// 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 "net/quic/chromium/quic_chromium_client_stream.h"

#include <utility>

#include "base/bind_helpers.h"
#include "base/callback_helpers.h"
#include "base/location.h"
#include "base/threading/thread_task_runner_handle.h"
#include "net/base/io_buffer.h"
#include "net/base/net_errors.h"
#include "net/log/net_log_event_type.h"
#include "net/quic/chromium/quic_chromium_client_session.h"
#include "net/quic/chromium/quic_http_utils.h"
#include "net/quic/core/quic_spdy_session.h"
#include "net/quic/core/quic_write_blocked_list.h"
#include "net/quic/core/spdy_utils.h"

namespace net {
namespace {
// Sets a boolean to a value, and restores it to the previous value once
// the saver goes out of scope.
class ScopedBoolSaver {
 public:
  ScopedBoolSaver(bool* var, bool new_val) : var_(var), old_val_(*var) {
    *var_ = new_val;
  }

  ~ScopedBoolSaver() { *var_ = old_val_; }

 private:
  bool* var_;
  bool old_val_;
};
}  // namespace

QuicChromiumClientStream::Handle::Handle(QuicChromiumClientStream* stream)
    : stream_(stream),
      may_invoke_callbacks_(true),
      read_headers_buffer_(nullptr),
      read_body_buffer_len_(0),
      net_error_(ERR_UNEXPECTED),
      net_log_(stream->net_log()),
      weak_factory_(this) {
  SaveState();
}

QuicChromiumClientStream::Handle::~Handle() {
  if (stream_) {
    stream_->ClearHandle();
    // TODO(rch): If stream_ is still valid, it should probably be Reset()
    // so that it does not leak.
    // stream_->Reset(QUIC_STREAM_CANCELLED);
  }
}

void QuicChromiumClientStream::Handle::OnInitialHeadersAvailable() {
  if (!read_headers_callback_)
    return;  // Wait for ReadInitialHeaders to be called.

  int rv = ERR_QUIC_PROTOCOL_ERROR;
  if (!stream_->DeliverInitialHeaders(read_headers_buffer_, &rv))
    rv = ERR_QUIC_PROTOCOL_ERROR;

  ResetAndRun(&read_headers_callback_, rv);
}

void QuicChromiumClientStream::Handle::OnTrailingHeadersAvailable() {
  if (!read_headers_callback_)
    return;  // Wait for ReadInitialHeaders to be called.

  int rv = ERR_QUIC_PROTOCOL_ERROR;
  if (!stream_->DeliverTrailingHeaders(read_headers_buffer_, &rv))
    rv = ERR_QUIC_PROTOCOL_ERROR;

  ResetAndRun(&read_headers_callback_, rv);
}

void QuicChromiumClientStream::Handle::OnDataAvailable() {
  if (!read_body_callback_)
    return;  // Wait for ReadBody to be called.

  int rv = stream_->Read(read_body_buffer_, read_body_buffer_len_);
  if (rv == ERR_IO_PENDING)
    return;  // Spurrious, likely because of trailers?

  read_body_buffer_ = nullptr;
  read_body_buffer_len_ = 0;
  ResetAndRun(&read_body_callback_, rv);
}

void QuicChromiumClientStream::Handle::OnCanWrite() {
  if (!write_callback_)
    return;

  ResetAndRun(&write_callback_, OK);
}

void QuicChromiumClientStream::Handle::OnClose() {
  if (net_error_ == ERR_UNEXPECTED) {
    if (stream_error() == QUIC_STREAM_NO_ERROR &&
        connection_error() == QUIC_NO_ERROR && fin_sent() && fin_received()) {
      net_error_ = ERR_CONNECTION_CLOSED;
    } else {
      net_error_ = ERR_QUIC_PROTOCOL_ERROR;
    }
  }
  OnError(net_error_);
}

void QuicChromiumClientStream::Handle::OnError(int error) {
  net_error_ = error;
  if (stream_)
    SaveState();
  stream_ = nullptr;

  // Post a task to invoke the callbacks to ensure that there is no reentrancy.
  // A ScopedPacketBundler might cause an error which closes the stream under
  // the call stack of the owner of the handle.
  base::ThreadTaskRunnerHandle::Get()->PostTask(
      FROM_HERE,
      base::Bind(&QuicChromiumClientStream::Handle::InvokeCallbacksOnClose,
                 weak_factory_.GetWeakPtr(), error));
}

void QuicChromiumClientStream::Handle::InvokeCallbacksOnClose(int error) {
  // Invoking a callback may cause |this| to be deleted. If this happens, no
  // more callbacks should be invoked. Guard against this by holding a WeakPtr
  // to |this| and ensuring it's still valid.
  auto guard(weak_factory_.GetWeakPtr());
  for (auto* callback :
       {&read_headers_callback_, &read_body_callback_, &write_callback_}) {
    if (*callback)
      ResetAndRun(callback, error);
    if (!guard.get())
      return;
  }
}

int QuicChromiumClientStream::Handle::ReadInitialHeaders(
    SpdyHeaderBlock* header_block,
    const CompletionCallback& callback) {
  ScopedBoolSaver saver(&may_invoke_callbacks_, false);
  if (!stream_)
    return net_error_;

  int frame_len = 0;
  if (stream_->DeliverInitialHeaders(header_block, &frame_len))
    return frame_len;

  read_headers_buffer_ = header_block;
  SetCallback(callback, &read_headers_callback_);
  return ERR_IO_PENDING;
}

int QuicChromiumClientStream::Handle::ReadBody(
    IOBuffer* buffer,
    int buffer_len,
    const CompletionCallback& callback) {
  ScopedBoolSaver saver(&may_invoke_callbacks_, false);
  if (IsDoneReading())
    return OK;

  if (!stream_)
    return net_error_;

  int rv = stream_->Read(buffer, buffer_len);
  if (rv != ERR_IO_PENDING)
    return rv;

  SetCallback(callback, &read_body_callback_);
  read_body_buffer_ = buffer;
  read_body_buffer_len_ = buffer_len;
  return ERR_IO_PENDING;
}

int QuicChromiumClientStream::Handle::ReadTrailingHeaders(
    SpdyHeaderBlock* header_block,
    const CompletionCallback& callback) {
  ScopedBoolSaver saver(&may_invoke_callbacks_, false);
  if (!stream_)
    return net_error_;

  int frame_len = 0;
  if (stream_->DeliverTrailingHeaders(header_block, &frame_len))
    return frame_len;

  read_headers_buffer_ = header_block;
  SetCallback(callback, &read_headers_callback_);
  return ERR_IO_PENDING;
}

int QuicChromiumClientStream::Handle::WriteHeaders(
    SpdyHeaderBlock header_block,
    bool fin,
    QuicReferenceCountedPointer<QuicAckListenerInterface>
        ack_notifier_delegate) {
  if (!stream_)
    return 0;
  return HandleIOComplete(stream_->WriteHeaders(std::move(header_block), fin,
                                                ack_notifier_delegate));
}

int QuicChromiumClientStream::Handle::WriteStreamData(
    base::StringPiece data,
    bool fin,
    const CompletionCallback& callback) {
  ScopedBoolSaver saver(&may_invoke_callbacks_, false);
  if (!stream_)
    return net_error_;

  if (stream_->WriteStreamData(data, fin))
    return HandleIOComplete(OK);

  SetCallback(callback, &write_callback_);
  return ERR_IO_PENDING;
}

int QuicChromiumClientStream::Handle::WritevStreamData(
    const std::vector<scoped_refptr<IOBuffer>>& buffers,
    const std::vector<int>& lengths,
    bool fin,
    const CompletionCallback& callback) {
  ScopedBoolSaver saver(&may_invoke_callbacks_, false);
  if (!stream_)
    return net_error_;

  if (stream_->WritevStreamData(buffers, lengths, fin))
    return HandleIOComplete(OK);

  SetCallback(callback, &write_callback_);
  return ERR_IO_PENDING;
}

int QuicChromiumClientStream::Handle::Read(IOBuffer* buf, int buf_len) {
  if (!stream_)
    return net_error_;
  return stream_->Read(buf, buf_len);
}

void QuicChromiumClientStream::Handle::OnFinRead() {
  read_headers_callback_.Reset();
  if (stream_)
    stream_->OnFinRead();
}

void QuicChromiumClientStream::Handle::DisableConnectionMigration() {
  if (stream_)
    stream_->DisableConnectionMigration();
}

void QuicChromiumClientStream::Handle::SetPriority(SpdyPriority priority) {
  if (stream_)
    stream_->SetPriority(priority);
}

void QuicChromiumClientStream::Handle::Reset(
    QuicRstStreamErrorCode error_code) {
  if (stream_)
    stream_->Reset(error_code);
}

QuicStreamId QuicChromiumClientStream::Handle::id() const {
  if (!stream_)
    return id_;
  return stream_->id();
}

QuicErrorCode QuicChromiumClientStream::Handle::connection_error() const {
  if (!stream_)
    return connection_error_;
  return stream_->connection_error();
}

QuicRstStreamErrorCode QuicChromiumClientStream::Handle::stream_error() const {
  if (!stream_)
    return stream_error_;
  return stream_->stream_error();
}

bool QuicChromiumClientStream::Handle::fin_sent() const {
  if (!stream_)
    return fin_sent_;
  return stream_->fin_sent();
}

bool QuicChromiumClientStream::Handle::fin_received() const {
  if (!stream_)
    return fin_received_;
  return stream_->fin_received();
}

uint64_t QuicChromiumClientStream::Handle::stream_bytes_read() const {
  if (!stream_)
    return stream_bytes_read_;
  return stream_->stream_bytes_read();
}

uint64_t QuicChromiumClientStream::Handle::stream_bytes_written() const {
  if (!stream_)
    return stream_bytes_written_;
  return stream_->stream_bytes_written();
}

size_t QuicChromiumClientStream::Handle::NumBytesConsumed() const {
  if (!stream_)
    return num_bytes_consumed_;
  return stream_->sequencer()->NumBytesConsumed();
}

bool QuicChromiumClientStream::Handle::HasBytesToRead() const {
  if (!stream_)
    return false;
  return stream_->sequencer()->HasBytesToRead();
}

bool QuicChromiumClientStream::Handle::IsDoneReading() const {
  if (!stream_)
    return is_done_reading_;
  return stream_->IsDoneReading();
}

bool QuicChromiumClientStream::Handle::IsFirstStream() const {
  if (!stream_)
    return is_first_stream_;
  return stream_->IsFirstStream();
}

void QuicChromiumClientStream::Handle::OnPromiseHeaderList(
    QuicStreamId promised_id,
    size_t frame_len,
    const QuicHeaderList& header_list) {
  stream_->OnPromiseHeaderList(promised_id, frame_len, header_list);
}

SpdyPriority QuicChromiumClientStream::Handle::priority() const {
  if (!stream_)
    return priority_;
  return stream_->priority();
}

bool QuicChromiumClientStream::Handle::can_migrate() {
  if (!stream_)
    return false;
  return stream_->can_migrate();
}

const NetLogWithSource& QuicChromiumClientStream::Handle::net_log() const {
  return net_log_;
}

void QuicChromiumClientStream::Handle::SaveState() {
  DCHECK(stream_);
  fin_sent_ = stream_->fin_sent();
  fin_received_ = stream_->fin_received();
  num_bytes_consumed_ = stream_->sequencer()->NumBytesConsumed();
  id_ = stream_->id();
  connection_error_ = stream_->connection_error();
  stream_error_ = stream_->stream_error();
  is_done_reading_ = stream_->IsDoneReading();
  is_first_stream_ = stream_->IsFirstStream();
  stream_bytes_read_ = stream_->stream_bytes_read();
  stream_bytes_written_ = stream_->stream_bytes_written();
  priority_ = stream_->priority();
}

void QuicChromiumClientStream::Handle::SetCallback(
    const CompletionCallback& new_callback,
    CompletionCallback* callback) {
  // TODO(rch): Convert this to a DCHECK once we ensure the API is stable and
  // bug free.
  CHECK(!may_invoke_callbacks_);
  *callback = new_callback;
}

void QuicChromiumClientStream::Handle::ResetAndRun(CompletionCallback* callback,
                                                   int rv) {
  // TODO(rch): Convert this to a DCHECK once we ensure the API is stable and
  // bug free.
  CHECK(may_invoke_callbacks_);
  ResetAndReturn(callback).Run(rv);
}

int QuicChromiumClientStream::Handle::HandleIOComplete(int rv) {
  // If |stream_| is still valid the stream has not been closed. If the stream
  // has not been closed, then just return |rv|.
  if (rv < 0 || stream_)
    return rv;

  if (stream_error_ == QUIC_STREAM_NO_ERROR &&
      connection_error_ == QUIC_NO_ERROR && fin_sent_ && fin_received_) {
    return rv;
  }

  return net_error_;
}

QuicChromiumClientStream::QuicChromiumClientStream(
    QuicStreamId id,
    QuicSpdyClientSessionBase* session,
    const NetLogWithSource& net_log)
    : QuicSpdyStream(id, session),
      net_log_(net_log),
      handle_(nullptr),
      headers_delivered_(false),
      initial_headers_sent_(false),
      session_(session),
      can_migrate_(true),
      initial_headers_frame_len_(0),
      trailing_headers_frame_len_(0),
      weak_factory_(this) {}

QuicChromiumClientStream::~QuicChromiumClientStream() {
  if (handle_)
    handle_->OnClose();
}

void QuicChromiumClientStream::OnInitialHeadersComplete(
    bool fin,
    size_t frame_len,
    const QuicHeaderList& header_list) {
  QuicSpdyStream::OnInitialHeadersComplete(fin, frame_len, header_list);

  SpdyHeaderBlock header_block;
  int64_t length = -1;
  if (!SpdyUtils::CopyAndValidateHeaders(header_list, &length, &header_block)) {
    DLOG(ERROR) << "Failed to parse header list: " << header_list.DebugString();
    ConsumeHeaderList();
    Reset(QUIC_BAD_APPLICATION_PAYLOAD);
    return;
  }

  ConsumeHeaderList();
  session_->OnInitialHeadersComplete(id(), header_block);

  // Buffer the headers and deliver them when the handle arrives.
  initial_headers_ = std::move(header_block);
  initial_headers_frame_len_ = frame_len;

  if (handle_) {
    // The handle will be notified of the headers via a posted task.
    NotifyHandleOfInitialHeadersAvailableLater();
  }
}

void QuicChromiumClientStream::OnTrailingHeadersComplete(
    bool fin,
    size_t frame_len,
    const QuicHeaderList& header_list) {
  QuicSpdyStream::OnTrailingHeadersComplete(fin, frame_len, header_list);
  trailing_headers_frame_len_ = frame_len;
  if (handle_) {
    // The handle will be notified of the headers via a posted task.
    NotifyHandleOfTrailingHeadersAvailableLater();
  }
}

void QuicChromiumClientStream::OnPromiseHeaderList(
    QuicStreamId promised_id,
    size_t frame_len,
    const QuicHeaderList& header_list) {
  SpdyHeaderBlock promise_headers;
  int64_t content_length = -1;
  if (!SpdyUtils::CopyAndValidateHeaders(header_list, &content_length,
                                         &promise_headers)) {
    DLOG(ERROR) << "Failed to parse header list: " << header_list.DebugString();
    ConsumeHeaderList();
    Reset(QUIC_BAD_APPLICATION_PAYLOAD);
    return;
  }
  ConsumeHeaderList();

  session_->HandlePromised(id(), promised_id, promise_headers);
}

void QuicChromiumClientStream::OnDataAvailable() {
  if (!FinishedReadingHeaders() || !headers_delivered_) {
    // Buffer the data in the sequencer until the headers have been read.
    return;
  }

  if (!sequencer()->HasBytesToRead() && !FinishedReadingTrailers()) {
    // If there is no data to read, wait until either FIN is received or
    // trailers are delivered.
    return;
  }

  // The handle will read the data via a posted task, and
  // will be able to, potentially, read all data which has queued up.
  if (handle_)
    NotifyHandleOfDataAvailableLater();
}

void QuicChromiumClientStream::OnClose() {
  if (handle_) {
    handle_->OnClose();
    handle_ = nullptr;
  }
  QuicStream::OnClose();
}

void QuicChromiumClientStream::OnCanWrite() {
  QuicStream::OnCanWrite();

  if (!HasBufferedData() && handle_)
    handle_->OnCanWrite();
}

size_t QuicChromiumClientStream::WriteHeaders(
    SpdyHeaderBlock header_block,
    bool fin,
    QuicReferenceCountedPointer<QuicAckListenerInterface> ack_listener) {
  if (!session()->IsCryptoHandshakeConfirmed()) {
    auto entry = header_block.find(":method");
    DCHECK(entry != header_block.end());
    DCHECK_NE("POST", entry->second);
  }
  net_log_.AddEvent(
      NetLogEventType::QUIC_CHROMIUM_CLIENT_STREAM_SEND_REQUEST_HEADERS,
      base::Bind(&QuicRequestNetLogCallback, id(), &header_block,
                 QuicSpdyStream::priority()));
  size_t len = QuicSpdyStream::WriteHeaders(std::move(header_block), fin,
                                            std::move(ack_listener));
  initial_headers_sent_ = true;
  return len;
}

SpdyPriority QuicChromiumClientStream::priority() const {
  return initial_headers_sent_ ? QuicSpdyStream::priority()
                               : kV3HighestPriority;
}

bool QuicChromiumClientStream::WriteStreamData(QuicStringPiece data, bool fin) {
  // Must not be called when data is buffered.
  DCHECK(!HasBufferedData());
  // Writes the data, or buffers it.
  WriteOrBufferData(data, fin, nullptr);
  return !HasBufferedData();  // Was all data written?
}

bool QuicChromiumClientStream::WritevStreamData(
    const std::vector<scoped_refptr<IOBuffer>>& buffers,
    const std::vector<int>& lengths,
    bool fin) {
  // Must not be called when data is buffered.
  DCHECK(!HasBufferedData());
  // Writes the data, or buffers it.
  if (session_->can_use_slices()) {
    WriteMemSlices(QuicMemSliceSpan(QuicMemSliceSpanImpl(
                       buffers.data(), lengths.data(), buffers.size())),
                   fin);
  } else {
    for (size_t i = 0; i < buffers.size(); ++i) {
      bool is_fin = fin && (i == buffers.size() - 1);
      QuicStringPiece string_data(buffers[i]->data(), lengths[i]);
      WriteOrBufferData(string_data, is_fin, nullptr);
    }
  }
  return !HasBufferedData();  // Was all data written?
}

std::unique_ptr<QuicChromiumClientStream::Handle>
QuicChromiumClientStream::CreateHandle() {
  DCHECK(!handle_);
  auto handle = std::unique_ptr<QuicChromiumClientStream::Handle>(
      new QuicChromiumClientStream::Handle(this));
  handle_ = handle.get();

  // Should this perhaps be via PostTask to make reasoning simpler?
  if (!initial_headers_.empty())
    handle_->OnInitialHeadersAvailable();

  return handle;
}

void QuicChromiumClientStream::ClearHandle() {
  handle_ = nullptr;
}

void QuicChromiumClientStream::OnError(int error) {
  if (handle_) {
    QuicChromiumClientStream::Handle* handle = handle_;
    handle_ = nullptr;
    handle->OnError(error);
  }
}

int QuicChromiumClientStream::Read(IOBuffer* buf, int buf_len) {
  if (IsDoneReading())
    return 0;  // EOF

  if (!HasBytesToRead())
    return ERR_IO_PENDING;

  iovec iov;
  iov.iov_base = buf->data();
  iov.iov_len = buf_len;
  size_t bytes_read = Readv(&iov, 1);
  // Since HasBytesToRead is true, Readv() must of read some data.
  DCHECK_NE(0u, bytes_read);
  return bytes_read;
}

void QuicChromiumClientStream::NotifyHandleOfInitialHeadersAvailableLater() {
  DCHECK(handle_);
  base::ThreadTaskRunnerHandle::Get()->PostTask(
      FROM_HERE,
      base::Bind(
          &QuicChromiumClientStream::NotifyHandleOfInitialHeadersAvailable,
          weak_factory_.GetWeakPtr()));
}

void QuicChromiumClientStream::NotifyHandleOfInitialHeadersAvailable() {
  if (!handle_)
    return;

  if (!headers_delivered_)
    handle_->OnInitialHeadersAvailable();
}

void QuicChromiumClientStream::NotifyHandleOfTrailingHeadersAvailableLater() {
  DCHECK(handle_);
  base::ThreadTaskRunnerHandle::Get()->PostTask(
      FROM_HERE,
      base::Bind(
          &QuicChromiumClientStream::NotifyHandleOfTrailingHeadersAvailable,
          weak_factory_.GetWeakPtr()));
}

void QuicChromiumClientStream::NotifyHandleOfTrailingHeadersAvailable() {
  if (!handle_)
    return;

  DCHECK(headers_delivered_);
  // Post an async task to notify handle of the FIN flag.
  NotifyHandleOfDataAvailableLater();
  handle_->OnTrailingHeadersAvailable();
}

bool QuicChromiumClientStream::DeliverInitialHeaders(SpdyHeaderBlock* headers,
                                                     int* frame_len) {
  if (initial_headers_.empty())
    return false;

  headers_delivered_ = true;
  net_log_.AddEvent(
      NetLogEventType::QUIC_CHROMIUM_CLIENT_STREAM_READ_RESPONSE_HEADERS,
      base::Bind(&SpdyHeaderBlockNetLogCallback, &initial_headers_));

  *headers = std::move(initial_headers_);
  *frame_len = initial_headers_frame_len_;
  return true;
}

bool QuicChromiumClientStream::DeliverTrailingHeaders(SpdyHeaderBlock* headers,
                                                      int* frame_len) {
  if (received_trailers().empty())
    return false;

  net_log_.AddEvent(
      NetLogEventType::QUIC_CHROMIUM_CLIENT_STREAM_READ_RESPONSE_TRAILERS,
      base::Bind(&SpdyHeaderBlockNetLogCallback, &received_trailers()));

  *headers = received_trailers().Clone();
  *frame_len = trailing_headers_frame_len_;

  MarkTrailersConsumed();
  return true;
}

void QuicChromiumClientStream::NotifyHandleOfDataAvailableLater() {
  DCHECK(handle_);
  base::ThreadTaskRunnerHandle::Get()->PostTask(
      FROM_HERE,
      base::Bind(&QuicChromiumClientStream::NotifyHandleOfDataAvailable,
                 weak_factory_.GetWeakPtr()));
}

void QuicChromiumClientStream::NotifyHandleOfDataAvailable() {
  if (handle_)
    handle_->OnDataAvailable();
}

void QuicChromiumClientStream::DisableConnectionMigration() {
  can_migrate_ = false;
}

bool QuicChromiumClientStream::IsFirstStream() {
  return id() == kHeadersStreamId + 2;
}

}  // namespace net