// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "remoting/host/file_transfer/file_transfer_message_handler.h"

#include <memory>
#include <string>
#include <utility>
#include <vector>

#include "base/containers/queue.h"
#include "base/functional/bind.h"
#include "base/memory/ptr_util.h"
#include "base/test/task_environment.h"
#include "net/base/io_buffer.h"
#include "remoting/base/compound_buffer.h"
#include "remoting/host/file_transfer/fake_file_operations.h"
#include "remoting/host/file_transfer/test_byte_vector_utils.h"
#include "remoting/protocol/fake_message_pipe.h"
#include "remoting/protocol/fake_message_pipe_wrapper.h"
#include "remoting/protocol/file_transfer_helpers.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace {

constexpr char kTestDatachannelName[] = "filetransfer-test";
constexpr char kTestFilename[] = "test-file.txt";

std::unique_ptr<remoting::CompoundBuffer> StringToBuffer(
    const std::string& data) {
  std::unique_ptr<remoting::CompoundBuffer> buffer =
      std::make_unique<remoting::CompoundBuffer>();
  buffer->Append(base::MakeRefCounted<net::StringIOBuffer>(data), data.size());
  return buffer;
}

std::unique_ptr<remoting::CompoundBuffer> MessageToBuffer(
    const remoting::protocol::FileTransfer& message) {
  return StringToBuffer(message.SerializeAsString());
}

std::unique_ptr<remoting::CompoundBuffer> DataToBuffer(
    const std::vector<std::uint8_t>& data) {
  remoting::protocol::FileTransfer message;
  message.mutable_data()->set_data(std::string(data.begin(), data.end()));
  return MessageToBuffer(message);
}

// base::queue doesn't provide operator==.
template <typename T>
bool QueuesEqual(const base::queue<T>& a, const base::queue<T>& b) {
  if (a.size() != b.size()) {
    return false;
  }

  auto a_copy = a;
  auto b_copy = b;
  while (!a_copy.empty()) {
    if (a_copy.front() != b_copy.front()) {
      return false;
    }
    a_copy.pop();
    b_copy.pop();
  }
  return true;
}

}  // namespace

namespace remoting {

class FileTransferMessageHandlerTest : public testing::Test {
 public:
  FileTransferMessageHandlerTest();
  ~FileTransferMessageHandlerTest() override;

  // testing::Test implementation.
  void SetUp() override;
  void TearDown() override;

 protected:
  const std::vector<std::uint8_t> kTestDataOne =
      ByteArrayFrom("this is the first test string");
  const std::vector<std::uint8_t> kTestDataTwo =
      ByteArrayFrom("this is the second test string");
  const std::vector<std::uint8_t> kTestDataThree =
      ByteArrayFrom("this is the third test string");

  base::test::TaskEnvironment task_environment_;
  std::unique_ptr<protocol::FakeMessagePipe> fake_pipe_;
  protocol::FileTransfer fake_metadata_;
  protocol::FileTransfer fake_end_;
  protocol::FileTransfer fake_request_transfer_;
  protocol::FileTransfer fake_success_;
};

FileTransferMessageHandlerTest::FileTransferMessageHandlerTest()
    : task_environment_(
          base::test::TaskEnvironment::MainThreadType::DEFAULT,
          base::test::TaskEnvironment::ThreadPoolExecutionMode::QUEUED) {}
FileTransferMessageHandlerTest::~FileTransferMessageHandlerTest() = default;

void FileTransferMessageHandlerTest::SetUp() {
  fake_pipe_ =
      base::WrapUnique(new protocol::FakeMessagePipe(false /* asynchronous */));

  fake_metadata_.mutable_metadata()->set_filename(kTestFilename);
  fake_metadata_.mutable_metadata()->set_size(
      kTestDataOne.size() + kTestDataTwo.size() + kTestDataThree.size());
  fake_end_.mutable_end();
  fake_request_transfer_.mutable_request_transfer();
  fake_success_.mutable_success();
}

void FileTransferMessageHandlerTest::TearDown() {}

// Upload tests.

// Verifies that the message handler creates, writes to, and closes a
// FileOperations::Writer without errors when given valid input.
TEST_F(FileTransferMessageHandlerTest, WritesThreeChunks) {
  FakeFileOperations::TestIo test_io;
  auto file_operations = std::make_unique<FakeFileOperations>(&test_io);

  // This will delete itself when fake_pipe_->ClosePipe() is called.
  new FileTransferMessageHandler(kTestDatachannelName, fake_pipe_->Wrap(),
                                 std::move(file_operations));

  fake_pipe_->OpenPipe();
  fake_pipe_->Receive(MessageToBuffer(fake_metadata_));
  fake_pipe_->Receive(DataToBuffer(kTestDataOne));
  fake_pipe_->Receive(DataToBuffer(kTestDataTwo));
  fake_pipe_->Receive(DataToBuffer(kTestDataThree));
  fake_pipe_->Receive(MessageToBuffer(fake_end_));
  task_environment_.RunUntilIdle();

  fake_pipe_->ClosePipe();

  ASSERT_EQ(test_io.files_written.size(), 1ul);
  ASSERT_FALSE(test_io.files_written[0].failed);
  std::vector<std::vector<std::uint8_t>> expected_chunks = {
      kTestDataOne, kTestDataTwo, kTestDataThree};
  ASSERT_EQ(test_io.files_written[0].chunks, expected_chunks);

  const base::queue<std::string>& actual_sent_messages =
      fake_pipe_->sent_messages();
  base::queue<std::string> expected_sent_messages;
  expected_sent_messages.push(fake_success_.SerializeAsString());
  ASSERT_TRUE(QueuesEqual(expected_sent_messages, actual_sent_messages));
}

// Verifies that the message handler sends an error protobuf when
// FileOperations::Writer returns an error.
TEST_F(FileTransferMessageHandlerTest, HandlesWriteError) {
  FakeFileOperations::TestIo test_io;
  auto file_operations = std::make_unique<FakeFileOperations>(&test_io);

  protocol::FileTransfer_Error fake_error = protocol::MakeFileTransferError(
      FROM_HERE, protocol::FileTransfer_Error_Type_IO_ERROR);

  // This will delete itself when fake_pipe_->ClosePipe() is called.
  new FileTransferMessageHandler(kTestDatachannelName, fake_pipe_->Wrap(),
                                 std::move(file_operations));

  fake_pipe_->OpenPipe();
  fake_pipe_->Receive(MessageToBuffer(fake_metadata_));
  fake_pipe_->Receive(DataToBuffer(kTestDataOne));
  fake_pipe_->Receive(DataToBuffer(kTestDataTwo));
  task_environment_.RunUntilIdle();
  test_io.io_error = fake_error;
  fake_pipe_->Receive(DataToBuffer(kTestDataTwo));
  fake_pipe_->Receive(MessageToBuffer(fake_end_));
  task_environment_.RunUntilIdle();

  fake_pipe_->ClosePipe();

  const base::queue<std::string>& actual_sent_messages =
      fake_pipe_->sent_messages();
  protocol::FileTransfer expected_response;
  *expected_response.mutable_error() = fake_error;
  base::queue<std::string> expected_sent_messages;
  expected_sent_messages.push(expected_response.SerializeAsString());
  ASSERT_TRUE(QueuesEqual(expected_sent_messages, actual_sent_messages));
}

// Verifies that the message handler cancels the write if an error is received
// from the sender.
TEST_F(FileTransferMessageHandlerTest, HandlesErrorMessage) {
  FakeFileOperations::TestIo test_io;
  auto file_operations = std::make_unique<FakeFileOperations>(&test_io);

  // This will delete itself when fake_pipe_->ClosePipe() is called.
  new FileTransferMessageHandler(kTestDatachannelName, fake_pipe_->Wrap(),
                                 std::move(file_operations));

  protocol::FileTransfer fake_error_message;
  *fake_error_message.mutable_error() = protocol::MakeFileTransferError(
      FROM_HERE, protocol::FileTransfer_Error_Type_IO_ERROR);

  fake_pipe_->OpenPipe();
  fake_pipe_->Receive(MessageToBuffer(fake_metadata_));
  fake_pipe_->Receive(DataToBuffer(kTestDataOne));
  fake_pipe_->Receive(DataToBuffer(kTestDataTwo));
  task_environment_.RunUntilIdle();
  fake_pipe_->Receive(MessageToBuffer(fake_error_message));
  task_environment_.RunUntilIdle();

  fake_pipe_->ClosePipe();

  ASSERT_EQ(test_io.files_written.size(), 1ul);
  ASSERT_TRUE(test_io.files_written[0].failed);
  std::vector<std::vector<std::uint8_t>> expected_chunks = {kTestDataOne,
                                                            kTestDataTwo};
  ASSERT_EQ(test_io.files_written[0].chunks, expected_chunks);

  const base::queue<std::string>& actual_sent_messages =
      fake_pipe_->sent_messages();
  // No messages
  base::queue<std::string> expected_sent_messages;
  ASSERT_TRUE(QueuesEqual(expected_sent_messages, actual_sent_messages));
}

// Verifies that the message handler cancels the write if the connection is
// closed prematurely.
TEST_F(FileTransferMessageHandlerTest, HandlesPrematureClose) {
  FakeFileOperations::TestIo test_io;
  auto file_operations = std::make_unique<FakeFileOperations>(&test_io);

  // This will delete itself when fake_pipe_->ClosePipe() is called.
  new FileTransferMessageHandler(kTestDatachannelName, fake_pipe_->Wrap(),
                                 std::move(file_operations));

  fake_pipe_->OpenPipe();
  fake_pipe_->Receive(MessageToBuffer(fake_metadata_));
  fake_pipe_->Receive(DataToBuffer(kTestDataOne));
  fake_pipe_->Receive(DataToBuffer(kTestDataTwo));
  task_environment_.RunUntilIdle();

  fake_pipe_->ClosePipe();

  ASSERT_EQ(test_io.files_written.size(), 1ul);
  ASSERT_TRUE(test_io.files_written[0].failed);
  std::vector<std::vector<std::uint8_t>> expected_chunks = {kTestDataOne,
                                                            kTestDataTwo};
  ASSERT_EQ(test_io.files_written[0].chunks, expected_chunks);
}

// Verifies that an error is sent if data is sent before/without metadata.
TEST_F(FileTransferMessageHandlerTest, ErrorsOnMissingMetadata) {
  FakeFileOperations::TestIo test_io;
  auto file_operations = std::make_unique<FakeFileOperations>(&test_io);

  // This will delete itself when fake_pipe_->ClosePipe() is called.
  new FileTransferMessageHandler(kTestDatachannelName, fake_pipe_->Wrap(),
                                 std::move(file_operations));

  fake_pipe_->OpenPipe();
  fake_pipe_->Receive(DataToBuffer(kTestDataOne));
  fake_pipe_->Receive(DataToBuffer(kTestDataTwo));
  fake_pipe_->Receive(DataToBuffer(kTestDataThree));
  fake_pipe_->Receive(MessageToBuffer(fake_end_));
  task_environment_.RunUntilIdle();

  fake_pipe_->ClosePipe();

  ASSERT_EQ(test_io.files_written.size(), 0ul);

  const base::queue<std::string>& sent_messages = fake_pipe_->sent_messages();
  ASSERT_EQ(sent_messages.size(), 1ul);
  protocol::FileTransfer response;
  response.ParseFromString(sent_messages.front());
  ASSERT_EQ(response.message_case(), protocol::FileTransfer::kError);
  ASSERT_EQ(response.error().type(),
            protocol::FileTransfer_Error_Type_PROTOCOL_ERROR);
}

// Verifies that an error is sent if another metadata message is sent.
TEST_F(FileTransferMessageHandlerTest, ErrorsOnNewMetadata) {
  FakeFileOperations::TestIo test_io;
  auto file_operations = std::make_unique<FakeFileOperations>(&test_io);

  // This will delete itself when fake_pipe_->ClosePipe() is called.
  new FileTransferMessageHandler(kTestDatachannelName, fake_pipe_->Wrap(),
                                 std::move(file_operations));

  fake_pipe_->OpenPipe();
  fake_pipe_->Receive(MessageToBuffer(fake_metadata_));
  fake_pipe_->Receive(DataToBuffer(kTestDataOne));
  fake_pipe_->Receive(DataToBuffer(kTestDataTwo));
  fake_pipe_->Receive(DataToBuffer(kTestDataThree));
  fake_pipe_->Receive(MessageToBuffer(fake_end_));
  task_environment_.RunUntilIdle();
  fake_pipe_->Receive(MessageToBuffer(fake_metadata_));

  fake_pipe_->ClosePipe();

  const base::queue<std::string>& sent_messages = fake_pipe_->sent_messages();
  // First is the success message, second should be a protocol error.
  ASSERT_EQ(sent_messages.size(), 2ul);
  protocol::FileTransfer response;
  response.ParseFromString(sent_messages.back());
  ASSERT_EQ(response.message_case(), protocol::FileTransfer::kError);
  ASSERT_EQ(response.error().type(),
            protocol::FileTransfer_Error_Type_PROTOCOL_ERROR);
}

// Verifies that an error is sent if more data is sent after Close.
TEST_F(FileTransferMessageHandlerTest, ErrorsOnDataAfterClose) {
  FakeFileOperations::TestIo test_io;
  auto file_operations = std::make_unique<FakeFileOperations>(&test_io);

  // This will delete itself when fake_pipe_->ClosePipe() is called.
  new FileTransferMessageHandler(kTestDatachannelName, fake_pipe_->Wrap(),
                                 std::move(file_operations));

  fake_pipe_->OpenPipe();
  fake_pipe_->Receive(MessageToBuffer(fake_metadata_));
  fake_pipe_->Receive(DataToBuffer(kTestDataOne));
  fake_pipe_->Receive(DataToBuffer(kTestDataTwo));
  fake_pipe_->Receive(DataToBuffer(kTestDataThree));
  fake_pipe_->Receive(MessageToBuffer(fake_end_));
  fake_pipe_->Receive(DataToBuffer(kTestDataOne));
  task_environment_.RunUntilIdle();

  fake_pipe_->ClosePipe();

  ASSERT_EQ(test_io.files_written.size(), 1ul);
  ASSERT_TRUE(test_io.files_written[0].failed);

  const base::queue<std::string>& sent_messages = fake_pipe_->sent_messages();
  // Because the error is triggered before RunUntilIdle is called, there should
  // be no complete message this time.
  ASSERT_EQ(sent_messages.size(), 1ul);
  protocol::FileTransfer response;
  response.ParseFromString(sent_messages.front());
  ASSERT_EQ(response.message_case(), protocol::FileTransfer::kError);
  ASSERT_EQ(response.error().type(),
            protocol::FileTransfer_Error_Type_PROTOCOL_ERROR);
}

// Download tests.

// Verifies that the message handler will read and respond with a file when a
// RequestTransfer message is received.
TEST_F(FileTransferMessageHandlerTest, ReadsFile) {
  FakeFileOperations::TestIo test_io;
  auto file_operations = std::make_unique<FakeFileOperations>(&test_io);

  test_io.input_file = FakeFileOperations::InputFile(
      base::FilePath::FromASCII(kTestFilename),
      ByteArrayFrom(kTestDataOne, kTestDataTwo, kTestDataThree), std::nullopt);

  // This will delete itself when fake_pipe_->ClosePipe() is called.
  new FileTransferMessageHandler(kTestDatachannelName, fake_pipe_->Wrap(),
                                 std::move(file_operations));

  fake_pipe_->OpenPipe();
  fake_pipe_->Receive(MessageToBuffer(fake_request_transfer_));
  task_environment_.RunUntilIdle();
  fake_pipe_->Receive(MessageToBuffer(fake_success_));
  task_environment_.RunUntilIdle();

  fake_pipe_->ClosePipe();

  const base::queue<std::string>& actual_sent_messages =
      fake_pipe_->sent_messages();
  base::queue<std::string> expected_sent_messages;
  expected_sent_messages.push(fake_metadata_.SerializeAsString());
  protocol::FileTransfer data;
  data.mutable_data()->set_data(std::string(test_io.input_file->data.begin(),
                                            test_io.input_file->data.end()));
  expected_sent_messages.push(data.SerializeAsString());
  expected_sent_messages.push(fake_end_.SerializeAsString());
  ASSERT_TRUE(QueuesEqual(expected_sent_messages, actual_sent_messages));
}

// Verifies that the message handler forwards errors from opening a file with
// the reader.
TEST_F(FileTransferMessageHandlerTest, ForwardsReaderOpenError) {
  FakeFileOperations::TestIo test_io;
  auto file_operations = std::make_unique<FakeFileOperations>(&test_io);

  test_io.input_file = protocol::MakeFileTransferError(
      FROM_HERE, protocol::FileTransfer_Error_Type_CANCELED);

  // This will delete itself when fake_pipe_->ClosePipe() is called.
  new FileTransferMessageHandler(kTestDatachannelName, fake_pipe_->Wrap(),
                                 std::move(file_operations));

  fake_pipe_->OpenPipe();
  fake_pipe_->Receive(MessageToBuffer(fake_request_transfer_));
  task_environment_.RunUntilIdle();

  fake_pipe_->ClosePipe();

  const base::queue<std::string>& actual_sent_messages =
      fake_pipe_->sent_messages();
  base::queue<std::string> expected_sent_messages;
  protocol::FileTransfer error;
  *error.mutable_error() = test_io.input_file.error();
  expected_sent_messages.push(error.SerializeAsString());
  ASSERT_TRUE(QueuesEqual(expected_sent_messages, actual_sent_messages));
}

// Verifies that the message handler forwards errors from reading a file.
TEST_F(FileTransferMessageHandlerTest, ForwardsReadError) {
  FakeFileOperations::TestIo test_io;
  auto file_operations = std::make_unique<FakeFileOperations>(&test_io);

  test_io.input_file = FakeFileOperations::InputFile(
      base::FilePath::FromASCII(kTestFilename),
      ByteArrayFrom(kTestDataOne, kTestDataTwo, kTestDataThree),
      protocol::MakeFileTransferError(
          FROM_HERE, protocol::FileTransfer_Error_Type_IO_ERROR));

  // This will delete itself when fake_pipe_->ClosePipe() is called.
  new FileTransferMessageHandler(kTestDatachannelName, fake_pipe_->Wrap(),
                                 std::move(file_operations));

  fake_pipe_->OpenPipe();
  fake_pipe_->Receive(MessageToBuffer(fake_request_transfer_));
  task_environment_.RunUntilIdle();

  fake_pipe_->ClosePipe();

  const base::queue<std::string>& actual_sent_messages =
      fake_pipe_->sent_messages();
  base::queue<std::string> expected_sent_messages;
  expected_sent_messages.push(fake_metadata_.SerializeAsString());
  protocol::FileTransfer data;
  data.mutable_data()->set_data(std::string(test_io.input_file->data.begin(),
                                            test_io.input_file->data.end()));
  expected_sent_messages.push(data.SerializeAsString());
  protocol::FileTransfer error;
  *error.mutable_error() = *test_io.input_file->io_error;
  expected_sent_messages.push(error.SerializeAsString());
  ASSERT_TRUE(QueuesEqual(expected_sent_messages, actual_sent_messages));
}

}  // namespace remoting