/*
 *  Copyright (c) 2017 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 MODULES_AUDIO_PROCESSING_AEC3_ERLE_ESTIMATOR_H_
#define MODULES_AUDIO_PROCESSING_AEC3_ERLE_ESTIMATOR_H_

#include <array>
#include <memory>

#include "absl/types/optional.h"
#include "api/array_view.h"
#include "modules/audio_processing/aec3/aec3_common.h"
#include "modules/audio_processing/aec3/fullband_erle_estimator.h"
#include "modules/audio_processing/aec3/subband_erle_estimator.h"
#include "modules/audio_processing/logging/apm_data_dumper.h"

namespace webrtc {

// Estimates the echo return loss enhancement. One estimate is done per subband
// and another one is done using the aggreation of energy over all the subbands.
class ErleEstimator {
 public:
  ErleEstimator(size_t startup_phase_length_blocks_,
                float min_erle,
                float max_erle_lf,
                float max_erle_hf);
  ~ErleEstimator();

  // Resets the fullband ERLE estimator and the subbands ERLE estimators.
  void Reset(bool delay_change);

  // Updates the ERLE estimates.
  void Update(rtc::ArrayView<const float> reverb_render_spectrum,
              rtc::ArrayView<const float> capture_spectrum,
              rtc::ArrayView<const float> subtractor_spectrum,
              bool converged_filter,
              bool onset_detection);

  // Returns the most recent subband ERLE estimates.
  const std::array<float, kFftLengthBy2Plus1>& Erle() const {
    return subband_erle_estimator_.Erle();
  }
  // Returns the subband ERLE that are estimated during onsets. Used
  // for logging/testing.
  const std::array<float, kFftLengthBy2Plus1>& ErleOnsets() const {
    return subband_erle_estimator_.ErleOnsets();
  }

  // Returns the fullband ERLE estimate.
  float FullbandErleLog2() const {
    return fullband_erle_estimator_.FullbandErleLog2();
  }

  // Returns an estimation of the current linear filter quality based on the
  // current and past fullband ERLE estimates. The returned value is a float
  // between 0 and 1 where 1 indicates that, at this current time instant, the
  // linear filter is reaching its maximum subtraction performance.
  absl::optional<float> GetInstLinearQualityEstimate() const {
    return fullband_erle_estimator_.GetInstLinearQualityEstimate();
  }

  void Dump(const std::unique_ptr<ApmDataDumper>& data_dumper) const;

 private:
  const size_t startup_phase_length_blocks__;
  FullBandErleEstimator fullband_erle_estimator_;
  SubbandErleEstimator subband_erle_estimator_;
  size_t blocks_since_reset_ = 0;
};

}  // namespace webrtc

#endif  // MODULES_AUDIO_PROCESSING_AEC3_ERLE_ESTIMATOR_H_