/*
 *  Copyright (c) 2012 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 "webrtc/test/testsupport/packet_reader.h"

#include "testing/gtest/include/gtest/gtest.h"
#include "webrtc/test/testsupport/unittest_utils.h"

namespace webrtc {
namespace test {

class PacketReaderTest: public PacketRelatedTest {
 protected:
  PacketReaderTest() {}
  virtual ~PacketReaderTest() {}
  void SetUp() {
    reader_ = new PacketReader();
  }
  void TearDown() {
    delete reader_;
  }
  void VerifyPacketData(size_t expected_length,
                        int actual_length,
                        uint8_t* original_data_pointer,
                        uint8_t* new_data_pointer) {
    EXPECT_EQ(static_cast<int>(expected_length), actual_length);
    EXPECT_EQ(*original_data_pointer, *new_data_pointer);
    EXPECT_EQ(0, memcmp(original_data_pointer, new_data_pointer,
                        actual_length));
  }
  PacketReader* reader_;
};

// Test lack of initialization
TEST_F(PacketReaderTest, Uninitialized) {
  uint8_t* data_pointer = NULL;
  EXPECT_EQ(-1, reader_->NextPacket(&data_pointer));
  EXPECT_EQ(NULL, data_pointer);
}

TEST_F(PacketReaderTest, InitializeZeroLengthArgument) {
  reader_->InitializeReading(packet_data_, 0, kPacketSizeInBytes);
  ASSERT_EQ(0, reader_->NextPacket(&packet_data_pointer_));
}

// Test with something smaller than one packet
TEST_F(PacketReaderTest, NormalSmallData) {
  const int kDataLengthInBytes = 1499;
  uint8_t data[kDataLengthInBytes];
  uint8_t* data_pointer = data;
  memset(data, 1, kDataLengthInBytes);

  reader_->InitializeReading(data, kDataLengthInBytes, kPacketSizeInBytes);
  int length_to_read = reader_->NextPacket(&data_pointer);
  VerifyPacketData(kDataLengthInBytes, length_to_read, data, data_pointer);
  EXPECT_EQ(0, data_pointer - data);  // pointer hasn't moved

  // Reading another one shall result in 0 bytes:
  length_to_read = reader_->NextPacket(&data_pointer);
  EXPECT_EQ(0, length_to_read);
  EXPECT_EQ(kDataLengthInBytes, data_pointer - data);
}

// Test with data length that exactly matches one packet
TEST_F(PacketReaderTest, NormalOnePacketData) {
  uint8_t data[kPacketSizeInBytes];
  uint8_t* data_pointer = data;
  memset(data, 1, kPacketSizeInBytes);

  reader_->InitializeReading(data, kPacketSizeInBytes, kPacketSizeInBytes);
  int length_to_read = reader_->NextPacket(&data_pointer);
  VerifyPacketData(kPacketSizeInBytes, length_to_read, data, data_pointer);
  EXPECT_EQ(0, data_pointer - data);  // pointer hasn't moved

  // Reading another one shall result in 0 bytes:
  length_to_read = reader_->NextPacket(&data_pointer);
  EXPECT_EQ(0, length_to_read);
  EXPECT_EQ(kPacketSizeInBytes, static_cast<size_t>(data_pointer - data));
}

// Test with data length that will result in 3 packets
TEST_F(PacketReaderTest, NormalLargeData) {
  reader_->InitializeReading(packet_data_, kPacketDataLength,
                             kPacketSizeInBytes);

  int length_to_read = reader_->NextPacket(&packet_data_pointer_);
  VerifyPacketData(kPacketSizeInBytes, length_to_read,
                   packet1_, packet_data_pointer_);

  length_to_read = reader_->NextPacket(&packet_data_pointer_);
  VerifyPacketData(kPacketSizeInBytes, length_to_read,
                   packet2_, packet_data_pointer_);

  length_to_read = reader_->NextPacket(&packet_data_pointer_);
  VerifyPacketData(1u, length_to_read,
                   packet3_, packet_data_pointer_);

  // Reading another one shall result in 0 bytes:
  length_to_read = reader_->NextPacket(&packet_data_pointer_);
  EXPECT_EQ(0, length_to_read);
  EXPECT_EQ(kPacketDataLength,
            static_cast<size_t>(packet_data_pointer_ - packet_data_));
}

// Test with empty data.
TEST_F(PacketReaderTest, EmptyData) {
  const int kDataLengthInBytes = 0;
  // But don't really try to allocate a zero-length array...
  uint8_t data[kPacketSizeInBytes];
  uint8_t* data_pointer = data;
  reader_->InitializeReading(data, kDataLengthInBytes, kPacketSizeInBytes);
  EXPECT_EQ(kDataLengthInBytes, reader_->NextPacket(&data_pointer));
  // Do it again to make sure nothing changes
  EXPECT_EQ(kDataLengthInBytes, reader_->NextPacket(&data_pointer));
}

}  // namespace test
}  // namespace webrtc