// Copyright 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 THERMALD_TEMPERATURE_MONITOR_INTERFACE_H_
#define THERMALD_TEMPERATURE_MONITOR_INTERFACE_H_

#include <memory>
#include <string>

#include "base/callback.h"
#include "base/callback_list.h"
#include "base/macros.h"

namespace thermald {

// Interface for temperature monitors.
//
// A temperature monitor observes a single temperature. Subscribers can
// register with the temperature monitor to be notified upon changes of
// the monitored temperature.
class TemperatureMonitorInterface {
 public:
  typedef base::Callback<void(int)> TemperatureMonitorCallback;
#if BASE_VER < 860220
  typedef base::CallbackList<void(int)>::Subscription Subscription;
#endif

  TemperatureMonitorInterface() {}
  virtual ~TemperatureMonitorInterface() {}

  virtual std::string name() const = 0;

  // Subscribe for notifications about temperature changes.
  //
  // Returns a subscription object. The caller must keep a reference to this
  // object for the time the subscription should be active. The subscription
  // is canceled when the object is deleted.
#if BASE_VER < 860220
  virtual std::unique_ptr<Subscription> Subscribe(
#else
  virtual base::CallbackListSubscription Subscribe(
#endif
      const TemperatureMonitorCallback &cb) = 0;

 private:
  DISALLOW_COPY_AND_ASSIGN(TemperatureMonitorInterface);
};

}  // namespace thermald

#endif  // THERMALD_TEMPERATURE_MONITOR_INTERFACE_H_