// Copyright (c) 2014 The Chromium OS 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 SHILL_DBUS_NAME_WATCHER_H_
#define SHILL_DBUS_NAME_WATCHER_H_

#include <string>

#include <base/callback.h>
#include <base/macros.h>
#include <base/memory/weak_ptr.h>

namespace shill {

class DBusManager;

class DBusNameWatcher : public base::SupportsWeakPtr<DBusNameWatcher> {
 public:
  typedef base::Callback<void(const std::string &name,
                              const std::string &owner)> NameAppearedCallback;
  typedef base::Callback<void(const std::string &name)> NameVanishedCallback;

  // Constructs a watcher to monitor a given DBus service |name|. When the
  // service appears, |name_appeared_callback| is invoked if non-null. When the
  // service vanishes, |name_vanished_callback| is invoked if non-null. At
  // construction, it registers to a DBus manager |dbus_manager| in order to
  // receive notifications when |name| appears on or vanishes from DBus. At
  // desctruction, it dereigisters from |dbus_manager|.
  DBusNameWatcher(DBusManager *dbus_manager,
                  const std::string &name,
                  const NameAppearedCallback &name_appeared_callback,
                  const NameVanishedCallback &name_vanished_callback);
  ~DBusNameWatcher();

  // Called by |dbus_manager_| when |name_| appears on or vanishes from DBus.
  // |name_appeared_callback_| or |name_vanished_callback_| is invoked
  // accordingly if non-null.
  void OnNameOwnerChanged(const std::string &name) const;

  const std::string &name() const { return name_; }

 private:
  base::WeakPtr<DBusManager> dbus_manager_;
  std::string name_;
  NameAppearedCallback name_appeared_callback_;
  NameVanishedCallback name_vanished_callback_;

  DISALLOW_COPY_AND_ASSIGN(DBusNameWatcher);
};

}  // namespace shill

#endif  // SHILL_DBUS_NAME_WATCHER_H_