// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

module device.mojom;

import "mojo/public/mojom/base/unguessable_token.mojom";
import "services/device/public/mojom/pressure_update.mojom";

// PressureManager.AddClient()'s return type.
enum PressureManagerAddClientResult {
  kNotSupported,
  kOk,
};

struct VirtualPressureSourceMetadata {
  // Whether a virtual pressure source should provide samples or report itself
  // as not available.
  bool available = true;
};

// This interface is used to subscribe to notification about OnPressureUpdated.
//
// This interface is implemented by PressureManagerImpl in services/device.
// PressureObserverManager in Blink uses this interface to make a
// PressureClient subscribe to notification about OnPressureUpdated.
interface PressureManager {
  // Creates a new virtual pressure source of type |source| handled by |token|.
  // Callers are responsible for ensuring that |token| does not contain a
  // pressure source of type |source|. If it does, a bad message will be
  // reported.
  AddVirtualPressureSource(
      mojo_base.mojom.UnguessableToken token, PressureSource source,
      VirtualPressureSourceMetadata metadata) => ();

  // Removes a virtual pressure source identified by |token| and |source|. Does
  // nothing if one does not exist.
  RemoveVirtualPressureSource(
      mojo_base.mojom.UnguessableToken token, PressureSource source) => ();

  // Sends state update and own contribution estimate update for a virtual
  // pressure source corresponding to |token| and |source|.
  // Does nothing if |token| does not  contain a pressure source of type
  // |source|.
  UpdateVirtualPressureSourceData(
      mojo_base.mojom.UnguessableToken token, PressureSource source,
      PressureState state, double own_contribution_estimate) => ();

  // Add a client that will be notified when a new PressureUpdate for `source`
  // is obtained.
  //
  // |token| can be used to identify a virtual pressure source created with a
  // call to AddVirtualPressureSource().
  AddClient(PressureSource source, mojo_base.mojom.UnguessableToken? token,
            pending_associated_remote<device.mojom.PressureClient> client) =>
      (PressureManagerAddClientResult result);
};

// Interface that client of the PressureManager interface must
// implement to receive PressureUpdate.
//
// This interface is implemented by PressureObserverManager in Blink.
// PressureManagerImpl uses this interface to deliver PressureUpdate to
// its client.
interface PressureClient {
  // Interface used to deliver PressureUpdate.
  OnPressureUpdated(PressureUpdate update);
};