/*
 *  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 <assert.h>

#include <algorithm>
#include <sstream>
#include <string>

#include "testing/gtest/include/gtest/gtest.h"

#include "webrtc/call.h"
#include "webrtc/modules/remote_bitrate_estimator/include/rtp_to_ntp.h"
#include "webrtc/modules/rtp_rtcp/interface/rtp_header_parser.h"
#include "webrtc/modules/rtp_rtcp/source/rtcp_utility.h"
#include "webrtc/system_wrappers/interface/critical_section_wrapper.h"
#include "webrtc/system_wrappers/interface/scoped_ptr.h"
#include "webrtc/test/direct_transport.h"
#include "webrtc/test/fake_audio_device.h"
#include "webrtc/test/fake_decoder.h"
#include "webrtc/test/fake_encoder.h"
#include "webrtc/test/frame_generator.h"
#include "webrtc/test/frame_generator_capturer.h"
#include "webrtc/test/rtp_rtcp_observer.h"
#include "webrtc/test/testsupport/fileutils.h"
#include "webrtc/test/testsupport/perf_test.h"
#include "webrtc/video/transport_adapter.h"
#include "webrtc/voice_engine/include/voe_base.h"
#include "webrtc/voice_engine/include/voe_codec.h"
#include "webrtc/voice_engine/include/voe_network.h"
#include "webrtc/voice_engine/include/voe_rtp_rtcp.h"
#include "webrtc/voice_engine/include/voe_video_sync.h"

namespace webrtc {

static unsigned int kLongTimeoutMs = 120 * 1000;
static const uint32_t kSendSsrc = 0x654321;
static const uint32_t kReceiverLocalSsrc = 0x123456;
static const uint8_t kSendPayloadType = 125;

class CallPerfTest : public ::testing::Test {
};

class SyncRtcpObserver : public test::RtpRtcpObserver {
 public:
  explicit SyncRtcpObserver(int delay_ms)
      : test::RtpRtcpObserver(kLongTimeoutMs, delay_ms),
        critical_section_(CriticalSectionWrapper::CreateCriticalSection()) {}

  virtual Action OnSendRtcp(const uint8_t* packet, size_t length) OVERRIDE {
    RTCPUtility::RTCPParserV2 parser(packet, length, true);
    EXPECT_TRUE(parser.IsValid());

    for (RTCPUtility::RTCPPacketTypes packet_type = parser.Begin();
         packet_type != RTCPUtility::kRtcpNotValidCode;
         packet_type = parser.Iterate()) {
      if (packet_type == RTCPUtility::kRtcpSrCode) {
        const RTCPUtility::RTCPPacket& packet = parser.Packet();
        synchronization::RtcpMeasurement ntp_rtp_pair(
            packet.SR.NTPMostSignificant,
            packet.SR.NTPLeastSignificant,
            packet.SR.RTPTimestamp);
        StoreNtpRtpPair(ntp_rtp_pair);
      }
    }
    return SEND_PACKET;
  }

  int64_t RtpTimestampToNtp(uint32_t timestamp) const {
    CriticalSectionScoped cs(critical_section_.get());
    int64_t timestamp_in_ms = -1;
    if (ntp_rtp_pairs_.size() == 2) {
      // TODO(stefan): We can't EXPECT_TRUE on this call due to a bug in the
      // RTCP sender where it sends RTCP SR before any RTP packets, which leads
      // to a bogus NTP/RTP mapping.
      synchronization::RtpToNtpMs(timestamp, ntp_rtp_pairs_, &timestamp_in_ms);
      return timestamp_in_ms;
    }
    return -1;
  }

 private:
  void StoreNtpRtpPair(synchronization::RtcpMeasurement ntp_rtp_pair) {
    CriticalSectionScoped cs(critical_section_.get());
    for (synchronization::RtcpList::iterator it = ntp_rtp_pairs_.begin();
         it != ntp_rtp_pairs_.end();
         ++it) {
      if (ntp_rtp_pair.ntp_secs == it->ntp_secs &&
          ntp_rtp_pair.ntp_frac == it->ntp_frac) {
        // This RTCP has already been added to the list.
        return;
      }
    }
    // We need two RTCP SR reports to map between RTP and NTP. More than two
    // will not improve the mapping.
    if (ntp_rtp_pairs_.size() == 2) {
      ntp_rtp_pairs_.pop_back();
    }
    ntp_rtp_pairs_.push_front(ntp_rtp_pair);
  }

  scoped_ptr<CriticalSectionWrapper> critical_section_;
  synchronization::RtcpList ntp_rtp_pairs_;
};

class VideoRtcpAndSyncObserver : public SyncRtcpObserver, public VideoRenderer {
  static const int kInSyncThresholdMs = 50;
  static const int kStartupTimeMs = 2000;
  static const int kMinRunTimeMs = 30000;

 public:
  VideoRtcpAndSyncObserver(Clock* clock,
                           int voe_channel,
                           VoEVideoSync* voe_sync,
                           SyncRtcpObserver* audio_observer)
      : SyncRtcpObserver(0),
        clock_(clock),
        voe_channel_(voe_channel),
        voe_sync_(voe_sync),
        audio_observer_(audio_observer),
        creation_time_ms_(clock_->TimeInMilliseconds()),
        first_time_in_sync_(-1) {}

  virtual void RenderFrame(const I420VideoFrame& video_frame,
                           int time_to_render_ms) OVERRIDE {
    int64_t now_ms = clock_->TimeInMilliseconds();
    uint32_t playout_timestamp = 0;
    if (voe_sync_->GetPlayoutTimestamp(voe_channel_, playout_timestamp) != 0)
      return;
    int64_t latest_audio_ntp =
        audio_observer_->RtpTimestampToNtp(playout_timestamp);
    int64_t latest_video_ntp = RtpTimestampToNtp(video_frame.timestamp());
    if (latest_audio_ntp < 0 || latest_video_ntp < 0)
      return;
    int time_until_render_ms =
        std::max(0, static_cast<int>(video_frame.render_time_ms() - now_ms));
    latest_video_ntp += time_until_render_ms;
    int64_t stream_offset = latest_audio_ntp - latest_video_ntp;
    std::stringstream ss;
    ss << stream_offset;
    webrtc::test::PrintResult(
        "stream_offset", "", "synchronization", ss.str(), "ms", false);
    int64_t time_since_creation = now_ms - creation_time_ms_;
    // During the first couple of seconds audio and video can falsely be
    // estimated as being synchronized. We don't want to trigger on those.
    if (time_since_creation < kStartupTimeMs)
      return;
    if (abs(latest_audio_ntp - latest_video_ntp) < kInSyncThresholdMs) {
      if (first_time_in_sync_ == -1) {
        first_time_in_sync_ = now_ms;
        webrtc::test::PrintResult("sync_convergence_time",
                                  "",
                                  "synchronization",
                                  time_since_creation,
                                  "ms",
                                  false);
      }
      if (time_since_creation > kMinRunTimeMs)
        observation_complete_->Set();
    }
  }

 private:
  Clock* clock_;
  int voe_channel_;
  VoEVideoSync* voe_sync_;
  SyncRtcpObserver* audio_observer_;
  int64_t creation_time_ms_;
  int64_t first_time_in_sync_;
};

TEST_F(CallPerfTest, PlaysOutAudioAndVideoInSync) {
  VoiceEngine* voice_engine = VoiceEngine::Create();
  VoEBase* voe_base = VoEBase::GetInterface(voice_engine);
  VoECodec* voe_codec = VoECodec::GetInterface(voice_engine);
  VoENetwork* voe_network = VoENetwork::GetInterface(voice_engine);
  VoEVideoSync* voe_sync = VoEVideoSync::GetInterface(voice_engine);
  const std::string audio_filename =
      test::ResourcePath("voice_engine/audio_long16", "pcm");
  ASSERT_STRNE("", audio_filename.c_str());
  test::FakeAudioDevice fake_audio_device(Clock::GetRealTimeClock(),
                                          audio_filename);
  EXPECT_EQ(0, voe_base->Init(&fake_audio_device, NULL));
  int channel = voe_base->CreateChannel();

  const int kVoiceDelayMs = 500;
  SyncRtcpObserver audio_observer(kVoiceDelayMs);
  VideoRtcpAndSyncObserver observer(
      Clock::GetRealTimeClock(), channel, voe_sync, &audio_observer);

  Call::Config receiver_config(observer.ReceiveTransport());
  receiver_config.voice_engine = voice_engine;
  scoped_ptr<Call> sender_call(
      Call::Create(Call::Config(observer.SendTransport())));
  scoped_ptr<Call> receiver_call(Call::Create(receiver_config));
  CodecInst isac = {103, "ISAC", 16000, 480, 1, 32000};
  EXPECT_EQ(0, voe_codec->SetSendCodec(channel, isac));

  class VoicePacketReceiver : public PacketReceiver {
   public:
    VoicePacketReceiver(int channel, VoENetwork* voe_network)
        : channel_(channel),
          voe_network_(voe_network),
          parser_(RtpHeaderParser::Create()) {}
    virtual bool DeliverPacket(const uint8_t* packet, size_t length) {
      int ret;
      if (parser_->IsRtcp(packet, static_cast<int>(length))) {
        ret = voe_network_->ReceivedRTCPPacket(
            channel_, packet, static_cast<unsigned int>(length));
      } else {
        ret = voe_network_->ReceivedRTPPacket(
            channel_, packet, static_cast<unsigned int>(length));
      }
      return ret == 0;
    }

   private:
    int channel_;
    VoENetwork* voe_network_;
    scoped_ptr<RtpHeaderParser> parser_;
  } voe_packet_receiver(channel, voe_network);

  audio_observer.SetReceivers(&voe_packet_receiver, &voe_packet_receiver);

  internal::TransportAdapter transport_adapter(audio_observer.SendTransport());
  EXPECT_EQ(0,
            voe_network->RegisterExternalTransport(channel, transport_adapter));

  observer.SetReceivers(receiver_call->Receiver(), sender_call->Receiver());

  test::FakeEncoder fake_encoder(Clock::GetRealTimeClock());
  test::FakeDecoder fake_decoder;

  VideoSendStream::Config send_config = sender_call->GetDefaultSendConfig();
  send_config.rtp.ssrcs.push_back(kSendSsrc);
  send_config.encoder = &fake_encoder;
  send_config.internal_source = false;
  test::FakeEncoder::SetCodecSettings(&send_config.codec, 1);
  send_config.codec.plType = kSendPayloadType;

  VideoReceiveStream::Config receive_config =
      receiver_call->GetDefaultReceiveConfig();
  receive_config.codecs.clear();
  receive_config.codecs.push_back(send_config.codec);
  ExternalVideoDecoder decoder;
  decoder.decoder = &fake_decoder;
  decoder.payload_type = send_config.codec.plType;
  receive_config.external_decoders.push_back(decoder);
  receive_config.rtp.remote_ssrc = send_config.rtp.ssrcs[0];
  receive_config.rtp.local_ssrc = kReceiverLocalSsrc;
  receive_config.renderer = &observer;
  receive_config.audio_channel_id = channel;

  VideoSendStream* send_stream =
      sender_call->CreateVideoSendStream(send_config);
  VideoReceiveStream* receive_stream =
      receiver_call->CreateVideoReceiveStream(receive_config);
  scoped_ptr<test::FrameGeneratorCapturer> capturer(
      test::FrameGeneratorCapturer::Create(send_stream->Input(),
                                           send_config.codec.width,
                                           send_config.codec.height,
                                           30,
                                           Clock::GetRealTimeClock()));
  receive_stream->StartReceiving();
  send_stream->StartSending();
  capturer->Start();

  fake_audio_device.Start();
  EXPECT_EQ(0, voe_base->StartPlayout(channel));
  EXPECT_EQ(0, voe_base->StartReceive(channel));
  EXPECT_EQ(0, voe_base->StartSend(channel));

  EXPECT_EQ(kEventSignaled, observer.Wait())
      << "Timed out while waiting for audio and video to be synchronized.";

  EXPECT_EQ(0, voe_base->StopSend(channel));
  EXPECT_EQ(0, voe_base->StopReceive(channel));
  EXPECT_EQ(0, voe_base->StopPlayout(channel));
  fake_audio_device.Stop();

  capturer->Stop();
  send_stream->StopSending();
  receive_stream->StopReceiving();
  observer.StopSending();
  audio_observer.StopSending();

  voe_base->DeleteChannel(channel);
  voe_base->Release();
  voe_codec->Release();
  voe_network->Release();
  voe_sync->Release();
  sender_call->DestroyVideoSendStream(send_stream);
  receiver_call->DestroyVideoReceiveStream(receive_stream);
  VoiceEngine::Delete(voice_engine);
}
}  // namespace webrtc