController, progress: Progress) {
        AssertIsOnMainThread()

        Logger.info("")

        guard let navigationController = fromViewController.navigationController else {
            owsFailDebug("Missing navigationController")
            return
        }

        guard !(navigationController.topViewController is OnboardingTransferProgressViewController) else {
            // qr code view is already presented, we don't need to push it again.
            return
        }

        let view = OnboardingTransferProgressViewController(onboardingController: self, progress: progress)
        navigationController.pushViewController(view, animated: true)
    }

    public func presentTransferOptions(viewController: UIViewController) {
        AssertIsOnMainThread()

        Logger.info("")

        guard let navigationController = viewController.navigationController else {
            owsFailDebug("Missing navigationController")
            return
        }

        guard !(navigationController.topViewController is OnboardingTransferChoiceViewController) else {
            // transfer view is already presented, we don't need to push it again.
            return
        }

        let view = OnboardingTransferChoiceViewController(onboardingController: self)
        navigationController.pushViewController(view, animated: true)
    }

    // MARK: - Verification

    public enum VerificationOutcome: Equatable {
        case success
        case invalidVerificationCode
        case invalid2FAPin
        case invalidV2RegistrationLockPin(remainingAttempts: UInt32)
        case exhaustedV2RegistrationLockAttempts
    }

    private var hasPendingRestoration: Bool {
        databaseStorage.read { KeyBackupService.hasPendingRestoration(transaction: $0) }
    }

    public func submitVerification(fromViewController: UIViewController,
                                   checkForAvailableTransfer: Bool = true,
                                   showModal: Bool = true,
                                   completion : @escaping (VerificationOutcome) -> Void) {
        AssertIsOnMainThread()

        // If we have credentials for KBS auth or we're trying to verify
        // after registering, we need to restore our keys from KBS.
        if kbsAuth != nil || hasPendingRestoration {
            guard let twoFAPin = twoFAPin else {
                owsFailDebug("We expected a 2fa attempt, but we don't have a code to try")
                return completion(.invalid2FAPin)
            }

            // Clear all cached values before doing restores during onboarding,
            // they could be stale from previous registrations.
            databaseStorage.write { KeyBackupService.clearKeys(transaction: $0) }

            KeyBackupService.restoreKeys(with: twoFAPin, and: self.kbsAuth).done {
                // If we restored successfully clear out KBS auth, the server will give it
                // to us again if we still need to do KBS operations.
                self.kbsAuth = nil

                if self.hasPendingRestoration {
                    firstly {
                        self.accountManager.performInitialStorageServiceRestore()
                    }.recover { error in
                        Logger.warn("Timed out performing storage service restore: \(error). Ignoring...")
                    }.done {
                        completion(.success)
                    }

                } else {
                    // We've restored our keys, we can now re-run this method to post our registration token
                    // We need to first mark reglock as enabled so we know to include the reglock token in our
                    // registration attempt.
                    self.databaseStorage.write { transaction in
                        self.ows2FAManager.markRegistrationLockV2Enabled(transaction: transaction)
                    }
                    self.submitVerification(fromViewController: fromViewController, completion: completion)
                }
            }.catch { error in
                guard let error = error as? KeyBackupService.KBSError else {
                    owsFailDebug("unexpected response from KBS")
                    return completion(.invalid2FAPin)
                }

                switch error {
                case .assertion:
                    owsFailDebug("unexpected response from KBS")
                    completion(.invalid2FAPin)
                case .invalidPin(let remainingAttempts):
                    Logger.warn("Invalid V2 PIN, \(remainingAttempts) attempt(s) remaining")
                    completion(.invalidV2RegistrationLockPin(remainingAttempts: remainingAttempts))
                case .backupMissing:
                    Logger.error("Invalid V2 PIN, attempts exhausted")
                    // We don't have a backup for this person, it probably
                    // was deleted due to too many failed attempts. They'll
                    // have to retry after the registration lock window expires.
                    completion(.exhaustedV2RegistrationLockAttempts)
                }
            }

            return
        }

        guard let phoneNumber = phoneNumber else {
            owsFailDebug("Missing phoneNumber.")
            return
        }
        guard let verificationCode = verificationCode else {
            completion(.invalidVerificationCode)
            return
        }

        // Ensure the account manager state is up-to-date.
        //
        // TODO: We could skip this in production.
        tsAccountManager.phoneNumberAwaitingVerification = phoneNumber.e164

        let twoFAPin = self.twoFAPin

        let promise = firstly {
            self.accountManager.register(
                verificationCode: verificationCode,
                pin: twoFAPin,
                checkForAvailableTransfer: checkForAvailableTransfer)

        }.then { () -> Promise<Void> in
            // Re-enable 2FA and RegLock with the registered pin, if any
            if let pin = twoFAPin {
                self.databaseStorage.write { transaction in
                    OWS2FAManager.shared.markEnabled(pin: pin, transaction: transaction)
                }
                if OWS2FAManager.shared.mode == .V2 {
                    return OWS2FAManager.shared.enableRegistrationLockV2()
                }
            }
            return Promise.value(())
        }

        if showModal {
            ModalActivityIndicatorViewController.present(fromViewController: fromViewController, canCancel: true) { modal in
                promise.done {
                    modal.dismiss {
                        self.verificationDidComplete(fromView: fromViewController)
                    }
                }.catch { error in
                    modal.dismiss(completion: {
                        Logger.warn("Error: \(error)")

                        self.verificationFailed(
                            fromViewController: fromViewController,
                            error: error as NSError,
                            completion: completion)
                    })
                }
            }
        } else {
            promise.done {
                self.verificationDidComplete(fromView: fromViewController)
            }.catch { error in
                Logger.warn("Error: \(error)")

                self.verificationFailed(
                    fromViewController: fromViewController,
                    error: error as NSError,
                    completion: completion)
            }
        }
    }

    private func verificationFailed(fromViewController: UIViewController,
                                    error: NSError,
                                    completion : @escaping (VerificationOutcome) -> Void) {
        AssertIsOnMainThread()

        if error.domain == OWSSignalServiceKitErrorDomain &&
            error.code == OWSErrorCode.registrationMissing2FAPIN.rawValue {

            Logger.info("Missing 2FA PIN.")

            // If we were provided KBS auth, we'll need to re-register using reg lock v2,
            // store this for that path.
            kbsAuth = error.userInfo[TSRemoteAttestationAuthErrorKey] as? RemoteAttestationAuth

            // Since we were told we need 2fa, clear out any stored KBS keys so we can
            // do a fresh verification.
            SDSDatabaseStorage.shared.write { transaction in
                KeyBackupService.clearKeys(transaction: transaction)
                self.ows2FAManager.markRegistrationLockV2Disabled(transaction: transaction)
            }

            completion(.invalid2FAPin)

            onboardingDidRequire2FAPin(viewController: fromViewController)
        } else if error.domain == OWSSignalServiceKitErrorDomain &&
            error.code == OWSErrorCode.registrationTransferAvailable.rawValue {
            Logger.info("Transfer available")

            presentTransferOptions(viewController: fromViewController)

            completion(.success)
        } else {
            if error.domain == OWSSignalServiceKitErrorDomain &&
                error.code == OWSErrorCode.userError.rawValue {
                completion(.invalidVerificationCode)
            }

            Logger.verbose("error: \(error.domain) \(error.code)")
            OWSActionSheets.showActionSheet(title: NSLocalizedString("REGISTRATION_VERIFICATION_FAILED_TITLE", comment: "Alert view title"),
                                message: error.userErrorDescription,
                                fromViewController: fromViewController)
        }
    }
}

// MARK: -

public extension UIView {
    func addBottomStroke() -> UIView {
        return addBottomStroke(color: Theme.middleGrayColor, strokeWidth: CGHairlineWidth())
    }

    func addBottomStroke(color: UIColor, strokeWidth: CGFloat) -> UIView {
        let strokeView = UIView()
        strokeView.backgroundColor = color
        addSubview(strokeView)
        strokeView.autoSetDimension(.height, toSize: strokeWidth)
        strokeView.autoPinWidthToSuperview()
        strokeView.autoPinEdge(toSuperviewEdge: .bottom)
        return strokeView
    }
}