/*
 * SystemBackend.h
 *
 * Copyright (C) 2008 Matthias Schiffer <matthias@gamezock.de>
 *
 * This program 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.
 *
 * This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef MAD_COMMON_SYSTEMBACKEND_H_
#define MAD_COMMON_SYSTEMBACKEND_H_

#include <set>

namespace Mad {
namespace Common {

class SystemBackend {
  public:
    struct UptimeInfo {
      unsigned long uptime;
      unsigned long idleTime;
    };

    struct MemoryInfo {
      unsigned long totalMem;
      unsigned long freeMem;
      unsigned long totalSwap;
      unsigned long freeSwap;
    };

    struct LoadInfo {
      unsigned long currentLoad;
      unsigned long nProcesses;
      float loadAvg1;
      float loadAvg5;
      float loadAvg15;
    };

  private:
    struct Compare {
      bool operator() (const SystemBackend *b1, const SystemBackend *b2) {
        if(b1->getPriority() == b2->getPriority())
          return (b1 > b2);
        else
          return (b1->getPriority() > b2->getPriority());
      }
    };

    static std::set<SystemBackend*, Compare> backends;

  protected:
    SystemBackend() {}

    static void registerBackend(SystemBackend *backend) {
      backends.insert(backend);
    }

    static void unregisterBackend(SystemBackend *backend) {
      backends.erase(backend);
    }

    virtual UptimeInfo uptimeInfo() {
      UptimeInfo ret = {0, 0};
      return ret;
    }

    virtual MemoryInfo memoryInfo() {
      MemoryInfo ret = {0, 0, 0, 0};
      return ret;
    }

    virtual LoadInfo loadInfo() {
      LoadInfo ret = {0, 0, 0, 0, 0};
      return ret;
    }

    virtual bool doShutdown() {return false;}
    virtual bool doReboot() {return false;}

    virtual int getPriority() const {
      return 0;
    }

  public:
    virtual ~SystemBackend() {}

    static UptimeInfo getUptimeInfo();
    static MemoryInfo getMemoryInfo();
    static LoadInfo getLoadInfo();

    static bool shutdown();
    static bool reboot();
};

}
}

#endif /* MAD_COMMON_SYSTEMBACKEND_H_ */