// 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/http/http_stream_factory_impl.h"

#include <string>

#include "base/logging.h"
#include "base/stl_util.h"
#include "net/base/net_util.h"
#include "net/http/http_network_session.h"
#include "net/http/http_server_properties.h"
#include "net/http/http_stream_factory_impl_job.h"
#include "net/http/http_stream_factory_impl_request.h"
#include "net/log/net_log.h"
#include "net/spdy/spdy_http_stream.h"
#include "url/gurl.h"

namespace net {

HttpStreamFactoryImpl::HttpStreamFactoryImpl(HttpNetworkSession* session,
                                             bool for_websockets)
    : session_(session),
      for_websockets_(for_websockets) {}

HttpStreamFactoryImpl::~HttpStreamFactoryImpl() {
  DCHECK(request_map_.empty());
  DCHECK(spdy_session_request_map_.empty());

  std::set<const Job*> tmp_job_set;
  tmp_job_set.swap(orphaned_job_set_);
  STLDeleteContainerPointers(tmp_job_set.begin(), tmp_job_set.end());
  DCHECK(orphaned_job_set_.empty());

  tmp_job_set.clear();
  tmp_job_set.swap(preconnect_job_set_);
  STLDeleteContainerPointers(tmp_job_set.begin(), tmp_job_set.end());
  DCHECK(preconnect_job_set_.empty());
}

HttpStreamRequest* HttpStreamFactoryImpl::RequestStream(
    const HttpRequestInfo& request_info,
    RequestPriority priority,
    const SSLConfig& server_ssl_config,
    const SSLConfig& proxy_ssl_config,
    HttpStreamRequest::Delegate* delegate,
    const BoundNetLog& net_log) {
  DCHECK(!for_websockets_);
  return RequestStreamInternal(request_info,
                               priority,
                               server_ssl_config,
                               proxy_ssl_config,
                               delegate,
                               NULL,
                               net_log);
}

HttpStreamRequest* HttpStreamFactoryImpl::RequestWebSocketHandshakeStream(
    const HttpRequestInfo& request_info,
    RequestPriority priority,
    const SSLConfig& server_ssl_config,
    const SSLConfig& proxy_ssl_config,
    HttpStreamRequest::Delegate* delegate,
    WebSocketHandshakeStreamBase::CreateHelper* create_helper,
    const BoundNetLog& net_log) {
  DCHECK(for_websockets_);
  DCHECK(create_helper);
  return RequestStreamInternal(request_info,
                               priority,
                               server_ssl_config,
                               proxy_ssl_config,
                               delegate,
                               create_helper,
                               net_log);
}

HttpStreamRequest* HttpStreamFactoryImpl::RequestStreamInternal(
    const HttpRequestInfo& request_info,
    RequestPriority priority,
    const SSLConfig& server_ssl_config,
    const SSLConfig& proxy_ssl_config,
    HttpStreamRequest::Delegate* delegate,
    WebSocketHandshakeStreamBase::CreateHelper*
        websocket_handshake_stream_create_helper,
    const BoundNetLog& net_log) {
  Request* request = new Request(request_info.url,
                                 this,
                                 delegate,
                                 websocket_handshake_stream_create_helper,
                                 net_log);
  Job* job = new Job(this, session_, request_info, priority, server_ssl_config,
                     proxy_ssl_config, net_log.net_log());
  request->AttachJob(job);

  const AlternativeServiceVector alternative_service_vector =
      GetAlternativeServicesFor(request_info.url);
  if (!alternative_service_vector.empty()) {
    // TODO(bnc): Pass on multiple alternative services to Job.
    const AlternativeService& alternative_service =
        alternative_service_vector[0];
    // Never share connection with other jobs for FTP requests.
    DCHECK(!request_info.url.SchemeIs("ftp"));

    Job* alternative_job =
        new Job(this, session_, request_info, priority, server_ssl_config,
                proxy_ssl_config, alternative_service, net_log.net_log());
    request->AttachJob(alternative_job);

    job->WaitFor(alternative_job);
    // Make sure to wait until we call WaitFor(), before starting
    // |alternative_job|, otherwise |alternative_job| will not notify |job|
    // appropriately.
    alternative_job->Start(request);
  }

  // Even if |alternative_job| has already finished, it will not have notified
  // the request yet, since we defer that to the next iteration of the
  // MessageLoop, so starting |job| is always safe.
  job->Start(request);
  return request;
}

void HttpStreamFactoryImpl::PreconnectStreams(
    int num_streams,
    const HttpRequestInfo& request_info,
    const SSLConfig& server_ssl_config,
    const SSLConfig& proxy_ssl_config) {
  DCHECK(!for_websockets_);
  AlternativeService alternative_service;
  AlternativeServiceVector alternative_service_vector =
      GetAlternativeServicesFor(request_info.url);
  if (!alternative_service_vector.empty()) {
    // TODO(bnc): Pass on multiple alternative services to Job.
    alternative_service = alternative_service_vector[0];
  }

  // Due to how the socket pools handle priorities and idle sockets, only IDLE
  // priority currently makes sense for preconnects. The priority for
  // preconnects is currently ignored (see RequestSocketsForPool()), but could
  // be used at some point for proxy resolution or something.
  Job* job =
      new Job(this, session_, request_info, IDLE, server_ssl_config,
              proxy_ssl_config, alternative_service, session_->net_log());
  preconnect_job_set_.insert(job);
  job->Preconnect(num_streams);
}

const HostMappingRules* HttpStreamFactoryImpl::GetHostMappingRules() const {
  return session_->params().host_mapping_rules;
}

AlternativeServiceVector HttpStreamFactoryImpl::GetAlternativeServicesFor(
    const GURL& original_url) {
  if (!session_->params().use_alternative_services)
    return AlternativeServiceVector();

  if (original_url.SchemeIs("ftp"))
    return AlternativeServiceVector();

  HostPortPair origin = HostPortPair::FromURL(original_url);
  HttpServerProperties& http_server_properties =
      *session_->http_server_properties();
  const AlternativeServiceVector alternative_service_vector =
      http_server_properties.GetAlternativeServices(origin);
  if (alternative_service_vector.empty())
    return AlternativeServiceVector();

  AlternativeServiceVector enabled_alternative_service_vector;
  for (const AlternativeService& alternative_service :
       alternative_service_vector) {
    DCHECK(IsAlternateProtocolValid(alternative_service.protocol));
    if (http_server_properties.IsAlternativeServiceBroken(
            alternative_service)) {
      HistogramAlternateProtocolUsage(ALTERNATE_PROTOCOL_USAGE_BROKEN);
      continue;
    }

    // Some shared unix systems may have user home directories (like
    // http://foo.com/~mike) which allow users to emit headers.  This is a bad
    // idea already, but with Alternate-Protocol, it provides the ability for a
    // single user on a multi-user system to hijack the alternate protocol.
    // These systems also enforce ports <1024 as restricted ports.  So don't
    // allow protocol upgrades to user-controllable ports.
    const int kUnrestrictedPort = 1024;
    if (!session_->params().enable_user_alternate_protocol_ports &&
        (alternative_service.port >= kUnrestrictedPort &&
         origin.port() < kUnrestrictedPort))
      continue;

    origin.set_port(alternative_service.port);
    if (alternative_service.protocol >= NPN_SPDY_MINIMUM_VERSION &&
        alternative_service.protocol <= NPN_SPDY_MAXIMUM_VERSION) {
      if (!HttpStreamFactory::spdy_enabled())
        continue;

      if (session_->HasSpdyExclusion(origin))
        continue;

      enabled_alternative_service_vector.push_back(alternative_service);
      continue;
    }

    DCHECK_EQ(QUIC, alternative_service.protocol);
    if (!session_->params().enable_quic)
      continue;

    if (session_->quic_stream_factory()->IsQuicDisabled(origin.port()))
      continue;

    if (!session_->params().enable_insecure_quic &&
        !original_url.SchemeIs("https")) {
      continue;
    }

    enabled_alternative_service_vector.push_back(alternative_service);
  }
  return enabled_alternative_service_vector;
}

void HttpStreamFactoryImpl::OrphanJob(Job* job, const Request* request) {
  DCHECK(ContainsKey(request_map_, job));
  DCHECK_EQ(request_map_[job], request);
  DCHECK(!ContainsKey(orphaned_job_set_, job));

  request_map_.erase(job);

  orphaned_job_set_.insert(job);
  job->Orphan(request);
}

void HttpStreamFactoryImpl::OnNewSpdySessionReady(
    const base::WeakPtr<SpdySession>& spdy_session,
    bool direct,
    const SSLConfig& used_ssl_config,
    const ProxyInfo& used_proxy_info,
    bool was_npn_negotiated,
    NextProto protocol_negotiated,
    bool using_spdy,
    const BoundNetLog& net_log) {
  while (true) {
    if (!spdy_session)
      break;
    const SpdySessionKey& spdy_session_key = spdy_session->spdy_session_key();
    // Each iteration may empty out the RequestSet for |spdy_session_key| in
    // |spdy_session_request_map_|. So each time, check for RequestSet and use
    // the first one.
    //
    // TODO(willchan): If it's important, switch RequestSet out for a FIFO
    // queue (Order by priority first, then FIFO within same priority). Unclear
    // that it matters here.
    if (!ContainsKey(spdy_session_request_map_, spdy_session_key))
      break;
    Request* request = *spdy_session_request_map_[spdy_session_key].begin();
    request->Complete(was_npn_negotiated, protocol_negotiated, using_spdy);
    if (for_websockets_) {
      // TODO(ricea): Restore this code path when WebSocket over SPDY
      // implementation is ready.
      NOTREACHED();
    } else {
      bool use_relative_url = direct || request->url().SchemeIs("https");
      request->OnStreamReady(
          NULL,
          used_ssl_config,
          used_proxy_info,
          new SpdyHttpStream(spdy_session, use_relative_url));
    }
  }
  // TODO(mbelshe): Alert other valid requests.
}

void HttpStreamFactoryImpl::OnOrphanedJobComplete(const Job* job) {
  orphaned_job_set_.erase(job);
  delete job;
}

void HttpStreamFactoryImpl::OnPreconnectsComplete(const Job* job) {
  preconnect_job_set_.erase(job);
  delete job;
  OnPreconnectsCompleteInternal();
}

}  // namespace net