// 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/url_request/url_request_context_builder.h"

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

#include "base/compiler_specific.h"
#include "base/logging.h"
#include "base/macros.h"
#include "base/single_thread_task_runner.h"
#include "base/strings/string_util.h"
#include "base/thread_task_runner_handle.h"
#include "base/threading/thread.h"
#include "net/base/cache_type.h"
#include "net/base/net_errors.h"
#include "net/base/network_delegate_impl.h"
#include "net/base/sdch_manager.h"
#include "net/cert/cert_verifier.h"
#include "net/cookies/cookie_monster.h"
#include "net/dns/host_resolver.h"
#include "net/ftp/ftp_network_layer.h"
#include "net/http/http_auth_handler_factory.h"
#include "net/http/http_cache.h"
#include "net/http/http_network_layer.h"
#include "net/http/http_server_properties_impl.h"
#include "net/http/http_server_properties_manager.h"
#include "net/http/transport_security_persister.h"
#include "net/http/transport_security_state.h"
#include "net/quic/quic_stream_factory.h"
#include "net/ssl/channel_id_service.h"
#include "net/ssl/default_channel_id_store.h"
#include "net/ssl/ssl_config_service_defaults.h"
#include "net/url_request/data_protocol_handler.h"
#include "net/url_request/static_http_user_agent_settings.h"
#include "net/url_request/url_request_backoff_manager.h"
#include "net/url_request/url_request_context.h"
#include "net/url_request/url_request_context_storage.h"
#include "net/url_request/url_request_intercepting_job_factory.h"
#include "net/url_request/url_request_interceptor.h"
#include "net/url_request/url_request_job_factory_impl.h"
#include "net/url_request/url_request_throttler_manager.h"

#if !defined(DISABLE_FILE_SUPPORT)
#include "net/url_request/file_protocol_handler.h"
#endif

#if !defined(DISABLE_FTP_SUPPORT)
#include "net/url_request/ftp_protocol_handler.h"
#endif

namespace net {

namespace {

class BasicNetworkDelegate : public NetworkDelegateImpl {
 public:
  BasicNetworkDelegate() {}
  ~BasicNetworkDelegate() override {}

 private:
  int OnBeforeURLRequest(URLRequest* request,
                         const CompletionCallback& callback,
                         GURL* new_url) override {
    return OK;
  }

  int OnBeforeSendHeaders(URLRequest* request,
                          const CompletionCallback& callback,
                          HttpRequestHeaders* headers) override {
    return OK;
  }

  void OnSendHeaders(URLRequest* request,
                     const HttpRequestHeaders& headers) override {}

  int OnHeadersReceived(
      URLRequest* request,
      const CompletionCallback& callback,
      const HttpResponseHeaders* original_response_headers,
      scoped_refptr<HttpResponseHeaders>* override_response_headers,
      GURL* allowed_unsafe_redirect_url) override {
    return OK;
  }

  void OnBeforeRedirect(URLRequest* request,
                        const GURL& new_location) override {}

  void OnResponseStarted(URLRequest* request) override {}

  void OnCompleted(URLRequest* request, bool started) override {}

  void OnURLRequestDestroyed(URLRequest* request) override {}

  void OnPACScriptError(int line_number, const base::string16& error) override {
  }

  NetworkDelegate::AuthRequiredResponse OnAuthRequired(
      URLRequest* request,
      const AuthChallengeInfo& auth_info,
      const AuthCallback& callback,
      AuthCredentials* credentials) override {
    return NetworkDelegate::AUTH_REQUIRED_RESPONSE_NO_ACTION;
  }

  bool OnCanGetCookies(const URLRequest& request,
                       const CookieList& cookie_list) override {
    return true;
  }

  bool OnCanSetCookie(const URLRequest& request,
                      const std::string& cookie_line,
                      CookieOptions* options) override {
    return true;
  }

  bool OnCanAccessFile(const URLRequest& request,
                       const base::FilePath& path) const override {
    return true;
  }

  DISALLOW_COPY_AND_ASSIGN(BasicNetworkDelegate);
};

// Define a context class that can self-manage the ownership of its components
// via a UrlRequestContextStorage object.
class ContainerURLRequestContext : public URLRequestContext {
 public:
  explicit ContainerURLRequestContext(
      const scoped_refptr<base::SingleThreadTaskRunner>& file_task_runner)
      : file_task_runner_(file_task_runner), storage_(this) {}
  ~ContainerURLRequestContext() override { AssertNoURLRequests(); }

  URLRequestContextStorage* storage() {
    return &storage_;
  }

  scoped_refptr<base::SingleThreadTaskRunner>& GetFileTaskRunner() {
    // Create a new thread to run file tasks, if needed.
    if (!file_task_runner_) {
      DCHECK(!file_thread_);
      file_thread_.reset(new base::Thread("Network File Thread"));
      file_thread_->StartWithOptions(
          base::Thread::Options(base::MessageLoop::TYPE_DEFAULT, 0));
      file_task_runner_ = file_thread_->task_runner();
    }
    return file_task_runner_;
  }

  void set_transport_security_persister(
      scoped_ptr<TransportSecurityPersister> transport_security_persister) {
    transport_security_persister_ = std::move(transport_security_persister);
  }

 private:
  // The thread should be torn down last.
  scoped_ptr<base::Thread> file_thread_;
  scoped_refptr<base::SingleThreadTaskRunner> file_task_runner_;

  URLRequestContextStorage storage_;
  scoped_ptr<TransportSecurityPersister> transport_security_persister_;

  DISALLOW_COPY_AND_ASSIGN(ContainerURLRequestContext);
};

}  // namespace

URLRequestContextBuilder::HttpCacheParams::HttpCacheParams()
    : type(IN_MEMORY),
      max_size(0) {}
URLRequestContextBuilder::HttpCacheParams::~HttpCacheParams() {}

URLRequestContextBuilder::HttpNetworkSessionParams::HttpNetworkSessionParams()
    : ignore_certificate_errors(false),
      host_mapping_rules(NULL),
      testing_fixed_http_port(0),
      testing_fixed_https_port(0),
      enable_spdy31(true),
      enable_http2(true),
      parse_alternative_services(false),
      enable_alternative_service_with_different_host(false),
      enable_quic(false),
      quic_max_server_configs_stored_in_properties(0),
      quic_delay_tcp_race(false),
      quic_max_number_of_lossy_connections(0),
      quic_prefer_aes(false),
      quic_packet_loss_threshold(1.0f),
      quic_idle_connection_timeout_seconds(kIdleConnectionTimeoutSeconds),
      quic_close_sessions_on_ip_change(false),
      quic_migrate_sessions_on_network_change(false),
      quic_migrate_sessions_early(false) {}

URLRequestContextBuilder::HttpNetworkSessionParams::~HttpNetworkSessionParams()
{}

URLRequestContextBuilder::URLRequestContextBuilder()
    : data_enabled_(false),
#if !defined(DISABLE_FILE_SUPPORT)
      file_enabled_(false),
#endif
#if !defined(DISABLE_FTP_SUPPORT)
      ftp_enabled_(false),
#endif
      http_cache_enabled_(true),
      throttling_enabled_(false),
      backoff_enabled_(false),
      sdch_enabled_(false),
      net_log_(nullptr) {
}

URLRequestContextBuilder::~URLRequestContextBuilder() {}

void URLRequestContextBuilder::SetHttpNetworkSessionComponents(
    const URLRequestContext* context,
    HttpNetworkSession::Params* params) {
  params->host_resolver = context->host_resolver();
  params->cert_verifier = context->cert_verifier();
  params->transport_security_state = context->transport_security_state();
  params->cert_transparency_verifier = context->cert_transparency_verifier();
  params->proxy_service = context->proxy_service();
  params->ssl_config_service = context->ssl_config_service();
  params->http_auth_handler_factory = context->http_auth_handler_factory();
  params->http_server_properties = context->http_server_properties();
  params->net_log = context->net_log();
  params->channel_id_service = context->channel_id_service();
}

void URLRequestContextBuilder::EnableHttpCache(const HttpCacheParams& params) {
  http_cache_enabled_ = true;
  http_cache_params_ = params;
}

void URLRequestContextBuilder::DisableHttpCache() {
  http_cache_enabled_ = false;
  http_cache_params_ = HttpCacheParams();
}

void URLRequestContextBuilder::SetSpdyAndQuicEnabled(bool spdy_enabled,
                                                     bool quic_enabled) {
  http_network_session_params_.enable_spdy31 = spdy_enabled;
  http_network_session_params_.enable_http2 = spdy_enabled;
  http_network_session_params_.enable_quic = quic_enabled;
}

void URLRequestContextBuilder::SetCertVerifier(
    scoped_ptr<CertVerifier> cert_verifier) {
  cert_verifier_ = std::move(cert_verifier);
}

void URLRequestContextBuilder::SetInterceptors(
    std::vector<scoped_ptr<URLRequestInterceptor>> url_request_interceptors) {
  url_request_interceptors_ = std::move(url_request_interceptors);
}

void URLRequestContextBuilder::SetCookieAndChannelIdStores(
    scoped_ptr<CookieStore> cookie_store,
    scoped_ptr<ChannelIDService> channel_id_service) {
  DCHECK(cookie_store);
  cookie_store_ = std::move(cookie_store);
  channel_id_service_ = std::move(channel_id_service);
}

void URLRequestContextBuilder::SetFileTaskRunner(
    const scoped_refptr<base::SingleThreadTaskRunner>& task_runner) {
  file_task_runner_ = task_runner;
}

void URLRequestContextBuilder::SetProtocolHandler(
    const std::string& scheme,
    scoped_ptr<URLRequestJobFactory::ProtocolHandler> protocol_handler) {
  DCHECK(protocol_handler);
  protocol_handlers_[scheme] = std::move(protocol_handler);
}

void URLRequestContextBuilder::SetHttpAuthHandlerFactory(
    scoped_ptr<HttpAuthHandlerFactory> factory) {
  http_auth_handler_factory_ = std::move(factory);
}

void URLRequestContextBuilder::SetHttpServerProperties(
    scoped_ptr<HttpServerProperties> http_server_properties) {
  http_server_properties_ = std::move(http_server_properties);
}

scoped_ptr<URLRequestContext> URLRequestContextBuilder::Build() {
  scoped_ptr<ContainerURLRequestContext> context(
      new ContainerURLRequestContext(file_task_runner_));
  URLRequestContextStorage* storage = context->storage();

  storage->set_http_user_agent_settings(make_scoped_ptr(
      new StaticHttpUserAgentSettings(accept_language_, user_agent_)));

  if (!network_delegate_)
    network_delegate_.reset(new BasicNetworkDelegate);
  storage->set_network_delegate(std::move(network_delegate_));

  if (net_log_) {
    // Unlike the other builder parameters, |net_log_| is not owned by the
    // builder or resulting context.
    context->set_net_log(net_log_);
  } else {
    storage->set_net_log(make_scoped_ptr(new NetLog));
  }

  if (!host_resolver_) {
    host_resolver_ = HostResolver::CreateDefaultResolver(context->net_log());
  }
  storage->set_host_resolver(std::move(host_resolver_));

  if (!proxy_service_) {
    // TODO(willchan): Switch to using this code when
    // ProxyService::CreateSystemProxyConfigService()'s signature doesn't suck.
#if !defined(OS_LINUX) && !defined(OS_ANDROID)
    if (!proxy_config_service_) {
      proxy_config_service_ = ProxyService::CreateSystemProxyConfigService(
          base::ThreadTaskRunnerHandle::Get().get(),
          context->GetFileTaskRunner());
    }
#endif  // !defined(OS_LINUX) && !defined(OS_ANDROID)
    proxy_service_ = ProxyService::CreateUsingSystemProxyResolver(
        std::move(proxy_config_service_),
        0,  // This results in using the default value.
        context->net_log());
  }
  storage->set_proxy_service(std::move(proxy_service_));

  storage->set_ssl_config_service(new SSLConfigServiceDefaults);

  if (!http_auth_handler_factory_) {
    http_auth_handler_factory_ =
        HttpAuthHandlerRegistryFactory::CreateDefault(context->host_resolver());
  }

  storage->set_http_auth_handler_factory(std::move(http_auth_handler_factory_));

  if (cookie_store_) {
    storage->set_cookie_store(std::move(cookie_store_));
    storage->set_channel_id_service(std::move(channel_id_service_));
  } else {
    storage->set_cookie_store(
        make_scoped_ptr(new CookieMonster(nullptr, nullptr)));
    // TODO(mmenke):  This always creates a file thread, even when it ends up
    // not being used.  Consider lazily creating the thread.
    storage->set_channel_id_service(make_scoped_ptr(new ChannelIDService(
        new DefaultChannelIDStore(NULL), context->GetFileTaskRunner())));
  }

  if (sdch_enabled_) {
    storage->set_sdch_manager(scoped_ptr<net::SdchManager>(new SdchManager()));
  }

  storage->set_transport_security_state(
      make_scoped_ptr(new TransportSecurityState()));
  if (!transport_security_persister_path_.empty()) {
    context->set_transport_security_persister(
        make_scoped_ptr<TransportSecurityPersister>(
            new TransportSecurityPersister(context->transport_security_state(),
                                           transport_security_persister_path_,
                                           context->GetFileTaskRunner(),
                                           false)));
  }

  if (http_server_properties_) {
    storage->set_http_server_properties(std::move(http_server_properties_));
  } else {
    storage->set_http_server_properties(
        scoped_ptr<HttpServerProperties>(new HttpServerPropertiesImpl()));
  }

  if (cert_verifier_) {
    storage->set_cert_verifier(std::move(cert_verifier_));
  } else {
    storage->set_cert_verifier(CertVerifier::CreateDefault());
  }

  if (throttling_enabled_) {
    storage->set_throttler_manager(
        make_scoped_ptr(new URLRequestThrottlerManager()));
  }

  if (backoff_enabled_) {
    storage->set_backoff_manager(
        make_scoped_ptr(new URLRequestBackoffManager()));
  }

  HttpNetworkSession::Params network_session_params;
  SetHttpNetworkSessionComponents(context.get(), &network_session_params);

  network_session_params.ignore_certificate_errors =
      http_network_session_params_.ignore_certificate_errors;
  network_session_params.host_mapping_rules =
      http_network_session_params_.host_mapping_rules;
  network_session_params.testing_fixed_http_port =
      http_network_session_params_.testing_fixed_http_port;
  network_session_params.testing_fixed_https_port =
      http_network_session_params_.testing_fixed_https_port;
  network_session_params.enable_spdy31 =
      http_network_session_params_.enable_spdy31;
  network_session_params.enable_http2 =
      http_network_session_params_.enable_http2;
  network_session_params.parse_alternative_services =
      http_network_session_params_.parse_alternative_services;
  network_session_params.enable_alternative_service_with_different_host =
      http_network_session_params_
          .enable_alternative_service_with_different_host;
  network_session_params.enable_quic = http_network_session_params_.enable_quic;
  network_session_params.quic_max_server_configs_stored_in_properties =
      http_network_session_params_.quic_max_server_configs_stored_in_properties;
  network_session_params.quic_delay_tcp_race =
      http_network_session_params_.quic_delay_tcp_race;
  network_session_params.quic_max_number_of_lossy_connections =
      http_network_session_params_.quic_max_number_of_lossy_connections;
  network_session_params.quic_packet_loss_threshold =
      http_network_session_params_.quic_packet_loss_threshold;
  network_session_params.quic_idle_connection_timeout_seconds =
      http_network_session_params_.quic_idle_connection_timeout_seconds;
  network_session_params.quic_connection_options =
      http_network_session_params_.quic_connection_options;
  network_session_params.quic_host_whitelist =
      http_network_session_params_.quic_host_whitelist;
  network_session_params.quic_close_sessions_on_ip_change =
      http_network_session_params_.quic_close_sessions_on_ip_change;
  network_session_params.quic_migrate_sessions_on_network_change =
      http_network_session_params_.quic_migrate_sessions_on_network_change;
  network_session_params.quic_user_agent_id =
      http_network_session_params_.quic_user_agent_id;
  network_session_params.quic_prefer_aes =
      http_network_session_params_.quic_prefer_aes;
  network_session_params.quic_migrate_sessions_early =
      http_network_session_params_.quic_migrate_sessions_early;
  if (proxy_delegate_) {
    network_session_params.proxy_delegate = proxy_delegate_.get();
    storage->set_proxy_delegate(std::move(proxy_delegate_));
  }

  storage->set_http_network_session(
      make_scoped_ptr(new HttpNetworkSession(network_session_params)));

  scoped_ptr<HttpTransactionFactory> http_transaction_factory;
  if (http_cache_enabled_) {
    scoped_ptr<HttpCache::BackendFactory> http_cache_backend;
    if (http_cache_params_.type != HttpCacheParams::IN_MEMORY) {
      BackendType backend_type =
          http_cache_params_.type == HttpCacheParams::DISK
              ? CACHE_BACKEND_DEFAULT
              : CACHE_BACKEND_SIMPLE;
      http_cache_backend.reset(new HttpCache::DefaultBackend(
          DISK_CACHE, backend_type, http_cache_params_.path,
          http_cache_params_.max_size, context->GetFileTaskRunner()));
    } else {
      http_cache_backend =
          HttpCache::DefaultBackend::InMemory(http_cache_params_.max_size);
    }

    http_transaction_factory.reset(new HttpCache(
        storage->http_network_session(), std::move(http_cache_backend), true));
  } else {
    http_transaction_factory.reset(
        new HttpNetworkLayer(storage->http_network_session()));
  }
  storage->set_http_transaction_factory(std::move(http_transaction_factory));

  URLRequestJobFactoryImpl* job_factory = new URLRequestJobFactoryImpl;
  // Adds caller-provided protocol handlers first so that these handlers are
  // used over data/file/ftp handlers below.
  for (auto& scheme_handler : protocol_handlers_) {
    job_factory->SetProtocolHandler(scheme_handler.first,
                                    std::move(scheme_handler.second));
  }
  protocol_handlers_.clear();

  if (data_enabled_)
    job_factory->SetProtocolHandler("data",
                                    make_scoped_ptr(new DataProtocolHandler));

#if !defined(DISABLE_FILE_SUPPORT)
  if (file_enabled_) {
    job_factory->SetProtocolHandler(
        "file",
        make_scoped_ptr(new FileProtocolHandler(context->GetFileTaskRunner())));
  }
#endif  // !defined(DISABLE_FILE_SUPPORT)

#if !defined(DISABLE_FTP_SUPPORT)
  if (ftp_enabled_) {
    ftp_transaction_factory_.reset(
        new FtpNetworkLayer(context->host_resolver()));
    job_factory->SetProtocolHandler(
        "ftp", make_scoped_ptr(
                   new FtpProtocolHandler(ftp_transaction_factory_.get())));
  }
#endif  // !defined(DISABLE_FTP_SUPPORT)

  scoped_ptr<net::URLRequestJobFactory> top_job_factory(job_factory);
  if (!url_request_interceptors_.empty()) {
    // Set up interceptors in the reverse order.

    for (auto i = url_request_interceptors_.rbegin();
         i != url_request_interceptors_.rend(); ++i) {
      top_job_factory.reset(new net::URLRequestInterceptingJobFactory(
          std::move(top_job_factory), std::move(*i)));
    }
    url_request_interceptors_.clear();
  }
  storage->set_job_factory(std::move(top_job_factory));
  // TODO(willchan): Support sdch.

  return std::move(context);
}

}  // namespace net