UserAuthenticator.swift

typealias AuthenticationViewSource = UIViewController & AuthServiceDelegate

class UserAuthenticator {
    private weak var source: AuthenticationViewSource?

    private var service: AuthService?

    init(_ viewController: AuthenticationViewSource) {
        self.source = viewController
    }

    func authenticate(_ type: PreferredAuthMethod) {
        guard let source = source else { return }
        service = type.getService(source: source, delegate: source)
        service?.authenticate()
    }

    func deAuthenticate(type: PreferredAuthMethod) {
        guard let source = source else { return }
        service = type.getService(source: source, delegate: source)
        service?.deAuthenticate()
    }
}