// Copyright 2016 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 "headless/lib/browser/headless_url_request_context_getter.h"

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

#include "base/task_scheduler/post_task.h"
#include "build/build_config.h"
#include "components/cookie_config/cookie_store_util.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/cookie_store_factory.h"
#include "content/public/browser/devtools_network_transaction_factory.h"
#include "headless/app/headless_shell_switches.h"
#include "headless/lib/browser/headless_browser_context_impl.h"
#include "headless/lib/browser/headless_browser_context_options.h"
#include "net/base/network_delegate_impl.h"
#include "net/cookies/cookie_store.h"
#include "net/dns/mapped_host_resolver.h"
#include "net/http/http_auth_handler_factory.h"
#include "net/http/http_auth_scheme.h"
#include "net/http/http_transaction_factory.h"
#include "net/http/http_util.h"
#include "net/proxy_resolution/proxy_resolution_service.h"
#include "net/ssl/channel_id_service.h"
#include "net/ssl/default_channel_id_store.h"
#include "net/traffic_annotation/network_traffic_annotation.h"
#include "net/url_request/url_request_context.h"
#include "net/url_request/url_request_context_builder.h"

#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
#include "base/command_line.h"
#include "components/os_crypt/key_storage_config_linux.h"
#include "components/os_crypt/os_crypt.h"
#endif

namespace headless {

namespace {

class DelegateImpl : public net::NetworkDelegateImpl {
 public:
  DelegateImpl() = default;
  ~DelegateImpl() override = default;

 private:
  // net::NetworkDelegateImpl implementation.
  bool OnCanAccessFile(const net::URLRequest& request,
                       const base::FilePath& original_path,
                       const base::FilePath& absolute_path) const override {
    return true;
  }

  DISALLOW_COPY_AND_ASSIGN(DelegateImpl);
};

}  // namespace

HeadlessURLRequestContextGetter::HeadlessURLRequestContextGetter(
    scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
    content::ProtocolHandlerMap* protocol_handlers,
    content::ProtocolHandlerMap context_protocol_handlers,
    content::URLRequestInterceptorScopedVector request_interceptors,
    HeadlessBrowserContextOptions* options,
    net::NetLog* net_log,
    HeadlessBrowserContextImpl* headless_browser_context)
    : io_task_runner_(std::move(io_task_runner)),
      accept_language_(options->accept_language()),
      user_agent_(options->user_agent()),
      host_resolver_rules_(options->host_resolver_rules()),
      proxy_config_(options->proxy_config()),
      request_interceptors_(std::move(request_interceptors)),
      net_log_(net_log) {
  // Must first be created on the UI thread.
  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);

  std::swap(protocol_handlers_, *protocol_handlers);
  for (auto& pair : context_protocol_handlers) {
    protocol_handlers_[pair.first] = std::move(pair.second);
  }

  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
  prefs_.SetServerWhitelist(
      command_line->GetSwitchValueASCII(switches::kAuthServerWhitelist));

  // We must create the proxy config service on the UI loop on Linux because it
  // must synchronously run on the glib message loop. This will be passed to
  // the URLRequestContextStorage on the IO thread in GetURLRequestContext().
  if (!proxy_config_) {
    proxy_config_service_ =
        net::ProxyResolutionService::CreateSystemProxyConfigService(
            io_task_runner_);
  }
  if (!headless_browser_context->IsOffTheRecord() &&
      !headless_browser_context->options()->user_data_dir().empty()) {
    user_data_path_ = headless_browser_context->GetPath();
  }
}

HeadlessURLRequestContextGetter::~HeadlessURLRequestContextGetter() = default;

net::URLRequestContext*
HeadlessURLRequestContextGetter::GetURLRequestContext() {
  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);

  if (shut_down_)
    return nullptr;

  if (url_request_context_)
    return url_request_context_.get();

  net::URLRequestContextBuilder builder;

  // Don't store cookies in incognito mode or if no user-data-dir was
  // specified
  // TODO: Enable this always once saving/restoring sessions is implemented
  // (https://crbug.com/617931)
  if (!user_data_path_.empty()) {
#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
    std::unique_ptr<os_crypt::Config> config(new os_crypt::Config());
    base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
    config->store = command_line->GetSwitchValueASCII(switches::kPasswordStore);
    config->product_name = "HeadlessChrome";
    // OSCrypt may target keyring, which requires calls from the main
    // thread.
    config->main_thread_runner = content::BrowserThread::GetTaskRunnerForThread(
        content::BrowserThread::UI);
    config->should_use_preference = false;
    config->user_data_path = user_data_path_;
    OSCrypt::SetConfig(std::move(config));
#endif

    content::CookieStoreConfig cookie_config(
        user_data_path_.Append(FILE_PATH_LITERAL("Cookies")), false, true,
        NULL);
    cookie_config.crypto_delegate = cookie_config::GetCookieCryptoDelegate();
    std::unique_ptr<net::CookieStore> cookie_store =
        CreateCookieStore(cookie_config);
    std::unique_ptr<net::ChannelIDService> channel_id_service =
        std::make_unique<net::ChannelIDService>(
            new net::DefaultChannelIDStore(nullptr));

    cookie_store->SetChannelIDServiceID(channel_id_service->GetUniqueID());
    builder.SetCookieAndChannelIdStores(std::move(cookie_store),
                                        std::move(channel_id_service));
  }

  builder.set_accept_language(
      net::HttpUtil::GenerateAcceptLanguageHeader(accept_language_));
  builder.set_user_agent(user_agent_);
  // TODO(skyostil): Make these configurable.
  builder.set_data_enabled(true);
  builder.set_file_enabled(true);
  if (proxy_config_) {
    net::NetworkTrafficAnnotationTag traffic_annotation =
        net::DefineNetworkTrafficAnnotation("proxy_config_headless", R"(
      semantics {
        sender: "Proxy Config"
        description:
          "Creates a proxy based on configuration received from headless "
          "command prompt."
        trigger:
          "User starts headless with proxy config."
        data:
          "Proxy configurations."
        destination: OTHER
        destination_other:
          "The proxy server specified in the configuration."
      }
      policy {
        cookies_allowed: NO
        setting:
          "This config is only used for headless mode and provided by user."
        policy_exception_justification:
          "This config is only used for headless mode and provided by user."
      })");

    builder.set_proxy_resolution_service(
        net::ProxyResolutionService::CreateFixed(net::ProxyConfigWithAnnotation(
            *proxy_config_, traffic_annotation)));
  } else {
    builder.set_proxy_config_service(std::move(proxy_config_service_));
  }

  builder.set_network_delegate(std::make_unique<DelegateImpl>());
  std::unique_ptr<net::HostResolver> host_resolver(
      net::HostResolver::CreateDefaultResolver(net_log_));

  if (!host_resolver_rules_.empty()) {
    std::unique_ptr<net::MappedHostResolver> mapped_host_resolver(
        new net::MappedHostResolver(std::move(host_resolver)));
    mapped_host_resolver->SetRulesFromString(host_resolver_rules_);
    host_resolver = std::move(mapped_host_resolver);
  }

  std::unique_ptr<net::HttpAuthHandlerRegistryFactory> factory =
      net::HttpAuthHandlerRegistryFactory::CreateDefault(host_resolver.get());
  factory->SetHttpAuthPreferences(net::kNegotiateAuthScheme, &prefs_);
  builder.SetHttpAuthHandlerFactory(std::move(factory));
  builder.set_host_resolver(std::move(host_resolver));

  // Extra headers are required for network emulation and are removed in
  // DevToolsNetworkTransaction. If a protocol handler is set for http or
  // https, then it is likely that the HttpTransactionFactoryCallback will
  // not be called and DevToolsNetworkTransaction would not remove the header.
  bool has_http_handler = false;
  for (auto& pair : protocol_handlers_) {
    builder.SetProtocolHandler(pair.first, std::move(pair.second));
    if (pair.first == url::kHttpScheme || pair.first == url::kHttpsScheme)
      has_http_handler = true;
  }
  protocol_handlers_.clear();
  builder.SetInterceptors(std::move(request_interceptors_));

  if (!has_http_handler) {
    builder.SetCreateHttpTransactionFactoryCallback(
        base::BindOnce(&content::CreateDevToolsNetworkTransactionFactory));
  }

  url_request_context_ = builder.Build();
  url_request_context_->set_net_log(net_log_);

  return url_request_context_.get();
}

scoped_refptr<base::SingleThreadTaskRunner>
HeadlessURLRequestContextGetter::GetNetworkTaskRunner() const {
  return io_task_runner_;
}

net::HostResolver* HeadlessURLRequestContextGetter::host_resolver() const {
  return url_request_context_->host_resolver();
}

void HeadlessURLRequestContextGetter::NotifyContextShuttingDown() {
  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
  shut_down_ = true;
  net::URLRequestContextGetter::NotifyContextShuttingDown();
  url_request_context_ = nullptr;  // deletes it
}

}  // namespace headless