#include "CoarseningManager.h"
#include "Mesh.h"
#include "AdaptStationary.h"
#include "AdaptInstationary.h"
#include "Traverse.h"
#include "MacroElement.h"
#include "RCNeighbourList.h"
#include "FixVec.h"

namespace AMDiS {

  Flag CoarseningManager::globalCoarsen(Mesh *aMesh, int mark)
  {
    if (mark >= 0) 
      return 0;

    TraverseStack stack;
    ElInfo *elInfo = stack.traverseFirst(aMesh, -1, Mesh::CALL_LEAF_EL);
    while (elInfo) {
      elInfo->getElement()->setMark(mark);
      elInfo = stack.traverseNext(elInfo);
    }
    
    return coarsenMesh(aMesh);
  }

  void CoarseningManager::spreadCoarsenMark()
  {
    TraverseStack stack;
    ElInfo *elInfo = stack.traverseFirst(mesh, -1, Mesh::CALL_EVERY_EL_POSTORDER);
    while (elInfo) {
      Element *el = elInfo->getElement();

      if (el->getChild(0)) {
	// interior node of the tree
	signed char mark = max(el->getChild(0)->getMark(), el->getChild(1)->getMark());
	el->setMark(std::min(mark + 1, 0));
      } else {
	// leaf node of the tree                                 
	if (el->getMark() < 0) 
	  el->setMark(el->getMark() - 1);
      }

      elInfo = stack.traverseNext(elInfo);
    }
  }

  void CoarseningManager::cleanUpAfterCoarsen()
  {
    TraverseStack stack;
    ElInfo *elInfo = stack.traverseFirst(mesh, -1, Mesh::CALL_LEAF_EL);
    while (elInfo) {
      Element *el = elInfo->getElement();
      el->setMark(max(el->getMark(), 0));
      elInfo = stack.traverseNext(elInfo);
    }
  }

  Flag CoarseningManager::coarsenMesh(Mesh *aMesh)
  {
    mesh = aMesh;
    int nElements = mesh->getNumberOfLeaves();

    spreadCoarsenMark();

    stack = new TraverseStack;

    do {
      doMore = false;
      ElInfo* el_info = 
	stack->traverseFirst(mesh, -1, Mesh::CALL_EVERY_EL_POSTORDER | Mesh::FILL_NEIGH);
      while (el_info) {
	coarsenFunction(el_info);
	el_info = stack->traverseNext(el_info);
      }
    } while (doMore);

    delete stack;

    cleanUpAfterCoarsen();

    nElements -= mesh->getNumberOfLeaves();

    if (nElements != 0) {
      aMesh->incChangeIndex();
      return MESH_COARSENED;
    } else {
      return Flag(0);
    }
  }

}