// Copyright 2014 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 "content/browser/loader/navigation_url_loader_impl_core.h"

#include "base/bind.h"
#include "base/location.h"
#include "base/time/time.h"
#include "content/browser/frame_host/navigation_request_info.h"
#include "content/browser/loader/navigation_resource_handler.h"
#include "content/browser/loader/resource_dispatcher_host_impl.h"
#include "content/browser/service_worker/service_worker_navigation_handle_core.h"
#include "content/common/navigation_params.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/stream_handle.h"
#include "content/public/common/resource_response.h"
#include "net/base/net_errors.h"
#include "net/url_request/redirect_info.h"

namespace content {

NavigationURLLoaderImplCore::NavigationURLLoaderImplCore(
    const base::WeakPtr<NavigationURLLoaderImpl>& loader)
    : loader_(loader),
      resource_handler_(nullptr) {
  // This object is created on the UI thread but otherwise is accessed and
  // deleted on the IO thread.
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
}

NavigationURLLoaderImplCore::~NavigationURLLoaderImplCore() {
  DCHECK_CURRENTLY_ON(BrowserThread::IO);

  if (resource_handler_)
    resource_handler_->Cancel();
}

void NavigationURLLoaderImplCore::Start(
    ResourceContext* resource_context,
    ServiceWorkerNavigationHandleCore* service_worker_handle_core,
    scoped_ptr<NavigationRequestInfo> request_info) {
  DCHECK_CURRENTLY_ON(BrowserThread::IO);

  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      base::Bind(&NavigationURLLoaderImpl::NotifyRequestStarted, loader_,
                 base::TimeTicks::Now()));

  // The ResourceDispatcherHostImpl can be null in unit tests.
  if (ResourceDispatcherHostImpl::Get()) {
    ResourceDispatcherHostImpl::Get()->BeginNavigationRequest(
        resource_context, *request_info, this, service_worker_handle_core);
  }
}

void NavigationURLLoaderImplCore::FollowRedirect() {
  DCHECK_CURRENTLY_ON(BrowserThread::IO);

  if (resource_handler_)
    resource_handler_->FollowRedirect();
}

void NavigationURLLoaderImplCore::NotifyRequestRedirected(
    const net::RedirectInfo& redirect_info,
    ResourceResponse* response) {
  DCHECK_CURRENTLY_ON(BrowserThread::IO);
  TRACE_EVENT_ASYNC_END0("navigation", "Navigation redirectDelay", this);

  // Make a copy of the ResourceResponse before it is passed to another thread.
  //
  // TODO(davidben): This copy could be avoided if ResourceResponse weren't
  // reference counted and the loader stack passed unique ownership of the
  // response. https://crbug.com/416050
  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      base::Bind(&NavigationURLLoaderImpl::NotifyRequestRedirected, loader_,
                 redirect_info, response->DeepCopy()));

  // TODO(carlosk): extend this trace to support non-PlzNavigate navigations.
  // For the trace below we're using the NavigationURLLoaderImplCore as the
  // async trace id and reporting the new redirect URL as a parameter.
  TRACE_EVENT_ASYNC_BEGIN2("navigation", "Navigation redirectDelay", this,
                           "&NavigationURLLoaderImplCore", this, "New URL",
                           redirect_info.new_url.spec());
}

void NavigationURLLoaderImplCore::NotifyResponseStarted(
    ResourceResponse* response,
    scoped_ptr<StreamHandle> body) {
  DCHECK_CURRENTLY_ON(BrowserThread::IO);
  TRACE_EVENT_ASYNC_END0("navigation", "Navigation redirectDelay", this);
  TRACE_EVENT_ASYNC_END2("navigation", "Navigation timeToResponseStarted", this,
                         "&NavigationURLLoaderImplCore", this, "success", true);

  // If, by the time the task reaches the UI thread, |loader_| has already been
  // destroyed, NotifyResponseStarted will not run. |body| will be destructed
  // and the request released at that point.

  // Make a copy of the ResourceResponse before it is passed to another thread.
  //
  // TODO(davidben): This copy could be avoided if ResourceResponse weren't
  // reference counted and the loader stack passed unique ownership of the
  // response. https://crbug.com/416050
  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      base::Bind(&NavigationURLLoaderImpl::NotifyResponseStarted, loader_,
                 response->DeepCopy(), base::Passed(&body)));
}

void NavigationURLLoaderImplCore::NotifyRequestFailed(bool in_cache,
                                                      int net_error) {
  DCHECK_CURRENTLY_ON(BrowserThread::IO);
  TRACE_EVENT_ASYNC_END0("navigation", "Navigation redirectDelay", this);
  TRACE_EVENT_ASYNC_END2("navigation", "Navigation timeToResponseStarted", this,
                         "&NavigationURLLoaderImplCore", this, "success",
                         false);

  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      base::Bind(&NavigationURLLoaderImpl::NotifyRequestFailed, loader_,
                 in_cache, net_error));
}

}  // namespace content
