// Copyright 2017 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.

#ifndef COMPONENTS_SAFE_BROWSING_RENDERER_RENDERER_URL_LOADER_THROTTLE_H_
#define COMPONENTS_SAFE_BROWSING_RENDERER_RENDERER_URL_LOADER_THROTTLE_H_

#include <memory>

#include "base/memory/weak_ptr.h"
#include "components/safe_browsing/common/safe_browsing.mojom.h"
#include "content/public/common/url_loader_throttle.h"
#include "mojo/public/cpp/bindings/binding_set.h"
#include "url/gurl.h"

namespace safe_browsing {

// RendererURLLoaderThrottle is used in renderer processes to query
// SafeBrowsing and determine whether a URL and its redirect URLs are safe to
// load. It defers response processing until all URL checks are completed;
// cancels the load if any URLs turn out to be bad.
class RendererURLLoaderThrottle : public content::URLLoaderThrottle,
                                  public mojom::UrlCheckNotifier {
 public:
  // |safe_browsing| must stay alive until WillStartRequest() (if it is called)
  // or the end of this object.
  // |render_frame_id| is used for displaying SafeBrowsing UI when necessary.
  RendererURLLoaderThrottle(mojom::SafeBrowsing* safe_browsing,
                            int render_frame_id);
  ~RendererURLLoaderThrottle() override;

 private:
  // content::URLLoaderThrottle implementation.
  void DetachFromCurrentSequence() override;
  void WillStartRequest(network::ResourceRequest* request,
                        bool* defer) override;
  void WillRedirectRequest(net::RedirectInfo* redirect_info,
                           const network::ResourceResponseHead& response_head,
                           bool* defer,
                           std::vector<std::string>* to_be_removed_headers,
                           net::HttpRequestHeaders* modified_headers) override;
  void WillProcessResponse(const GURL& response_url,
                           network::ResourceResponseHead* response_head,
                           bool* defer) override;

  // mojom::UrlCheckNotifier implementation.
  void OnCompleteCheck(bool proceed, bool showed_interstitial) override;

  void OnCheckUrlResult(mojom::UrlCheckNotifierRequest slow_check_notifier,
                        bool proceed,
                        bool showed_interstitial);

  // Called by the two methods above.
  // |slow_check| indicates whether it reports the result of a slow check.
  // (Please see comments in safe_browsing.mojom for what slow check means).
  void OnCompleteCheckInternal(bool slow_check,
                               bool proceed,
                               bool showed_interstitial);

  void OnConnectionError();

  mojom::SafeBrowsing* safe_browsing_;
  const int render_frame_id_;

  // These fields hold the connection to this instance's private connection to
  // the Safe Browsing service if DetachFromCurrentThread has been called.
  mojom::SafeBrowsingPtrInfo safe_browsing_ptr_info_;
  mojom::SafeBrowsingPtr safe_browsing_ptr_;

  mojom::SafeBrowsingUrlCheckerPtr url_checker_;

  size_t pending_checks_ = 0;
  size_t pending_slow_checks_ = 0;
  bool blocked_ = false;

  // The time when we started deferring the request.
  base::TimeTicks defer_start_time_;
  bool deferred_ = false;

  // The total delay caused by SafeBrowsing deferring the resource load.
  base::TimeDelta total_delay_;
  // Whether the interstitial page has been shown and therefore user action has
  // been involved.
  bool user_action_involved_ = false;

  std::unique_ptr<mojo::BindingSet<mojom::UrlCheckNotifier>> notifier_bindings_;

  GURL original_url_;

  base::WeakPtrFactory<RendererURLLoaderThrottle> weak_factory_{this};
};

}  // namespace safe_browsing

#endif  // COMPONENTS_SAFE_BROWSING_RENDERER_RENDERER_URL_LOADER_THROTTLE_H_
