// 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/tools/quic/quic_spdy_server_stream.h"

#include "base/logging.h"
#include "base/stl_util.h"
#include "base/strings/string_number_conversions.h"
#include "net/quic/quic_session.h"
#include "net/quic/spdy_utils.h"
#include "net/spdy/spdy_protocol.h"
#include "net/tools/quic/quic_in_memory_cache.h"

using base::StringPiece;
using base::StringToInt;
using std::string;

namespace net {
namespace tools {

QuicSpdyServerStream::QuicSpdyServerStream(QuicStreamId id,
                                           QuicSession* session)
    : QuicDataStream(id, session),
      content_length_(-1) {
}

QuicSpdyServerStream::~QuicSpdyServerStream() {
}

uint32 QuicSpdyServerStream::ProcessData(const char* data, uint32 data_len) {
  if (!headers_decompressed()) {
    // Let the headers data accumulate in the underlying QuicDataStream.
    return 0;
  }
  if (request_headers_.empty()) {
    if (!ParseRequestHeaders(data, data_len)) {
      // Headers were invalid.
      SendErrorResponse();
      return 0;
    }
  } else {
    body_.append(data, data_len);
  }
  DCHECK(!request_headers_.empty());
  if (content_length_ >= 0 &&
      static_cast<int>(body_.size()) > content_length_) {
    SendErrorResponse();
    return 0;
  }
  DVLOG(1) << "Processed " << data_len << " bytes for stream " << id();
  return data_len;
}

void QuicSpdyServerStream::OnFinRead() {
  ReliableQuicStream::OnFinRead();
  if (write_side_closed() || fin_buffered()) {
    return;
  }

  if (request_headers_.empty()) {
    SendErrorResponse();
    return;
  }

  if (content_length_ > 0 &&
      content_length_ != static_cast<int>(body_.size())) {
    SendErrorResponse();
    return;
  }

  SendResponse();
}

bool QuicSpdyServerStream::ParseRequestHeaders(const char* data,
                                               uint32 data_len) {
  DCHECK(headers_decompressed());
  SpdyFramer framer(SPDY3);
  size_t len = framer.ParseHeaderBlockInBuffer(data,
                                               data_len,
                                               &request_headers_);
  DCHECK_LE(len, data_len);
  if (len == 0 || request_headers_.empty()) {
    return false;  // Headers were invalid.
  }

  if (data_len > len) {
    body_.append(data + len, data_len - len);
  }
  if (ContainsKey(request_headers_, "content-length") &&
      !StringToInt(request_headers_["content-length"], &content_length_)) {
    return false;  // Invalid content-length.
  }
  return true;
}

void QuicSpdyServerStream::SendResponse() {
  if (!ContainsKey(request_headers_, GetHostKey()) ||
      !ContainsKey(request_headers_, ":path")) {
    SendErrorResponse();
    return;
  }

  // Find response in cache. If not found, send error response.
  const QuicInMemoryCache::Response* response =
      QuicInMemoryCache::GetInstance()->GetResponse(
          request_headers_[GetHostKey()], request_headers_[":path"]);
  if (response == nullptr) {
    SendErrorResponse();
    return;
  }

  if (response->response_type() == QuicInMemoryCache::CLOSE_CONNECTION) {
    DVLOG(1) << "Special response: closing connection.";
    CloseConnection(QUIC_NO_ERROR);
    return;
  }

  if (response->response_type() == QuicInMemoryCache::IGNORE_REQUEST) {
    DVLOG(1) << "Special response: ignoring request.";
    return;
  }

  DVLOG(1) << "Sending response for stream " << id();
  if (version() > QUIC_VERSION_24) {
    SendHeadersAndBody(
        SpdyUtils::ConvertSpdy3ResponseHeadersToSpdy4(response->headers()),
        response->body());
    return;
  }

  SendHeadersAndBody(response->headers(), response->body());
}

void QuicSpdyServerStream::SendErrorResponse() {
  DVLOG(1) << "Sending error response for stream " << id();
  SpdyHeaderBlock headers;
  if (version() <= QUIC_VERSION_24) {
    headers[":version"] = "HTTP/1.1";
    headers[":status"] = "500 Server Error";
  } else {
    headers[":status"] = "500";
  }
  headers["content-length"] = "3";
  SendHeadersAndBody(headers, "bad");
}

void QuicSpdyServerStream::SendHeadersAndBody(
    const SpdyHeaderBlock& response_headers,
    StringPiece body) {
  // We only support SPDY and HTTP, and neither handles bidirectional streaming.
  if (!read_side_closed()) {
    CloseReadSide();
  }

  WriteHeaders(response_headers, body.empty(), nullptr);

  if (!body.empty()) {
    WriteOrBufferData(body, true, nullptr);
  }
}

const string QuicSpdyServerStream::GetHostKey() {
  // SPDY/4 uses ":authority" instead of ":host".
  return version() > QUIC_VERSION_24 ? ":authority" : ":host";
}

}  // namespace tools
}  // namespace net