// 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.
@available(added=7)
library fuchsia.update.channelcontrol;

using fuchsia.update.channel;

/// Control the target update channel, this is the channel we will use on the next update check.
@discoverable
closed protocol ChannelControl {
    compose fuchsia.update.channel.Provider;

    /// Set a new desired target channel.  This tells the updater to attempt to
    /// check for updates using a new channel.  This is tentative, and won't be
    /// persisted unless an update check on that channel is successful.
    ///
    /// A response is generated when the new target channel has been verified as
    /// valid.
    ///
    /// + request `channel` the new target channel name (name used by the updater)
    strict SetTarget(struct {
        channel string:128;
    }) -> ();

    /// Get the current tentative target channel for updates.
    /// This returns the channel that the update client is using to perform update
    /// checks.  It's always one of:
    ///    - the current channel
    ///    - the default channel
    ///    - a new target that's different, but hasn't been OTA'd from yet.
    ///
    /// - response `channel` the current target channel.
    strict GetTarget() -> (struct {
        channel string:128;
    });

    /// Get the list of well-known target channels that can be passed to SetTarget().
    /// There may be other, unlisted channels.
    strict GetTargetList() -> (struct {
        channels vector<string:128>:100;
    });
};