/*

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

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 Demonstrates the APIs to check and request access to Bluetooth information.

 */

import Foundation

import CoreBluetooth

class BluetoothAccessProvider: NSObject {

    lazy var bluetoothManager: CBCentralManager = CBCentralManager(delegate: self, queue: nil)

    var requestAccessCompletionHandler: PrivacyActionRequestAccessHandler?

}

extension BluetoothAccessProvider : PrivateDataAccessProvider {

    var accessLevel: PrivateDataAccessLevel {

        let state = bluetoothManager.state

        return state.accessLevel

    }

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

        requestAccessCompletionHandler = completionHandler

        if accessLevel == .undetermined {

            /*

             The user is presented with a consent dialog when the application requests to start

             scanning for bluetooth devices. The delegate is only called once after starting a scan.

             */

            bluetoothManager.scanForPeripherals(withServices: nil, options: nil)

        }

        else {

            dispatchAccessResult(PrivateDataRequestAccessResult(self.accessLevel))

        }

    }

    private func dispatchAccessResult(_ accessResult: PrivateDataRequestAccessResult) {

        DispatchQueue.main.async {

            if let completionHandler = self.requestAccessCompletionHandler {

                completionHandler(accessResult)

                // Breaks reference cycle so this object can deinit.

                self.requestAccessCompletionHandler = nil

            }

        }

    }

}

extension BluetoothAccessProvider : CBCentralManagerDelegate {

    func centralManagerDidUpdateState(_ central: CBCentralManager) {

        /*

         The delegate method will be called when the permission status changes

         the application should then attempt to handle the change appropriately

         by changing UI or setting up or tearing down data structures.

         */

        dispatchAccessResult(PrivateDataRequestAccessResult(self.accessLevel))

    }

}

extension CBManagerState: PrivateDataAccessLevelConvertible {

    var accessLevel: PrivateDataAccessLevel {

        switch self {

        case .unknown:

            return .undetermined

        case .unauthorized:

            return .denied

       default:

            return .granted

        }

    }

}