/* -*- mode: c++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/*

 Copyright (C) 2008 Andreas Gaida

 Copyright (C) 2008 Ralph Schreyer

 Copyright (C) 2008 Klaus Spanderen

 This file is part of QuantLib, a free-software/open-source library

 for financial quantitative analysts and developers - http://quantlib.org/

 QuantLib is free software: you can redistribute it and/or modify it

 under the terms of the QuantLib license.  You should have received a

 copy of the license along with this program; if not, please email

 <quantlib-dev@lists.sf.net>. The license is also available online at

 <http://quantlib.org/license.shtml>.

 This program 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 license for more details.

*/

#include <ql/methods/finitedifferences/operators/fdmlinearoplayout.hpp>

#include <ql/methods/finitedifferences/utilities/fdmindicesonboundary.hpp>

namespace QuantLib {

    FdmIndicesOnBoundary::FdmIndicesOnBoundary(

        const ext::shared_ptr<FdmLinearOpLayout>& layout,

        Size direction, FdmDirichletBoundary::Side side) {

        std::vector<Size> newDim(layout->dim());

        newDim[direction] = 1;

        const Size hyperSize

            = std::accumulate(newDim.begin(), newDim.end(), Size(1), std::multiplies<>());

        indices_.resize(hyperSize);

        Size i=0;

        for (const auto& iter : *layout) {

            if (   (   side == FdmDirichletBoundary::Lower

                    && iter.coordinates()[direction] == 0)

                || (   side == FdmDirichletBoundary::Upper

                    && iter.coordinates()[direction]

                                            == layout->dim()[direction]-1)) {

                QL_REQUIRE(hyperSize > i, "index missmatch");

                indices_[i++] = iter.index();

            }

        }

    }

    const std::vector<Size>& FdmIndicesOnBoundary::getIndices() const {

        return indices_;

    }

}