// 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.

#ifndef CHROME_BROWSER_UI_SYNC_ONE_CLICK_SIGNIN_HELPER_H_
#define CHROME_BROWSER_UI_SYNC_ONE_CLICK_SIGNIN_HELPER_H_

#include <string>

#include "base/gtest_prod_util.h"
#include "base/memory/weak_ptr.h"
#include "chrome/browser/signin/signin_promo.h"
#include "chrome/browser/sync/profile_sync_service_observer.h"
#include "chrome/browser/ui/sync/one_click_signin_sync_starter.h"
#include "components/signin/core/browser/signin_oauth_helper.h"
#include "content/public/browser/navigation_controller.h"
#include "content/public/browser/web_contents_observer.h"
#include "content/public/browser/web_contents_user_data.h"
#include "google_apis/gaia/google_service_auth_error.h"

class Browser;
class GURL;
class ProfileIOData;

namespace autofill {
struct PasswordForm;
}

namespace content {
class WebContents;
struct FrameNavigateParams;
struct LoadCommittedDetails;
}

namespace net {
class URLRequest;
}

namespace password_manager {
class PasswordManager;
}

// Per-tab one-click signin helper.  When a user signs in to a Google service
// and the profile is not yet connected to a Google account, will start the
// process of helping the user connect his profile with one click.  The process
// begins with an infobar and is followed with a confirmation dialog explaining
// more about what this means.
class OneClickSigninHelper
    : public content::WebContentsObserver,
      public content::WebContentsUserData<OneClickSigninHelper> {
 public:
  // Represents user's decision about sign in process.
  enum AutoAccept {
    // User decision not yet known.  Assume cancel.
    AUTO_ACCEPT_NONE,

    // User has explicitly accepted to sign in.  A bubble is shown with the
    // option to start sync, configure it first, or abort.
    AUTO_ACCEPT_ACCEPTED,

    // User has explicitly accepted to sign in, but wants to configure sync
    // settings before turning it on.
    AUTO_ACCEPT_CONFIGURE,

    // User has explicitly rejected to sign in.  Furthermore, the user does
    // not want to be prompted to see the interstitial again in this profile.
    AUTO_ACCEPT_REJECTED_FOR_PROFILE,

    // This is an explicit sign in from either first run, NTP, wrench menu,
    // or settings page.  The user will be signed in automatically with sync
    // enabled using default settings.
    AUTO_ACCEPT_EXPLICIT
  };

  // Return value of CanOfferOnIOThread().
  enum Offer {
    CAN_OFFER,
    DONT_OFFER,
    IGNORE_REQUEST
  };

  // Argument to CanOffer().
  enum CanOfferFor {
    CAN_OFFER_FOR_ALL,
    CAN_OFFER_FOR_INTERSTITAL_ONLY,
    CAN_OFFER_FOR_SECONDARY_ACCOUNT
    // TODO(guohui): needs to handle adding secondary account through
    // interstitial.
  };

  // Arguments used with StartSync function.  base::Bind() cannot support too
  // many args for performance reasons, so they are packaged up into a struct.
  struct StartSyncArgs {
    // Default contructor for testing only.
    StartSyncArgs();
    StartSyncArgs(Profile* profile,
                  Browser* browser,
                  OneClickSigninHelper::AutoAccept auto_accept,
                  const std::string& session_index,
                  const std::string& email,
                  const std::string& password,
                  const std::string& refresh_token,
                  content::WebContents* web_contents,
                  bool untrusted_confirmation_required,
                  signin_metrics::Source source,
                  OneClickSigninSyncStarter::Callback callback);
    ~StartSyncArgs();

    Profile* profile;
    Browser* browser;
    OneClickSigninHelper::AutoAccept auto_accept;
    std::string session_index;
    std::string email;
    std::string password;
    std::string refresh_token;

    // Web contents in which the sync setup page should be displayed,
    // if necessary. Can be NULL.
    content::WebContents* web_contents;

    OneClickSigninSyncStarter::ConfirmationRequired confirmation_required;
    signin_metrics::Source source;
    OneClickSigninSyncStarter::Callback callback;
  };

  // Wrapper to call OneClickSigninSyncStarter after fetching the refresh token
  // if needed.  Also verifies that the cookies are correct if no password is
  // specified, and checks that the email from the cookies match the expected
  // email address.
  class SyncStarterWrapper : public SigninOAuthHelper::Consumer,
                             public chrome::BrowserListObserver {
   public:
    SyncStarterWrapper(
        const OneClickSigninHelper::StartSyncArgs& args,
        OneClickSigninSyncStarter::StartSyncMode start_mode);
    ~SyncStarterWrapper() override;

    void Start();

   private:
    void VerifyGaiaCookiesBeforeSignIn();
    void OnGaiaCookiesFetched(const std::string session_index,
                              const net::CookieList& cookie_list);

    // Virtual to be overridden in tests.
    virtual void DisplayErrorBubble(const std::string& error_message);
    virtual void StartSigninOAuthHelper();
    virtual void StartOneClickSigninSyncStarter(
        const std::string& email,
        const std::string& refresh_token);

    // Overriden from SigninOAuthHelper::Consumer.
    void OnSigninOAuthInformationAvailable(
        const std::string& email,
        const std::string& display_email,
        const std::string& refresh_token) override;
    void OnSigninOAuthInformationFailure(
        const GoogleServiceAuthError& error) override;

    // Overriden from chrome::BrowserListObserver.
    void OnBrowserRemoved(Browser* browser) override;

    OneClickSigninHelper::StartSyncArgs args_;
    chrome::HostDesktopType desktop_type_;
    OneClickSigninSyncStarter::StartSyncMode start_mode_;
    scoped_ptr<SigninOAuthHelper> signin_oauth_helper_;
    base::WeakPtrFactory<SyncStarterWrapper> weak_pointer_factory_;

    DISALLOW_COPY_AND_ASSIGN(SyncStarterWrapper);
  };

  static void LogHistogramValue(int action);

  // Returns true if the one-click signin feature can be offered at this time.
  // If |email| is not empty, then the profile is checked to see if it's
  // already connected to a google account or if the user has already rejected
  // one-click sign-in with this email, in which cases a one click signin
  // should not be offered.
  //
  // If |can_offer_for| is |CAN_OFFER_FOR_INTERSTITAL_ONLY|, then only do the
  // checks that would affect the interstitial page.  Otherwise, do the checks
  // that would affect the interstitial and the explicit sign ins.
  //
  // Returns in |error_message_id| an explanation as a string resource ID for
  // why one-clicked cannot be offered.  |error_message_id| is valid only if
  // the return value is false.  If no explanation is needed, |error_message_id|
  // may be null.
  static bool CanOffer(content::WebContents* web_contents,
                       CanOfferFor can_offer_for,
                       const std::string& email,
                       std::string* error_message);

  // Returns true if the one-click signin feature can be offered at this time.
  // It can be offered if the io_data is not in an incognito window and if the
  // origin of |url| is a valid Gaia sign in origin.  This function is meant
  // to called only from the IO thread.
  static Offer CanOfferOnIOThread(net::URLRequest* request,
                                  ProfileIOData* io_data);

  // Looks for the Google-Accounts-SignIn response header, and if found,
  // tries to display an infobar in the tab contents identified by the
  // child/route id.
  static void ShowInfoBarIfPossible(net::URLRequest* request,
                                    ProfileIOData* io_data,
                                    int child_id,
                                    int route_id);

  // Handles cross account sign in error. If the supplied |email| does not match
  // the last signed in email of the current profile, then Chrome will show a
  // confirmation dialog before starting sync. It returns true if there is a
  // cross account error, and false otherwise.
  static bool HandleCrossAccountError(
      Profile* profile,
      const std::string& session_index,
      const std::string& email,
      const std::string& password,
      const std::string& refresh_token,
      OneClickSigninHelper::AutoAccept auto_accept,
      signin_metrics::Source source,
      OneClickSigninSyncStarter::StartSyncMode start_mode,
      OneClickSigninSyncStarter::Callback sync_callback);

  static void RedirectToNtpOrAppsPage(
      content::WebContents* contents, signin_metrics::Source source);

  // If the |source| is not settings page/webstore, redirects to
  // the NTP/Apps page.
  static void RedirectToNtpOrAppsPageIfNecessary(
      content::WebContents* contents, signin_metrics::Source source);

  // Remove the item currently at the top of the history list if it's
  // the Gaia redirect URL. Due to limitations of the NavigationController
  // this cannot be done until a new page becomes "current".
  static void RemoveSigninRedirectURLHistoryItem(
      content::WebContents* web_contents);

  static void LogConfirmHistogramValue(int action);

 private:
  friend class content::WebContentsUserData<OneClickSigninHelper>;
  friend class OneClickSigninHelperTest;
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperIncognitoTest,
                           ShowInfoBarUIThreadIncognito);
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperTest,
                           SigninFromWebstoreWithConfigSyncfirst);
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperTest,
                           ShowSigninBubbleAfterSigninComplete);
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperTest, SigninCancelled);
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperTest, SigninFailed);
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperTest,
                           CleanTransientStateOnNavigate);
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperIOTest, CanOfferOnIOThread);
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperIOTest,
                           CanOfferOnIOThreadIncognito);
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperIOTest,
                           CanOfferOnIOThreadNoIOData);
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperIOTest,
                           CanOfferOnIOThreadBadURL);
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperIOTest,
                           CanOfferOnIOThreadDisabled);
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperIOTest,
                           CanOfferOnIOThreadSignedIn);
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperIOTest,
                           CanOfferOnIOThreadEmailNotAllowed);
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperIOTest,
                           CanOfferOnIOThreadEmailAlreadyUsed);
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperIOTest,
                           CreateTestProfileIOData);
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperIOTest,
                           CanOfferOnIOThreadWithRejectedEmail);
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperIOTest,
                           CanOfferOnIOThreadNoSigninCookies);
  FRIEND_TEST_ALL_PREFIXES(OneClickSigninHelperIOTest,
                           CanOfferOnIOThreadDisabledByPolicy);

  // Maximum number of navigations away from the set of valid Gaia URLs before
  // clearing the internal state of the helper.  This is necessary to support
  // SAML-based accounts, but causes bug crbug.com/181163.
  static const int kMaxNavigationsSince;

  explicit OneClickSigninHelper(content::WebContents* web_contents);

  ~OneClickSigninHelper() override;

  // Returns true if the one-click signin feature can be offered at this time.
  // It can be offered if the io_data is not in an incognito window and if the
  // origin of |url| is a valid Gaia sign in origin.  This function is meant
  // to called only from the IO thread.
  static Offer CanOfferOnIOThreadImpl(const GURL& url,
                                      base::SupportsUserData* request,
                                      ProfileIOData* io_data);

  // The portion of ShowInfoBarIfPossible() that needs to run on the UI thread.
  // |session_index| and |email| are extracted from the Google-Accounts-SignIn
  // header.  |auto_accept| is extracted from the Google-Chrome-SignIn header.
  // |source| is used to determine which of the explicit sign in mechanism is
  // being used.
  //
  // |continue_url| is where Gaia will continue to when the sign in process is
  // done.  For explicit sign ins, this is a URL chrome controls. For one-click
  // sign in, this could be any google property.  This URL is used to know
  // when the sign process is over and to collect infomation from the user
  // entered on the Gaia sign in page (for explicit sign ins).
  static void ShowInfoBarUIThread(const std::string& session_index,
                                  const std::string& email,
                                  AutoAccept auto_accept,
                                  signin_metrics::Source source,
                                  const GURL& continue_url,
                                  int child_id,
                                  int route_id);

  void RedirectToSignin();

  // Clear all data member of the helper, except for the error.
  void CleanTransientState();

  // Unitests that use a TestingProfile should call this.
  // Otherwise, clearing the pending e-mail crashes because the code expects
  // a real ResourceContext rather than the MockResourceContext a
  // TestingProfile provides.
  void SetDoNotClearPendingEmailForTesting();

  // In unit tests, disable starting the actual sync.
  void set_do_not_start_sync_for_testing();

  // Called when password has been submitted.
  void PasswordSubmitted(const autofill::PasswordForm& form);

  // content::WebContentsObserver overrides.
  void DidStartNavigationToPendingEntry(
      const GURL& url,
      content::NavigationController::ReloadType reload_type) override;
  void DidNavigateMainFrame(
      const content::LoadCommittedDetails& details,
      const content::FrameNavigateParams& params) override;
  void DidStopLoading(content::RenderViewHost* render_view_host) override;

  OneClickSigninSyncStarter::Callback CreateSyncStarterCallback();

  // Callback invoked when OneClickSigninSyncStarter completes sync setup.
  void SyncSetupCompletedCallback(
      OneClickSigninSyncStarter::SyncSetupResult result);

  // Tracks if we are in the process of showing the signin or one click
  // interstitial page. It's set to true the first time we load one of those
  // pages and set to false when transient state is cleaned.
  // Note: This should only be used for logging purposes.
  bool showing_signin_;

  // Information about the account that has just logged in.
  std::string session_index_;
  std::string email_;
  std::string password_;
  AutoAccept auto_accept_;
  signin_metrics::Source source_;
  bool switched_to_advanced_;
  GURL continue_url_;
  // The orignal continue URL after sync setup is complete.
  GURL original_continue_url_;
  std::string error_message_;

  // Number of navigations since starting a sign in that is outside the
  // the set of trusted Gaia URLs.  Sign in attempts that include visits to
  // one more untrusted will cause a modal dialog to appear asking the user
  // to confirm, similar to the interstitial flow.
  int untrusted_navigations_since_signin_visit_;

  // Whether a Gaia URL during the sign in process was not handled by the
  // dedicated sign in process (e.g. SAML login, which redirects to a
  // non-google-controlled domain).
  // This is set to true if at least one such URL is detected.
  bool untrusted_confirmation_required_;

  // Allows unittests to avoid accessing the ResourceContext for clearing a
  // pending e-mail.
  bool do_not_clear_pending_email_;

  // Allows unittest to avoid starting sync for real.
  bool do_not_start_sync_for_testing_;

  base::WeakPtrFactory<OneClickSigninHelper> weak_pointer_factory_;

  DISALLOW_COPY_AND_ASSIGN(OneClickSigninHelper);
};

#endif  // CHROME_BROWSER_UI_SYNC_ONE_CLICK_SIGNIN_HELPER_H_