【Swift UI】Bluejay(Bluetoothライブラリ)の使い方！

github "steamclock/bluejay" ~> 0.8
github "DaveWoodCom/XCGLogger" ~> 6.1.0

PodFile
pod 'Bluejay', '~> 0.8'

Privacy - Bluetooth Always Usage Description

let service = ServiceIdentifier(uuid: "00000000-0000-1111-1111-111111111111")
let readCharacteristic = CharacteristicIdentifier(uuid: "00000000-1111-1111-1111-111111111111", service: service)
let writeCharacteristic = CharacteristicIdentifier(uuid: "00000000-2222-1111-1111-111111111111", service: service)

BluejayManager.swift
class BluejayManager: ObservableObject {

    /// シングルトン
    static var shared = BluejayManager()

    /// ログ出力用
    @Published  var log = ""
    
    /// bluejayインスタンス
    public var bluejay = Bluejay()
    
    /// スキャン時に発見したペリフェラル一覧
    private var discoveries: [ScanDiscovery] = []
    
    init() {
        config()
    }

    /// 初期設定
    private func config() {
        self.bluejay.register(logObserver: self)
        bluejay.registerDisconnectHandler(handler: self)
        bluejay.register(connectionObserver: self)
        bluejay.register(serviceObserver: self)
        self.bluejay.start()
    }
}

BluejayManager.swift
extension BluejayManager: LogObserver, ConnectionObserver, ServiceObserver, DisconnectHandler {
    
    func didDisconnect(from peripheral: PeripheralIdentifier, with error: Error?, willReconnect autoReconnect: Bool) -> AutoReconnectMode {
        AutoReconnectMode.noChange
    }
    
    func didModifyServices(from peripheral: PeripheralIdentifier, invalidatedServices: [ServiceIdentifier]) { }
    
    func bluetoothAvailable(_ available: Bool) { }
    
    func connected(to peripheral: PeripheralIdentifier) { }

    func disconnected(from peripheral: PeripheralIdentifier) { }
    
    func debug(_ text: String) { }
}

bluejay.scan(
    serviceIdentifiers: [service], // 検索したいサービス一覧
    discovery: { (discovery, discoveries) -> ScanAction in
        // ScanDiscovery型でペリフェラル情報を取得
        return .continue
    },
    stopped: { (discoveries, error) in
        // エラー発生時
    }
)

public enum ScanAction {
    case `continue`
    case blacklist
    case stop
    case connect(ScanDiscovery, (ConnectionResult) -> Void)
}

BluejayManager.swift
public func startScan() {
    log.append("スキャン開始\n")
    
    bluejay.scan(
        serviceIdentifiers: [service],
        discovery: { [weak self] (discovery, discoveries) -> ScanAction in
            guard let self = self else { return .stop }
            
            if discoveries.count != 0 {
                self.log.append("発見: \(discoveries.count)個\n")
                self.discoveries = discoveries
                return .connect(discoveries.first!, .none, .default) { result in
                    switch result {
                    case .success:
                        self.log.append("コネクト成功: \n")
                    case .failure(let error):
                        self.log.append("コネクト失敗エラー: \(error.localizedDescription)\n")
                    }
                }
            } else {
                self.log.append("見つかりませんでした\n")
                return .continue
            }
            
        },
        stopped: { [weak self]  (discoveries, error) in
            guard let self = self else { return }
            if let error = error {
                self.log.append("スキャン停止エラー: \(error.localizedDescription)\n")
            } else {
                self.log.append("スキャン停止\n")
            }
        })
}

BluejayManager.swift
/// コネクト
public func connect() {
    log.append("コネクト\n")
    guard let peripheral = discoveries.first else {
        log.append("サービスなし\n")
        return
    }
    bluejay.connect(peripheral.peripheralIdentifier, timeout: .seconds(15)) { result in
        switch result {
        case .success:
            self.log.append("コネクト成功: \(peripheral.peripheralIdentifier)\n")
        case .failure(let error):
            self.log.append("コネクト失敗エラー: \(error.localizedDescription)\n")
        }
    }
}

BluejayManager.swift
/// Read処理
public func read() {
    bluejay.read(from: readCharacteristic) { [weak self] (result: ReadResult<UInt8>) in
        guard let self = self else { return }
        switch result {
        case .success(let location):
            self.log.append("Read成功: \(location)\n")
        case .failure(let error):
            self.log.append("Read失敗: \(error.localizedDescription)\n")
        }
    }
}

BluejayManager.swift
/// Write処理
public func registerData() {
    bluejay.write(to: writeCharacteristic, value: "Hello") { [weak self] (result: WriteResult) in
        guard let self = self else { return }
        switch result {
        case .success:
            self.log.append("Write成功: \n")
        case .failure(let error):
            self.log.append("Write失敗: \(error.localizedDescription)\n")
        }
    }
}

BluejayManager.swift
 /// 切断
public func disconnect() {
    if bluejay.isConnected {
        log.append("切断\n")
        /// 切断(キューの終了を待って)
        bluejay.disconnect()
        /// 即時切断(キューの終了を待たずに)
        // bluejay.disconnect(immediate: true)
    }
}

BluejayManager.swift
/// リセット
public func cancelEverything() {
    log.append("リセット\n")
    /// キューをリセット
    bluejay.cancelEverything()
}

BluejayManager.swift
/// 次節の「Core Bluetoothから移行する」のために保持
private var cbPeripheral: CBPeripheral?
private var cbCentralManager: CBCentralManager!

/// CoreBluetoothへの移行
public func stopAndExtractBluetoothState() {
    log.append("移行\n")
    // 定義：public func stopAndExtractBluetoothState() -> (manager: CBCentralManager, peripheral: CBPeripheral?) {}
    let status = bluejay.stopAndExtractBluetoothState()
    cbCentralManager = status.manager
    if let peripheral = status.peripheral {
        cbPeripheral = peripheral
    }
}

BluejayManager.swift

/// 移行後に再スタート
public func reStart() {
    guard let cbPeripheral = self.cbPeripheral else {
        return
    }
    log.append("再スタート\n")
    bluejay.start(mode: .use(manager: cbCentralManager, peripheral: cbPeripheral))
}