import UIKit

import LocalAuthentication

//指纹识别必须用真机测试,并且在iOS8以上系统，如果是FaceID至少IOS11以上.

class AuthenticationTool: NSObject {

    let lc = LAContext()

    func hasTouchID() -> Bool{

        if NSFoundationVersionNumber < NSFoundationVersionNumber_iOS_8_0 {

            return false

        }

        /*

         在这里简单介绍一下LAPolicy,它是一个枚举.我们根据自己的需要选择LAPolicy，它提供两个值:

         LAPolicyDeviceOwnerAuthenticationWithBiometrics和LAPolicyDeviceOwnerAuthentication.

         LAPolicyDeviceOwnerAuthenticationWithBiometrics是支持iOS8以上系统,使用该设备的TouchID进行验证,当输入TouchID验证5次失败后,TouchID被锁定,只能通过锁屏后解锁设备时输入正确的解锁密码来解锁TouchID。

         LAPolicyDeviceOwnerAuthentication是支持iOS9以上系统,使用该设备的TouchID或设备密码进行验证，当输入TouchID验证5次失败后，TouchID被锁定，会触发设备密码页面进行验证。

         */

        lc.localizedFallbackTitle = "请输入密码"

        var error:NSError!

        if lc.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error) {

            return false

        }

        return true

    }

    typealias TouchIDBlock = (_ result:Dictionary<String, String>) -> Void

    var tblock:TouchIDBlock?

    func authenticationTouchID(block:@escaping TouchIDBlock){

        tblock = block

        if hasTouchID() {

            /*context.evaluatedPolicyDomainState用于判断设备上的指纹是否被更改，

             在LAContext被创建的时候，evaluatedPolicyDomainState才生效，

             可在TouchID验证成功时，将它记录下来，用于下次使用TouchID时校验，提高安全性。

             */

            //IOS11之后如果支持faceId也是走同样的逻辑，faceId和TouchId只能选一个

            if #available(iOS 9.0, *) {

                lc.evaluatePolicy(.deviceOwnerAuthentication, localizedReason: "通过验证支持touchID") { (sucess, error) in

                    if sucess{

                        if let block = self.tblock {

                            block(["reason":"sucess"])

                        }

                    }else{

                        if let erro =  error as NSError?{

                            var reason = ""

                            if #available(iOS 11.0, *){

                                switch erro.code {

                                case LAError.biometryNotEnrolled.rawValue:

                                    reason = "TouchID 无法启动,因为用户没有设置TouchID"

                                default:

                                    reason = "未知原因"

                                }

                            }else{

                                switch erro.code {

                                case LAError.appCancel.rawValue:

                                    reason = "当前软件被挂起并取消了授权 (如App进入了后台等)"

                                case LAError.invalidContext.rawValue:

                                    reason = "当前软件被挂起并取消了授权 (LAContext对象无效)"

                                case LAError.touchIDLockout.rawValue:

                                    reason = "TouchID 被锁定(连续多次验证TouchID失败,系统需要用户手动输入密码"

                                default:

                                    reason = "未知原因"

                                }

                            }

                            block(["reason":reason])

                        }

                    }

                }

            } else {

                lc.evaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, localizedReason: "通过验证支持touchID") { (sucess, erro) in

                    if sucess{

                        if let block = self.tblock {

                            block(["reason":"sucess"])

                        }

                    }else{

                        if let erro =  erro as NSError?{

                            var reason = ""

                            // Fallback on earlier versions

                            switch erro.code {

                            case LAError.authenticationFailed.rawValue:

                                reason = "TouchID 验证失败"

                            case LAError.passcodeNotSet.rawValue:

                                reason = "TouchID 无法启动,因为用户没有设置密码"

                            case LAError.systemCancel.rawValue:

                                reason = "TouchID 被系统取消 (如遇到来电,锁屏,按了Home键等)"

                            case LAError.touchIDNotAvailable.rawValue:

                                reason = "TouchID 无效"

                            case LAError.userCancel.rawValue:

                                reason = "TouchID 被用户手动取消"

                            case LAError.userFallback.rawValue:

                                reason = "用户不使用TouchID,选择手动输入密码"

                            default:

                                reason = "未知原因"

                            }

                            block(["reason":reason])

                        }

                    }

                }

            }

            if let block = tblock {

                block(["reason":"nonsupport"])

            }

        }

    }

}