/*

 Copyright (C) 2017 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 Demonstrates the APIs to request FaceID access from LocalAuthentication.

 */

import Foundation

import LocalAuthentication

class FaceIDAccessProvider: PrivateDataAccessRequestProvider {

    func requestAccess(completionHandler: @escaping (PrivateDataRequestAccessResult) -> Void) {

        let authenticationContext = LAContext()

        let reason = NSLocalizedString("FACE_ID_REASON", comment: "Reset password prompt for FaceID")        

        var authenticationError: NSError?

        if authenticationContext.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &authenticationError) {

            guard authenticationContext.biometryType == .faceID else {

                DispatchQueue.main.async {

                    let result = PrivateDataRequestAccessResult(.unavailable,

                                                                error:nil,

                                                                errorMessageKey: "LOCAL_AUTHENTICATION_REQUIRES_FACE_ID")

                    completionHandler(result)

                }

                return

            }

            authenticationContext.evaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, localizedReason: reason) { success, evaluateError in

                if success {

                    DispatchQueue.main.async {

                        let result = PrivateDataRequestAccessResult(.granted)

                        completionHandler(result)

                    }

                } else {

                    DispatchQueue.main.async {

                        let result = PrivateDataRequestAccessResult(.denied,

                                                                    error: evaluateError as NSError?,

                                                                    errorMessageKey: "LOCAL_AUTHENTICATION_ERROR")

                        completionHandler(result)

                    }

                }

            }

        } else {

            DispatchQueue.main.async {

                let result = PrivateDataRequestAccessResult(.undetermined,

                                                            error: authenticationError,

                                                            errorMessageKey: "LOCAL_AUTHENTICATION_ERROR")

                completionHandler(result)

            }

        }

    }

}