BiometricManager (Swift 6 compatibility)

BiometricManager.swift

import LocalAuthentication

@MainActor
protocol BiometricManagerProtocol: Sendable {
    func biometricType() -> BiometricManager.BiometricType
    func isBiometricAvailable() -> Bool
    func authenticate(reason: String?) async throws -> Bool
    func updateLoginReason(_ newReason: String)
}

@MainActor
final class BiometricManager: BiometricManagerProtocol {
    // MARK: - Properties

    enum BiometricType: String, Sendable, CaseIterable {
        case faceID
        case opticID
        case touchID
        case unknown
    }

    static let shared = BiometricManager()

    private var loginReason: String

    // MARK: - Init

    private init() {
        self.loginReason = "Authenticate to access"
    }

    // MARK: - Public functions

    func biometricType() -> BiometricType {
        let context = LAContext()

        var error: NSError?

        guard context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error) else {
            return .unknown
        }

        if #available(iOS 11.0, *) {
            switch context.biometryType {
            case .none:
                return .unknown
            case .touchID:
                return .touchID
            case .faceID:
                return .faceID
            case .opticID:
                return .opticID
            @unknown default:
                return .unknown
            }
        } else {
            return .touchID
        }
    }

    func isBiometricAvailable() -> Bool {
        let context = LAContext()

        var error: NSError?

        return context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error)
    }

    func authenticate(reason: String?) async throws -> Bool {
        let context = LAContext()
        let authReason = reason ?? loginReason
        let policy: LAPolicy = .deviceOwnerAuthentication

        return try await withCheckedThrowingContinuation { [context] continuation in
            context.evaluatePolicy(policy, localizedReason: authReason) { success, error in
                continuation.resume(with: Result {
                    if success {
                        return true
                    } else if let error {
                        throw error
                    } else {
                        throw LAError(.appCancel)
                    }
                })
            }
        }
    }

    func updateLoginReason(_ newReason: String) {
        loginReason = newReason
    }
}