chromeos/components/phonehub/notification_access_manager.h

// Copyright 2020 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 CHROMEOS_COMPONENTS_PHONEHUB_NOTIFICATION_ACCESS_MANAGER_H_
#define CHROMEOS_COMPONENTS_PHONEHUB_NOTIFICATION_ACCESS_MANAGER_H_

#include <ostream>

#include "base/containers/flat_map.h"
#include "base/memory/weak_ptr.h"
#include "base/observer_list.h"
#include "base/observer_list_types.h"
#include "chromeos/components/phonehub/notification_access_setup_operation.h"

namespace chromeos {
namespace phonehub {

// Tracks the status of whether the user has enabled notification access on
// their phone. While Phone Hub can be enabled via Chrome OS, access to
// notifications requires that the user grant access via Android settings. If a
// Phone Hub connection to the phone has never succeeded, we assume that access
// has not yet been granted. If there is no active Phone Hub connection, we
// assume that the last access value seen is the current value.
//
// Additionally, this class provides an API for requesting the notification
// access setup flow via AttemptNotificationSetup().
class NotificationAccessManager {
 public:
  // Status of notification access. Numerical values are stored in prefs and
  // should not be changed or reused.
  enum class AccessStatus {
    // Access has not been granted and is prohibited from being granted (e.g.,
    // if the phone is using a Work Profile).
    kProhibited = 0,

    // Access has not been granted, but the user is free to grant access.
    kAvailableButNotGranted = 1,

    // Access has been granted by the user.
    kAccessGranted = 2
  };

  class Observer : public base::CheckedObserver {
   public:
    ~Observer() override = default;

    // Called when notification access has changed; use GetAccessStatus()
    // for the new status.
    virtual void OnNotificationAccessChanged() = 0;
  };

  NotificationAccessManager(const NotificationAccessManager&) = delete;
  NotificationAccessManager& operator=(const NotificationAccessManager&) =
      delete;
  virtual ~NotificationAccessManager();

  virtual AccessStatus GetAccessStatus() const = 0;

  virtual bool HasNotificationSetupUiBeenDismissed() const = 0;

  // Disables the ability to show the banner within the PhoneHub UI.
  virtual void DismissSetupRequiredUi() = 0;

  // Starts an attempt to enable the notification access. |delegate| will be
  // updated with the status of the flow as long as the operation object
  // returned by this function remains instantiated.
  //
  // To cancel an ongoing setup attempt, delete the operation. If a setup
  // attempt fails, clients can retry by calling AttemptNotificationSetup()
  // again to start a new attempt.
  //
  // If notification access has already been granted, this function returns null
  // since there is nothing to set up.
  std::unique_ptr<NotificationAccessSetupOperation> AttemptNotificationSetup(
      NotificationAccessSetupOperation::Delegate* delegate);

  void AddObserver(Observer* observer);
  void RemoveObserver(Observer* observer);

 protected:
  NotificationAccessManager();

  void NotifyNotificationAccessChanged();
  void SetNotificationSetupOperationStatus(
      NotificationAccessSetupOperation::Status new_status);

  bool IsSetupOperationInProgress() const;

  virtual void OnSetupRequested() {}

 private:
  friend class NotificationAccessManagerImplTest;
  friend class PhoneStatusProcessor;

  // Sets the internal AccessStatus but does not send a request for a new
  // status to the remote phone device.
  virtual void SetAccessStatusInternal(AccessStatus access_status) = 0;

  void OnSetupOperationDeleted(int operation_id);

  int next_operation_id_ = 0;
  base::flat_map<int, NotificationAccessSetupOperation*> id_to_operation_map_;
  base::ObserverList<Observer> observer_list_;
  base::WeakPtrFactory<NotificationAccessManager> weak_ptr_factory_{this};
};

std::ostream& operator<<(std::ostream& stream,
                         NotificationAccessManager::AccessStatus status);

}  // namespace phonehub
}  // namespace chromeos

#endif  // CHROMEOS_COMPONENTS_PHONEHUB_NOTIFICATION_ACCESS_MANAGER_H_