payfrit-beacon-ios/PayfritBeacon/BeaconProvisioner.swift
Luna 1e3e0198b1 refactor: v2 BeaconProvisioner — prevention over recovery
Major cleanup of the BLE provisioning flow:

- Remove frames 3-6 disable steps (no longer overwriting "extra frames")
  Only Frame 1 (device info) and Frame 2 (iBeacon) are configured now.
  Command count drops from 24 to 16.

- Eliminate 5 layers of retry/reconnect/resume logic:
  No more disconnect retry counter (was 5 retries)
  No more resume-from-position after reconnect
  No more characteristic re-discovery attempts
  No more device info read/skip dance
  If connection drops mid-write, fail cleanly — let user retry.

- Prevention approach: verify all 3 required characteristics (FFE1/FFE2/FFE3)
  are confirmed before starting any writes. No mid-write discovery.

- Add POST_AUTH_DELAY (1.5s) to let beacon stabilize after auth before writes.

- Keep response gating (wait for FFE1 after each write) — this is the key
  mechanism that prevents blasting commands faster than the MCU can handle.

- 191 insertions, 476 deletions — nearly half the code removed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-22 03:57:02 +00:00

1309 lines
52 KiB
Swift

import Foundation
import CoreBluetooth
/// Structured provisioning error codes (matches Android's BeaconConfig error codes)
enum ProvisioningError: String, LocalizedError {
case bluetoothUnavailable = "BLUETOOTH_UNAVAILABLE"
case connectionFailed = "CONNECTION_FAILED"
case connectionTimeout = "CONNECTION_TIMEOUT"
case serviceNotFound = "SERVICE_NOT_FOUND"
case authFailed = "AUTH_FAILED"
case writeFailed = "WRITE_FAILED"
case verificationFailed = "VERIFICATION_FAILED"
case disconnected = "DISCONNECTED"
case noConfig = "NO_CONFIG"
case timeout = "TIMEOUT"
case unknown = "UNKNOWN"
var errorDescription: String? {
switch self {
case .bluetoothUnavailable: return "Bluetooth not available"
case .connectionFailed: return "Failed to connect to beacon"
case .connectionTimeout: return "Connection timed out"
case .serviceNotFound: return "Config service not found on device"
case .authFailed: return "Authentication failed - all passwords rejected"
case .writeFailed: return "Failed to write configuration"
case .verificationFailed: return "Beacon not broadcasting expected values"
case .disconnected: return "Unexpected disconnect"
case .noConfig: return "No configuration provided"
case .timeout: return "Operation timed out"
case .unknown: return "Unknown error"
}
}
}
/// Result of a provisioning operation
enum ProvisioningResult {
case success(macAddress: String?)
case failure(String)
case failureWithCode(ProvisioningError, detail: String? = nil)
}
/// Configuration to write to a beacon
struct BeaconConfig {
let uuid: String // 32-char hex, no dashes
let major: UInt16
let minor: UInt16
let measuredPower: Int8 // RSSI@1m (e.g., -59) - from server, NOT hardcoded
let advInterval: UInt8 // Advertising interval raw value (e.g., 2 = 200ms) - from server
let txPower: UInt8 // TX power level - from server
let deviceName: String? // Service point name (max 20 ASCII chars for DX-Smart)
init(uuid: String, major: UInt16, minor: UInt16, measuredPower: Int8, advInterval: UInt8, txPower: UInt8, deviceName: String? = nil) {
self.uuid = uuid
self.major = major
self.minor = minor
self.measuredPower = measuredPower
self.advInterval = advInterval
self.txPower = txPower
self.deviceName = deviceName
}
}
/// Result of reading a beacon's current configuration
struct BeaconCheckResult {
// Parsed DX-Smart iBeacon config
var uuid: String? // iBeacon UUID (formatted with dashes)
var major: UInt16?
var minor: UInt16?
var rssiAt1m: Int8?
var advInterval: UInt16? // Raw value (multiply by 100 for ms)
var txPower: UInt8?
var deviceName: String?
var battery: UInt8?
var macAddress: String?
var frameSlots: [UInt8]?
// Discovery info
var servicesFound: [String] = []
var characteristicsFound: [String] = []
var rawResponses: [String] = [] // Raw response hex for debugging
var hasConfig: Bool {
uuid != nil || major != nil || minor != nil || deviceName != nil
}
}
/// Handles GATT connection and provisioning of beacons
///
/// v2: Prevention over recovery. Instead of layers of retry/reconnect/resume logic,
/// we ensure a solid connection and confirmed characteristics before ever writing.
/// No extra frame overwriting only configure Frame 1 (device info) and Frame 2 (iBeacon).
class BeaconProvisioner: NSObject, ObservableObject {
// MARK: - DX-Smart CP28 GATT Characteristics
private static let DXSMART_SERVICE = CBUUID(string: "0000FFE0-0000-1000-8000-00805F9B34FB")
private static let DXSMART_NOTIFY_CHAR = CBUUID(string: "0000FFE1-0000-1000-8000-00805F9B34FB") // Notifications (RX)
private static let DXSMART_COMMAND_CHAR = CBUUID(string: "0000FFE2-0000-1000-8000-00805F9B34FB") // Commands (TX)
private static let DXSMART_PASSWORD_CHAR = CBUUID(string: "0000FFE3-0000-1000-8000-00805F9B34FB") // Password auth
// DX-Smart packet header
private static let DXSMART_HEADER: [UInt8] = [0x4E, 0x4F]
// DX-Smart connection passwords (tried in order until one works)
private static let DXSMART_PASSWORDS = ["555555", "dx1234", "000000"]
// DX-Smart command codes
private enum DXCmd: UInt8 {
case frameTable = 0x10
case frameSelectSlot0 = 0x11 // Frame 1 (device info)
case frameSelectSlot1 = 0x12 // Frame 2 (iBeacon)
case frameSelectSlot2 = 0x13 // Frame 3
case frameSelectSlot3 = 0x14 // Frame 4
case frameSelectSlot4 = 0x15 // Frame 5
case frameSelectSlot5 = 0x16 // Frame 6
case authCheck = 0x25
case deviceInfo = 0x30
case deviceName = 0x43 // Read device name
case saveConfig = 0x60
case deviceInfoType = 0x61 // Set frame as device info (broadcasts name)
case iBeaconType = 0x62 // Set frame as iBeacon
case deviceNameWrite = 0x71 // Write device name (max 20 ASCII chars)
case uuid = 0x74
case major = 0x75
case minor = 0x76
case rssiAt1m = 0x77
case advInterval = 0x78
case txPower = 0x79
case triggerOff = 0xA0
case frameDisable = 0xFF
}
@Published var state: ProvisioningState = .idle
@Published var progress: String = ""
enum ProvisioningState: Equatable {
case idle
case connecting
case discoveringServices
case authenticating
case writing
case verifying
case success
case failed(String)
}
private var centralManager: CBCentralManager!
private var peripheral: CBPeripheral?
private var beaconType: BeaconType = .unknown
private var config: BeaconConfig?
private var completion: ((ProvisioningResult) -> Void)?
private var configService: CBService?
private var characteristics: [CBUUID: CBCharacteristic] = [:]
private var passwordIndex = 0
// DX-Smart provisioning state
private var dxSmartAuthenticated = false
private var dxSmartNotifySubscribed = false
private var dxSmartCommandQueue: [Data] = []
private var dxSmartWriteIndex = 0
private var provisioningMacAddress: String?
private var isTerminating = false // guards against re-entrant disconnect handling
// Read config mode
private enum OperationMode { case provisioning, readingConfig }
private var operationMode: OperationMode = .provisioning
private var readCompletion: ((BeaconCheckResult?, String?) -> Void)?
private var readResult = BeaconCheckResult()
private var readTimeout: DispatchWorkItem?
// Read config exploration state
private var allDiscoveredServices: [CBService] = []
private var servicesToExplore: [CBService] = []
// DX-Smart read query state
private var dxReadQueries: [Data] = []
private var dxReadQueryIndex = 0
private var responseBuffer: [UInt8] = []
// Connection state
private var connectionRetryCount = 0
private static let MAX_CONNECTION_RETRIES = 2
private var currentBeacon: DiscoveredBeacon?
// Per-write timeout if beacon doesn't ACK within this time, fail cleanly
private var writeTimeoutTimer: DispatchWorkItem?
private static let WRITE_TIMEOUT_SECONDS: Double = 5.0
// Response gating wait for beacon's FFE1 notification after each write
// before sending next command. Matches Android's responseChannel.receive(1000ms).
// This is the KEY prevention mechanism: we never blast commands faster than
// the beacon can process them.
private var awaitingCommandResponse = false
private var responseGateTimer: DispatchWorkItem?
private static let RESPONSE_GATE_TIMEOUT: Double = 1.0
// Inter-command delay gives the beacon MCU breathing room between commands.
// Prevention > recovery: generous delays prevent supervision timeouts.
private static let INTER_COMMAND_DELAY: Double = 0.5
private static let HEAVY_COMMAND_DELAY: Double = 1.0 // After frame select/type changes
private static let POST_AUTH_DELAY: Double = 1.5 // After auth, before first write
// Readiness gate don't start writing until we've confirmed all 3 chars
private var requiredCharsConfirmed = false
override init() {
super.init()
centralManager = CBCentralManager(delegate: self, queue: .main)
}
/// Re-retrieve peripheral from our own CBCentralManager (the one from scanner may not work)
private func resolvePeripheral(_ beacon: DiscoveredBeacon) -> CBPeripheral {
let retrieved = centralManager.retrievePeripherals(withIdentifiers: [beacon.peripheral.identifier])
return retrieved.first ?? beacon.peripheral
}
// MARK: - Provision
/// Provision a beacon with the given configuration
func provision(beacon: DiscoveredBeacon, config: BeaconConfig, completion: @escaping (ProvisioningResult) -> Void) {
guard centralManager.state == .poweredOn else {
completion(.failureWithCode(.bluetoothUnavailable))
return
}
let resolvedPeripheral = resolvePeripheral(beacon)
self.peripheral = resolvedPeripheral
self.beaconType = beacon.type
self.config = config
self.completion = completion
self.operationMode = .provisioning
self.passwordIndex = 0
self.characteristics.removeAll()
self.dxSmartAuthenticated = false
self.dxSmartNotifySubscribed = false
self.dxSmartCommandQueue.removeAll()
self.dxSmartWriteIndex = 0
self.provisioningMacAddress = nil
self.isTerminating = false
self.awaitingCommandResponse = false
self.requiredCharsConfirmed = false
cancelResponseGateTimeout()
self.connectionRetryCount = 0
self.currentBeacon = beacon
state = .connecting
progress = "Connecting to \(beacon.displayName)..."
centralManager.connect(resolvedPeripheral, options: nil)
// Global timeout: 45 seconds if we haven't succeeded by then, something is fundamentally wrong.
// No infinite retry loops. Fail fast, let the user retry.
DispatchQueue.main.asyncAfter(deadline: .now() + 45) { [weak self] in
guard let self = self else { return }
if self.state != .success && self.state != .idle {
if case .failed = self.state { return }
self.fail("Operation timed out after 45s", code: .timeout)
}
}
}
/// Cancel current provisioning
func cancel() {
if let peripheral = peripheral {
centralManager.cancelPeripheralConnection(peripheral)
}
cleanup()
}
// MARK: - Read Config
/// Read the current configuration from a beacon
func readConfig(beacon: DiscoveredBeacon, completion: @escaping (BeaconCheckResult?, String?) -> Void) {
guard centralManager.state == .poweredOn else {
completion(nil, "Bluetooth not available")
return
}
let resolvedPeripheral = resolvePeripheral(beacon)
self.peripheral = resolvedPeripheral
self.beaconType = beacon.type
self.operationMode = .readingConfig
self.readCompletion = completion
self.readResult = BeaconCheckResult()
self.passwordIndex = 0
self.characteristics.removeAll()
self.dxSmartAuthenticated = false
self.dxSmartNotifySubscribed = false
self.responseBuffer.removeAll()
self.dxReadQueries.removeAll()
self.dxReadQueryIndex = 0
self.allDiscoveredServices.removeAll()
self.connectionRetryCount = 0
self.isTerminating = false
self.currentBeacon = beacon
self.servicesToExplore.removeAll()
state = .connecting
progress = "Connecting to \(beacon.displayName)..."
centralManager.connect(resolvedPeripheral, options: nil)
// 15-second timeout for read operations
let timeout = DispatchWorkItem { [weak self] in
guard let self = self, self.operationMode == .readingConfig else { return }
DebugLog.shared.log("BLE: Read timeout reached")
self.finishRead()
}
readTimeout = timeout
DispatchQueue.main.asyncAfter(deadline: .now() + 15, execute: timeout)
}
// MARK: - Cleanup
private func cleanup() {
cancelWriteTimeout()
cancelResponseGateTimeout()
awaitingCommandResponse = false
peripheral = nil
config = nil
completion = nil
configService = nil
characteristics.removeAll()
dxSmartAuthenticated = false
dxSmartNotifySubscribed = false
dxSmartCommandQueue.removeAll()
dxSmartWriteIndex = 0
provisioningMacAddress = nil
isTerminating = false
requiredCharsConfirmed = false
connectionRetryCount = 0
currentBeacon = nil
state = .idle
progress = ""
}
private func fail(_ message: String, code: ProvisioningError? = nil) {
guard !isTerminating else {
DebugLog.shared.log("BLE: fail() called but already terminating, ignoring")
return
}
isTerminating = true
DebugLog.shared.log("BLE: FAIL [\(code?.rawValue ?? "UNTYPED")] - \(message)")
state = .failed(message)
if let peripheral = peripheral, peripheral.state == .connected {
centralManager.cancelPeripheralConnection(peripheral)
}
if let code = code {
completion?(.failureWithCode(code, detail: message))
} else {
completion?(.failure(message))
}
cleanup()
}
private func succeed() {
guard !isTerminating else {
DebugLog.shared.log("BLE: succeed() called but already terminating, ignoring")
return
}
isTerminating = true
DebugLog.shared.log("BLE: SUCCESS! MAC=\(provisioningMacAddress ?? "unknown")")
state = .success
if let peripheral = peripheral, peripheral.state == .connected {
centralManager.cancelPeripheralConnection(peripheral)
}
let mac = provisioningMacAddress
completion?(.success(macAddress: mac))
cleanup()
}
// MARK: - DX-Smart CP28 Provisioning
private func provisionDXSmart() {
guard let service = configService else {
fail("DX-Smart config service not found", code: .serviceNotFound)
return
}
state = .discoveringServices
progress = "Discovering characteristics..."
peripheral?.discoverCharacteristics([
BeaconProvisioner.DXSMART_NOTIFY_CHAR,
BeaconProvisioner.DXSMART_COMMAND_CHAR,
BeaconProvisioner.DXSMART_PASSWORD_CHAR
], for: service)
}
/// Verify all 3 required characteristics are present before proceeding.
/// This is PREVENTION: we confirm readiness upfront instead of discovering
/// missing chars mid-write and trying to recover.
private func verifyCharacteristicsAndProceed() {
let hasFFE1 = characteristics[BeaconProvisioner.DXSMART_NOTIFY_CHAR] != nil
let hasFFE2 = characteristics[BeaconProvisioner.DXSMART_COMMAND_CHAR] != nil
let hasFFE3 = characteristics[BeaconProvisioner.DXSMART_PASSWORD_CHAR] != nil
DebugLog.shared.log("BLE: Char check — FFE1=\(hasFFE1) FFE2=\(hasFFE2) FFE3=\(hasFFE3)")
guard hasFFE2 && hasFFE3 else {
fail("Required characteristics not found (FFE2=\(hasFFE2) FFE3=\(hasFFE3))", code: .serviceNotFound)
return
}
requiredCharsConfirmed = true
// Subscribe to FFE1 notifications first (if available), then authenticate
if hasFFE1 {
DebugLog.shared.log("BLE: Subscribing to FFE1 notifications")
peripheral?.setNotifyValue(true, for: characteristics[BeaconProvisioner.DXSMART_NOTIFY_CHAR]!)
} else {
DebugLog.shared.log("BLE: FFE1 not found, proceeding to auth directly")
dxSmartNotifySubscribed = true
dxSmartAuthenticate()
}
}
/// Write password to FFE3 (tries multiple passwords in sequence)
private func dxSmartAuthenticate() {
guard let passwordChar = characteristics[BeaconProvisioner.DXSMART_PASSWORD_CHAR] else {
fail("FFE3 not found", code: .serviceNotFound)
return
}
guard passwordIndex < BeaconProvisioner.DXSMART_PASSWORDS.count else {
fail("Authentication failed - all passwords rejected", code: .authFailed)
return
}
state = .authenticating
let currentPassword = BeaconProvisioner.DXSMART_PASSWORDS[passwordIndex]
progress = "Authenticating (\(passwordIndex + 1)/\(BeaconProvisioner.DXSMART_PASSWORDS.count))..."
let passwordData = Data(currentPassword.utf8)
DebugLog.shared.log("BLE: Auth attempt \(passwordIndex + 1)/\(BeaconProvisioner.DXSMART_PASSWORDS.count)")
peripheral?.writeValue(passwordData, for: passwordChar, type: .withResponse)
}
/// Called when a password attempt fails tries the next one
private func dxSmartRetryNextPassword() {
passwordIndex += 1
if passwordIndex < BeaconProvisioner.DXSMART_PASSWORDS.count {
DebugLog.shared.log("BLE: Password rejected, trying next")
DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) { [weak self] in
self?.dxSmartAuthenticate()
}
} else {
fail("All \(BeaconProvisioner.DXSMART_PASSWORDS.count) passwords rejected", code: .authFailed)
}
}
/// Build the command queue and start writing.
///
/// v2 command sequence only Frame 1 + Frame 2, no extra frame overwrites:
/// 1. DeviceName 0x71 [name bytes] service point name (max 20 ASCII)
/// 2. Frame1_Select 0x11 select frame 1
/// 3. Frame1_Type 0x61 device info (broadcasts name)
/// 4. Frame1_RSSI 0x77 [measuredPower]
/// 5. Frame1_AdvInt 0x78 [advInterval]
/// 6. Frame1_TxPow 0x79 [txPower]
/// 7. Frame2_Select 0x12 select frame 2
/// 8. Frame2_Type 0x62 iBeacon
/// 9. UUID 0x74 [16 bytes]
/// 10. Major 0x75 [2 bytes BE]
/// 11. Minor 0x76 [2 bytes BE]
/// 12. RSSI@1m 0x77 [measuredPower]
/// 13. AdvInterval 0x78 [advInterval]
/// 14. TxPower 0x79 [txPower]
/// 15. TriggerOff 0xA0
/// 16. SaveConfig 0x60 persist to flash
///
/// Frames 3-6 are left untouched (not disabled/overwritten).
private func dxSmartWriteConfig() {
guard let config = config else {
fail("No config provided", code: .noConfig)
return
}
state = .writing
progress = "Writing configuration..."
dxSmartCommandQueue.removeAll()
dxSmartWriteIndex = 0
let measuredPowerByte = UInt8(bitPattern: config.measuredPower)
// 1. DeviceName (0x71)
if let name = config.deviceName, !name.isEmpty {
let truncatedName = String(name.prefix(20))
let nameBytes = Array(truncatedName.utf8)
dxSmartCommandQueue.append(buildDXPacket(cmd: .deviceNameWrite, data: nameBytes))
}
// --- Frame 1: Device Info ---
dxSmartCommandQueue.append(buildDXPacket(cmd: .frameSelectSlot0, data: [])) // 2. Select frame 1
dxSmartCommandQueue.append(buildDXPacket(cmd: .deviceInfoType, data: [])) // 3. Device info type
dxSmartCommandQueue.append(buildDXPacket(cmd: .rssiAt1m, data: [measuredPowerByte])) // 4. RSSI
dxSmartCommandQueue.append(buildDXPacket(cmd: .advInterval, data: [config.advInterval])) // 5. Adv interval
dxSmartCommandQueue.append(buildDXPacket(cmd: .txPower, data: [config.txPower])) // 6. TX power
// --- Frame 2: iBeacon ---
dxSmartCommandQueue.append(buildDXPacket(cmd: .frameSelectSlot1, data: [])) // 7. Select frame 2
dxSmartCommandQueue.append(buildDXPacket(cmd: .iBeaconType, data: [])) // 8. iBeacon type
// 9. UUID (16 bytes)
if let uuidData = hexStringToData(config.uuid) {
dxSmartCommandQueue.append(buildDXPacket(cmd: .uuid, data: Array(uuidData)))
}
// 10. Major (2 bytes BE)
let majorHi = UInt8((config.major >> 8) & 0xFF)
let majorLo = UInt8(config.major & 0xFF)
dxSmartCommandQueue.append(buildDXPacket(cmd: .major, data: [majorHi, majorLo]))
// 11. Minor (2 bytes BE)
let minorHi = UInt8((config.minor >> 8) & 0xFF)
let minorLo = UInt8(config.minor & 0xFF)
dxSmartCommandQueue.append(buildDXPacket(cmd: .minor, data: [minorHi, minorLo]))
// 12-14. RSSI, AdvInterval, TxPower for frame 2
dxSmartCommandQueue.append(buildDXPacket(cmd: .rssiAt1m, data: [measuredPowerByte]))
dxSmartCommandQueue.append(buildDXPacket(cmd: .advInterval, data: [config.advInterval]))
dxSmartCommandQueue.append(buildDXPacket(cmd: .txPower, data: [config.txPower]))
// 15. TriggerOff
dxSmartCommandQueue.append(buildDXPacket(cmd: .triggerOff, data: []))
// 16. SaveConfig persist to flash
dxSmartCommandQueue.append(buildDXPacket(cmd: .saveConfig, data: []))
DebugLog.shared.log("BLE: Command queue built: \(dxSmartCommandQueue.count) commands (no extra frame overwrites)")
dxSmartSendNextCommand()
}
/// Send the next command in the queue
private func dxSmartSendNextCommand() {
guard dxSmartWriteIndex < dxSmartCommandQueue.count else {
cancelWriteTimeout()
DebugLog.shared.log("BLE: All commands written successfully!")
progress = "Configuration saved!"
succeed()
return
}
guard let commandChar = characteristics[BeaconProvisioner.DXSMART_COMMAND_CHAR] else {
// If FFE2 is gone after we already confirmed it, something went very wrong.
// Don't try to re-discover fail cleanly. Prevention means we don't get here.
fail("FFE2 characteristic lost during write", code: .writeFailed)
return
}
let packet = dxSmartCommandQueue[dxSmartWriteIndex]
let current = dxSmartWriteIndex + 1
let total = dxSmartCommandQueue.count
progress = "Writing config (\(current)/\(total))..."
DebugLog.shared.log("BLE: Write \(current)/\(total): \(packet.map { String(format: "%02X", $0) }.joined(separator: " "))")
scheduleWriteTimeout()
peripheral?.writeValue(packet, for: commandChar, type: .withResponse)
}
/// Per-write timeout fail cleanly if beacon doesn't ACK
private func scheduleWriteTimeout() {
cancelWriteTimeout()
let timer = DispatchWorkItem { [weak self] in
guard let self = self, self.state == .writing else { return }
let current = self.dxSmartWriteIndex + 1
let total = self.dxSmartCommandQueue.count
let isSaveConfig = self.dxSmartWriteIndex >= total - 1
if isSaveConfig {
// SaveConfig may not ACK beacon reboots. That's success.
DebugLog.shared.log("BLE: SaveConfig timeout (beacon rebooted) — success")
self.succeed()
} else {
// Any other command timing out is a real problem
DebugLog.shared.log("BLE: Write timeout at step \(current)/\(total)")
self.fail("Write timeout at step \(current)/\(total)", code: .writeFailed)
}
}
writeTimeoutTimer = timer
DispatchQueue.main.asyncAfter(deadline: .now() + BeaconProvisioner.WRITE_TIMEOUT_SECONDS, execute: timer)
}
private func cancelWriteTimeout() {
writeTimeoutTimer?.cancel()
writeTimeoutTimer = nil
}
/// Calculate delay for the command we just wrote.
/// Frame selection and type commands need extra time (MCU state change).
private func delayForCommand(at index: Int) -> Double {
guard index < dxSmartCommandQueue.count else { return BeaconProvisioner.INTER_COMMAND_DELAY }
let packet = dxSmartCommandQueue[index]
guard packet.count >= 3 else { return BeaconProvisioner.INTER_COMMAND_DELAY }
let cmd = packet[2]
switch DXCmd(rawValue: cmd) {
case .frameSelectSlot0, .frameSelectSlot1,
.deviceInfoType, .iBeaconType:
return BeaconProvisioner.HEAVY_COMMAND_DELAY
case .uuid:
return BeaconProvisioner.HEAVY_COMMAND_DELAY // Large payload
default:
return BeaconProvisioner.INTER_COMMAND_DELAY
}
}
// MARK: - Response Gating
/// After a successful write, wait for FFE1 response then advance.
private func advanceToNextCommand() {
let justWritten = dxSmartWriteIndex
dxSmartWriteIndex += 1
let delay = delayForCommand(at: justWritten)
DispatchQueue.main.asyncAfter(deadline: .now() + delay) { [weak self] in
self?.dxSmartSendNextCommand()
}
}
/// Wait up to 1s for beacon FFE1 response. If none, advance anyway.
private func scheduleResponseGateTimeout() {
cancelResponseGateTimeout()
let timer = DispatchWorkItem { [weak self] in
guard let self = self, self.awaitingCommandResponse else { return }
self.awaitingCommandResponse = false
DebugLog.shared.log("BLE: No FFE1 response within 1s for cmd \(self.dxSmartWriteIndex + 1) — advancing")
self.advanceToNextCommand()
}
responseGateTimer = timer
DispatchQueue.main.asyncAfter(deadline: .now() + BeaconProvisioner.RESPONSE_GATE_TIMEOUT, execute: timer)
}
private func cancelResponseGateTimeout() {
responseGateTimer?.cancel()
responseGateTimer = nil
}
// MARK: - DX-Smart Packet Builder
/// Build a DX-Smart CP28 packet: [4E][4F][CMD][LEN][DATA...][XOR_CHECKSUM]
private func buildDXPacket(cmd: DXCmd, data: [UInt8]) -> Data {
var packet: [UInt8] = []
packet.append(contentsOf: BeaconProvisioner.DXSMART_HEADER) // 4E 4F
packet.append(cmd.rawValue)
packet.append(UInt8(data.count))
packet.append(contentsOf: data)
var checksum: UInt8 = cmd.rawValue ^ UInt8(data.count)
for byte in data {
checksum ^= byte
}
packet.append(checksum)
return Data(packet)
}
// MARK: - Read Config: Service Exploration
private func startReadExplore() {
guard let services = peripheral?.services, !services.isEmpty else {
readFail("No services found on device")
return
}
allDiscoveredServices = services
servicesToExplore = services
state = .discoveringServices
progress = "Exploring \(services.count) services..."
DebugLog.shared.log("BLE: Read mode — found \(services.count) services")
for s in services {
readResult.servicesFound.append(s.uuid.uuidString)
}
exploreNextService()
}
private func exploreNextService() {
guard !servicesToExplore.isEmpty else {
DebugLog.shared.log("BLE: All services explored, starting DX-Smart read")
startDXSmartRead()
return
}
let service = servicesToExplore.removeFirst()
DebugLog.shared.log("BLE: Discovering chars for service \(service.uuid)")
progress = "Exploring \(service.uuid.uuidString.prefix(8))..."
peripheral?.discoverCharacteristics(nil, for: service)
}
// MARK: - Read Config: DX-Smart Protocol
private func startDXSmartRead() {
guard characteristics[BeaconProvisioner.DXSMART_PASSWORD_CHAR] != nil,
characteristics[BeaconProvisioner.DXSMART_COMMAND_CHAR] != nil else {
DebugLog.shared.log("BLE: No FFE0 service — not a DX-Smart beacon")
progress = "No DX-Smart service found"
finishRead()
return
}
if let notifyChar = characteristics[BeaconProvisioner.DXSMART_NOTIFY_CHAR] {
DebugLog.shared.log("BLE: Read mode — subscribing to FFE1")
progress = "Subscribing to notifications..."
peripheral?.setNotifyValue(true, for: notifyChar)
} else {
DebugLog.shared.log("BLE: FFE1 not found, attempting auth without notifications")
dxSmartReadAuth()
}
}
private func dxSmartReadAuth() {
guard let passwordChar = characteristics[BeaconProvisioner.DXSMART_PASSWORD_CHAR] else {
DebugLog.shared.log("BLE: No FFE3 for auth, finishing")
finishRead()
return
}
guard passwordIndex < BeaconProvisioner.DXSMART_PASSWORDS.count else {
DebugLog.shared.log("BLE: All passwords exhausted in read mode")
finishRead()
return
}
state = .authenticating
let currentPassword = BeaconProvisioner.DXSMART_PASSWORDS[passwordIndex]
progress = "Authenticating (\(passwordIndex + 1)/\(BeaconProvisioner.DXSMART_PASSWORDS.count))..."
let passwordData = Data(currentPassword.utf8)
DebugLog.shared.log("BLE: Read mode — auth attempt \(passwordIndex + 1)")
peripheral?.writeValue(passwordData, for: passwordChar, type: .withResponse)
}
private func dxSmartReadQueryAfterAuth() {
dxReadQueries.removeAll()
dxReadQueryIndex = 0
responseBuffer.removeAll()
dxReadQueries.append(buildDXPacket(cmd: .frameTable, data: [])) // Frame table
dxReadQueries.append(buildDXPacket(cmd: .iBeaconType, data: [])) // iBeacon config
dxReadQueries.append(buildDXPacket(cmd: .deviceInfo, data: [])) // Device info
dxReadQueries.append(buildDXPacket(cmd: .deviceName, data: [])) // Device name
DebugLog.shared.log("BLE: Sending \(dxReadQueries.count) read queries")
state = .verifying
progress = "Reading config..."
dxSmartSendNextReadQuery()
}
private func dxSmartSendNextReadQuery() {
guard dxReadQueryIndex < dxReadQueries.count else {
DebugLog.shared.log("BLE: All read queries sent, waiting 2s for responses")
progress = "Collecting responses..."
DispatchQueue.main.asyncAfter(deadline: .now() + 2.0) { [weak self] in
guard let self = self, self.operationMode == .readingConfig else { return }
self.finishRead()
}
return
}
guard let commandChar = characteristics[BeaconProvisioner.DXSMART_COMMAND_CHAR] else {
DebugLog.shared.log("BLE: FFE2 not found, finishing read")
finishRead()
return
}
let packet = dxReadQueries[dxReadQueryIndex]
let current = dxReadQueryIndex + 1
let total = dxReadQueries.count
progress = "Reading \(current)/\(total)..."
DebugLog.shared.log("BLE: Read query \(current)/\(total): \(packet.map { String(format: "%02X", $0) }.joined(separator: " "))")
peripheral?.writeValue(packet, for: commandChar, type: .withResponse)
}
// MARK: - Read Config: Response Parsing
private func processFFE1Response(_ data: Data) {
let hex = data.map { String(format: "%02X", $0) }.joined(separator: " ")
DebugLog.shared.log("BLE: FFE1 raw: \(hex)")
responseBuffer.append(contentsOf: data)
while responseBuffer.count >= 5 {
guard let headerIdx = findDXHeader() else {
responseBuffer.removeAll()
break
}
if headerIdx > 0 {
responseBuffer.removeFirst(headerIdx)
}
guard responseBuffer.count >= 5 else { break }
let cmd = responseBuffer[2]
let len = Int(responseBuffer[3])
let frameLen = 4 + len + 1
guard responseBuffer.count >= frameLen else { break }
let frame = Array(responseBuffer[0..<frameLen])
responseBuffer.removeFirst(frameLen)
var xor: UInt8 = 0
for i in 2..<(frameLen - 1) {
xor ^= frame[i]
}
let frameData = Array(frame[4..<(4 + len)])
if xor == frame[frameLen - 1] {
parseResponseCmd(cmd: cmd, data: frameData)
} else {
let frameHex = frame.map { String(format: "%02X", $0) }.joined(separator: " ")
DebugLog.shared.log("BLE: XOR checksum failed: \(frameHex)")
readResult.rawResponses.append("0x\(String(format: "%02X", cmd)) XOR_FAIL: \(frameHex)")
}
}
}
private func findDXHeader() -> Int? {
guard responseBuffer.count >= 2 else { return nil }
for i in 0..<(responseBuffer.count - 1) {
if responseBuffer[i] == 0x4E && responseBuffer[i + 1] == 0x4F {
return i
}
}
return nil
}
private func parseResponseCmd(cmd: UInt8, data: [UInt8]) {
let dataHex = data.map { String(format: "%02X", $0) }.joined(separator: " ")
DebugLog.shared.log("BLE: Response cmd=0x\(String(format: "%02X", cmd)) len=\(data.count) data=[\(dataHex)]")
readResult.rawResponses.append("0x\(String(format: "%02X", cmd)): \(dataHex)")
switch DXCmd(rawValue: cmd) {
case .frameTable:
readResult.frameSlots = data
DebugLog.shared.log("BLE: Frame slots: \(data.map { String(format: "0x%02X", $0) })")
case .iBeaconType:
guard data.count >= 2 else { return }
var offset = 1
if data.count >= offset + 16 {
let uuidBytes = Array(data[offset..<(offset + 16)])
let uuidHex = uuidBytes.map { String(format: "%02X", $0) }.joined()
readResult.uuid = formatUUID(uuidHex)
offset += 16
}
if data.count >= offset + 2 {
readResult.major = UInt16(data[offset]) << 8 | UInt16(data[offset + 1])
offset += 2
}
if data.count >= offset + 2 {
readResult.minor = UInt16(data[offset]) << 8 | UInt16(data[offset + 1])
offset += 2
}
if data.count >= offset + 1 {
readResult.rssiAt1m = Int8(bitPattern: data[offset])
offset += 1
}
if data.count >= offset + 1 {
readResult.advInterval = UInt16(data[offset])
offset += 1
}
if data.count >= offset + 1 {
readResult.txPower = data[offset]
offset += 1
}
DebugLog.shared.log("BLE: iBeacon — UUID=\(readResult.uuid ?? "?") Major=\(readResult.major ?? 0) Minor=\(readResult.minor ?? 0)")
case .deviceInfo:
if data.count >= 1 {
readResult.battery = data[0]
}
if data.count >= 7 {
let macBytes = Array(data[1..<7])
readResult.macAddress = macBytes.map { String(format: "%02X", $0) }.joined(separator: ":")
}
DebugLog.shared.log("BLE: Device info — battery=\(readResult.battery ?? 0)% MAC=\(readResult.macAddress ?? "?")")
case .deviceName:
readResult.deviceName = String(bytes: data, encoding: .utf8)?.trimmingCharacters(in: .controlCharacters)
DebugLog.shared.log("BLE: Device name = \(readResult.deviceName ?? "?")")
case .authCheck:
if data.count >= 1 {
DebugLog.shared.log("BLE: Auth required: \(data[0] != 0x00)")
}
default:
DebugLog.shared.log("BLE: Unhandled response cmd 0x\(String(format: "%02X", cmd))")
}
}
// MARK: - Read Config: Finish
private func finishRead() {
readTimeout?.cancel()
readTimeout = nil
if let peripheral = peripheral {
centralManager.cancelPeripheralConnection(peripheral)
}
let result = readResult
state = .success
progress = ""
readCompletion?(result, nil)
cleanupRead()
}
private func readFail(_ message: String) {
DebugLog.shared.log("BLE: Read failed - \(message)")
readTimeout?.cancel()
readTimeout = nil
if let peripheral = peripheral {
centralManager.cancelPeripheralConnection(peripheral)
}
state = .failed(message)
readCompletion?(nil, message)
cleanupRead()
}
private func cleanupRead() {
peripheral = nil
readCompletion = nil
readResult = BeaconCheckResult()
readTimeout = nil
dxReadQueries.removeAll()
dxReadQueryIndex = 0
responseBuffer.removeAll()
allDiscoveredServices.removeAll()
servicesToExplore.removeAll()
configService = nil
characteristics.removeAll()
connectionRetryCount = 0
currentBeacon = nil
operationMode = .provisioning
state = .idle
progress = ""
}
// MARK: - Helpers
private func hexStringToData(_ hex: String) -> Data? {
let clean = hex.normalizedUUID
guard clean.count == 32 else { return nil }
var data = Data()
var index = clean.startIndex
while index < clean.endIndex {
let nextIndex = clean.index(index, offsetBy: 2)
let byteString = String(clean[index..<nextIndex])
if let byte = UInt8(byteString, radix: 16) {
data.append(byte)
} else {
return nil
}
index = nextIndex
}
return data
}
private func formatUUID(_ hex: String) -> String {
let clean = hex.uppercased()
guard clean.count == 32 else { return hex }
let c = Array(clean)
return "\(String(c[0..<8]))-\(String(c[8..<12]))-\(String(c[12..<16]))-\(String(c[16..<20]))-\(String(c[20..<32]))"
}
}
// MARK: - CBCentralManagerDelegate
extension BeaconProvisioner: CBCentralManagerDelegate {
func centralManagerDidUpdateState(_ central: CBCentralManager) {
DebugLog.shared.log("BLE: Central state = \(central.state.rawValue)")
}
func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) {
DebugLog.shared.log("BLE: Connected to \(peripheral.name ?? "unknown")")
peripheral.delegate = self
let maxWriteLen = peripheral.maximumWriteValueLength(for: .withResponse)
DebugLog.shared.log("BLE: Max write length: \(maxWriteLen) bytes")
if maxWriteLen < 21 {
DebugLog.shared.log("BLE: WARNING — max write \(maxWriteLen) < 21 bytes needed for UUID packet")
}
state = .discoveringServices
progress = "Discovering services..."
if operationMode == .readingConfig {
peripheral.discoverServices(nil)
} else {
peripheral.discoverServices([BeaconProvisioner.DXSMART_SERVICE])
}
}
func centralManager(_ central: CBCentralManager, didFailToConnect peripheral: CBPeripheral, error: Error?) {
let errorMsg = error?.localizedDescription ?? "unknown error"
DebugLog.shared.log("BLE: Connection failed: \(errorMsg)")
// Simple retry: up to 2 attempts with short delay
if connectionRetryCount < BeaconProvisioner.MAX_CONNECTION_RETRIES {
connectionRetryCount += 1
let delay = Double(connectionRetryCount)
progress = "Connection failed, retrying (\(connectionRetryCount)/\(BeaconProvisioner.MAX_CONNECTION_RETRIES))..."
DebugLog.shared.log("BLE: Retrying connection in \(delay)s")
DispatchQueue.main.asyncAfter(deadline: .now() + delay) { [weak self] in
guard let self = self, let beacon = self.currentBeacon else { return }
guard self.state == .connecting else { return }
let resolvedPeripheral = self.resolvePeripheral(beacon)
self.peripheral = resolvedPeripheral
self.centralManager.connect(resolvedPeripheral, options: nil)
}
} else {
let msg = "Failed to connect after \(BeaconProvisioner.MAX_CONNECTION_RETRIES) attempts: \(errorMsg)"
if operationMode == .readingConfig {
readFail(msg)
} else {
fail(msg, code: .connectionFailed)
}
}
}
func centralManager(_ central: CBCentralManager, didDisconnectPeripheral peripheral: CBPeripheral, error: Error?) {
DebugLog.shared.log("BLE: Disconnected | state=\(state) mode=\(operationMode) writeIdx=\(dxSmartWriteIndex) queueCount=\(dxSmartCommandQueue.count) error=\(error?.localizedDescription ?? "none")")
// Expected cleanup disconnect
if isTerminating {
DebugLog.shared.log("BLE: Disconnect during termination, ignoring")
return
}
if operationMode == .readingConfig {
if state != .success && state != .idle {
finishRead()
}
return
}
// Already terminal
if state == .success || state == .idle { return }
if case .failed = state { return }
// SaveConfig was the last command beacon rebooted. That's success.
if state == .writing && dxSmartCommandQueue.count > 0 && dxSmartWriteIndex >= dxSmartCommandQueue.count - 1 {
DebugLog.shared.log("BLE: Disconnect after SaveConfig — treating as success")
succeed()
return
}
// Cancel pending timers
cancelWriteTimeout()
cancelResponseGateTimeout()
awaitingCommandResponse = false
// Any other disconnect during active work = fail immediately.
// Prevention philosophy: if the connection dropped, something is wrong.
// Don't try to reconnect and resume let the user retry cleanly.
fail("Beacon disconnected during \(state). Move closer and try again.", code: .disconnected)
}
}
// MARK: - CBPeripheralDelegate
extension BeaconProvisioner: CBPeripheralDelegate {
func peripheral(_ peripheral: CBPeripheral, didDiscoverServices error: Error?) {
if let error = error {
if operationMode == .readingConfig {
readFail("Service discovery failed: \(error.localizedDescription)")
} else {
fail("Service discovery failed: \(error.localizedDescription)", code: .serviceNotFound)
}
return
}
guard let services = peripheral.services else {
if operationMode == .readingConfig {
readFail("No services found")
} else {
fail("No services found", code: .serviceNotFound)
}
return
}
DebugLog.shared.log("BLE: Discovered \(services.count) services")
if operationMode == .readingConfig {
startReadExplore()
return
}
// Provisioning: look for DX-Smart service
for service in services {
if service.uuid == BeaconProvisioner.DXSMART_SERVICE {
configService = service
provisionDXSmart()
return
}
}
fail("Config service not found on device", code: .serviceNotFound)
}
func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {
if let error = error {
if operationMode == .readingConfig {
DebugLog.shared.log("BLE: Char discovery failed for \(service.uuid): \(error.localizedDescription)")
exploreNextService()
} else {
fail("Characteristic discovery failed: \(error.localizedDescription)", code: .serviceNotFound)
}
return
}
guard let chars = service.characteristics else {
if operationMode == .readingConfig {
exploreNextService()
} else {
fail("No characteristics found", code: .serviceNotFound)
}
return
}
DebugLog.shared.log("BLE: Discovered \(chars.count) characteristics for \(service.uuid)")
for char in chars {
let props = char.properties
let propStr = [
props.contains(.read) ? "R" : "",
props.contains(.write) ? "W" : "",
props.contains(.writeWithoutResponse) ? "Wn" : "",
props.contains(.notify) ? "N" : "",
props.contains(.indicate) ? "I" : ""
].filter { !$0.isEmpty }.joined(separator: ",")
DebugLog.shared.log(" Char: \(char.uuid) [\(propStr)]")
characteristics[char.uuid] = char
if operationMode == .readingConfig {
readResult.characteristicsFound.append("\(char.uuid.uuidString)[\(propStr)]")
}
}
if operationMode == .readingConfig {
exploreNextService()
} else {
// PREVENTION: verify all required chars exist before proceeding
verifyCharacteristicsAndProceed()
}
}
func peripheral(_ peripheral: CBPeripheral, didWriteValueFor characteristic: CBCharacteristic, error: Error?) {
cancelWriteTimeout()
if let error = error {
DebugLog.shared.log("BLE: Write failed for \(characteristic.uuid): \(error.localizedDescription)")
// Password rejected
if characteristic.uuid == BeaconProvisioner.DXSMART_PASSWORD_CHAR {
if passwordIndex + 1 < BeaconProvisioner.DXSMART_PASSWORDS.count {
dxSmartRetryNextPassword()
} else if operationMode == .readingConfig {
readFail("Authentication failed - all passwords rejected")
} else {
fail("All passwords rejected", code: .authFailed)
}
return
}
// Command write failed
if characteristic.uuid == BeaconProvisioner.DXSMART_COMMAND_CHAR {
if operationMode == .readingConfig {
dxReadQueryIndex += 1
DispatchQueue.main.asyncAfter(deadline: .now() + 0.4) { [weak self] in
self?.dxSmartSendNextReadQuery()
}
} else {
let isSaveConfig = dxSmartWriteIndex >= dxSmartCommandQueue.count - 1
let isFrame1Command = dxSmartWriteIndex < 6 // Frame 1 commands are non-fatal
if isSaveConfig {
// SaveConfig write "error" = beacon rebooted mid-ACK. Success.
DebugLog.shared.log("BLE: SaveConfig write error (beacon rebooted) — success")
succeed()
} else if isFrame1Command {
// Frame 1 (device info) commands are optional skip and continue
DebugLog.shared.log("BLE: Non-fatal command failed at step \(dxSmartWriteIndex + 1), skipping")
dxSmartWriteIndex += 1
DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) { [weak self] in
self?.dxSmartSendNextCommand()
}
} else {
fail("Write failed at step \(dxSmartWriteIndex + 1)/\(dxSmartCommandQueue.count): \(error.localizedDescription)", code: .writeFailed)
}
}
return
}
if operationMode == .readingConfig { return }
fail("Write failed: \(error.localizedDescription)", code: .writeFailed)
return
}
DebugLog.shared.log("BLE: Write OK for \(characteristic.uuid)")
// Password auth succeeded
if characteristic.uuid == BeaconProvisioner.DXSMART_PASSWORD_CHAR {
DebugLog.shared.log("BLE: Authenticated!")
dxSmartAuthenticated = true
if operationMode == .readingConfig {
dxSmartReadQueryAfterAuth()
} else {
// Give the beacon breathing room after auth before we start writing
DebugLog.shared.log("BLE: Waiting \(BeaconProvisioner.POST_AUTH_DELAY)s before writing...")
progress = "Authenticated, preparing to write..."
DispatchQueue.main.asyncAfter(deadline: .now() + BeaconProvisioner.POST_AUTH_DELAY) { [weak self] in
self?.dxSmartWriteConfig()
}
}
return
}
// Command write succeeded gate on FFE1 response
if characteristic.uuid == BeaconProvisioner.DXSMART_COMMAND_CHAR {
if operationMode == .readingConfig {
dxReadQueryIndex += 1
DispatchQueue.main.asyncAfter(deadline: .now() + 0.4) { [weak self] in
self?.dxSmartSendNextReadQuery()
}
} else {
awaitingCommandResponse = true
scheduleResponseGateTimeout()
}
return
}
}
func peripheral(_ peripheral: CBPeripheral, didUpdateNotificationStateFor characteristic: CBCharacteristic, error: Error?) {
if let error = error {
DebugLog.shared.log("BLE: Notification state failed for \(characteristic.uuid): \(error.localizedDescription)")
} else {
DebugLog.shared.log("BLE: Notifications \(characteristic.isNotifying ? "enabled" : "disabled") for \(characteristic.uuid)")
}
if characteristic.uuid == BeaconProvisioner.DXSMART_NOTIFY_CHAR {
dxSmartNotifySubscribed = true
if operationMode == .readingConfig {
dxSmartReadAuth()
} else {
dxSmartAuthenticate()
}
}
}
func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) {
if let error = error {
DebugLog.shared.log("BLE: Read error for \(characteristic.uuid): \(error.localizedDescription)")
return
}
let data = characteristic.value ?? Data()
if operationMode == .readingConfig {
if characteristic.uuid == BeaconProvisioner.DXSMART_NOTIFY_CHAR {
processFFE1Response(data)
} else {
let hex = data.map { String(format: "%02X", $0) }.joined(separator: " ")
DebugLog.shared.log("BLE: Read \(characteristic.uuid): \(hex)")
}
} else {
// Provisioning mode FFE1 notification
if characteristic.uuid == BeaconProvisioner.DXSMART_NOTIFY_CHAR {
let hex = data.map { String(format: "%02X", $0) }.joined(separator: " ")
DebugLog.shared.log("BLE: FFE1 notification: \(hex)")
if awaitingCommandResponse {
awaitingCommandResponse = false
cancelResponseGateTimeout()
// Check for rejection (4E 4F 00 = command rejected)
let bytes = [UInt8](data)
if bytes.count >= 3 && bytes[0] == 0x4E && bytes[1] == 0x4F && bytes[2] == 0x00 {
let isFrame1 = dxSmartWriteIndex < 6
DebugLog.shared.log("BLE: Command \(dxSmartWriteIndex + 1) rejected\(isFrame1 ? " (non-fatal)" : "")")
}
advanceToNextCommand()
}
}
}
}
}