/*
 *  Copyright (c) 2020 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.
 */

#include "video/alignment_adjuster.h"

#include <cstddef>
#include <optional>
#include <tuple>
#include <vector>

#include "api/video/video_codec_type.h"
#include "api/video_codecs/video_encoder.h"
#include "test/encoder_settings.h"
#include "test/gtest.h"
#include "video/config/video_encoder_config.h"

namespace webrtc {
namespace test {
namespace {
VideoEncoder::EncoderInfo GetEncoderInfo(int alignment, bool apply) {
  VideoEncoder::EncoderInfo info;
  info.requested_resolution_alignment = alignment;
  info.apply_alignment_to_all_simulcast_layers = apply;
  return info;
}
}  // namespace

class AlignmentAdjusterTest
    : public ::testing::TestWithParam<::testing::tuple<
          int,
          std::tuple<std::vector<double>, std::vector<double>, int>>> {
 protected:
  AlignmentAdjusterTest()
      : kRequestedAlignment(std::get<0>(GetParam())),
        kScaleFactors(std::get<0>(std::get<1>(GetParam()))),
        kAdjustedScaleFactors(std::get<1>(std::get<1>(GetParam()))),
        kAdjustedAlignment(std::get<2>(std::get<1>(GetParam()))) {}

  const int kRequestedAlignment;
  const std::vector<double> kScaleFactors;
  const std::vector<double> kAdjustedScaleFactors;
  const int kAdjustedAlignment;
};

INSTANTIATE_TEST_SUITE_P(
    ScaleFactorsAndAlignment,
    AlignmentAdjusterTest,
    ::testing::Combine(
        ::testing::Values(2),  // kRequestedAlignment
        ::testing::Values(
            std::make_tuple(std::vector<double>{-1.0},  // kScaleFactors
                            std::vector<double>{-1.0},  // kAdjustedScaleFactors
                            2),  // default: {1.0}      // kAdjustedAlignment
            std::make_tuple(std::vector<double>{-1.0, -1.0},
                            std::vector<double>{-1.0, -1.0},
                            4),  // default: {1.0, 2.0}
            std::make_tuple(std::vector<double>{-1.0, -1.0, -1.0},
                            std::vector<double>{-1.0, -1.0, -1.0},
                            8),  // default: {1.0, 2.0, 4.0}
            std::make_tuple(std::vector<double>{1.0, 2.0, 4.0},
                            std::vector<double>{1.0, 2.0, 4.0},
                            8),
            std::make_tuple(std::vector<double>{9999.0, -1.0, 1.0},
                            std::vector<double>{8.0, 1.0, 1.0},
                            16),  // kMaxAlignment
            std::make_tuple(std::vector<double>{3.99, 2.01, 1.0},
                            std::vector<double>{4.0, 2.0, 1.0},
                            8),
            std::make_tuple(std::vector<double>{2.9, 2.1},
                            std::vector<double>{6.0 / 2.0, 6.0 / 3.0},
                            12),
            std::make_tuple(std::vector<double>{4.9, 1.7, 1.2},
                            std::vector<double>{5.0, 5.0 / 3.0, 5.0 / 4.0},
                            10),
            std::make_tuple(std::vector<double>{1.0, 1.3},
                            std::vector<double>{4.0 / 4.0, 4.0 / 3.0},
                            8),
            std::make_tuple(std::vector<double>{1.75, 3.5},
                            std::vector<double>{7.0 / 4.0, 7.0 / 2.0},
                            7),
            std::make_tuple(std::vector<double>{1.5, 2.5},
                            std::vector<double>{1.5, 2.5},
                            15))));

class AlignmentAdjusterTestTwoLayers : public AlignmentAdjusterTest {
 protected:
  const int kMaxLayers = 2;
};

INSTANTIATE_TEST_SUITE_P(
    ScaleFactorsAndAlignmentWithMaxLayers,
    AlignmentAdjusterTestTwoLayers,
    ::testing::Combine(
        ::testing::Values(2),  // kRequestedAlignment
        ::testing::Values(
            std::make_tuple(std::vector<double>{-1.0},  // kScaleFactors
                            std::vector<double>{-1.0},  // kAdjustedScaleFactors
                            2),  // default: {1.0}      // kAdjustedAlignment
            std::make_tuple(std::vector<double>{-1.0, -1.0},
                            std::vector<double>{-1.0, -1.0},
                            4),  // default: {1.0, 2.0}
            std::make_tuple(std::vector<double>{-1.0, -1.0, -1.0},
                            std::vector<double>{-1.0, -1.0, -1.0},
                            4),  // default: {1.0, 2.0, 4.0}
            std::make_tuple(std::vector<double>{1.0, 2.0, 4.0},
                            std::vector<double>{1.0, 2.0, 4.0},
                            8))));

TEST_P(AlignmentAdjusterTest, AlignmentAppliedToAllLayers) {
  const bool kApplyAlignmentToAllLayers = true;

  // Fill config with the scaling factor by which to reduce encoding size.
  const int num_streams = kScaleFactors.size();
  VideoEncoderConfig config;
  test::FillEncoderConfiguration(kVideoCodecVP8, num_streams, &config);
  for (int i = 0; i < num_streams; ++i) {
    config.simulcast_layers[i].scale_resolution_down_by = kScaleFactors[i];
  }

  // Verify requested alignment from sink.
  VideoEncoder::EncoderInfo info =
      GetEncoderInfo(kRequestedAlignment, kApplyAlignmentToAllLayers);
  int alignment = AlignmentAdjuster::GetAlignmentAndMaybeAdjustScaleFactors(
      info, &config, std::nullopt);
  EXPECT_EQ(alignment, kAdjustedAlignment);

  // Verify adjusted scale factors.
  for (int i = 0; i < num_streams; ++i) {
    EXPECT_EQ(config.simulcast_layers[i].scale_resolution_down_by,
              kAdjustedScaleFactors[i]);
  }
}

TEST_P(AlignmentAdjusterTest, AlignmentNotAppliedToAllLayers) {
  const bool kApplyAlignmentToAllLayers = false;

  // Fill config with the scaling factor by which to reduce encoding size.
  const int num_streams = kScaleFactors.size();
  VideoEncoderConfig config;
  test::FillEncoderConfiguration(kVideoCodecVP8, num_streams, &config);
  for (int i = 0; i < num_streams; ++i) {
    config.simulcast_layers[i].scale_resolution_down_by = kScaleFactors[i];
  }

  // Verify requested alignment from sink, alignment is not adjusted.
  VideoEncoder::EncoderInfo info =
      GetEncoderInfo(kRequestedAlignment, kApplyAlignmentToAllLayers);
  int alignment = AlignmentAdjuster::GetAlignmentAndMaybeAdjustScaleFactors(
      info, &config, std::nullopt);
  EXPECT_EQ(alignment, kRequestedAlignment);

  // Verify that scale factors are not adjusted.
  for (int i = 0; i < num_streams; ++i) {
    EXPECT_EQ(config.simulcast_layers[i].scale_resolution_down_by,
              kScaleFactors[i]);
  }
}

TEST_P(AlignmentAdjusterTestTwoLayers, AlignmentAppliedToAllLayers) {
  const bool kApplyAlignmentToAllLayers = true;

  // Fill config with the scaling factor by which to reduce encoding size.
  const int num_streams = kScaleFactors.size();
  VideoEncoderConfig config;
  test::FillEncoderConfiguration(kVideoCodecVP8, num_streams, &config);
  for (int i = 0; i < num_streams; ++i) {
    config.simulcast_layers[i].scale_resolution_down_by = kScaleFactors[i];
  }

  // Verify requested alignment from sink, alignment is not adjusted.
  VideoEncoder::EncoderInfo info =
      GetEncoderInfo(kRequestedAlignment, kApplyAlignmentToAllLayers);
  int alignment = AlignmentAdjuster::GetAlignmentAndMaybeAdjustScaleFactors(
      info, &config, std::optional<size_t>(kMaxLayers));
  EXPECT_EQ(alignment, kAdjustedAlignment);

  // Verify adjusted scale factors.
  for (int i = 0; i < num_streams; ++i) {
    EXPECT_EQ(config.simulcast_layers[i].scale_resolution_down_by,
              kAdjustedScaleFactors[i]);
  }
}

}  // namespace test
}  // namespace webrtc