/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Copyright (C) 2016-2018 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

\*---------------------------------------------------------------------------*/

#include "binaryNode.H"

// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

template<class CompType, class ThermoType>
Foam::binaryNode<CompType, ThermoType>::binaryNode()
  :
leafLeft_(nullptr),
leafRight_(nullptr),
nodeLeft_(nullptr),
nodeRight_(nullptr),
parent_(nullptr),
nAdditionalEqns_(0)
{}


template<class CompType, class ThermoType>
Foam::binaryNode<CompType, ThermoType>::binaryNode
(
    chemPointISAT<CompType, ThermoType>* elementLeft,
    chemPointISAT<CompType, ThermoType>* elementRight,
    binaryNode<CompType, ThermoType>* parent
)
  :
leafLeft_(elementLeft),
leafRight_(elementRight),
nodeLeft_(nullptr),
nodeRight_(nullptr),
parent_(parent),
v_(elementLeft->completeSpaceSize(), 0)
{
  if (elementLeft->variableTimeStep()) {
    nAdditionalEqns_ = 3;
  } else {
    nAdditionalEqns_ = 2;
  }

  calcV(elementLeft, elementRight, v_);
  a_ = calcA(elementLeft, elementRight);
}


// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

template<class CompType, class ThermoType>
void Foam::binaryNode<CompType, ThermoType>::calcV
(
    chemPointISAT<CompType, ThermoType>*& elementLeft,
    chemPointISAT<CompType, ThermoType>*& elementRight,
    scalarField& v
)
{
  // LT is the transpose of the L matrix
  scalarSquareMatrix& LT = elementLeft->LT();
  bool mechReductionActive = elementLeft->chemistry().mechRed()->active();

  // Difference of composition in the full species domain
  scalarField phiDif(elementRight->phi() - elementLeft->phi());
  const scalarField& scaleFactor(elementLeft->scaleFactor());
  scalar epsTol = elementLeft->tolerance();

  // v = LT.T()*LT*phiDif
  for (label i=0; i<elementLeft->completeSpaceSize(); i++) {
    label si = i;
    bool outOfIndexI = true;
    if (mechReductionActive) {
      if (i<elementLeft->completeSpaceSize() - nAdditionalEqns_) {
        si = elementLeft->completeToSimplifiedIndex()[i];
        outOfIndexI = (si == -1);
      } else { // temperature and pressure
        outOfIndexI = false;
        const label dif =
            i - (elementLeft->completeSpaceSize() - nAdditionalEqns_);
        si = elementLeft->nActiveSpecies() + dif;
      }
    }
    if (!mechReductionActive || (mechReductionActive && !(outOfIndexI))) {
      v[i] = 0;
      for (label j=0; j<elementLeft->completeSpaceSize(); j++) {
        label sj = j;
        bool outOfIndexJ = true;
        if (mechReductionActive) {
          if (j < elementLeft->completeSpaceSize() - nAdditionalEqns_) {
            sj = elementLeft->completeToSimplifiedIndex()[j];
            outOfIndexJ = (sj==-1);
          } else {
            outOfIndexJ = false;
            const label dif =
                j
                - (
                    elementLeft->completeSpaceSize()
                    - nAdditionalEqns_
                );
            sj = elementLeft->nActiveSpecies() + dif;
          }
        }
        if
        (
            !mechReductionActive
            ||(mechReductionActive && !(outOfIndexJ))
        ) {
          // Since L is a lower triangular matrix k=0->min(i, j)
          for (label k=0; k<=min(si, sj); k++) {
            v[i] += LT(k, si)*LT(k, sj)*phiDif[j];
          }
        }
      }
    } else {
      // When it is an inactive species the diagonal element of LT is
      // 1/(scaleFactor*epsTol)
      v[i] = phiDif[i]/sqr(scaleFactor[i]*epsTol);
    }
  }
}


template<class CompType, class ThermoType>
Foam::scalar Foam::binaryNode<CompType, ThermoType>::calcA
(
    chemPointISAT<CompType, ThermoType>* elementLeft,
    chemPointISAT<CompType, ThermoType>* elementRight
)
{
  scalarField phih((elementLeft->phi() + elementRight->phi())/2);
  scalar a = 0;
  forAll(phih, i) {
    a += v_[i]*phih[i];
  }

  return a;
}


// ************************************************************************* //
