/*
 *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#ifndef WEBRTC_MODULES_AUDIO_MIXER_INCLUDE_AUDIO_MIXER_DEFINES_H_
#define WEBRTC_MODULES_AUDIO_MIXER_INCLUDE_AUDIO_MIXER_DEFINES_H_

#include "webrtc/base/checks.h"
#include "webrtc/modules/include/module_common_types.h"
#include "webrtc/typedefs.h"

namespace webrtc {
class NewMixHistory;

// A callback class that all mixer participants must inherit from/implement.
class MixerAudioSource {
 public:
  // The implementation of this function should update audioFrame with new
  // audio every time it's called.
  //
  // If it returns -1, the frame will not be added to the mix.
  //
  // NOTE: This function should not be called. It will remain for a short
  // time so that subclasses can override it without getting warnings.
  // TODO(henrik.lundin) Remove this function.
  virtual int32_t GetAudioFrame(int32_t id, AudioFrame* audioFrame) {
    RTC_CHECK(false);
    return -1;
  }

  // The implementation of GetAudioFrameWithMuted should update audio_frame
  // with new audio every time it's called. The return value will be
  // interpreted as follows.
  enum class AudioFrameInfo {
    kNormal,  // The samples in audio_frame are valid and should be used.
    kMuted,   // The samples in audio_frame should not be used, but should be
              // implicitly interpreted as zero. Other fields in audio_frame
              // may be read and should contain meaningful values.
    kError    // audio_frame will not be used.
  };

  virtual AudioFrameInfo GetAudioFrameWithMuted(int32_t id,
                                                AudioFrame* audio_frame) {
    return GetAudioFrame(id, audio_frame) == -1 ? AudioFrameInfo::kError
                                                : AudioFrameInfo::kNormal;
  }

  // Returns true if the participant was mixed this mix iteration.
  bool IsMixed() const;

  // This function specifies the sampling frequency needed for the AudioFrame
  // for future GetAudioFrame(..) calls.
  virtual int32_t NeededFrequency(int32_t id) const = 0;

  NewMixHistory* _mixHistory;

 protected:
  MixerAudioSource();
  virtual ~MixerAudioSource();
};

class OldAudioMixerOutputReceiver {
 public:
  // This callback function provides the mixed audio for this mix iteration.
  // Note that uniqueAudioFrames is an array of AudioFrame pointers with the
  // size according to the size parameter.
  virtual void NewMixedAudio(const int32_t id,
                             const AudioFrame& generalAudioFrame,
                             const AudioFrame** uniqueAudioFrames,
                             const uint32_t size) = 0;

 protected:
  OldAudioMixerOutputReceiver() {}
  virtual ~OldAudioMixerOutputReceiver() {}
};
}  // namespace webrtc

#endif  // WEBRTC_MODULES_AUDIO_MIXER_INCLUDE_AUDIO_MIXER_DEFINES_H_