// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "quiche/quic/test_tools/quic_test_client.h"

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

#include "absl/strings/match.h"
#include "absl/strings/string_view.h"
#include "openssl/x509.h"
#include "quiche/quic/core/crypto/proof_verifier.h"
#include "quiche/quic/core/http/quic_spdy_client_stream.h"
#include "quiche/quic/core/http/spdy_utils.h"
#include "quiche/quic/core/io/quic_default_event_loop.h"
#include "quiche/quic/core/quic_default_clock.h"
#include "quiche/quic/core/quic_packet_writer_wrapper.h"
#include "quiche/quic/core/quic_server_id.h"
#include "quiche/quic/core/quic_stream_priority.h"
#include "quiche/quic/core/quic_utils.h"
#include "quiche/quic/platform/api/quic_flags.h"
#include "quiche/quic/platform/api/quic_logging.h"
#include "quiche/quic/platform/api/quic_stack_trace.h"
#include "quiche/quic/test_tools/crypto_test_utils.h"
#include "quiche/quic/test_tools/quic_connection_peer.h"
#include "quiche/quic/test_tools/quic_spdy_session_peer.h"
#include "quiche/quic/test_tools/quic_spdy_stream_peer.h"
#include "quiche/quic/test_tools/quic_test_utils.h"
#include "quiche/quic/tools/quic_url.h"
#include "quiche/common/quiche_callbacks.h"
#include "quiche/common/quiche_text_utils.h"

namespace quic {
namespace test {
namespace {

// RecordingProofVerifier accepts any certificate chain and records the common
// name of the leaf and then delegates the actual verification to an actual
// verifier. If no optional verifier is provided, then VerifyProof will return
// success.
class RecordingProofVerifier : public ProofVerifier {
 public:
  explicit RecordingProofVerifier(std::unique_ptr<ProofVerifier> verifier)
      : verifier_(std::move(verifier)) {}

  // ProofVerifier interface.
  QuicAsyncStatus VerifyProof(
      const std::string& hostname, const uint16_t port,
      const std::string& server_config, QuicTransportVersion transport_version,
      absl::string_view chlo_hash, const std::vector<std::string>& certs,
      const std::string& cert_sct, const std::string& signature,
      const ProofVerifyContext* context, std::string* error_details,
      std::unique_ptr<ProofVerifyDetails>* details,
      std::unique_ptr<ProofVerifierCallback> callback) override {
    QuicAsyncStatus status = ProcessCerts(certs, cert_sct);
    if (verifier_ == nullptr) {
      return status;
    }
    return verifier_->VerifyProof(hostname, port, server_config,
                                  transport_version, chlo_hash, certs, cert_sct,
                                  signature, context, error_details, details,
                                  std::move(callback));
  }

  QuicAsyncStatus VerifyCertChain(
      const std::string& hostname, const uint16_t port,
      const std::vector<std::string>& certs, const std::string& ocsp_response,
      const std::string& cert_sct, const ProofVerifyContext* context,
      std::string* error_details, std::unique_ptr<ProofVerifyDetails>* details,
      uint8_t* out_alert,
      std::unique_ptr<ProofVerifierCallback> callback) override {
    // Record the cert.
    QuicAsyncStatus status = ProcessCerts(certs, cert_sct);
    if (verifier_ == nullptr) {
      return status;
    }
    return verifier_->VerifyCertChain(hostname, port, certs, ocsp_response,
                                      cert_sct, context, error_details, details,
                                      out_alert, std::move(callback));
  }

  std::unique_ptr<ProofVerifyContext> CreateDefaultContext() override {
    return verifier_ != nullptr ? verifier_->CreateDefaultContext() : nullptr;
  }

  const std::string& common_name() const { return common_name_; }

  const std::string& cert_sct() const { return cert_sct_; }

 private:
  QuicAsyncStatus ProcessCerts(const std::vector<std::string>& certs,
                               const std::string& cert_sct) {
    common_name_.clear();
    if (certs.empty()) {
      return QUIC_FAILURE;
    }

    // Parse the cert into an X509 structure.
    const uint8_t* data;
    data = reinterpret_cast<const uint8_t*>(certs[0].data());
    bssl::UniquePtr<X509> cert(d2i_X509(nullptr, &data, certs[0].size()));
    if (!cert.get()) {
      return QUIC_FAILURE;
    }

    // Extract the CN field
    X509_NAME* subject = X509_get_subject_name(cert.get());
    const int index = X509_NAME_get_index_by_NID(subject, NID_commonName, -1);
    if (index < 0) {
      return QUIC_FAILURE;
    }
    ASN1_STRING* name_data =
        X509_NAME_ENTRY_get_data(X509_NAME_get_entry(subject, index));
    if (name_data == nullptr) {
      return QUIC_FAILURE;
    }

    // Convert the CN to UTF8, in case the cert represents it in a different
    // format.
    unsigned char* buf = nullptr;
    const int len = ASN1_STRING_to_UTF8(&buf, name_data);
    if (len <= 0) {
      return QUIC_FAILURE;
    }
    bssl::UniquePtr<unsigned char> deleter(buf);

    common_name_.assign(reinterpret_cast<const char*>(buf), len);
    cert_sct_ = cert_sct;
    return QUIC_SUCCESS;
  }

  std::unique_ptr<ProofVerifier> verifier_;
  std::string common_name_;
  std::string cert_sct_;
};
}  // namespace

void MockableQuicClientDefaultNetworkHelper::ProcessPacket(
    const QuicSocketAddress& self_address,
    const QuicSocketAddress& peer_address, const QuicReceivedPacket& packet) {
  QuicClientDefaultNetworkHelper::ProcessPacket(self_address, peer_address,
                                                packet);
  if (track_last_incoming_packet_) {
    last_incoming_packet_ = packet.Clone();
  }
}

SocketFd MockableQuicClientDefaultNetworkHelper::CreateUDPSocket(
    QuicSocketAddress server_address, bool* overflow_supported) {
  SocketFd fd = QuicClientDefaultNetworkHelper::CreateUDPSocket(
      server_address, overflow_supported);
  if (fd < 0) {
    return fd;
  }

  if (socket_fd_configurator_ != nullptr) {
    socket_fd_configurator_(fd);
  }
  return fd;
}

QuicPacketWriter*
MockableQuicClientDefaultNetworkHelper::CreateQuicPacketWriter() {
  QuicPacketWriter* writer =
      QuicClientDefaultNetworkHelper::CreateQuicPacketWriter();
  if (!test_writer_) {
    return writer;
  }
  test_writer_->set_writer(writer);
  return test_writer_;
}

void MockableQuicClientDefaultNetworkHelper::set_socket_fd_configurator(
    quiche::MultiUseCallback<void(SocketFd)> socket_fd_configurator) {
  socket_fd_configurator_ = std::move(socket_fd_configurator);
}

const QuicReceivedPacket*
MockableQuicClientDefaultNetworkHelper::last_incoming_packet() {
  return last_incoming_packet_.get();
}

void MockableQuicClientDefaultNetworkHelper::set_track_last_incoming_packet(
    bool track) {
  track_last_incoming_packet_ = track;
}

void MockableQuicClientDefaultNetworkHelper::UseWriter(
    QuicPacketWriterWrapper* writer) {
  QUICHE_CHECK(test_writer_ == nullptr);
  test_writer_ = writer;
}

void MockableQuicClientDefaultNetworkHelper::set_peer_address(
    const QuicSocketAddress& address) {
  QUICHE_CHECK(test_writer_ != nullptr);
  test_writer_->set_peer_address(address);
}

MockableQuicClient::MockableQuicClient(
    QuicSocketAddress server_address, const QuicServerId& server_id,
    const ParsedQuicVersionVector& supported_versions,
    QuicEventLoop* event_loop)
    : MockableQuicClient(server_address, server_id, QuicConfig(),
                         supported_versions, event_loop) {}

MockableQuicClient::MockableQuicClient(
    QuicSocketAddress server_address, const QuicServerId& server_id,
    const QuicConfig& config, const ParsedQuicVersionVector& supported_versions,
    QuicEventLoop* event_loop)
    : MockableQuicClient(server_address, server_id, config, supported_versions,
                         event_loop, nullptr) {}

MockableQuicClient::MockableQuicClient(
    QuicSocketAddress server_address, const QuicServerId& server_id,
    const QuicConfig& config, const ParsedQuicVersionVector& supported_versions,
    QuicEventLoop* event_loop, std::unique_ptr<ProofVerifier> proof_verifier)
    : MockableQuicClient(server_address, server_id, config, supported_versions,
                         event_loop, std::move(proof_verifier), nullptr) {}

MockableQuicClient::MockableQuicClient(
    QuicSocketAddress server_address, const QuicServerId& server_id,
    const QuicConfig& config, const ParsedQuicVersionVector& supported_versions,
    QuicEventLoop* event_loop, std::unique_ptr<ProofVerifier> proof_verifier,
    std::unique_ptr<SessionCache> session_cache)
    : QuicDefaultClient(
          server_address, server_id, supported_versions, config, event_loop,
          std::make_unique<MockableQuicClientDefaultNetworkHelper>(event_loop,
                                                                   this),
          std::make_unique<RecordingProofVerifier>(std::move(proof_verifier)),
          std::move(session_cache)),
      override_client_connection_id_(EmptyQuicConnectionId()),
      client_connection_id_overridden_(false) {}

MockableQuicClient::~MockableQuicClient() {
  if (connected()) {
    Disconnect();
  }
}

MockableQuicClientDefaultNetworkHelper*
MockableQuicClient::mockable_network_helper() {
  return static_cast<MockableQuicClientDefaultNetworkHelper*>(
      default_network_helper());
}

const MockableQuicClientDefaultNetworkHelper*
MockableQuicClient::mockable_network_helper() const {
  return static_cast<const MockableQuicClientDefaultNetworkHelper*>(
      default_network_helper());
}

QuicConnectionId MockableQuicClient::GetClientConnectionId() {
  if (client_connection_id_overridden_) {
    return override_client_connection_id_;
  }
  if (override_client_connection_id_length_ >= 0) {
    return QuicUtils::CreateRandomConnectionId(
        override_client_connection_id_length_);
  }
  return QuicDefaultClient::GetClientConnectionId();
}

void MockableQuicClient::UseClientConnectionId(
    QuicConnectionId client_connection_id) {
  client_connection_id_overridden_ = true;
  override_client_connection_id_ = client_connection_id;
}

void MockableQuicClient::UseClientConnectionIdLength(
    int client_connection_id_length) {
  override_client_connection_id_length_ = client_connection_id_length;
}

void MockableQuicClient::UseWriter(QuicPacketWriterWrapper* writer) {
  mockable_network_helper()->UseWriter(writer);
}

void MockableQuicClient::set_peer_address(const QuicSocketAddress& address) {
  mockable_network_helper()->set_peer_address(address);
  if (client_session() != nullptr) {
    client_session()->connection()->AddKnownServerAddress(address);
  }
}

const QuicReceivedPacket* MockableQuicClient::last_incoming_packet() {
  return mockable_network_helper()->last_incoming_packet();
}

void MockableQuicClient::set_track_last_incoming_packet(bool track) {
  mockable_network_helper()->set_track_last_incoming_packet(track);
}

QuicTestClient::QuicTestClient(
    QuicSocketAddress server_address, const std::string& server_hostname,
    const ParsedQuicVersionVector& supported_versions)
    : QuicTestClient(server_address, server_hostname, QuicConfig(),
                     supported_versions) {}

QuicTestClient::QuicTestClient(
    QuicSocketAddress server_address, const std::string& server_hostname,
    const QuicConfig& config, const ParsedQuicVersionVector& supported_versions)
    : event_loop_(GetDefaultEventLoop()->Create(QuicDefaultClock::Get())),
      client_(std::make_unique<MockableQuicClient>(
          server_address,
          QuicServerId(server_hostname, server_address.port(), false), config,
          supported_versions, event_loop_.get())) {
  Initialize();
}

QuicTestClient::QuicTestClient(
    QuicSocketAddress server_address, const std::string& server_hostname,
    const QuicConfig& config, const ParsedQuicVersionVector& supported_versions,
    std::unique_ptr<ProofVerifier> proof_verifier)
    : event_loop_(GetDefaultEventLoop()->Create(QuicDefaultClock::Get())),
      client_(std::make_unique<MockableQuicClient>(
          server_address,
          QuicServerId(server_hostname, server_address.port(), false), config,
          supported_versions, event_loop_.get(), std::move(proof_verifier))) {
  Initialize();
}

QuicTestClient::QuicTestClient(
    QuicSocketAddress server_address, const std::string& server_hostname,
    const QuicConfig& config, const ParsedQuicVersionVector& supported_versions,
    std::unique_ptr<ProofVerifier> proof_verifier,
    std::unique_ptr<SessionCache> session_cache)
    : event_loop_(GetDefaultEventLoop()->Create(QuicDefaultClock::Get())),
      client_(std::make_unique<MockableQuicClient>(
          server_address,
          QuicServerId(server_hostname, server_address.port(), false), config,
          supported_versions, event_loop_.get(), std::move(proof_verifier),
          std::move(session_cache))) {
  Initialize();
}

QuicTestClient::QuicTestClient(
    QuicSocketAddress server_address, const std::string& server_hostname,
    const QuicConfig& config, const ParsedQuicVersionVector& supported_versions,
    std::unique_ptr<ProofVerifier> proof_verifier,
    std::unique_ptr<SessionCache> session_cache,
    std::unique_ptr<QuicEventLoop> event_loop)
    : event_loop_(std::move(event_loop)),
      client_(std::make_unique<MockableQuicClient>(
          server_address,
          QuicServerId(server_hostname, server_address.port(), false), config,
          supported_versions, event_loop_.get(), std::move(proof_verifier),
          std::move(session_cache))) {
  Initialize();
}

QuicTestClient::QuicTestClient() = default;

QuicTestClient::~QuicTestClient() {
  for (std::pair<QuicStreamId, QuicSpdyClientStream*> stream : open_streams_) {
    stream.second->set_visitor(nullptr);
  }
}

void QuicTestClient::Initialize() {
  priority_ = 3;
  connect_attempted_ = false;
  auto_reconnect_ = false;
  buffer_body_ = true;
  num_requests_ = 0;
  num_responses_ = 0;
  ClearPerConnectionState();
  // As chrome will generally do this, we want it to be the default when it's
  // not overridden.
  if (!client_->config()->HasSetBytesForConnectionIdToSend()) {
    client_->config()->SetBytesForConnectionIdToSend(0);
  }
}

void QuicTestClient::SetUserAgentID(const std::string& user_agent_id) {
  client_->SetUserAgentID(user_agent_id);
}

int64_t QuicTestClient::SendRequest(const std::string& uri) {
  spdy::Http2HeaderBlock headers;
  if (!PopulateHeaderBlockFromUrl(uri, &headers)) {
    return 0;
  }
  return SendMessage(headers, "");
}

int64_t QuicTestClient::SendRequestAndRstTogether(const std::string& uri) {
  spdy::Http2HeaderBlock headers;
  if (!PopulateHeaderBlockFromUrl(uri, &headers)) {
    return 0;
  }

  QuicSpdyClientSession* session = client()->client_session();
  QuicConnection::ScopedPacketFlusher flusher(session->connection());
  int64_t ret = SendMessage(headers, "", /*fin=*/true, /*flush=*/false);

  QuicStreamId stream_id = GetNthClientInitiatedBidirectionalStreamId(
      session->transport_version(), 0);
  session->ResetStream(stream_id, QUIC_STREAM_CANCELLED);
  return ret;
}

void QuicTestClient::SendRequestsAndWaitForResponses(
    const std::vector<std::string>& url_list) {
  for (const std::string& url : url_list) {
    SendRequest(url);
  }
  while (client()->WaitForEvents()) {
  }
}

int64_t QuicTestClient::GetOrCreateStreamAndSendRequest(
    const spdy::Http2HeaderBlock* headers, absl::string_view body, bool fin,
    quiche::QuicheReferenceCountedPointer<QuicAckListenerInterface>
        ack_listener) {
  // Maybe it's better just to overload this.  it's just that we need
  // for the GetOrCreateStream function to call something else...which
  // is icky and complicated, but maybe not worse than this.
  QuicSpdyClientStream* stream = GetOrCreateStream();
  if (stream == nullptr) {
    return 0;
  }
  QuicSpdyStreamPeer::set_ack_listener(stream, ack_listener);

  int64_t ret = 0;
  if (headers != nullptr) {
    spdy::Http2HeaderBlock spdy_headers(headers->Clone());
    if (spdy_headers[":authority"].as_string().empty()) {
      spdy_headers[":authority"] = client_->server_id().host();
    }
    ret = stream->SendRequest(std::move(spdy_headers), body, fin);
    ++num_requests_;
  } else {
    stream->WriteOrBufferBody(std::string(body), fin);
    ret = body.length();
  }
  return ret;
}

int64_t QuicTestClient::SendMessage(const spdy::Http2HeaderBlock& headers,
                                    absl::string_view body) {
  return SendMessage(headers, body, /*fin=*/true);
}

int64_t QuicTestClient::SendMessage(const spdy::Http2HeaderBlock& headers,
                                    absl::string_view body, bool fin) {
  return SendMessage(headers, body, fin, /*flush=*/true);
}

int64_t QuicTestClient::SendMessage(const spdy::Http2HeaderBlock& headers,
                                    absl::string_view body, bool fin,
                                    bool flush) {
  // Always force creation of a stream for SendMessage.
  latest_created_stream_ = nullptr;

  int64_t ret = GetOrCreateStreamAndSendRequest(&headers, body, fin, nullptr);

  if (flush) {
    WaitForWriteToFlush();
  }
  return ret;
}

int64_t QuicTestClient::SendData(const std::string& data, bool last_data) {
  return SendData(data, last_data, nullptr);
}

int64_t QuicTestClient::SendData(
    const std::string& data, bool last_data,
    quiche::QuicheReferenceCountedPointer<QuicAckListenerInterface>
        ack_listener) {
  return GetOrCreateStreamAndSendRequest(nullptr, absl::string_view(data),
                                         last_data, std::move(ack_listener));
}

bool QuicTestClient::response_complete() const { return response_complete_; }

int64_t QuicTestClient::response_body_size() const {
  return response_body_size_;
}

bool QuicTestClient::buffer_body() const { return buffer_body_; }

void QuicTestClient::set_buffer_body(bool buffer_body) {
  buffer_body_ = buffer_body;
}

const std::string& QuicTestClient::response_body() const { return response_; }

std::string QuicTestClient::SendCustomSynchronousRequest(
    const spdy::Http2HeaderBlock& headers, const std::string& body) {
  // Clear connection state here and only track this synchronous request.
  ClearPerConnectionState();
  if (SendMessage(headers, body) == 0) {
    QUIC_DLOG(ERROR) << "Failed the request for: " << headers.DebugString();
    // Set the response_ explicitly.  Otherwise response_ will contain the
    // response from the previously successful request.
    response_ = "";
  } else {
    WaitForResponse();
  }
  return response_;
}

std::string QuicTestClient::SendSynchronousRequest(const std::string& uri) {
  spdy::Http2HeaderBlock headers;
  if (!PopulateHeaderBlockFromUrl(uri, &headers)) {
    return "";
  }
  return SendCustomSynchronousRequest(headers, "");
}

void QuicTestClient::SendConnectivityProbing() {
  QuicConnection* connection = client()->client_session()->connection();
  connection->SendConnectivityProbingPacket(connection->writer(),
                                            connection->peer_address());
}

void QuicTestClient::SetLatestCreatedStream(QuicSpdyClientStream* stream) {
  latest_created_stream_ = stream;
  if (latest_created_stream_ != nullptr) {
    open_streams_[stream->id()] = stream;
    stream->set_visitor(this);
  }
}

QuicSpdyClientStream* QuicTestClient::GetOrCreateStream() {
  if (!connect_attempted_ || auto_reconnect_) {
    if (!connected()) {
      Connect();
    }
    if (!connected()) {
      return nullptr;
    }
  }
  if (open_streams_.empty()) {
    ClearPerConnectionState();
  }
  if (!latest_created_stream_) {
    SetLatestCreatedStream(client_->CreateClientStream());
    if (latest_created_stream_) {
      latest_created_stream_->SetPriority(QuicStreamPriority(
          HttpStreamPriority{priority_, /* incremental = */ false}));
    }
  }

  return latest_created_stream_;
}

QuicErrorCode QuicTestClient::connection_error() const {
  return client()->connection_error();
}

const std::string& QuicTestClient::cert_common_name() const {
  return reinterpret_cast<RecordingProofVerifier*>(client_->proof_verifier())
      ->common_name();
}

const std::string& QuicTestClient::cert_sct() const {
  return reinterpret_cast<RecordingProofVerifier*>(client_->proof_verifier())
      ->cert_sct();
}

const QuicTagValueMap& QuicTestClient::GetServerConfig() const {
  QuicCryptoClientConfig* config = client_->crypto_config();
  const QuicCryptoClientConfig::CachedState* state =
      config->LookupOrCreate(client_->server_id());
  const CryptoHandshakeMessage* handshake_msg = state->GetServerConfig();
  return handshake_msg->tag_value_map();
}

bool QuicTestClient::connected() const { return client_->connected(); }

void QuicTestClient::Connect() {
  if (connected()) {
    QUIC_BUG(quic_bug_10133_1) << "Cannot connect already-connected client";
    return;
  }
  if (!connect_attempted_) {
    client_->Initialize();
  }

  // If we've been asked to override SNI, set it now
  if (override_sni_set_) {
    client_->set_server_id(
        QuicServerId(override_sni_, address().port(), false));
  }

  client_->Connect();
  connect_attempted_ = true;
}

void QuicTestClient::ResetConnection() {
  Disconnect();
  Connect();
}

void QuicTestClient::Disconnect() {
  ClearPerConnectionState();
  if (client_->initialized()) {
    client_->Disconnect();
  }
  connect_attempted_ = false;
}

QuicSocketAddress QuicTestClient::local_address() const {
  return client_->network_helper()->GetLatestClientAddress();
}

void QuicTestClient::ClearPerRequestState() {
  stream_error_ = QUIC_STREAM_NO_ERROR;
  response_ = "";
  response_complete_ = false;
  response_headers_complete_ = false;
  response_headers_.clear();
  response_trailers_.clear();
  bytes_read_ = 0;
  bytes_written_ = 0;
  response_body_size_ = 0;
}

bool QuicTestClient::HaveActiveStream() { return !open_streams_.empty(); }

bool QuicTestClient::WaitUntil(
    int timeout_ms, std::optional<quiche::UnretainedCallback<bool()>> trigger) {
  QuicTime::Delta timeout = QuicTime::Delta::FromMilliseconds(timeout_ms);
  const QuicClock* clock = client()->session()->connection()->clock();
  QuicTime end_waiting_time = clock->Now() + timeout;
  while (connected() && !(trigger.has_value() && (*trigger)()) &&
         (timeout_ms < 0 || clock->Now() < end_waiting_time)) {
    event_loop_->RunEventLoopOnce(timeout);
    client_->WaitForEventsPostprocessing();
  }
  ReadNextResponse();
  if (trigger.has_value() && !(*trigger)()) {
    QUIC_VLOG(1) << "Client WaitUntil returning with trigger returning false.";
    return false;
  }
  return true;
}

int64_t QuicTestClient::Send(absl::string_view data) {
  return SendData(std::string(data), false);
}

bool QuicTestClient::response_headers_complete() const {
  for (std::pair<QuicStreamId, QuicSpdyClientStream*> stream : open_streams_) {
    if (stream.second->headers_decompressed()) {
      return true;
    }
  }
  return response_headers_complete_;
}

const spdy::Http2HeaderBlock* QuicTestClient::response_headers() const {
  for (std::pair<QuicStreamId, QuicSpdyClientStream*> stream : open_streams_) {
    if (stream.second->headers_decompressed()) {
      response_headers_ = stream.second->response_headers().Clone();
      break;
    }
  }
  return &response_headers_;
}

const spdy::Http2HeaderBlock& QuicTestClient::response_trailers() const {
  return response_trailers_;
}

int64_t QuicTestClient::response_size() const { return bytes_read(); }

size_t QuicTestClient::bytes_read() const {
  for (std::pair<QuicStreamId, QuicSpdyClientStream*> stream : open_streams_) {
    size_t bytes_read = stream.second->total_body_bytes_read() +
                        stream.second->header_bytes_read();
    if (bytes_read > 0) {
      return bytes_read;
    }
  }
  return bytes_read_;
}

size_t QuicTestClient::bytes_written() const {
  for (std::pair<QuicStreamId, QuicSpdyClientStream*> stream : open_streams_) {
    size_t bytes_written = stream.second->stream_bytes_written() +
                           stream.second->header_bytes_written();
    if (bytes_written > 0) {
      return bytes_written;
    }
  }
  return bytes_written_;
}

absl::string_view QuicTestClient::partial_response_body() const {
  return latest_created_stream_ == nullptr ? ""
                                           : latest_created_stream_->data();
}

void QuicTestClient::OnClose(QuicSpdyStream* stream) {
  if (stream == nullptr) {
    return;
  }
  // Always close the stream, regardless of whether it was the last stream
  // written.
  client()->OnClose(stream);
  ++num_responses_;
  if (open_streams_.find(stream->id()) == open_streams_.end()) {
    return;
  }
  if (latest_created_stream_ == stream) {
    latest_created_stream_ = nullptr;
  }
  QuicSpdyClientStream* client_stream =
      static_cast<QuicSpdyClientStream*>(stream);
  QuicStreamId id = client_stream->id();
  closed_stream_states_.insert(std::make_pair(
      id,
      PerStreamState(
          // Set response_complete to true iff stream is closed while connected.
          client_stream->stream_error(), connected(),
          client_stream->headers_decompressed(),
          client_stream->response_headers(),
          (buffer_body() ? std::string(client_stream->data()) : ""),
          client_stream->received_trailers(),
          // Use NumBytesConsumed to avoid counting retransmitted stream frames.
          client_stream->total_body_bytes_read() +
              client_stream->header_bytes_read(),
          client_stream->stream_bytes_written() +
              client_stream->header_bytes_written(),
          client_stream->data().size())));
  open_streams_.erase(id);
}

void QuicTestClient::UseWriter(QuicPacketWriterWrapper* writer) {
  client_->UseWriter(writer);
}

void QuicTestClient::UseConnectionId(QuicConnectionId server_connection_id) {
  QUICHE_DCHECK(!connected());
  client_->set_server_connection_id_override(server_connection_id);
}

void QuicTestClient::UseConnectionIdLength(
    uint8_t server_connection_id_length) {
  QUICHE_DCHECK(!connected());
  client_->set_server_connection_id_length(server_connection_id_length);
}

void QuicTestClient::UseClientConnectionId(
    QuicConnectionId client_connection_id) {
  QUICHE_DCHECK(!connected());
  client_->UseClientConnectionId(client_connection_id);
}

void QuicTestClient::UseClientConnectionIdLength(
    uint8_t client_connection_id_length) {
  QUICHE_DCHECK(!connected());
  client_->UseClientConnectionIdLength(client_connection_id_length);
}

bool QuicTestClient::MigrateSocket(const QuicIpAddress& new_host) {
  return client_->MigrateSocket(new_host);
}

bool QuicTestClient::MigrateSocketWithSpecifiedPort(
    const QuicIpAddress& new_host, int port) {
  client_->set_local_port(port);
  return client_->MigrateSocket(new_host);
}

QuicIpAddress QuicTestClient::bind_to_address() const {
  return client_->bind_to_address();
}

void QuicTestClient::set_bind_to_address(QuicIpAddress address) {
  client_->set_bind_to_address(address);
}

const QuicSocketAddress& QuicTestClient::address() const {
  return client_->server_address();
}

void QuicTestClient::WaitForWriteToFlush() {
  while (connected() && client()->session()->HasDataToWrite()) {
    client_->WaitForEvents();
  }
}

QuicTestClient::PerStreamState::PerStreamState(const PerStreamState& other)
    : stream_error(other.stream_error),
      response_complete(other.response_complete),
      response_headers_complete(other.response_headers_complete),
      response_headers(other.response_headers.Clone()),
      response(other.response),
      response_trailers(other.response_trailers.Clone()),
      bytes_read(other.bytes_read),
      bytes_written(other.bytes_written),
      response_body_size(other.response_body_size) {}

QuicTestClient::PerStreamState::PerStreamState(
    QuicRstStreamErrorCode stream_error, bool response_complete,
    bool response_headers_complete,
    const spdy::Http2HeaderBlock& response_headers, const std::string& response,
    const spdy::Http2HeaderBlock& response_trailers, uint64_t bytes_read,
    uint64_t bytes_written, int64_t response_body_size)
    : stream_error(stream_error),
      response_complete(response_complete),
      response_headers_complete(response_headers_complete),
      response_headers(response_headers.Clone()),
      response(response),
      response_trailers(response_trailers.Clone()),
      bytes_read(bytes_read),
      bytes_written(bytes_written),
      response_body_size(response_body_size) {}

QuicTestClient::PerStreamState::~PerStreamState() = default;

bool QuicTestClient::PopulateHeaderBlockFromUrl(
    const std::string& uri, spdy::Http2HeaderBlock* headers) {
  std::string url;
  if (absl::StartsWith(uri, "https://") || absl::StartsWith(uri, "http://")) {
    url = uri;
  } else if (uri[0] == '/') {
    url = "https://" + client_->server_id().host() + uri;
  } else {
    url = "https://" + uri;
  }
  return SpdyUtils::PopulateHeaderBlockFromUrl(url, headers);
}

void QuicTestClient::ReadNextResponse() {
  if (closed_stream_states_.empty()) {
    return;
  }

  PerStreamState state(closed_stream_states_.front().second);

  stream_error_ = state.stream_error;
  response_ = state.response;
  response_complete_ = state.response_complete;
  response_headers_complete_ = state.response_headers_complete;
  response_headers_ = state.response_headers.Clone();
  response_trailers_ = state.response_trailers.Clone();
  bytes_read_ = state.bytes_read;
  bytes_written_ = state.bytes_written;
  response_body_size_ = state.response_body_size;

  closed_stream_states_.pop_front();
}

void QuicTestClient::ClearPerConnectionState() {
  ClearPerRequestState();
  open_streams_.clear();
  closed_stream_states_.clear();
  latest_created_stream_ = nullptr;
}

void QuicTestClient::WaitForDelayedAcks() {
  // kWaitDuration is a period of time that is long enough for all delayed
  // acks to be sent and received on the other end.
  const QuicTime::Delta kWaitDuration =
      4 * QuicTime::Delta::FromMilliseconds(GetDefaultDelayedAckTimeMs());

  const QuicClock* clock = client()->client_session()->connection()->clock();

  QuicTime wait_until = clock->ApproximateNow() + kWaitDuration;
  while (connected() && clock->ApproximateNow() < wait_until) {
    // This waits for up to 50 ms.
    client()->WaitForEvents();
  }
}

}  // namespace test
}  // namespace quic