// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

library fuchsia.lowpan;

enum State : int32 {
    /// Offline state.
    ///
    /// This is the initial state of the LoWPAN
    /// interface when the underlying driver starts.
    /// In this state the NCP is idle and not
    /// connected to any network.
    ///
    /// This state can be explicitly entered by
    /// calling `Reset`, `Leave`, or `setUp(false)`,
    /// with the later two only working if we were not
    /// previously in `State::FAULT`.
    OFFLINE = 1;

    /// Attaching state.
    ///
    /// The interface enters this state when it starts
    /// the process of trying to find other nodes so
    /// that it can attach to any pre-existing network
    /// fragment, or when it is in the process of
    /// calculating the optimal values for unspecified
    /// parameters when forming a new network.
    ///
    /// The interface may stay in this state for a
    /// prolonged period of time (or may spontaneously
    /// enter this state from `State::ATTACHED` if the
    /// underlying network technology is hierarchical
    /// (like ZigBee IP) or if the device role is that
    /// of an "end-device" (`Role::END_DEVICE`). This
    /// is because such roles cannot create their own
    /// network fragments.
    ATTACHING = 2;

    /// Attached state.
    ///
    /// This state indicates that we are an active
    /// participant on a network that has at least one
    /// other peer node in range.
    ///
    /// The Interface can enter this state from
    /// `State::ATTACHING`.
    ATTACHED = 3;

    /// Isolated state.
    ///
    /// This state indicates that there are no nearby
    /// nodes for the provisioned network in range.
    /// Once other nodes come into range, the
    /// interface will automatically switch to
    /// `State::ATTACHED`.
    ///
    /// The interface can enter this state from either
    /// `State::ATTACHING` or `State::ATTACHED`.
    ISOLATED = 4;

    /// Fault state.
    ///
    /// The interface will enter this state when
    /// the driver has detected some sort of problem
    /// from which it was not immediately able to
    /// recover.
    ///
    /// This state can be entered spontaneously from
    /// any other state. Calling `Reset` will cause
    /// the device to return to `State::OFFLINE`.
    FAULT = 5;

    /// Commissioning state.
    ///
    /// The interface enters this state after a call
    /// to `startCommissioningSession(LowpanBeaconInfo)`.
    /// This state may only be entered directly from
    /// `State::OFFLINE`.
    COMMISSIONING = 6;
};