// Copyright (c) 2010 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_CROS_SYSTEM_LIBRARY_H_
#define CHROME_BROWSER_CHROMEOS_CROS_SYSTEM_LIBRARY_H_
#pragma once

#include "base/observer_list.h"
#include "base/singleton.h"
#include "cros/chromeos_system.h"
#include "unicode/timezone.h"

namespace chromeos {

// This interface defines interaction with the ChromeOS system APIs.
class SystemLibrary {
 public:
  class Observer {
   public:
    // Called when the timezone has changed. |timezone| is non-null.
    virtual void TimezoneChanged(const icu::TimeZone& timezone) = 0;
  };

  virtual ~SystemLibrary() {}

  virtual void AddObserver(Observer* observer) = 0;
  virtual void RemoveObserver(Observer* observer) = 0;

  // Returns the current timezone as an icu::Timezone object.
  virtual const icu::TimeZone& GetTimezone() = 0;

  // Sets the current timezone. |timezone| must be non-null.
  virtual void SetTimezone(const icu::TimeZone* timezone) = 0;

  // Retrieve the named machine statistic (e.g. "hardware_class").
  // This does not update the statistcs (i.e. does not call into libcros).
  virtual bool GetMachineStatistic(const std::string& name,
                                   std::string* result) = 0;

  // Factory function, creates a new instance and returns ownership.
  // For normal usage, access the singleton via CrosLibrary::Get().
  static SystemLibrary* GetImpl(bool stub);
};

}  // namespace chromeos

#endif  // CHROME_BROWSER_CHROMEOS_CROS_SYSTEM_LIBRARY_H_