/*
 *  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.
 */

#include <algorithm>
#include <array>

#include "api/array_view.h"
#include "common_audio/wav_file.h"
#include "common_audio/wav_header.h"
#include "modules/audio_device/include/test_audio_device.h"
#include "rtc_base/logging.h"
#include "test/gmock.h"
#include "test/gtest.h"
#include "test/testsupport/fileutils.h"

namespace webrtc {

namespace {

void RunTestViaRtcPlatformFileAPI(
    rtc::ArrayView<const int16_t> input_samples,
    rtc::ArrayView<const int16_t> expected_samples,
    size_t samples_per_frame) {
  const ::testing::TestInfo* const test_info =
      ::testing::UnitTest::GetInstance()->current_test_info();

  const std::string output_filename =
      test::OutputPath() + "BoundedWavFileWriterTest_" + test_info->name() +
      "_" + std::to_string(std::rand()) + ".wav";

  static const size_t kSamplesPerFrame = 8;
  static const int kSampleRate = kSamplesPerFrame * 100;
  EXPECT_EQ(TestAudioDeviceModule::SamplesPerFrame(kSampleRate),
            kSamplesPerFrame);

  // Test through rtc::PlatformFile API.
  {
    auto file = rtc::CreatePlatformFile(output_filename);
    std::unique_ptr<TestAudioDeviceModule::Renderer> writer =
        TestAudioDeviceModule::CreateBoundedWavFileWriter(file, 800);

    for (size_t i = 0; i < input_samples.size(); i += kSamplesPerFrame) {
      EXPECT_TRUE(writer->Render(rtc::ArrayView<const int16_t>(
          &input_samples[i],
          std::min(kSamplesPerFrame, input_samples.size() - i))));
    }
  }

  {
    auto file = rtc::OpenPlatformFile(output_filename);
    WavReader reader(file);
    std::vector<int16_t> read_samples(expected_samples.size());
    EXPECT_EQ(expected_samples.size(),
              reader.ReadSamples(read_samples.size(), read_samples.data()));
    EXPECT_THAT(expected_samples, testing::ElementsAreArray(read_samples));

    EXPECT_EQ(0u, reader.ReadSamples(read_samples.size(), read_samples.data()));
  }

  remove(output_filename.c_str());
}

void RunTest(const std::vector<int16_t>& input_samples,
             const std::vector<int16_t>& expected_samples,
             size_t samples_per_frame) {
  const ::testing::TestInfo* const test_info =
      ::testing::UnitTest::GetInstance()->current_test_info();

  const std::string output_filename =
      test::OutputPath() + "BoundedWavFileWriterTest_" + test_info->name() +
      "_" + std::to_string(std::rand()) + ".wav";

  static const size_t kSamplesPerFrame = 8;
  static const int kSampleRate = kSamplesPerFrame * 100;
  EXPECT_EQ(TestAudioDeviceModule::SamplesPerFrame(kSampleRate),
            kSamplesPerFrame);

  // Test through file name API.
  {
    std::unique_ptr<TestAudioDeviceModule::Renderer> writer =
        TestAudioDeviceModule::CreateBoundedWavFileWriter(output_filename, 800);

    for (size_t i = 0; i < input_samples.size(); i += kSamplesPerFrame) {
      EXPECT_TRUE(writer->Render(rtc::ArrayView<const int16_t>(
          &input_samples[i],
          std::min(kSamplesPerFrame, input_samples.size() - i))));
    }
  }

  {
    WavReader reader(output_filename);
    std::vector<int16_t> read_samples(expected_samples.size());
    EXPECT_EQ(expected_samples.size(),
              reader.ReadSamples(read_samples.size(), read_samples.data()));
    EXPECT_EQ(expected_samples, read_samples);

    EXPECT_EQ(0u, reader.ReadSamples(read_samples.size(), read_samples.data()));
  }

  remove(output_filename.c_str());
}
}  // namespace

TEST(BoundedWavFileWriterTest, NoSilence) {
  static const std::vector<int16_t> kInputSamples = {
      75,   1234,  243,    -1231, -22222, 0,    3,      88,
      1222, -1213, -13222, -7,    -3525,  5787, -25247, 8};
  static const std::vector<int16_t> kExpectedSamples = kInputSamples;
  RunTest(kInputSamples, kExpectedSamples, 8);
}

TEST(BoundedWavFileWriterTest, SomeStartSilence) {
  static const std::vector<int16_t> kInputSamples = {
      0, 0, 0, 0, 3, 0, 0, 0, 0, 3, -13222, -7, -3525, 5787, -25247, 8};
  static const std::vector<int16_t> kExpectedSamples(kInputSamples.begin() + 10,
                                                     kInputSamples.end());
  RunTest(kInputSamples, kExpectedSamples, 8);
}

TEST(BoundedWavFileWriterTest, SomeStartSilenceRtcFile) {
  static const std::vector<int16_t> kInputSamples = {
      0, 0, 0, 0, 3, 0, 0, 0, 0, 3, -13222, -7, -3525, 5787, -25247, 8};
  static const std::vector<int16_t> kExpectedSamples(kInputSamples.begin() + 10,
                                                     kInputSamples.end());
  RunTestViaRtcPlatformFileAPI(kInputSamples, kExpectedSamples, 8);
}

TEST(BoundedWavFileWriterTest, NegativeStartSilence) {
  static const std::vector<int16_t> kInputSamples = {
      0, -4, -6, 0, 3, 0, 0, 0, 0, 3, -13222, -7, -3525, 5787, -25247, 8};
  static const std::vector<int16_t> kExpectedSamples(kInputSamples.begin() + 2,
                                                     kInputSamples.end());
  RunTest(kInputSamples, kExpectedSamples, 8);
}

TEST(BoundedWavFileWriterTest, SomeEndSilence) {
  static const std::vector<int16_t> kInputSamples = {
      75, 1234, 243, -1231, -22222, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0};
  static const std::vector<int16_t> kExpectedSamples(kInputSamples.begin(),
                                                     kInputSamples.end() - 9);
  RunTest(kInputSamples, kExpectedSamples, 8);
}

TEST(BoundedWavFileWriterTest, DoubleEndSilence) {
  static const std::vector<int16_t> kInputSamples = {
      75, 1234,  243,    -1231, -22222, 0,    0, 0,
      0,  -1213, -13222, -7,    -3525,  5787, 0, 0};
  static const std::vector<int16_t> kExpectedSamples(kInputSamples.begin(),
                                                     kInputSamples.end() - 2);
  RunTest(kInputSamples, kExpectedSamples, 8);
}

TEST(BoundedWavFileWriterTest, DoubleSilence) {
  static const std::vector<int16_t> kInputSamples = {0,     -1213, -13222, -7,
                                                     -3525, 5787,  0,      0};
  static const std::vector<int16_t> kExpectedSamples(kInputSamples.begin() + 1,
                                                     kInputSamples.end() - 2);
  RunTest(kInputSamples, kExpectedSamples, 8);
}

TEST(BoundedWavFileWriterTest, EndSilenceCutoff) {
  static const std::vector<int16_t> kInputSamples = {
      75, 1234, 243, -1231, -22222, 0, 1, 0, 0, 0, 0};
  static const std::vector<int16_t> kExpectedSamples(kInputSamples.begin(),
                                                     kInputSamples.end() - 4);
  RunTest(kInputSamples, kExpectedSamples, 8);
}

TEST(PulsedNoiseCapturerTest, SetMaxAmplitude) {
  const int16_t kAmplitude = 50;
  std::unique_ptr<TestAudioDeviceModule::PulsedNoiseCapturer> capturer =
      TestAudioDeviceModule::CreatePulsedNoiseCapturer(
          kAmplitude, /*sampling_frequency_in_hz=*/8000);
  rtc::BufferT<int16_t> recording_buffer;

  // Verify that the capturer doesn't create entries louder than than
  // kAmplitude. Since the pulse generator alternates between writing
  // zeroes and actual entries, we need to do the capturing twice.
  capturer->Capture(&recording_buffer);
  capturer->Capture(&recording_buffer);
  int16_t max_sample =
      *std::max_element(recording_buffer.begin(), recording_buffer.end());
  EXPECT_LE(max_sample, kAmplitude);

  // Increase the amplitude and verify that the samples can now be louder
  // than the previous max.
  capturer->SetMaxAmplitude(kAmplitude * 2);
  capturer->Capture(&recording_buffer);
  capturer->Capture(&recording_buffer);
  max_sample =
      *std::max_element(recording_buffer.begin(), recording_buffer.end());
  EXPECT_GT(max_sample, kAmplitude);
}

}  // namespace webrtc