BLEPeripheral.swift

//
//  BLEPeripheral.swift
//  BLEPeripheral
//
//  Created by ooba on 26/07/2017.
//  Copyright © 2017 mercari. All rights reserved.
//

import Foundation
import CoreBluetooth

class BLEPeripheral: NSObject {
    
    var peripheralManager: CBPeripheralManager?
    
    let serviceUUID = CBUUID(string: "00001523-1212-EFDE-1523-785FEABCD123")
    let characteristicUUID = CBUUID(string: "00001524-1212-EFDE-1523-785FEABCD123")
    
    var characteristic: CBMutableCharacteristic?
    
    override init() {
        super.init()
        peripheralManager = CBPeripheralManager(delegate: self, queue: nil)
    }
    
    func startAdvertising() {
        let advertisementData: [String : Any] = [
            CBAdvertisementDataLocalNameKey: "BLE Peripheral",
            CBAdvertisementDataServiceUUIDsKey: [serviceUUID],
            ]
        peripheralManager?.startAdvertising(advertisementData)
    }
    
    func stopAdvertising() {
        peripheralManager?.stopAdvertising()
    }
    
    func addService() {
        peripheralManager?.removeAllServices()
        
        let service = CBMutableService(type: serviceUUID, primary: true)
        
        let characteristic = CBMutableCharacteristic(type: characteristicUUID, properties: [.read, .write, .notify], value: nil, permissions: [.readable, .writeable])
        
        service.characteristics = [characteristic]
        
        peripheralManager?.add(service)

        characteristic.value = "ABC".data(using: .utf8)
        self.characteristic = characteristic
    }
    
    func updateValue(string: String) {
        guard let characteristic = characteristic else { return }
        guard let data = string.data(using: .utf8) else { return }
        
        characteristic.value = data
        peripheralManager?.updateValue(data, for: characteristic, onSubscribedCentrals: nil)
    }
}

extension BLEPeripheral: CBPeripheralManagerDelegate {
    
    func peripheralManagerDidUpdateState(_ peripheral: CBPeripheralManager) {
        switch peripheral.state {
        case .poweredOn:
            print("poweredOn")
            addService()
        case .poweredOff:
            print("poweredOff")
        case .resetting:
            print("resetting")
        case .unsupported:
            print("unsupported")
        case .unauthorized:
            print("unauthorized")
        case .unknown:
            print("unknown")
        }
    }
    
    func peripheralManagerDidStartAdvertising(_ peripheral: CBPeripheralManager, error: Error?) {
        print("didStartAdvertising:", error ?? "success")
    }
    
    func peripheralManager(_ peripheral: CBPeripheralManager, didAdd service: CBService, error: Error?) {
        print("didAdd:", service, error ?? "success")
    }
    
    func peripheralManager(_ peripheral: CBPeripheralManager, didReceiveRead request: CBATTRequest) {
        print("didReceiveRead:", request)
        
        if let characteristic = characteristic, request.characteristic.uuid == characteristic.uuid {
            request.value = characteristic.value
            peripheralManager?.respond(to: request, withResult: .success)
        } else {
            peripheralManager?.respond(to: request, withResult: .requestNotSupported)
        }
    }
    
    func peripheralManager(_ peripheral: CBPeripheralManager, didReceiveWrite requests: [CBATTRequest]) {
        print("didReceiveWrite:", requests)
        
        guard let firstRequest = requests.first else {
            fatalError()
        }
        
        for request in requests {
            if let characteristic = characteristic, request.characteristic.uuid == characteristic.uuid {
                characteristic.value = request.value
            } else {
                peripheralManager?.respond(to: firstRequest, withResult: .requestNotSupported)
                return
            }
        }
        
        peripheralManager?.respond(to: firstRequest, withResult: .success)
    }
    
    func peripheralManager(_ peripheral: CBPeripheralManager, central: CBCentral, didSubscribeTo characteristic: CBCharacteristic) {
        print("didSubscribeTo:", central, characteristic)
    }
    
    func peripheralManager(_ peripheral: CBPeripheralManager, central: CBCentral, didUnsubscribeFrom characteristic: CBCharacteristic) {
        print("didUnsubscribeFrom:", central, characteristic)
    }
}