TouchIDAuthenticationObject.swift

//
//  TouchIDAuthenticationObject.swift
//
//  Created by Kalpesh Talkar on 03/06/16.
//  Copyright © 2016 Kalpesh. All rights reserved.
//

import UIKit
import LocalAuthentication

class TouchIDAuthenticationObject: NSObject {
    
    let context = LAContext()
    var error: NSError?
    
    func authenticateWithReason(reason: String, completion:(success: Bool, error: NSError?, laerror: LAError?) -> Void) {
        if context.canEvaluatePolicy(LAPolicy.DeviceOwnerAuthenticationWithBiometrics, error:&error) {
            context.evaluatePolicy(LAPolicy.DeviceOwnerAuthenticationWithBiometrics, localizedReason: reason, reply: { (success, error) in
                if success {
                    completion(success: success, error: error, laerror: nil)
                } else {
                    switch error!.code {
                    case LAError.AuthenticationFailed.rawValue:
                        // authentication failed
                        completion(success: success, error: error, laerror: LAError.AuthenticationFailed)
                    case LAError.UserCancel.rawValue:
                        // user canceled authentication
                        completion(success: success, error: error, laerror: LAError.UserCancel)
                    case LAError.SystemCancel.rawValue:
                        // system canceled authentication
                        completion(success: success, error: error, laerror: LAError.SystemCancel)
                    case LAError.PasscodeNotSet.rawValue:
                        // passcode not set
                        completion(success: success, error: error, laerror: LAError.PasscodeNotSet)
                    case LAError.UserFallback.rawValue:
                        // user chose password
                        completion(success: success, error: error, laerror: LAError.UserFallback)
                    default:
                        // unable to authenticate user
                        completion(success: success, error: error, laerror: nil)
                    }
                }
            })
        } else {
            switch error!.code {
            case LAError.TouchIDNotAvailable.rawValue:
                // Touch ID not available on device
                completion(success: false, error: error, laerror: LAError.TouchIDNotAvailable)
            case LAError.TouchIDNotEnrolled.rawValue:
                // Touch ID is not enrolled yet"
                completion(success: false, error: error, laerror: LAError.TouchIDNotEnrolled)
            case LAError.PasscodeNotSet.rawValue:
                // Passcode not set
                completion(success: false, error: error, laerror: LAError.PasscodeNotSet)
            default:
                // Local authentication not available
                completion(success: false, error: error, laerror: nil)
            }
        }
    }
}