// 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.
//
// A notifier that uses p2p notifications based on XMPP push
// notifications.  Used only for sync integration tests.

#ifndef SYNC_NOTIFIER_P2P_NOTIFIER_H_
#define SYNC_NOTIFIER_P2P_NOTIFIER_H_

#include <string>

#include "base/compiler_specific.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/observer_list.h"
#include "base/threading/thread_checker.h"
#include "jingle/notifier/listener/push_client_observer.h"
#include "sync/internal_api/public/base/model_type.h"
#include "sync/notifier/notifications_disabled_reason.h"
#include "sync/notifier/sync_notifier.h"

namespace notifier {
class PushClient;
}  // namespace notifier

namespace syncer {

// The channel to use for sync notifications.
extern const char* kSyncP2PNotificationChannel;

// The intended recipient(s) of a P2P notification.
enum P2PNotificationTarget {
  NOTIFY_SELF,
  FIRST_NOTIFICATION_TARGET = NOTIFY_SELF,
  NOTIFY_OTHERS,
  NOTIFY_ALL,
  LAST_NOTIFICATION_TARGET = NOTIFY_ALL
};

std::string P2PNotificationTargetToString(
    P2PNotificationTarget target);

// If |target_str| can't be parsed, assumes NOTIFY_SELF.
P2PNotificationTarget P2PNotificationTargetFromString(
    const std::string& target_str);

// Helper notification data class that can be serialized to and
// deserialized from a string.
class P2PNotificationData {
 public:
  // Initializes with an empty sender ID, target set to NOTIFY_SELF,
  // and empty changed types.
  P2PNotificationData();
  P2PNotificationData(const std::string& sender_id,
                      P2PNotificationTarget target,
                      syncer::ModelTypeSet changed_types);

  ~P2PNotificationData();

  // Returns true if the given ID is targeted by this notification.
  bool IsTargeted(const std::string& id) const;

  syncer::ModelTypeSet GetChangedTypes() const;

  bool Equals(const P2PNotificationData& other) const;

  std::string ToString() const;

  // Returns whether parsing |str| was successful.  If parsing was
  // unsuccessful, the state of the notification is undefined.
  bool ResetFromString(const std::string& str);

 private:
  // The unique ID of the client that sent the notification.
  std::string sender_id_;
  // The intendent recipient(s) of the notification.
  P2PNotificationTarget target_;
  // The types the notification is for.
  syncer::ModelTypeSet changed_types_;
};

class P2PNotifier
    : public SyncNotifier,
      public notifier::PushClientObserver {
 public:
  // The |send_notification_target| parameter was added to allow us to send
  // self-notifications in some cases, but not others.  The value should be
  // either NOTIFY_ALL to send notifications to all clients, or NOTIFY_OTHERS
  // to send notifications to all clients except for the one that triggered the
  // notification.  See crbug.com/97780.
  P2PNotifier(scoped_ptr<notifier::PushClient> push_client,
              P2PNotificationTarget send_notification_target);

  virtual ~P2PNotifier();

  // SyncNotifier implementation
  virtual void AddObserver(SyncNotifierObserver* observer) OVERRIDE;
  virtual void RemoveObserver(SyncNotifierObserver* observer) OVERRIDE;
  virtual void SetUniqueId(const std::string& unique_id) OVERRIDE;
  virtual void SetStateDeprecated(const std::string& state) OVERRIDE;
  virtual void UpdateCredentials(
      const std::string& email, const std::string& token) OVERRIDE;
  virtual void UpdateEnabledTypes(
      syncer::ModelTypeSet enabled_types) OVERRIDE;
  virtual void SendNotification(
      syncer::ModelTypeSet changed_types) OVERRIDE;

  // PushClientObserver implementation.
  virtual void OnNotificationsEnabled() OVERRIDE;
  virtual void OnNotificationsDisabled(
      notifier::NotificationsDisabledReason reason) OVERRIDE;
  virtual void OnIncomingNotification(
      const notifier::Notification& notification) OVERRIDE;

  void SendNotificationDataForTest(
      const P2PNotificationData& notification_data);

 private:
  void SendNotificationData(const P2PNotificationData& notification_data);

  base::ThreadChecker thread_checker_;

  ObserverList<SyncNotifierObserver> observer_list_;

  // The push client.
  scoped_ptr<notifier::PushClient> push_client_;
  // Our unique ID.
  std::string unique_id_;
  // Whether we have called UpdateCredentials() yet.
  bool logged_in_;
  bool notifications_enabled_;
  // Which set of clients should be sent notifications.
  P2PNotificationTarget send_notification_target_;

  syncer::ModelTypeSet enabled_types_;
};

}  // namespace syncer

#endif  // SYNC_NOTIFIER_P2P_NOTIFIER_H_