// 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.
//
// Classes for managing the SafeBrowsing interstitial pages.
//
// When a user is about to visit a page the SafeBrowsing system has deemed to
// be malicious, either as malware or a phishing page, we show an interstitial
// page with some options (go back, continue) to give the user a chance to avoid
// the harmful page.
//
// The SafeBrowsingBlockingPage is created by the SafeBrowsingUIManager on the
// UI thread when we've determined that a page is malicious. The operation of
// the blocking page occurs on the UI thread, where it waits for the user to
// make a decision about what to do: either go back or continue on.
//
// The blocking page forwards the result of the user's choice back to the
// SafeBrowsingUIManager so that we can cancel the request for the new page,
// or allow it to continue.
//
// A web page may contain several resources flagged as malware/phishing.  This
// results into more than one interstitial being shown.  On the first unsafe
// resource received we show an interstitial.  Any subsequent unsafe resource
// notifications while the first interstitial is showing is queued.  If the user
// decides to proceed in the first interstitial, we display all queued unsafe
// resources in a new interstitial.

#ifndef CHROME_BROWSER_SAFE_BROWSING_SAFE_BROWSING_BLOCKING_PAGE_H_
#define CHROME_BROWSER_SAFE_BROWSING_SAFE_BROWSING_BLOCKING_PAGE_H_

#include <map>
#include <string>
#include <vector>

#include "base/gtest_prod_util.h"
#include "base/task/cancelable_task_tracker.h"
#include "base/time/time.h"
#include "chrome/browser/history/history_service.h"
#include "chrome/browser/safe_browsing/ui_manager.h"
#include "content/public/browser/interstitial_page_delegate.h"
#include "url/gurl.h"

class MalwareDetails;
class SafeBrowsingBlockingPageFactory;

namespace base {
class DictionaryValue;
class MessageLoop;
}

namespace content {
class InterstitialPage;
class WebContents;
}

#if defined(ENABLE_EXTENSIONS)
namespace extensions {
class ExperienceSamplingEvent;
}
#endif

class SafeBrowsingBlockingPage : public content::InterstitialPageDelegate {
 public:
  typedef SafeBrowsingUIManager::UnsafeResource UnsafeResource;
  typedef std::vector<UnsafeResource> UnsafeResourceList;
  typedef std::map<content::WebContents*, UnsafeResourceList> UnsafeResourceMap;

  ~SafeBrowsingBlockingPage() override;

  // Creates a blocking page. Use ShowBlockingPage if you don't need to access
  // the blocking page directly.
  static SafeBrowsingBlockingPage* CreateBlockingPage(
      SafeBrowsingUIManager* ui_manager,
      content::WebContents* web_contents,
      const UnsafeResource& unsafe_resource);

  // Shows a blocking page warning the user about phishing/malware for a
  // specific resource.
  // You can call this method several times, if an interstitial is already
  // showing, the new one will be queued and displayed if the user decides
  // to proceed on the currently showing interstitial.
  static void ShowBlockingPage(
      SafeBrowsingUIManager* ui_manager, const UnsafeResource& resource);

  // Makes the passed |factory| the factory used to instantiate
  // SafeBrowsingBlockingPage objects. Useful for tests.
  static void RegisterFactory(SafeBrowsingBlockingPageFactory* factory) {
    factory_ = factory;
  }

  // InterstitialPageDelegate method:
  std::string GetHTMLContents() override;
  void OnProceed() override;
  void OnDontProceed() override;
  void CommandReceived(const std::string& command) override;
  void OverrideRendererPrefs(content::RendererPreferences* prefs) override;

 protected:
  friend class SafeBrowsingBlockingPageTest;
  FRIEND_TEST_ALL_PREFIXES(SafeBrowsingBlockingPageTest,
                           ProceedThenDontProceed);

  void DontCreateViewForTesting();
  void Show();
  void SetReportingPreference(bool report);
  void UpdateReportingPref();  // Used for the transition from old to new pref.

  // Don't instantiate this class directly, use ShowBlockingPage instead.
  SafeBrowsingBlockingPage(SafeBrowsingUIManager* ui_manager,
                           content::WebContents* web_contents,
                           const UnsafeResourceList& unsafe_resources);

  // After a malware interstitial where the user opted-in to the
  // report but clicked "proceed anyway", we delay the call to
  // MalwareDetails::FinishCollection() by this much time (in
  // milliseconds), in order to get data from the blocked resource itself.
  int64 malware_details_proceed_delay_ms_;
  content::InterstitialPage* interstitial_page() const {
    return interstitial_page_;
  }

  FRIEND_TEST_ALL_PREFIXES(SafeBrowsingBlockingPageTest,
      MalwareReportsTransitionDisabled);
  FRIEND_TEST_ALL_PREFIXES(SafeBrowsingBlockingPageTest,
      MalwareReportsToggling);

  // These enums are used for histograms.  Don't reorder, delete, or insert
  // elements.  New elements should be added before MAX_ACTION only.
  enum Decision {
    SHOW,
    PROCEED,
    DONT_PROCEED,
    PROCEEDING_DISABLED,
    MAX_DECISION
  };
  enum Interaction {
    TOTAL_VISITS,
    SHOW_ADVANCED,
    SHOW_PRIVACY_POLICY,
    SHOW_DIAGNOSTIC,
    SHOW_LEARN_MORE,
    MAX_INTERACTION
  };

  // Record a user decision or interaction to the appropriate UMA histogram.
  void RecordUserDecision(Decision decision);
  void RecordUserInteraction(Interaction interaction);

  // Used to query the HistoryService to see if the URL is in history. For UMA.
  void OnGotHistoryCount(bool success, int num_visits, base::Time first_visit);

  // Checks if we should even show the malware details option. For example, we
  // don't show it in incognito mode.
  bool CanShowMalwareDetailsOption();

  // Called when the insterstitial is going away. If there is a
  // pending malware details object, we look at the user's
  // preferences, and if the option to send malware details is
  // enabled, the report is scheduled to be sent on the |ui_manager_|.
  void FinishMalwareDetails(int64 delay_ms);

  // Returns the boolean value of the given |pref| from the PrefService of the
  // Profile associated with |web_contents_|.
  bool IsPrefEnabled(const char* pref);

  // A list of SafeBrowsingUIManager::UnsafeResource for a tab that the user
  // should be warned about.  They are queued when displaying more than one
  // interstitial at a time.
  static UnsafeResourceMap* GetUnsafeResourcesMap();

  // Notifies the SafeBrowsingUIManager on the IO thread whether to proceed
  // or not for the |resources|.
  static void NotifySafeBrowsingUIManager(
      SafeBrowsingUIManager* ui_manager,
      const UnsafeResourceList& resources, bool proceed);

  // Returns true if the passed |unsafe_resources| is blocking the load of
  // the main page.
  static bool IsMainPageLoadBlocked(
      const UnsafeResourceList& unsafe_resources);

  friend class SafeBrowsingBlockingPageFactoryImpl;

  // For reporting back user actions.
  SafeBrowsingUIManager* ui_manager_;
  base::MessageLoop* report_loop_;

  // True if the interstitial is blocking the main page because it is on one
  // of our lists.  False if a subresource is being blocked, or in the case of
  // client-side detection where the interstitial is shown after page load
  // finishes.
  bool is_main_frame_load_blocked_;

  // The index of a navigation entry that should be removed when DontProceed()
  // is invoked, -1 if not entry should be removed.
  int navigation_entry_index_to_remove_;

  // The list of unsafe resources this page is warning about.
  UnsafeResourceList unsafe_resources_;

  // A MalwareDetails object that we start generating when the
  // blocking page is shown. The object will be sent when the warning
  // is gone (if the user enables the feature).
  scoped_refptr<MalwareDetails> malware_details_;

  bool proceeded_;

  content::WebContents* web_contents_;
  GURL url_;
  content::InterstitialPage* interstitial_page_;  // Owns us

  // Whether the interstitial should create a view.
  bool create_view_;

  // Which type of interstitial this is.
  enum {
    TYPE_MALWARE,
    TYPE_HARMFUL,
    TYPE_PHISHING,
  } interstitial_type_;

  // The factory used to instantiate SafeBrowsingBlockingPage objects.
  // Usefull for tests, so they can provide their own implementation of
  // SafeBrowsingBlockingPage.
  static SafeBrowsingBlockingPageFactory* factory_;

  // How many times is this same URL in history? Used for histogramming.
  int num_visits_;
  base::CancelableTaskTracker request_tracker_;

 private:
  // Fills the passed dictionary with the values to be passed to the template
  // when creating the HTML.
  void PopulateMalwareLoadTimeData(base::DictionaryValue* load_time_data);
  void PopulateHarmfulLoadTimeData(base::DictionaryValue* load_time_data);
  void PopulatePhishingLoadTimeData(base::DictionaryValue* load_time_data);

#if defined(ENABLE_EXTENSIONS)
  scoped_ptr<extensions::ExperienceSamplingEvent> sampling_event_;
#endif

  DISALLOW_COPY_AND_ASSIGN(SafeBrowsingBlockingPage);
};

// Factory for creating SafeBrowsingBlockingPage.  Useful for tests.
class SafeBrowsingBlockingPageFactory {
 public:
  virtual ~SafeBrowsingBlockingPageFactory() { }

  virtual SafeBrowsingBlockingPage* CreateSafeBrowsingPage(
      SafeBrowsingUIManager* ui_manager,
      content::WebContents* web_contents,
      const SafeBrowsingBlockingPage::UnsafeResourceList& unsafe_resources) = 0;
};

#endif  // CHROME_BROWSER_SAFE_BROWSING_SAFE_BROWSING_BLOCKING_PAGE_H_