// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// The <code>chrome.webrtcAudioPrivate</code> API allows enumeration
// of audio output (sink) devices.
//
// Note that device IDs as used in this API are opaque (i.e. they are
// not the hardware identifier of the device) and while they are
// unique and persistent across sessions, they are valid only to the
// extension calling this API (i.e. they cannot be shared between
// extensions).
//
// See http://goo.gl/8rOmgk for further documentation of this API.

namespace webrtcAudioPrivate {

  dictionary SinkInfo {
    // The opaque identifier of the audio sink device, which is unique
    // and static for the extension calling the API but invalid for
    // others.
    DOMString sinkId;
    // The user-friendly name (e.g. "Bose Amplifier").
    DOMString sinkLabel;
    // Current sample rate of the device, in Hz. Useful e.g. to know
    // if the remote side should be asked to send a lower sampling
    // rate.
    long sampleRate;
    // True if the device is ready to play out audio. E.g. if it is a
    // device that takes an audio jack, whether a jack is plugged in.
    //
    // TODO(joi): Do unplugged devices even get included in enumeration?
    boolean isReady;
    // True if this device is the default audio sink device on the
    // machine.
    boolean isDefault;
  };

  callback GetSinksCallback = void(SinkInfo[] sinkInfo);
  callback SinkIdCallback = void(DOMString sinkId);

  dictionary RequestInfo {
    // The tab identifier from the chrome.tabs API, if the request is from a
    // tab.
    long? tabId;
    // The guest process id for the requester, if the request is from a
    // webview.
    long? guestProcessId;
  };

  dictionary AudioExperiments {
    // Enables or disables the new acoustic echo canceller (AEC3) in WebRTC.
    boolean? enableAec3;
  };

  interface Functions {
    // Retrieves a list of available audio sink devices.
    static void getSinks(GetSinksCallback callback);

    // Given a security origin and an input device ID valid for that
    // security origin, retrieve an audio sink ID valid for the
    // extension, or the empty string if there is no associated audio
    // sink.
    //
    // The associated sink ID can be used as a sink ID for
    // setActiveSink. It is valid irrespective of which process you are
    // setting the active sink for.
    static void getAssociatedSink(DOMString securityOrigin,
                                  DOMString sourceIdInOrigin,
                                  SinkIdCallback cb);

    // Sets the active audio experiments.
    // |request|: Information about the requesting process.
    // |securityOrigin|: The origin to restrict the settings to.
    // |audioExperiments|: The experiments to enable or disable.
    static void setAudioExperiments(RequestInfo request,
                                    DOMString securityOrigin,
                                    AudioExperiments audioExperiments);
  };

  interface Events {
    // Fired when audio sink devices are added or removed.
    static void onSinksChanged();
  };
};
