/**
 * @file   interface.cpp
 * @author Julian Iseringhausen <isering@ins.uni-bonn.de>
 * @date   Mon Apr 18 12:55:48 2011
 *
 * @brief  VMG::Interface
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <cmath>

#include "base/helper.hpp"
#include "interface/interface.hpp"

using namespace VMG;

Interface::Interface(BC boundary, int levelMin_, int levelMax_, vmg_float box_begin_, vmg_float box_end_,
		     int coarseningSteps, vmg_float alpha)
{
  bc = boundary;
  levelMin = levelMin_;
  levelMax = levelMax_;

  bool restricted = false;

  const vmg_float box_center = 0.5 * (box_begin_ + box_end_);
  const vmg_float box_size = box_end_ - box_begin_;

  for (int i=0; i<coarseningSteps; ++i) {

    global.push_back(GlobalIndices());
    extent.push_back(SpatialExtent());

    extent.back().SizeFactor() = Helper::intpow(2, static_cast<int>(log(pow(alpha, i+1)) / log(2.0) + 1.0));

    extent.back().Size() = box_size * static_cast<Vector>(extent.back().SizeFactor());
    extent.back().Begin() = box_center - 0.5 * extent.back().Size();
    extent.back().End() = extent.back().Begin() + extent.back().Size();
    extent.back().MeshWidth() = pow(2.0, i-levelMax);

    global.back().Size() = static_cast<Index>(static_cast<Vector>(extent.back().Size()) / extent.back().MeshWidth() + 0.5) + 1;
    global.back().Begin() = 0;
    global.back().End() = global.back().Size();

  }

  for (int i=0; i<coarseningSteps; ++i) {

    if (restricted) {
      global[i].BoundaryType() = GlobalCoarsened;
    }else if (extent[i].SizeFactor() == extent.back().SizeFactor()) {
      global[i].BoundaryType() = GlobalMax;
      restricted = true;
    }else {
      global[i].BoundaryType() = LocallyRefined;
    }

    if (i==0) {
      global[0].AlignmentBegin() = (global[0].Size() - static_cast<int>( pow(2.0, levelMax) + 0.5) - 1) / 2;
    }else if (global[i].BoundaryType() == LocallyRefined)
      global[i].AlignmentBegin() = (extent[i].Size() - extent[i-1].Size()) * pow(2.0, levelMax-i-1) + 0.5;
    else if (global[i].BoundaryType() == GlobalMax)
      global[i].AlignmentBegin() = (extent[i].Size() - extent[i-1].Size()) * pow(2.0, levelMax-i-1) - 0.5;
    else
      global[i].AlignmentBegin() = 0;

    global[i].AlignmentEnd() = global[i].Size() - global[i].AlignmentBegin();
  }

  while (global.size() == 0 || global.back().Size().Max() > Helper::intpow(2,levelMin)+1) {

    global.push_back(GlobalIndices());
    extent.push_back(SpatialExtent());

    extent.back().SizeFactor() = (global.size() > 1 ? (++extent.rbegin())->Size() : 1);
    extent.back().Size() = (global.size() > 1 ?  (++extent.rbegin())->Size() : box_size);
    extent.back().Begin() = box_center - 0.5 * static_cast<Vector>(extent.back().Size());
    extent.back().End() = extent.back().Begin() + extent.back().Size();
    extent.back().MeshWidth() = pow(2.0, static_cast<int>(global.size())-levelMax-1);

    global.back().Size() = static_cast<Index>(static_cast<Vector>(extent.back().Size()) / extent.back().MeshWidth() + 0.5) + 1;
    global.back().Begin() = 0;
    global.back().End() = global.back().Size();

    if (global.size() > 1)
      global.back().BoundaryType() = GlobalCoarsened;
    else
      global.back().BoundaryType() = GlobalMax;

    global.back().AlignmentBegin() = 0;
    global.back().AlignmentEnd() = global.back().Size();

  }

  if (boundary == Periodic)
    for (std::vector<GlobalIndices>::iterator iter=global.begin(); iter!=global.end(); ++iter)
      iter->Size() -= 1;

  levelMin = levelMax - global.size() + 1;
}