/**
 * This file is part of GPGFrontend.
 *
 * GPGFrontend is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Foobar is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Foobar.  If not, see <https://www.gnu.org/licenses/>.
 *
 * The initial version of the source code is inherited from gpg4usb-team.
 * Their source code version also complies with GNU General Public License.
 *
 * The source code version of this software was modified and released
 * by Saturneric<eric@bktus.com> starting on May 12, 2021.
 *
 */

#ifndef GPGFRONTEND_ZH_CN_TS_FUNCTIONOBJECT_H
#define GPGFRONTEND_ZH_CN_TS_FUNCTIONOBJECT_H

#include <memory>
#include <mutex>

#include <easyloggingpp/easylogging++.h>

namespace GpgFrontend {
template <typename T> class SingletonFunctionObject {
public:
  static T &GetInstance() {
    LOG(INFO) << "SingletonFunctionObject GetInstance Calling "
              << typeid(T).name();
    std::lock_guard<std::mutex> guard(_instance_mutex);
    if (_instance == nullptr)
      _instance = std::make_unique<T>();
    return *_instance;
  }

  SingletonFunctionObject(T &&) = delete;

  SingletonFunctionObject(const T &) = delete;

  void operator=(const T &) = delete;

protected:
  SingletonFunctionObject() = default;

  virtual ~SingletonFunctionObject() = default;

private:
  static std::mutex _instance_mutex;
  static std::unique_ptr<T> _instance;
};

template <typename T> std::mutex SingletonFunctionObject<T>::_instance_mutex;

template <typename T>
std::unique_ptr<T> SingletonFunctionObject<T>::_instance = nullptr;

} // namespace GpgFrontend

#endif // GPGFRONTEND_ZH_CN_TS_FUNCTIONOBJECT_H