/*
 *  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 <memory>
#include <vector>

#include "api/test/mock_video_decoder.h"
#include "modules/video_coding/include/mock/mock_vcm_callbacks.h"
#include "modules/video_coding/include/video_coding.h"
#include "modules/video_coding/timing.h"
#include "modules/video_coding/video_coding_impl.h"
#include "system_wrappers/include/clock.h"
#include "test/gtest.h"
#include "test/video_codec_settings.h"

using ::testing::_;
using ::testing::AnyNumber;
using ::testing::NiceMock;

namespace webrtc {
namespace vcm {
namespace {

class TestVideoReceiver : public ::testing::Test {
 protected:
  static const int kUnusedPayloadType = 10;

  TestVideoReceiver() : clock_(0) {}

  virtual void SetUp() {
    timing_.reset(new VCMTiming(&clock_));
    receiver_.reset(new VideoReceiver(&clock_, timing_.get()));
    receiver_->RegisterExternalDecoder(&decoder_, kUnusedPayloadType);
    const size_t kMaxNackListSize = 250;
    const int kMaxPacketAgeToNack = 450;
    receiver_->SetNackSettings(kMaxNackListSize, kMaxPacketAgeToNack, 0);

    webrtc::test::CodecSettings(kVideoCodecVP8, &settings_);
    settings_.plType = kUnusedPayloadType;  // Use the mocked encoder.
    EXPECT_EQ(0, receiver_->RegisterReceiveCodec(&settings_, 1, true));

    // Since we call Decode, we need to provide a valid receive callback.
    // However, for the purposes of these tests, we ignore the callbacks.
    EXPECT_CALL(receive_callback_, OnIncomingPayloadType(_)).Times(AnyNumber());
    EXPECT_CALL(receive_callback_, OnDecoderImplementationName(_))
        .Times(AnyNumber());
    receiver_->RegisterReceiveCallback(&receive_callback_);
  }

  void InsertAndVerifyPaddingFrame(const uint8_t* payload,
                                   WebRtcRTPHeader* header) {
    ASSERT_TRUE(header != NULL);
    for (int j = 0; j < 5; ++j) {
      // Padding only packets are passed to the VCM with payload size 0.
      EXPECT_EQ(0, receiver_->IncomingPacket(payload, 0, *header));
      ++header->header.sequenceNumber;
    }
    receiver_->Process();
    EXPECT_CALL(decoder_, Decode(_, _, _, _)).Times(0);
    EXPECT_EQ(VCM_FRAME_NOT_READY, receiver_->Decode(100));
  }

  void InsertAndVerifyDecodableFrame(const uint8_t* payload,
                                     size_t length,
                                     WebRtcRTPHeader* header) {
    ASSERT_TRUE(header != NULL);
    EXPECT_EQ(0, receiver_->IncomingPacket(payload, length, *header));
    ++header->header.sequenceNumber;
    EXPECT_CALL(packet_request_callback_, ResendPackets(_, _)).Times(0);
    receiver_->Process();
    EXPECT_CALL(decoder_, Decode(_, _, _, _)).Times(1);
    EXPECT_EQ(0, receiver_->Decode(100));
  }

  SimulatedClock clock_;
  VideoCodec settings_;
  NiceMock<MockVideoDecoder> decoder_;
  NiceMock<MockPacketRequestCallback> packet_request_callback_;

  std::unique_ptr<VCMTiming> timing_;
  MockVCMReceiveCallback receive_callback_;
  std::unique_ptr<VideoReceiver> receiver_;
};

TEST_F(TestVideoReceiver, PaddingOnlyFrames) {
  EXPECT_EQ(0, receiver_->SetVideoProtection(kProtectionNack, true));
  EXPECT_EQ(
      0, receiver_->RegisterPacketRequestCallback(&packet_request_callback_));
  const size_t kPaddingSize = 220;
  const uint8_t payload[kPaddingSize] = {0};
  WebRtcRTPHeader header = {};
  header.frameType = kEmptyFrame;
  header.header.markerBit = false;
  header.header.paddingLength = kPaddingSize;
  header.header.payloadType = kUnusedPayloadType;
  header.header.ssrc = 1;
  header.header.headerLength = 12;
  header.video_header().codec = kVideoCodecVP8;
  for (int i = 0; i < 10; ++i) {
    EXPECT_CALL(packet_request_callback_, ResendPackets(_, _)).Times(0);
    InsertAndVerifyPaddingFrame(payload, &header);
    clock_.AdvanceTimeMilliseconds(33);
    header.header.timestamp += 3000;
  }
}

TEST_F(TestVideoReceiver, PaddingOnlyFramesWithLosses) {
  EXPECT_EQ(0, receiver_->SetVideoProtection(kProtectionNack, true));
  EXPECT_EQ(
      0, receiver_->RegisterPacketRequestCallback(&packet_request_callback_));
  const size_t kFrameSize = 1200;
  const size_t kPaddingSize = 220;
  const uint8_t payload[kFrameSize] = {0};
  WebRtcRTPHeader header = {};
  header.frameType = kEmptyFrame;
  header.header.markerBit = false;
  header.header.paddingLength = kPaddingSize;
  header.header.payloadType = kUnusedPayloadType;
  header.header.ssrc = 1;
  header.header.headerLength = 12;
  header.video_header().codec = kVideoCodecVP8;
  header.video_header().video_type_header.emplace<RTPVideoHeaderVP8>();
  // Insert one video frame to get one frame decoded.
  header.frameType = kVideoFrameKey;
  header.video_header().is_first_packet_in_frame = true;
  header.header.markerBit = true;
  InsertAndVerifyDecodableFrame(payload, kFrameSize, &header);
  clock_.AdvanceTimeMilliseconds(33);
  header.header.timestamp += 3000;

  header.frameType = kEmptyFrame;
  header.video_header().is_first_packet_in_frame = false;
  header.header.markerBit = false;
  // Insert padding frames.
  for (int i = 0; i < 10; ++i) {
    // Lose one packet from the 6th frame.
    if (i == 5) {
      ++header.header.sequenceNumber;
    }
    // Lose the 4th frame.
    if (i == 3) {
      header.header.sequenceNumber += 5;
    } else {
      if (i > 3 && i < 5) {
        EXPECT_CALL(packet_request_callback_, ResendPackets(_, 5)).Times(1);
      } else if (i >= 5) {
        EXPECT_CALL(packet_request_callback_, ResendPackets(_, 6)).Times(1);
      } else {
        EXPECT_CALL(packet_request_callback_, ResendPackets(_, _)).Times(0);
      }
      InsertAndVerifyPaddingFrame(payload, &header);
    }
    clock_.AdvanceTimeMilliseconds(33);
    header.header.timestamp += 3000;
  }
}

TEST_F(TestVideoReceiver, PaddingOnlyAndVideo) {
  EXPECT_EQ(0, receiver_->SetVideoProtection(kProtectionNack, true));
  EXPECT_EQ(
      0, receiver_->RegisterPacketRequestCallback(&packet_request_callback_));
  const size_t kFrameSize = 1200;
  const size_t kPaddingSize = 220;
  const uint8_t payload[kFrameSize] = {0};
  WebRtcRTPHeader header = {};
  header.frameType = kEmptyFrame;
  header.video_header().is_first_packet_in_frame = false;
  header.header.markerBit = false;
  header.header.paddingLength = kPaddingSize;
  header.header.payloadType = kUnusedPayloadType;
  header.header.ssrc = 1;
  header.header.headerLength = 12;
  header.video_header().codec = kVideoCodecVP8;
  auto& vp8_header =
      header.video.video_type_header.emplace<RTPVideoHeaderVP8>();
  vp8_header.pictureId = -1;
  vp8_header.tl0PicIdx = -1;
  for (int i = 0; i < 3; ++i) {
    // Insert 2 video frames.
    for (int j = 0; j < 2; ++j) {
      if (i == 0 && j == 0)  // First frame should be a key frame.
        header.frameType = kVideoFrameKey;
      else
        header.frameType = kVideoFrameDelta;
      header.video_header().is_first_packet_in_frame = true;
      header.header.markerBit = true;
      InsertAndVerifyDecodableFrame(payload, kFrameSize, &header);
      clock_.AdvanceTimeMilliseconds(33);
      header.header.timestamp += 3000;
    }

    // Insert 2 padding only frames.
    header.frameType = kEmptyFrame;
    header.video_header().is_first_packet_in_frame = false;
    header.header.markerBit = false;
    for (int j = 0; j < 2; ++j) {
      // InsertAndVerifyPaddingFrame(payload, &header);
      clock_.AdvanceTimeMilliseconds(33);
      header.header.timestamp += 3000;
    }
  }
}

}  // namespace
}  // namespace vcm
}  // namespace webrtc