/**
 * @file   multigrid.hpp
 * @author Julian Iseringhausen <isering@ins.uni-bonn.de>
 * @date   Mon Apr 18 12:54:51 2011
 *
 * @brief  VMG::Multigrid
 *
 */

#ifndef MULTIGRID_HPP_
#define MULTIGRID_HPP_

#include <vector>

#include "grid/grid_indexing.hpp"

namespace VMG
{

class Comm;
class Grid;
class Index;
class Interface;

class Multigrid : public Object
{
public:
  Multigrid(Comm* comm, const Interface* interface);

  virtual ~Multigrid();

  Grid& operator()() {return *grids[levelIndex];}
  Grid& operator()(const int& level) {return *grids[levelMax-level];}

  const Grid& operator()() const {return *grids[levelIndex];}
  const Grid& operator()(const int& level) const {return *grids[levelMax-level];}

  const int& Level() const {return levelCurrent;}        ///< Current level
  int LevelIndex() const {return levelMax-levelCurrent;} ///< Index of current level

  const int& GlobalMaxLevel() const {return levelGlobalMax;}
  const int& MaxLevel() const {return levelMax;}             ///< Maximum level
  const int& MinLevel() const {return levelMin;}             ///< Minimum level
  const int& NumLevels() const {return numLevels;}           ///< Number of levels

  void SetLevel(int level);

  void ToCoarserLevel(); ///< Switch to next coarser level if possible
  void ToFinerLevel();   ///< Switch to next finer level if possible

  void ClearAll();             ///< Overwrites all grid points with zeros
  void ClearAllCoarseLevels(); ///< Overwrites all grid points on all levels except the finest one with zeros

  void SetCoarserDirichletValues();

protected:

  std::vector<Grid*> grids;

  int levelGlobalMax, levelMin, levelMax;
  int levelIndex, levelCurrent;
  int numLevels;

private:
  LocalIndices InitDirichlet(const GlobalIndices& global,
			       const SpatialExtent& extent,
			       const Index& pos,
			       const Index& procs);

  LocalIndices InitPeriodic(const GlobalIndices& global,
			      const SpatialExtent& extent,
			      const Index& pos,
			      const Index& procs);
};

}

#endif /* MULTIGRID_HPP_ */