/*
 *  Copyright (c) 2013 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 "common_audio/include/audio_util.h"

#include <cstddef>
#include <cstdint>
#include <iterator>

#include "api/audio/audio_view.h"
#include "test/gmock.h"
#include "test/gtest.h"

namespace webrtc {
namespace {

using ::testing::ElementsAreArray;

void ExpectArraysEq(const int16_t* ref, const int16_t* test, size_t length) {
  for (size_t i = 0; i < length; ++i) {
    EXPECT_EQ(ref[i], test[i]);
  }
}

void ExpectArraysEq(const float* ref, const float* test, size_t length) {
  for (size_t i = 0; i < length; ++i) {
    EXPECT_NEAR(ref[i], test[i], 0.01f);
  }
}

TEST(AudioUtilTest, S16ToFloat) {
  static constexpr int16_t kInput[] = {0, 1, -1, 16384, -16384, 32767, -32768};
  static constexpr float kReference[] = {
      0.f, 1.f / 32767.f, -1.f / 32768.f, 16384.f / 32767.f, -0.5f, 1.f, -1.f};
  static constexpr size_t kSize = std::size(kInput);
  static_assert(std::size(kReference) == kSize);
  float output[kSize];
  S16ToFloat(kInput, kSize, output);
  ExpectArraysEq(kReference, output, kSize);
}

TEST(AudioUtilTest, FloatS16ToS16) {
  static constexpr float kInput[] = {0.f,   0.4f,    0.5f,    -0.4f,
                                     -0.5f, 32768.f, -32769.f};
  static constexpr int16_t kReference[] = {0, 0, 1, 0, -1, 32767, -32768};
  static constexpr size_t kSize = std::size(kInput);
  static_assert(std::size(kReference) == kSize);
  int16_t output[kSize];
  FloatS16ToS16(kInput, kSize, output);
  ExpectArraysEq(kReference, output, kSize);
}

TEST(AudioUtilTest, FloatToFloatS16) {
  static constexpr float kInput[] = {0.f,
                                     0.4f / 32768.f,
                                     0.6f / 32768.f,
                                     -0.4f / 32768.f,
                                     -0.6f / 32768.f,
                                     1.f,
                                     -1.f,
                                     1.f,
                                     -1.f};
  static constexpr float kReference[] = {
      0.f, 0.4f, 0.6f, -0.4f, -0.6f, 32768.f, -32768.f, 32768.f, -32768.f};
  static constexpr size_t kSize = std::size(kInput);
  static_assert(std::size(kReference) == kSize);
  float output[kSize];
  FloatToFloatS16(kInput, kSize, output);
  ExpectArraysEq(kReference, output, kSize);
}

TEST(AudioUtilTest, FloatS16ToFloat) {
  static constexpr float kInput[] = {0.f,     0.4f,     0.6f,    -0.4f,   -0.6f,
                                     32767.f, -32768.f, 32767.f, -32768.f};
  static constexpr float kReference[] = {0.f,
                                         0.4f / 32768.f,
                                         0.6f / 32768.f,
                                         -0.4f / 32768.f,
                                         -0.6f / 32768.f,
                                         1.f,
                                         -1.f,
                                         1.f,
                                         -1.f};
  static constexpr size_t kSize = std::size(kInput);
  static_assert(std::size(kReference) == kSize);
  float output[kSize];
  FloatS16ToFloat(kInput, kSize, output);
  ExpectArraysEq(kReference, output, kSize);
}

TEST(AudioUtilTest, DbfsToFloatS16) {
  static constexpr float kInput[] = {-90.f, -70.f, -30.f, -20.f, -10.f,
                                     -5.f,  -1.f,  0.f,   1.f};
  static constexpr float kReference[] = {
      1.036215186f, 10.36215115f, 1036.215088f, 3276.800049f, 10362.15137f,
      18426.80078f, 29204.51172f, 32768.f,      36766.30078f};
  static constexpr size_t kSize = std::size(kInput);
  static_assert(std::size(kReference) == kSize);
  float output[kSize];
  for (size_t i = 0; i < kSize; ++i) {
    output[i] = DbfsToFloatS16(kInput[i]);
  }
  ExpectArraysEq(kReference, output, kSize);
}

TEST(AudioUtilTest, FloatS16ToDbfs) {
  static constexpr float kInput[] = {1.036215143f, 10.36215143f,  1036.215143f,
                                     3276.8f,      10362.151436f, 18426.800543f,
                                     29204.51074f, 32768.0f,      36766.30071f};

  static constexpr float kReference[] = {
      -90.f, -70.f, -30.f, -20.f, -10.f, -5.f, -1.f, 0.f, 0.9999923706f};
  static constexpr size_t kSize = std::size(kInput);
  static_assert(std::size(kReference) == kSize);

  float output[kSize];
  for (size_t i = 0; i < kSize; ++i) {
    output[i] = FloatS16ToDbfs(kInput[i]);
  }
  ExpectArraysEq(kReference, output, kSize);
}

TEST(AudioUtilTest, InterleavingStereo) {
  constexpr int16_t kInterleaved[] = {2, 3, 4, 9, 8, 27, 16, 81};
  constexpr size_t kSamplesPerChannel = 4;
  constexpr int kNumChannels = 2;
  constexpr size_t kLength = kSamplesPerChannel * kNumChannels;
  int16_t deinterleaved[kLength] = {};
  DeinterleavedView<int16_t> deinterleaved_view(
      &deinterleaved[0], kSamplesPerChannel, kNumChannels);
  Deinterleave({&kInterleaved[0], kSamplesPerChannel, kNumChannels},
               deinterleaved_view);
  const int16_t kRefLeft[] = {2, 4, 8, 16};
  const int16_t kRefRight[] = {3, 9, 27, 81};
  ExpectArraysEq(kRefLeft, deinterleaved_view[0].data(), kSamplesPerChannel);
  ExpectArraysEq(kRefRight, deinterleaved_view[1].data(), kSamplesPerChannel);

  int16_t interleaved[kLength];
  Interleave<int16_t>({&deinterleaved[0], kSamplesPerChannel, kNumChannels},
                      {&interleaved[0], kSamplesPerChannel, kNumChannels});
  ExpectArraysEq(kInterleaved, interleaved, kLength);
}

TEST(AudioUtilTest, InterleavingMonoIsIdentical) {
  const int16_t kInterleaved[] = {1, 2, 3, 4, 5};
  const size_t kSamplesPerChannel = 5;
  const int kNumChannels = 1;
  int16_t mono[kSamplesPerChannel];
  DeinterleavedView<int16_t> deinterleaved_view(&mono[0], kSamplesPerChannel,
                                                kNumChannels);
  Deinterleave({kInterleaved, kSamplesPerChannel, kNumChannels},
               deinterleaved_view);
  ExpectArraysEq(kInterleaved, deinterleaved_view.AsMono().data(),
                 kSamplesPerChannel);

  int16_t interleaved[kSamplesPerChannel];
  Interleave<int16_t>(deinterleaved_view,
                      {&interleaved[0], kSamplesPerChannel, kNumChannels});
  ExpectArraysEq(mono, interleaved, kSamplesPerChannel);
}

TEST(AudioUtilTest, DownmixInterleavedToMono) {
  {
    const size_t kNumFrames = 4;
    const int kNumChannels = 1;
    const int16_t interleaved[kNumChannels * kNumFrames] = {1, 2, -1, -3};
    int16_t deinterleaved[kNumFrames];

    DownmixInterleavedToMono(interleaved, kNumFrames, kNumChannels,
                             deinterleaved);

    EXPECT_THAT(deinterleaved, ElementsAreArray(interleaved));
  }
  {
    const size_t kNumFrames = 2;
    const int kNumChannels = 2;
    const int16_t interleaved[kNumChannels * kNumFrames] = {10, 20, -10, -30};
    int16_t deinterleaved[kNumFrames];

    DownmixInterleavedToMono(interleaved, kNumFrames, kNumChannels,
                             deinterleaved);
    const int16_t expected[kNumFrames] = {15, -20};

    EXPECT_THAT(deinterleaved, ElementsAreArray(expected));
  }
  {
    const size_t kNumFrames = 3;
    const int kNumChannels = 3;
    const int16_t interleaved[kNumChannels * kNumFrames] = {
        30000, 30000, 24001, -5, -10, -20, -30000, -30999, -30000};
    int16_t deinterleaved[kNumFrames];

    DownmixInterleavedToMono(interleaved, kNumFrames, kNumChannels,
                             deinterleaved);
    const int16_t expected[kNumFrames] = {28000, -11, -30333};

    EXPECT_THAT(deinterleaved, ElementsAreArray(expected));
  }
}

}  // namespace
}  // namespace webrtc