/*
 *  Copyright (c) 2015 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 "modules/rtp_rtcp/source/rtcp_packet/nack.h"

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

#include "api/array_view.h"
#include "rtc_base/buffer.h"
#include "test/gmock.h"
#include "test/gtest.h"
#include "test/rtcp_packet_parser.h"

namespace webrtc {
namespace {

using rtcp::Nack;
using ::testing::_;
using ::testing::ElementsAre;
using ::testing::ElementsAreArray;
using ::testing::Invoke;
using ::testing::make_tuple;
using ::testing::MockFunction;
using ::testing::UnorderedElementsAreArray;

constexpr uint32_t kSenderSsrc = 0x12345678;
constexpr uint32_t kRemoteSsrc = 0x23456789;

constexpr uint8_t kRtpVersionBits = 2 << 6;
constexpr uint16_t kList[] = {0, 1, 3, 8, 16};
// clang-format off
constexpr uint8_t kPacket[] = {
    kRtpVersionBits | Nack::kFeedbackMessageType, Nack::kPacketType, 0, 3,
    0x12, 0x34, 0x56, 0x78,
    0x23, 0x45, 0x67, 0x89,
    0x00, 0x00, 0x80, 0x85};

constexpr uint16_t kWrapList[] = {0xffdc, 0xffec, 0xfffe, 0xffff, 0x0000,
                                  0x0001, 0x0003, 0x0014, 0x0064};
constexpr size_t kWrapListLength = sizeof(kWrapList) / sizeof(kWrapList[0]);
constexpr uint8_t kWrapPacket[] = {
    kRtpVersionBits | Nack::kFeedbackMessageType, Nack::kPacketType, 0, 6,
    0x12, 0x34, 0x56, 0x78,
    0x23, 0x45, 0x67, 0x89,
    0xff, 0xdc, 0x80, 0x00,
    0xff, 0xfe, 0x00, 0x17,
    0x00, 0x14, 0x00, 0x00,
    0x00, 0x64, 0x00, 0x00};
constexpr uint8_t kTooSmallPacket[] = {
    kRtpVersionBits | Nack::kFeedbackMessageType, Nack::kPacketType, 0, 2,
    0x12, 0x34, 0x56, 0x78,
    0x23, 0x45, 0x67, 0x89};
// clang-format on
}  // namespace

TEST(RtcpPacketNackTest, Create) {
  Nack nack;
  nack.SetSenderSsrc(kSenderSsrc);
  nack.SetMediaSsrc(kRemoteSsrc);
  nack.SetPacketIds(kList, std::size(kList));

  Buffer packet = nack.Build();

  EXPECT_THAT(make_tuple(packet.data(), packet.size()),
              ElementsAreArray(kPacket));
}

TEST(RtcpPacketNackTest, Parse) {
  Nack parsed;
  EXPECT_TRUE(test::ParseSinglePacket(kPacket, &parsed));
  const Nack& const_parsed = parsed;

  EXPECT_EQ(kSenderSsrc, const_parsed.sender_ssrc());
  EXPECT_EQ(kRemoteSsrc, const_parsed.media_ssrc());
  EXPECT_THAT(const_parsed.packet_ids(), ElementsAreArray(kList));
}

TEST(RtcpPacketNackTest, CreateWrap) {
  Nack nack;
  nack.SetSenderSsrc(kSenderSsrc);
  nack.SetMediaSsrc(kRemoteSsrc);
  nack.SetPacketIds(kWrapList, kWrapListLength);

  Buffer packet = nack.Build();

  EXPECT_THAT(make_tuple(packet.data(), packet.size()),
              ElementsAreArray(kWrapPacket));
}

TEST(RtcpPacketNackTest, ParseWrap) {
  Nack parsed;
  EXPECT_TRUE(test::ParseSinglePacket(kWrapPacket, &parsed));

  EXPECT_EQ(kSenderSsrc, parsed.sender_ssrc());
  EXPECT_EQ(kRemoteSsrc, parsed.media_ssrc());
  EXPECT_THAT(parsed.packet_ids(), ElementsAreArray(kWrapList));
}

TEST(RtcpPacketNackTest, BadOrder) {
  // Does not guarantee optimal packing, but should guarantee correctness.
  const uint16_t kUnorderedList[] = {1, 25, 13, 12, 9, 27, 29};
  const size_t kUnorderedListLength =
      sizeof(kUnorderedList) / sizeof(kUnorderedList[0]);
  Nack nack;
  nack.SetSenderSsrc(kSenderSsrc);
  nack.SetMediaSsrc(kRemoteSsrc);
  nack.SetPacketIds(kUnorderedList, kUnorderedListLength);

  Buffer packet = nack.Build();

  Nack parsed;
  EXPECT_TRUE(test::ParseSinglePacket(packet, &parsed));

  EXPECT_EQ(kSenderSsrc, parsed.sender_ssrc());
  EXPECT_EQ(kRemoteSsrc, parsed.media_ssrc());
  EXPECT_THAT(parsed.packet_ids(), UnorderedElementsAreArray(kUnorderedList));
}

TEST(RtcpPacketNackTest, CreateFragmented) {
  Nack nack;
  const uint16_t kFragmentedList[] = {1, 100, 200, 300, 400};
  nack.SetSenderSsrc(kSenderSsrc);
  nack.SetMediaSsrc(kRemoteSsrc);
  nack.SetPacketIds(kFragmentedList, std::size(kFragmentedList));

  const size_t kBufferSize = 12 + (3 * 4);  // Fits common header + 3 nack items

  MockFunction<void(ArrayView<const uint8_t>)> callback;
  EXPECT_CALL(callback, Call(_))
      .WillOnce(Invoke([&](ArrayView<const uint8_t> packet) {
        Nack nack;
        EXPECT_TRUE(test::ParseSinglePacket(packet, &nack));
        EXPECT_EQ(kSenderSsrc, nack.sender_ssrc());
        EXPECT_EQ(kRemoteSsrc, nack.media_ssrc());
        EXPECT_THAT(nack.packet_ids(), ElementsAre(1, 100, 200));
      }))
      .WillOnce(Invoke([&](ArrayView<const uint8_t> packet) {
        Nack nack;
        EXPECT_TRUE(test::ParseSinglePacket(packet, &nack));
        EXPECT_EQ(kSenderSsrc, nack.sender_ssrc());
        EXPECT_EQ(kRemoteSsrc, nack.media_ssrc());
        EXPECT_THAT(nack.packet_ids(), ElementsAre(300, 400));
      }));

  EXPECT_TRUE(nack.Build(kBufferSize, callback.AsStdFunction()));
}

TEST(RtcpPacketNackTest, CreateFailsWithTooSmallBuffer) {
  const uint16_t kSmallList[] = {1};
  const size_t kMinNackBlockSize = 16;
  Nack nack;
  nack.SetSenderSsrc(kSenderSsrc);
  nack.SetMediaSsrc(kRemoteSsrc);
  nack.SetPacketIds(kSmallList, std::size(kSmallList));

  MockFunction<void(ArrayView<const uint8_t>)> callback;
  EXPECT_CALL(callback, Call(_)).Times(0);
  EXPECT_FALSE(nack.Build(kMinNackBlockSize - 1, callback.AsStdFunction()));
}

TEST(RtcpPacketNackTest, ParseFailsWithTooSmallBuffer) {
  Nack parsed;
  EXPECT_FALSE(test::ParseSinglePacket(kTooSmallPacket, &parsed));
}

}  // namespace webrtc