AppFlowController+Protocols.swift

protocol AppFlowControlling: FlowControlling {
    var appFlowController: AppFlowPresenting { get }
}

protocol AppFlowPresenting: FlowPresenting {
    func showMainView()
}

extension AppFlowControlling where Self: UIResponder {
    var appFlowController: AppFlowPresenting {
        return flowController()
    }
}

extension UIResponder {
    func flowController<T>() -> T {
        var current: UIResponder? = self
        repeat {
            if let presenter = current as? T {
                return presenter
            }
            current = current?.next
        } while current != nil
        fatalError()
    }
}