AuthorizationStateMachine.kt

private sealed class State {
    object KerberosAuthorization : State()
    object EmailAuthorization : State()
    object UsernameAuthorization : State()
    object ExchangeUrlAuthorization : State()
}

private sealed class Event {
    object OnKerberosAuthorizationFailed : Event()
    object OnEmailAuthorizationFailed : Event()
    object OnUsernameAuthorizationFailed : Event()
}

private class SideEffect

private val stateMachine = StateMachine.create<State, Event, SideEffect> {
    initialState(State.KerberosAuthorization)
    state<State.KerberosAuthorization> {
        on<Event.OnKerberosAuthorizationFailed> {
            transitionTo(State.EmailAuthorization, SideEffect())
        }
    }
    state<State.EmailAuthorization> {
        on<Event.OnEmailAuthorizationFailed> {
            transitionTo(State.UsernameAuthorization, SideEffect())
        }
    }
    state<State.UsernameAuthorization> {
        on<Event.OnUsernameAuthorizationFailed> {
            transitionTo(State.ExchangeUrlAuthorization, SideEffect())
        }
    }
    onTransition {
        val validTransition = it as? StateMachine.Transition.Valid ?: return@onTransition
        state.postValue(validTransition.toState)
    }
}