// Copyright (c) 2013 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_CHROMEOS_LOGIN_USER_IMAGE_MANAGER_IMPL_H_
#define CHROME_BROWSER_CHROMEOS_LOGIN_USER_IMAGE_MANAGER_IMPL_H_

#include <map>
#include <set>
#include <string>

#include "base/basictypes.h"
#include "base/memory/linked_ptr.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/time/time.h"
#include "base/timer/timer.h"
#include "base/values.h"
#include "chrome/browser/chromeos/login/user.h"
#include "chrome/browser/chromeos/login/user_image_loader.h"
#include "chrome/browser/chromeos/login/user_image_manager.h"
#include "chrome/browser/profiles/profile_downloader_delegate.h"
#include "ui/gfx/image/image_skia.h"

class ProfileDownloader;
class UserImage;

namespace base {
class FilePath;
class SequencedTaskRunner;
}

namespace chromeos {
class UserImageSyncObserver;
}

namespace chromeos {

class UserImageManagerImpl : public UserImageManager,
                             public ProfileDownloaderDelegate {
 public:
  UserImageManagerImpl();

  // UserImageManager:
  virtual ~UserImageManagerImpl();
  virtual void LoadUserImages(const UserList& users) OVERRIDE;
  virtual void UserLoggedIn(const std::string& user_id,
                            bool user_is_new,
                            bool user_is_local) OVERRIDE;
  virtual void SaveUserDefaultImageIndex(const std::string& user_id,
                                         int default_image_index) OVERRIDE;
  virtual void SaveUserImage(const std::string& user_id,
                             const UserImage& user_image) OVERRIDE;
  virtual void SaveUserImageFromFile(const std::string& user_id,
                                     const base::FilePath& path) OVERRIDE;
  virtual void SaveUserImageFromProfileImage(
      const std::string& user_id) OVERRIDE;
  virtual void DeleteUserImage(const std::string& user_id) OVERRIDE;
  virtual void DownloadProfileImage(const std::string& reason) OVERRIDE;
  virtual const gfx::ImageSkia& DownloadedProfileImage() const OVERRIDE;
  virtual UserImageSyncObserver* GetSyncObserver() const OVERRIDE;
  virtual void Shutdown() OVERRIDE;

  static void IgnoreProfileDataDownloadDelayForTesting();

 private:
  friend class UserImageManagerTest;

  // Every image load or update is encapsulated by a Job. Whenever an image load
  // or update is requested for a user, the Job currently running for that user
  // (if any) is canceled. This ensures that at most one Job is running per user
  // at any given time. There are two further guarantees:
  //
  // * Changes to User objects and local state are performed on the thread that
  //   |this| runs on.
  // * File writes and deletions are performed via |background_task_runner_|.
  //
  // With the above, it is guaranteed that any changes made by a canceled Job
  // cannot race against against changes made by the superseding Job.
  class Job;

  // ProfileDownloaderDelegate:
  virtual bool NeedsProfilePicture() const OVERRIDE;
  virtual int GetDesiredImageSideLength() const OVERRIDE;
  virtual Profile* GetBrowserProfile() OVERRIDE;
  virtual std::string GetCachedPictureURL() const OVERRIDE;
  virtual void OnProfileDownloadSuccess(ProfileDownloader* downloader) OVERRIDE;
  virtual void OnProfileDownloadFailure(
      ProfileDownloader* downloader,
      ProfileDownloaderDelegate::FailureReason reason) OVERRIDE;

  // Randomly chooses one of the default images for the specified user, sends a
  // LOGIN_USER_IMAGE_CHANGED notification and updates local state.
  void SetInitialUserImage(const std::string& user_id);

  // Initializes the |downloaded_profile_image_| for the currently logged-in
  // user to a profile image that had been downloaded and saved before if such
  // a saved image is available and no updated image has been downloaded yet.
  void TryToInitDownloadedProfileImage();

  // Returns true if the profile image needs to be downloaded. This is the case
  // when a GAIA user is logged in and at least one of the following applies:
  // * The profile image has explicitly been requested by a call to
  //   DownloadProfileImage() and has not been successfully downloaded since.
  // * The user's user image is the profile image.
  bool NeedProfileImage() const;

  // Downloads the profile data for the currently logged-in user. The user's
  // full name and, if NeedProfileImage() is true, the profile image are
  // downloaded. |reason| is an arbitrary string (used to report UMA histograms
  // with download times).
  void DownloadProfileData(const std::string& reason);

  // Removes |user_id| from the dictionary |prefs_dict_root| in local state and
  // deletes the image file that the dictionary referenced for that user.
  void DeleteUserImageAndLocalStateEntry(const std::string& user_id,
                                         const char* prefs_dict_root);

  // Called when a Job updates the copy of the user image held in memory by
  // |user|. Allows |this| to update |downloaded_profile_image_| and send a
  // NOTIFICATION_LOGIN_USER_IMAGE_CHANGED notification.
  void OnJobChangedUserImage(const User* user);

  // Called when a Job for |user_id| finishes. If a migration was required for
  // the user, the migration is now complete and the old image file for that
  // user, if any, is deleted.
  void OnJobDone(const std::string& user_id);

  // Completes migration by removing |user_id| from the old prefs dictionary.
  void UpdateLocalStateAfterMigration(const std::string& user_id);

  // Loader for JPEG user images.
  scoped_refptr<UserImageLoader> image_loader_;

  // Unsafe loader instance for all user images formats.
  scoped_refptr<UserImageLoader> unsafe_image_loader_;

  // Whether the |profile_downloader_| is downloading the profile image for the
  // currently logged-in user (and not just the full name). Only valid when a
  // download is currently in progress.
  bool downloading_profile_image_;

  // Download reason given to DownloadProfileImage(), used for UMA histograms.
  // Only valid when a download is currently in progress and
  // |downloading_profile_image_| is true.
  std::string profile_image_download_reason_;

  // Time when the profile image download started. Only valid when a download is
  // currently in progress and |downloading_profile_image_| is true.
  base::TimeTicks profile_image_load_start_time_;

  // Downloader for the current user's profile data. NULL when no download is
  // currently in progress.
  scoped_ptr<ProfileDownloader> profile_downloader_;

  // The currently logged-in user's downloaded profile image, if successfully
  // downloaded or initialized from a previously downloaded and saved image.
  gfx::ImageSkia downloaded_profile_image_;

  // Data URL corresponding to |downloaded_profile_image_|. Empty if no
  // |downloaded_profile_image_| is currently available.
  std::string downloaded_profile_image_data_url_;

  // URL from which |downloaded_profile_image_| was downloaded. Empty if no
  // |downloaded_profile_image_| is currently available.
  GURL profile_image_url_;

  // Whether a download of the currently logged-in user's profile image has been
  // explicitly requested by a call to DownloadProfileImage() and has not been
  // satisfied by a successful download yet.
  bool profile_image_requested_;

  // Timer used to start a profile data download shortly after login and to
  // restart the download after network errors.
  base::OneShotTimer<UserImageManagerImpl> profile_download_one_shot_timer_;

  // Timer used to periodically start a profile data, ensuring the profile data
  // stays up to date.
  base::RepeatingTimer<UserImageManagerImpl> profile_download_periodic_timer_;

  // Users whose user images need to be migrated from the old dictionary pref to
  // the new dictionary pref, converting any non-default images to JPEG format.
  std::set<std::string> users_to_migrate_;

  // Sync observer for the currently logged-in user.
  scoped_ptr<UserImageSyncObserver> user_image_sync_observer_;

  // Background task runner on which Jobs perform file I/O and the image
  // decoders run.
  scoped_refptr<base::SequencedTaskRunner> background_task_runner_;

  // The currently running jobs.
  std::map<std::string, linked_ptr<Job> > jobs_;

  base::WeakPtrFactory<UserImageManagerImpl> weak_factory_;

  DISALLOW_COPY_AND_ASSIGN(UserImageManagerImpl);
};

}  // namespace chromeos

#endif  // CHROME_BROWSER_CHROMEOS_LOGIN_USER_IMAGE_MANAGER_IMPL_H_