// global max = max of given sample inputs
class CalibrationStatisticsCollectorMinMax
    : public CalibrationStatisticsCollectorBase {
 public:
  explicit CalibrationStatisticsCollectorMinMax() { ClearData(); }

  void ClearData() override;

  void Collect(float min, float max,
               absl::Span<const int64_t> histogram) override;

  std::optional<CalibrationStatistics> GetStatistics() const override;

 private:

class CalibrationStatisticsCollectorAverageMinMax
    : public CalibrationStatisticsCollectorBase {
 public:
  explicit CalibrationStatisticsCollectorAverageMinMax() { ClearData(); }

  void ClearData() override;

  void Collect(float min, float max,
               absl::Span<const int64_t> histogram) override;

  std::optional<CalibrationStatistics> GetStatistics() const override;

 private:

namespace tensorflow {
namespace calibrator {


class CalibrationStatisticsCollectorHistogram
    : public CalibrationStatisticsCollectorBase {
 public:
  explicit CalibrationStatisticsCollectorHistogram() { ClearData(); }

  void ClearData() override;

  void Collect(float min, float max,
               absl::Span<const int64_t> histogram) override;

  std::optional<CalibrationStatistics> GetStatistics() const override;

 private:

class CalibrationStatisticsCollectorBase {
 public:
  // Collect data for calibration.
  virtual void Collect(float min, float max,
                       absl::Span<const int64_t> histogram) = 0;

  virtual void ClearData() = 0;
  // Return the statistics needed for a given calibration method.
  virtual std::optional<CalibrationStatistics> GetStatistics() const = 0;
  virtual ~CalibrationStatisticsCollectorBase() = default;
};

#include "absl/types/span.h"
#include "tensorflow/compiler/mlir/quantization/tensorflow/calibrator/calibration_statistics.pb.h"

namespace tensorflow {
namespace calibrator {

void CalibrationStatisticsCollectorMinMax::ClearData() {
  // global_min will be updated by std::min(global_min, input_value) so
  // it is initialized with the value numeric_limits<float>::max().
  min_max_statistics_.set_global_min(std::numeric_limits<float>::max());

#include "absl/types/span.h"
#include "tensorflow/compiler/mlir/quantization/tensorflow/calibrator/calibration_statistics.pb.h"

namespace tensorflow {
namespace calibrator {

void CalibrationStatisticsCollectorAverageMinMax::ClearData() {
  average_min_max_statistics_.set_min_sum(0.0);
  average_min_max_statistics_.set_max_sum(0.0);
  average_min_max_statistics_.set_num_samples(0);
}

void CalibrationStatisticsCollectorAverageMinMax::Collect(

  EXPECT_TRUE(statistics.has_value());
  EXPECT_EQ(statistics.value().min_max_statistics().global_min(), -5.0f);
  EXPECT_EQ(statistics.value().min_max_statistics().global_max(), 10.0f);

  collector.ClearData();
  statistics = collector.GetStatistics();
  EXPECT_FALSE(statistics.has_value());

  collector.Collect(
      /*min=*/1.0f, /*max=*/10.f, /*histogram=*/{});
  collector.Collect(

    freq_sum += histogram[idx] * proportion;
  }
  return freq_sum;
}

}  // namespace

void CalibrationStatisticsCollectorHistogram::ClearData() {
  hist_freq_.clear();
}

void CalibrationStatisticsCollectorHistogram::Collect(
    const float min, const float max, absl::Span<const int64_t> histogram) {
  if (histogram.empty()) return;