// Copyright 2016 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef STARBOARD_SHARED_STARBOARD_PLAYER_FILTER_AUDIO_RENDERER_IMPL_INTERNAL_H_
#define STARBOARD_SHARED_STARBOARD_PLAYER_FILTER_AUDIO_RENDERER_IMPL_INTERNAL_H_

#include <vector>

#include "starboard/atomic.h"
#include "starboard/audio_sink.h"
#include "starboard/common/scoped_ptr.h"
#include "starboard/log.h"
#include "starboard/media.h"
#include "starboard/shared/internal_only.h"
#include "starboard/shared/starboard/player/closure.h"
#include "starboard/shared/starboard/player/decoded_audio_internal.h"
#include "starboard/shared/starboard/player/filter/audio_decoder_internal.h"
#include "starboard/shared/starboard/player/filter/audio_frame_tracker.h"
#include "starboard/shared/starboard/player/filter/audio_renderer_internal.h"
#include "starboard/shared/starboard/player/filter/audio_resampler.h"
#include "starboard/shared/starboard/player/filter/audio_time_stretcher.h"
#include "starboard/shared/starboard/player/input_buffer_internal.h"
#include "starboard/shared/starboard/player/job_queue.h"
#include "starboard/types.h"

namespace starboard {
namespace shared {
namespace starboard {
namespace player {
namespace filter {

// A default implementation of |AudioRenderer| that only depends on the
// |AudioDecoder| interface, rather than a platform specific implementation.
class AudioRendererImpl : public AudioRenderer, private JobQueue::JobOwner {
 public:
  static const size_t kDefaultMaxCachedFrames = 256 * 1024;
  static const size_t kDefaultMaxFramesPerAppend = 16384;

  // |max_cached_frames| is a soft limit for the max audio frames this class can
  // cache so it can:
  // 1. Avoid using too much memory.
  // 2. Have the audio cache full to simulate the state that the renderer can no
  //    longer accept more data.
  // |max_frames_per_append| is the max number of frames that the audio renderer
  // tries to append to the sink buffer at once.
  AudioRendererImpl(scoped_ptr<AudioDecoder> decoder,
                    const SbMediaAudioHeader& audio_header,
                    size_t max_cached_frames = kDefaultMaxCachedFrames,
                    size_t max_frames_per_append = kDefaultMaxFramesPerAppend);
  ~AudioRendererImpl() SB_OVERRIDE;

  void Initialize(const Closure& error_cb) SB_OVERRIDE;
  void WriteSample(const InputBuffer& input_buffer) SB_OVERRIDE;
  void WriteEndOfStream() SB_OVERRIDE;

  void Play() SB_OVERRIDE;
  void Pause() SB_OVERRIDE;
  void SetPlaybackRate(double playback_rate) SB_OVERRIDE;
  void SetVolume(double volume) SB_OVERRIDE;
  void Seek(SbMediaTime seek_to_pts) SB_OVERRIDE;

  bool IsEndOfStreamWritten() const SB_OVERRIDE {
    return eos_state_.load() >= kEOSWrittenToDecoder;
  };
  bool IsEndOfStreamPlayed() const SB_OVERRIDE;
  bool CanAcceptMoreData() const SB_OVERRIDE;
  bool IsSeekingInProgress() const SB_OVERRIDE;

  // This function can be called from any thread.
  SbMediaTime GetCurrentTime() SB_OVERRIDE;

 protected:
  enum EOSState {
    kEOSNotReceived,
    kEOSWrittenToDecoder,
    kEOSDecoded,
    kEOSSentToSink
  };

  const size_t max_cached_frames_;
  const size_t max_frames_per_append_;

  atomic_bool paused_;
  atomic_bool consume_frames_called_;
  atomic_bool seeking_;
  SbMediaTime seeking_to_pts_;
  AudioFrameTracker audio_frame_tracker_;

  atomic_int64_t frames_sent_to_sink_;
  atomic_int64_t frames_consumed_by_sink_;
  atomic_int32_t frames_consumed_by_sink_since_last_get_current_time_;

  scoped_ptr<AudioDecoder> decoder_;

  atomic_int64_t frames_consumed_set_at_;
  atomic_double playback_rate_;

 private:
  void CreateAudioSinkAndResampler();
  void UpdateSourceStatus(int* frames_in_buffer,
                          int* offset_in_frames,
                          bool* is_playing,
                          bool* is_eos_reached);
  void ConsumeFrames(int frames_consumed);
  void LogFramesConsumed();

  void OnDecoderConsumed();
  void OnDecoderOutput();
  void ProcessAudioData();
  void FillResamplerAndTimeStretcher();
  bool AppendAudioToFrameBuffer(bool* is_frame_buffer_full);

  // SbAudioSink callbacks
  static void UpdateSourceStatusFunc(int* frames_in_buffer,
                                     int* offset_in_frames,
                                     bool* is_playing,
                                     bool* is_eos_reached,
                                     void* context);
  static void ConsumeFramesFunc(int frames_consumed, void* context);

  atomic_int32_t eos_state_;
  const int channels_;
  const SbMediaAudioSampleType sink_sample_type_;
  const int bytes_per_frame_;

  scoped_ptr<AudioResampler> resampler_;
  AudioTimeStretcher time_stretcher_;
  double volume_;

  std::vector<uint8_t> frame_buffer_;
  uint8_t* frame_buffers_[1];

  int32_t pending_decoder_outputs_;
  Closure log_frames_consumed_closure_;

  SbAudioSink audio_sink_;

  bool can_accept_more_data_;
  bool process_audio_data_scheduled_;
  Closure process_audio_data_closure_;

  // Our owner will attempt to seek to pts 0 when playback begins.  In
  // general, seeking could require a full reset of the underlying decoder on
  // some platforms, so we make an effort to improve playback startup
  // performance by keeping track of whether we already have a fresh decoder,
  // and can thus avoid doing a full reset.
  bool decoder_needs_full_reset_;
};

}  // namespace filter
}  // namespace player
}  // namespace starboard
}  // namespace shared
}  // namespace starboard

#endif  // STARBOARD_SHARED_STARBOARD_PLAYER_FILTER_AUDIO_RENDERER_IMPL_INTERNAL_H_