//
// Software License for AMDiS
//
// Copyright (c) 2010 Dresden University of Technology 
// All rights reserved.
// Authors: Simon Vey, Thomas Witkowski et al.
//
// This file is part of AMDiS
//
// See also license.opensource.txt in the distribution.


#include "MeshStructure.h"
#include "MeshStructure_ED.h"
#include "Mesh.h"
#include "Element.h"
#include "Traverse.h"
#include "ElInfo.h"
#include "RefinementManager.h"
#include "Debug.h"
#include "DOFVector.h"

namespace AMDiS {

  const int MeshStructure::structureSize = 64;


  void MeshStructure::insertElement(bool isLeaf) 
  {
    // overflow? -> next index
    if (pos >= structureSize) {
      code.push_back(currentCode);
      pos = 0;
      currentCode = 0;
    }

    // insert element in binary code
    if (!isLeaf) {
      uint64_t one = 1;
      currentCode += (one << pos);
    } 

    pos++;
    nElements++;
  }


  void MeshStructure::clear()
  {
    currentCode = 0;
    code.resize(0);
    pos = 0;
    nElements = 0;
    currentElement = 0;
  }


  void MeshStructure::init(Mesh *mesh, int macroElIndex) 
  {
    clear();

    TraverseStack stack;
    ElInfo *elInfo = stack.traverseFirst(mesh, -1, Mesh::CALL_EVERY_EL_PREORDER);
    while (elInfo) {
      if (macroElIndex == -1 ||
	  elInfo->getMacroElement()->getIndex() == macroElIndex)
	insertElement(elInfo->getElement()->isLeaf());

      elInfo = stack.traverseNext(elInfo);
    }
  
    commit();
  }


  void MeshStructure::init(BoundaryObject &bound)
  {
    FUNCNAME("MeshStructure::init()");

    Element *el = bound.el;

    TEST_EXIT_DBG(el)("No element!\n");

    clear();

    int s1 = el->getSubObjOfChild(0, bound.subObj, bound.ithObj, bound.elType);
    int s2 = el->getSubObjOfChild(1, bound.subObj, bound.ithObj, bound.elType);
    
    TEST_EXIT(s1 != -1 || s2 != -1)("This should not happen!\n");

    if (debugMode) {
      MSG("addAlondSide(%d, %d, %d, %d)\n",
	  bound.elIndex, bound.ithObj, bound.elType, bound.reverseMode);
      MSG("Element is leaf: %d\n", el->isLeaf());
      MSG("s1 = %d    s2 = %d\n", s1, s2);
    }
    
    if (!el->isLeaf()) {
      if (s1 == -1)
	addAlongSide(el->getSecondChild(), bound.subObj, s2, 
		     el->getChildType(bound.elType), bound.reverseMode);
      else if (s2 == -1)
	addAlongSide(el->getFirstChild(), bound.subObj, s1, 
		     el->getChildType(bound.elType), bound.reverseMode);
      else
	addAlongSide(el, bound.subObj, bound.ithObj, bound.elType, bound.reverseMode);
    }

    commit();    
  }


  void MeshStructure::addAlongSide(Element *el, GeoIndex subObj, int ithObj, 
				   int elType, bool reverseOrder)
  {
    FUNCNAME("MeshStructure::addAlongSide()");

    if (debugMode) {
      MSG("addAlondSide(%d, %d, %d, %d)\n",
	  el->getIndex(), ithObj, elType, reverseOrder);
      MSG("Element is leaf: %d\n", el->isLeaf());
    }
    
    insertElement(el->isLeaf());
    
    if (!el->isLeaf()) {
      int s1 = el->getSubObjOfChild(0, subObj, ithObj, elType);
      int s2 = el->getSubObjOfChild(1, subObj, ithObj, elType);

      if (debugMode) {
	MSG("Child index %d  %d\n", 
	    el->getFirstChild()->getIndex(),
	    el->getSecondChild()->getIndex());
	MSG("s1 = %d    s2 = %d\n", s1, s2);
	MSG("   \n");
      }

      if (!reverseOrder) {
	if (s1 != -1) 
	  addAlongSide(el->getFirstChild(), subObj, s1, el->getChildType(elType), reverseOrder);
	if (s2 != -1)
	  addAlongSide(el->getSecondChild(), subObj, s2, el->getChildType(elType), reverseOrder);
      } else {
	if (s2 != -1)
	  addAlongSide(el->getSecondChild(), subObj, s2, el->getChildType(elType), reverseOrder);
	if (s1 != -1) 
	  addAlongSide(el->getFirstChild(), subObj, s1, el->getChildType(elType), reverseOrder);
      }
    }
  }


  void MeshStructure::reset() 
  {
    currentIndex = 0;
    pos = 0;
    currentElement = 0;

    if (code.size() > 0)
      currentCode = code[0];
    else 
      currentCode = 0;
  }


  bool MeshStructure::nextElement(MeshStructure *insert)
  {
    FUNCNAME("MeshStructure::nextElement()");

    if (insert)
      insert->insertElement(isLeafElement());

    pos++;
    currentElement++;

    if (currentElement >= nElements) 
      return false;

    if (pos >= structureSize) {
      currentIndex++;
      TEST_EXIT_DBG(currentIndex < static_cast<int>(code.size()))
	("End of structure reached!\n");
      pos = 0;
      currentCode = code[currentIndex];
    } else {
      currentCode >>= 1;
    }

    return true;
  }


  int MeshStructure::lookAhead(unsigned int n)
  {
    FUNCNAME("MeshStructure::lookAhead()");

    int returnValue = 0;

    int tmp_pos = pos;
    int tmp_currentElement = currentElement;
    int tmp_currentIndex = currentIndex;
    uint64_t tmp_currentCode = currentCode;

    for (unsigned int i = 0; i < n; i++) {
      if (nextElement() == false) {
	returnValue = -1;      
	break;
      }
    }

    if (returnValue != -1)
      returnValue = static_cast<int>(!isLeafElement());

    pos = tmp_pos;
    currentElement = tmp_currentElement;
    currentIndex = tmp_currentIndex;
    currentCode = tmp_currentCode;

    return returnValue;
  }


  bool MeshStructure::skipBranch(MeshStructure *insert)
  {
    FUNCNAME("MeshStructure::skipBranch()");

    if (isLeafElement()) {
      return nextElement(insert);
    } else {
      bool cont = nextElement(insert);
      cont = skipBranch(insert); // left branch
      TEST_EXIT_DBG(cont)("Invalid structure!\n");
      cont = skipBranch(insert); // righ branch
      return cont;
    }
  }


  void MeshStructure::merge(MeshStructure *structure1,
			    MeshStructure *structure2,
			    MeshStructure *result)
  {
    FUNCNAME("MeshStructure::merge()");

    result->clear();
    structure1->reset();
    structure2->reset();

    bool cont = true;
    while (cont) {
      bool cont1, cont2;
      if (structure1->isLeafElement() == structure2->isLeafElement()) {
	cont1 = structure1->nextElement(result);
	cont2 = structure2->nextElement();
      } else {
	if (structure1->isLeafElement()) {
	  cont1 = structure1->nextElement();
	  cont2 = structure2->skipBranch(result);
	} else {
	  cont1 = structure1->skipBranch(result);
	  cont2 = structure2->nextElement();
	}
      }
      TEST_EXIT_DBG(cont1 == cont2)("Structures don't match!\n");
      cont = cont1;
    }

    result->commit();
  }


  void MeshStructure::fitMeshToStructure(Mesh *mesh,
					 RefinementManager *manager,
					 bool debugMode,
					 int macroElIndex,
					 bool ignoreFinerMesh) 
  {
    FUNCNAME("MeshStructure::fitMeshToStructure()");

    bool cont = true;

    // decorate leaf data
    reset();
    TraverseStack stack;
    ElInfo *elInfo = NULL;
    if (macroElIndex == -1)
      elInfo = stack.traverseFirst(mesh, -1, Mesh::CALL_EVERY_EL_PREORDER);
    else
      elInfo = stack.traverseFirstOneMacro(mesh, macroElIndex, -1, Mesh::CALL_EVERY_EL_PREORDER);


    while (elInfo) {
      Element *element = elInfo->getElement();

      TEST_EXIT(cont)("unexpected structure code end!\n");

      if (isLeafElement()) {
	if (ignoreFinerMesh && !element->isLeaf()) {
	  int level = elInfo->getLevel();
	  while (elInfo && level >= elInfo->getLevel())
	    elInfo = stack.traverseNext(elInfo);
	} else {
	  TEST_EXIT(element->isLeaf())
	    ("Mesh is finer than strucutre code! (Element index: %d Macro element index: %d)\n", 
	     element->getIndex(), elInfo->getMacroElement()->getIndex());
	}
      } 

      TEST_EXIT_DBG(element)("Should not happen!\n");

      if (element->isLeaf() && !isLeafElement()) {
	MeshStructure *structure = new MeshStructure();
	cont = skipBranch(structure);
	structure->commit();

	MeshStructure_ED *elData = new MeshStructure_ED(element->getElementData());
	elData->setStructure(structure);
	element->setElementData(elData);
      } else {
	cont = nextElement();
      }

      if (elInfo)
	elInfo = stack.traverseNext(elInfo);
    }

    // refine mesh
    bool finished = true;

    do {
      finished = true;
      if (macroElIndex == -1)
	elInfo = stack.traverseFirst(mesh, -1, Mesh::CALL_LEAF_EL);
      else
	elInfo = stack.traverseFirstOneMacro(mesh, macroElIndex, -1, Mesh::CALL_LEAF_EL);      
      while (elInfo) {
	Element *element = elInfo->getElement();
	if (element->getElementData(MESH_STRUCTURE) != NULL) {
	  element->setMark(1);
	  finished = false;
	} else {
	  element->setMark(0);
	}
	elInfo = stack.traverseNext(elInfo);
      }

      if (!finished) {
#if (DEBUG != 0)
	int oldMeshIndex = mesh->getChangeIndex();
#endif

	if (macroElIndex == -1)
	  manager->refineMesh(mesh);
	else
	  manager->refineMacroElement(mesh, macroElIndex);

#if (DEBUG != 0)
	TEST_EXIT(oldMeshIndex != mesh->getChangeIndex())
	  ("Mesh has not been changed by refinement procedure!\n");
#endif
      }
    } while (!finished);
  }


  string MeshStructure::toStr(bool resetCode)
  {
    std::stringstream oss;
    
    if (empty()) {
      oss << "-" << std::endl;
    }	else {	
      if (resetCode)
	reset();

      bool cont = true;
      while (cont) {
	if (isLeafElement())
	  oss << "0";
	else
	  oss << "1";
	
	cont = nextElement();
      }
    }

    return oss.str();
  }


  void MeshStructure::print(bool resetCode)
  {
    FUNCNAME("MeshStructure::print()");
    
    string str = toStr(resetCode);
   
    if (str.length() < 255) {
      MSG("Mesh structure code: %s\n", str.c_str());
    } else {
#ifdef HAVE_PARALLEL_DOMAIN_AMDIS
      std::cout << "[" << MPI::COMM_WORLD.Get_rank() << "]                Mesh structure code: " << str << "\n";
#else
      std::cout << "                Mesh structure code: " << str << "\n";
#endif
    }
  }


  bool MeshStructure::compare(MeshStructure &other)
  {
    return (other.getCode() == code);
  }


  void MeshStructure::getMeshStructureValues(Mesh *mesh,
					     int macroElIndex,
					     const DOFVector<double>* vec,
					     std::vector<double>& values)
  {
    FUNCNAME("MeshStructure::getMeshStructureValues()");

    TEST_EXIT_DBG(mesh)("No mesh defined!\n");
    TEST_EXIT_DBG(vec)("No DOFVector defined!\n");

    values.clear();

    TraverseStack stack;
    ElInfo *elInfo = stack.traverseFirstOneMacro(mesh, macroElIndex, -1, 
						 Mesh::CALL_EVERY_EL_PREORDER);
    while (elInfo) {
      if (elInfo->getLevel() == 0)
	for (int i = 0; i < mesh->getGeo(VERTEX); i++)
	  values.push_back((*vec)[elInfo->getElement()->getDof(i, 0)]);

      if (!elInfo->getElement()->isLeaf())
	values.push_back((*vec)[elInfo->getElement()->getChild(0)->getDof(mesh->getDim(), 0)]);      

      elInfo = stack.traverseNext(elInfo);
    }
  }


  void MeshStructure::setMeshStructureValues(Mesh *mesh,
					     int macroElIndex,
					     DOFVector<double>* vec,
					     const std::vector<double>& values)
  {
    FUNCNAME("MeshStructure::setMeshStructureValues()");

    TEST_EXIT_DBG(mesh)("No mesh defined!\n");
    TEST_EXIT_DBG(vec)("No DOFVector defined!\n");
    TEST_EXIT_DBG(static_cast<int>(values.size()) >= mesh->getGeo(VERTEX))
      ("Should not happen!\n");

    unsigned int counter = 0;

    TraverseStack stack;
    ElInfo *elInfo = stack.traverseFirstOneMacro(mesh, macroElIndex, -1, 
						 Mesh::CALL_EVERY_EL_PREORDER);
    while (elInfo) {
      if (elInfo->getLevel() == 0)
	for (int i = 0; i < mesh->getGeo(VERTEX); i++)
	  (*vec)[elInfo->getElement()->getDof(i, 0)] = values[counter++];      

      if (!elInfo->getElement()->isLeaf()) {
	TEST_EXIT_DBG(counter < values.size())("Should not happen!\n");
	
	(*vec)[elInfo->getElement()->getChild(0)->getDof(mesh->getDim(), 0)] =
	  values[counter++];      
      }

      elInfo = stack.traverseNext(elInfo);
    }
      
  }

}