/*
 *  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 <stddef.h>
#include <stdint.h>

#include <memory>
#include <vector>

#include "absl/types/optional.h"
#include "api/test/create_frame_generator.h"
#include "api/test/frame_generator_interface.h"
#include "api/video_codecs/video_codec.h"
#include "api/video_codecs/video_encoder.h"
#include "modules/video_coding/codecs/av1/libaom_av1_decoder.h"
#include "modules/video_coding/codecs/av1/libaom_av1_encoder.h"
#include "modules/video_coding/codecs/av1/scalability_structure_l1t2.h"
#include "modules/video_coding/codecs/av1/scalable_video_controller.h"
#include "modules/video_coding/codecs/av1/scalable_video_controller_no_layering.h"
#include "modules/video_coding/include/video_codec_interface.h"
#include "modules/video_coding/include/video_error_codes.h"
#include "test/gmock.h"
#include "test/gtest.h"

namespace webrtc {
namespace {

using ::testing::ContainerEq;
using ::testing::Each;
using ::testing::ElementsAreArray;
using ::testing::Ge;
using ::testing::IsEmpty;
using ::testing::Not;
using ::testing::NotNull;
using ::testing::SizeIs;
using ::testing::Truly;
using ::testing::Values;

// Use small resolution for this test to make it faster.
constexpr int kWidth = 320;
constexpr int kHeight = 180;
constexpr int kFramerate = 30;
constexpr int kRtpTicksPerSecond = 90000;

class TestAv1Encoder {
 public:
  struct Encoded {
    EncodedImage encoded_image;
    CodecSpecificInfo codec_specific_info;
  };

  TestAv1Encoder() : encoder_(CreateLibaomAv1Encoder()) { InitEncoder(); }
  explicit TestAv1Encoder(
      std::unique_ptr<ScalableVideoController> svc_controller)
      : encoder_(CreateLibaomAv1Encoder(std::move(svc_controller))) {
    InitEncoder();
  }
  // This class requires pointer stability and thus not copyable nor movable.
  TestAv1Encoder(const TestAv1Encoder&) = delete;
  TestAv1Encoder& operator=(const TestAv1Encoder&) = delete;

  void EncodeAndAppend(const VideoFrame& frame, std::vector<Encoded>* encoded) {
    callback_.SetEncodeStorage(encoded);
    std::vector<VideoFrameType> frame_types = {
        VideoFrameType::kVideoFrameDelta};
    EXPECT_EQ(encoder_->Encode(frame, &frame_types), WEBRTC_VIDEO_CODEC_OK);
    // Prefer to crash checking nullptr rather than writing to random memory.
    callback_.SetEncodeStorage(nullptr);
  }

 private:
  class EncoderCallback : public EncodedImageCallback {
   public:
    void SetEncodeStorage(std::vector<Encoded>* storage) { storage_ = storage; }

   private:
    Result OnEncodedImage(
        const EncodedImage& encoded_image,
        const CodecSpecificInfo* codec_specific_info,
        const RTPFragmentationHeader* /*fragmentation*/) override {
      RTC_CHECK(storage_);
      storage_->push_back({encoded_image, *codec_specific_info});
      return Result(Result::Error::OK);
    }

    std::vector<Encoded>* storage_ = nullptr;
  };

  void InitEncoder() {
    RTC_CHECK(encoder_);
    VideoCodec codec_settings;
    codec_settings.width = kWidth;
    codec_settings.height = kHeight;
    codec_settings.maxFramerate = kFramerate;
    codec_settings.maxBitrate = 1000;
    VideoEncoder::Settings encoder_settings(
        VideoEncoder::Capabilities(/*loss_notification=*/false),
        /*number_of_cores=*/1, /*max_payload_size=*/1200);
    EXPECT_EQ(encoder_->InitEncode(&codec_settings, encoder_settings),
              WEBRTC_VIDEO_CODEC_OK);
    EXPECT_EQ(encoder_->RegisterEncodeCompleteCallback(&callback_),
              WEBRTC_VIDEO_CODEC_OK);
  }

  EncoderCallback callback_;
  std::unique_ptr<VideoEncoder> encoder_;
};

class TestAv1Decoder {
 public:
  explicit TestAv1Decoder(int decoder_id)
      : decoder_id_(decoder_id), decoder_(CreateLibaomAv1Decoder()) {
    if (decoder_ == nullptr) {
      ADD_FAILURE() << "Failed to create a decoder#" << decoder_id_;
      return;
    }
    EXPECT_EQ(decoder_->InitDecode(/*codec_settings=*/nullptr,
                                   /*number_of_cores=*/1),
              WEBRTC_VIDEO_CODEC_OK);
    EXPECT_EQ(decoder_->RegisterDecodeCompleteCallback(&callback_),
              WEBRTC_VIDEO_CODEC_OK);
  }
  // This class requires pointer stability and thus not copyable nor movable.
  TestAv1Decoder(const TestAv1Decoder&) = delete;
  TestAv1Decoder& operator=(const TestAv1Decoder&) = delete;

  void Decode(int64_t frame_id, const EncodedImage& image) {
    ASSERT_THAT(decoder_, NotNull());
    int32_t error = decoder_->Decode(image, /*missing_frames=*/false,
                                     /*render_time_ms=*/image.capture_time_ms_);
    if (error != WEBRTC_VIDEO_CODEC_OK) {
      ADD_FAILURE() << "Failed to decode frame id " << frame_id
                    << " with error code " << error << " by decoder#"
                    << decoder_id_;
      return;
    }
    decoded_ids_.push_back(frame_id);
  }

  const std::vector<int64_t>& decoded_frame_ids() const { return decoded_ids_; }
  size_t num_output_frames() const { return callback_.num_called(); }

 private:
  // Decoder callback that only counts how many times it was called.
  // While it is tempting to replace it with a simple mock, that one requires
  // to set expectation on number of calls in advance. Tests below unsure about
  // expected number of calls until after calls are done.
  class DecoderCallback : public DecodedImageCallback {
   public:
    size_t num_called() const { return num_called_; }

   private:
    int32_t Decoded(VideoFrame& /*decoded_image*/) override {
      ++num_called_;
      return 0;
    }
    void Decoded(VideoFrame& /*decoded_image*/,
                 absl::optional<int32_t> /*decode_time_ms*/,
                 absl::optional<uint8_t> /*qp*/) override {
      ++num_called_;
    }

    int num_called_ = 0;
  };

  const int decoder_id_;
  std::vector<int64_t> decoded_ids_;
  DecoderCallback callback_;
  const std::unique_ptr<VideoDecoder> decoder_;
};

class VideoFrameGenerator {
 public:
  VideoFrame NextFrame() {
    return VideoFrame::Builder()
        .set_video_frame_buffer(frame_buffer_generator_->NextFrame().buffer)
        .set_timestamp_rtp(timestamp_ += kRtpTicksPerSecond / kFramerate)
        .build();
  }

 private:
  uint32_t timestamp_ = 1000;
  std::unique_ptr<test::FrameGeneratorInterface> frame_buffer_generator_ =
      test::CreateSquareFrameGenerator(
          kWidth,
          kHeight,
          test::FrameGeneratorInterface::OutputType::kI420,
          absl::nullopt);
};

TEST(LibaomAv1Test, EncodeDecode) {
  TestAv1Decoder decoder(0);
  TestAv1Encoder encoder;
  VideoFrameGenerator generator;

  std::vector<TestAv1Encoder::Encoded> encoded_frames;
  for (size_t i = 0; i < 4; ++i) {
    encoder.EncodeAndAppend(generator.NextFrame(), &encoded_frames);
  }
  for (size_t frame_id = 0; frame_id < encoded_frames.size(); ++frame_id) {
    decoder.Decode(static_cast<int64_t>(frame_id),
                   encoded_frames[frame_id].encoded_image);
  }

  // Check encoder produced some frames for decoder to decode.
  ASSERT_THAT(encoded_frames, Not(IsEmpty()));
  // Check decoder found all of them valid.
  EXPECT_THAT(decoder.decoded_frame_ids(), SizeIs(encoded_frames.size()));
  // Check each of them produced an output frame.
  EXPECT_EQ(decoder.num_output_frames(), decoder.decoded_frame_ids().size());
}

struct SvcTestParam {
  std::function<std::unique_ptr<ScalableVideoController>()> svc_factory;
  int num_frames_to_generate;
};

class LibaomAv1SvcTest : public ::testing::TestWithParam<SvcTestParam> {};

TEST_P(LibaomAv1SvcTest, EncodeAndDecodeAllDecodeTargets) {
  std::unique_ptr<ScalableVideoController> svc_controller =
      GetParam().svc_factory();
  size_t num_decode_targets =
      svc_controller->DependencyStructure().num_decode_targets;

  std::vector<TestAv1Encoder::Encoded> encoded_frames;
  TestAv1Encoder encoder(std::move(svc_controller));
  VideoFrameGenerator generator;
  for (int temporal_unit = 0; temporal_unit < GetParam().num_frames_to_generate;
       ++temporal_unit) {
    encoder.EncodeAndAppend(generator.NextFrame(), &encoded_frames);
  }

  ASSERT_THAT(
      encoded_frames, Each(Truly([&](const TestAv1Encoder::Encoded& frame) {
        return frame.codec_specific_info.generic_frame_info &&
               frame.codec_specific_info.generic_frame_info
                       ->decode_target_indications.size() == num_decode_targets;
      })));

  for (size_t dt = 0; dt < num_decode_targets; ++dt) {
    TestAv1Decoder decoder(dt);
    std::vector<int64_t> requested_ids;
    for (int64_t frame_id = 0;
         frame_id < static_cast<int64_t>(encoded_frames.size()); ++frame_id) {
      const TestAv1Encoder::Encoded& frame = encoded_frames[frame_id];
      if (frame.codec_specific_info.generic_frame_info
              ->decode_target_indications[dt] !=
          DecodeTargetIndication::kNotPresent) {
        requested_ids.push_back(frame_id);
        decoder.Decode(frame_id, frame.encoded_image);
      }
    }

    ASSERT_THAT(requested_ids, SizeIs(Ge(2u)));
    // Check decoder found all of them valid.
    EXPECT_THAT(decoder.decoded_frame_ids(), ContainerEq(requested_ids))
        << "Decoder#" << dt;
    // Check each of them produced an output frame.
    EXPECT_EQ(decoder.num_output_frames(), decoder.decoded_frame_ids().size())
        << "Decoder#" << dt;
  }
}

INSTANTIATE_TEST_SUITE_P(
    Svc,
    LibaomAv1SvcTest,
    Values(SvcTestParam{std::make_unique<ScalableVideoControllerNoLayering>,
                        /*num_frames_to_generate=*/4},
           SvcTestParam{std::make_unique<ScalabilityStructureL1T2>,
                        /*num_frames_to_generate=*/4}));

}  // namespace
}  // namespace webrtc