// ============================================================================
// ==                                                                        ==
// == AMDiS - Adaptive multidimensional simulations                          ==
// ==                                                                        ==
// ============================================================================
// ==                                                                        ==
// ==  TU Dresden                                                            ==
// ==                                                                        ==
// ==  Institut für Wissenschaftliches Rechnen                               ==
// ==  Zellescher Weg 12-14                                                  ==
// ==  01069 Dresden                                                         ==
// ==  germany                                                               ==
// ==                                                                        ==
// ============================================================================
// ==                                                                        ==
// ==  https://gforge.zih.tu-dresden.de/projects/amdis/                      ==
// ==                                                                        ==
// ============================================================================

/** \file Tetrahedron.h */

#ifndef AMDIS_TETRAHEDRON_H
#define AMDIS_TETRAHEDRON_H

#include "Element.h"

namespace AMDiS {

  /** \ingroup Triangulation 
   * \brief
   * A Tetrahedron is a 3-dimensional Element. 
   *
   * A Tetrahedron and its refinements:
   *
   * <img src = "tetrahedron.png">
   */
  class Tetrahedron : public Element
  {
  public:
    
    /// calls base class contructor.
    Tetrahedron(Mesh* aMesh) 
      : Element(aMesh) 
    {}

    /// implements Element::clone
    inline Element *clone() { 
      return new Tetrahedron(mesh); 
    }

    /// implements Element::getVertexOfEdge
    inline int getVertexOfEdge(int i, int j) const 
    {
      return vertexOfEdge[i][j];
    }

    /// implements Element::getVertexOfPosition
    int getVertexOfPosition(GeoIndex position,
			    int positionIndex,
			    int vertexIndex) const;


    virtual int getPositionOfVertex(int side, int vertex) const 
    {
      static int positionOfVertex[4][4] = {{-1,0,1,2},
					   {0,-1,1,2},
					   {0,1,-1,2},
					   {0,1,2,-1}};
      return positionOfVertex[side][vertex];
    }

    /// implements Element::getGeo
    inline int getGeo(GeoIndex i) const 
    {
      switch (i) {
      case VERTEX: case PARTS: case NEIGH:
	return 4;
	break;
      case EDGE:
	return 6;
      case FACE:
	return 4;
      case CENTER:
	return 1;
	break;
      case DIMEN:
	return 3;
	break;
      case BOUNDARY:
	return 14;
	break;
      case PROJECTION:
	return 10;
	break;
      default:
	ERROR_EXIT("invalid geo-index\n");
	return 0;
      }
    }

    /// implements Element::hasSide
    bool hasSide(Element* sideElem) const;

    /// implements Element::sortFaceIndices
    const FixVec<int,WORLD>& sortFaceIndices(int face, 
					     FixVec<int,WORLD> *vec) const;

    /// implements Element::isLine. Returns false because this element is a Tetrahedron
    inline bool isLine() const 
    { 
      return false; 
    }

    /** \brief
     * implements Element::isTriangle. Returns false because this element is a 
     * Tetrahedron
     */
    inline bool isTriangle() const 
    { 
      return false; 
    }
 
    /** \brief
     * implements Element::isTetrahedron. Returns true because this element is a 
     * Tetrahedron
     */
    inline bool isTetrahedron() const 
    { 
      return true; 
    }
 
    std::string getTypeName() const 
    { 
      return "Tetrahedron"; 
    }

  public:
    /** \brief
     * nChildEdge[el_type][ichild][dir]                                      
     * gives local index of new edge on child[ichild] part of face [2+dir] on
     * the parent  
     */
    static const unsigned char nChildEdge[3][2][2];

    /** \brief
     * nChildFace[el_type][ichild][dir]                                     
     * gives local index of sub-face on child[ichild] part of face [2+dir] on
     * the parent   
     */
    static const unsigned char nChildFace[3][2][2];

    /** \brief
     * childVertex[el_type][child][i] =
     * parent's local vertex index of new vertex i.
     * 4 stands for the newly generated vertex                            
     */
    static const int childVertex[3][2][4];
 
    /** \brief
     * childEdge[el_type][child][i] =
     * parent's local edge index of new edge i
     * new edge 2 is half of old edge 0,
     * new edges 4,5 are really new edges, and value is different:
     * childEdge[][][4,5] = index of same edge in other child
     */
    static const int childEdge[3][2][6];

    /** \brief
     * adjacentChild[position][ichild]                                      
     * gives number of the adjacent child on a neighbour element:             
     *   position = 0  same position of element and neigh at refinement edge, 
     *   position = 1  different ...                                         
     */
    static const unsigned char adjacentChild[2][2];

    /** \brief
     * childOrientation[el_type][child] =
     *   +1 if orientation is not changed during refinement, 
     *   -1 if orientation is changed during refinement
     */
    static const signed char childOrientation[3][2];

    /// edgeOfDOFs[i][j]: gives the local index of edge with vertices i and j 
    static const unsigned char edgeOfDOFs[4][4];

    ///
    static const int edgeOfFace[4][3];

    /// implements Element::getSideOfChild()
    virtual int getSideOfChild(int child, int side, int elType = 0) const 
    {
      FUNCNAME("Tetrahedron::getSideOfChild()");
      TEST_EXIT_DBG(child==0 || child==1)("child must be in (0,1)\n");
      TEST_EXIT_DBG(side >= 0 && side <= 3)("side must be between 0 and 3\n");
      TEST_EXIT_DBG(elType >= 0 && elType <= 2)("elType must be between 0 and 2\n");
      return sideOfChild[elType][child][side];
    }

    /// implements Element::getVertexOfParent()
    virtual int getVertexOfParent(int child, int side, int elType = 0) const 
    {
      FUNCNAME("Tetrahedron::getVertexOfParent()");
      TEST_EXIT_DBG(child==0 || child==1)("child must be in (0,1)\n");
      TEST_EXIT_DBG(side >= 0 && side <= 3)("side must be between 0 and 3\n");
      TEST_EXIT_DBG(elType >= 0 && elType <= 2)("elType must be between 0 and 2\n");
      return vertexOfParent[elType][child][side];
    }

    inline int getEdgeOfFace(int face, int edge) const 
    {
      TEST_EXIT_DBG(face >= 0 && face < 4)("invalid face\n");
      TEST_EXIT_DBG(edge >= 0 && edge < 3)("invalid edge\n");
      return edgeOfFace[face][edge];
    }

  protected:

    /// vertexOfEdge[i][j] is the local number of the j-vertex of edge i
    static const int vertexOfEdge[6][2]; 

    /// vertexOfFace[i][j] is the local number of the j-vertex of face i
    static const int vertexOfFace[4][3];

    ///
    static const int sideOfChild[3][2][4];

    ///
    static const int vertexOfParent[3][2][4];
  };

}

#endif // AMDIS_TETRAHEDRON_H