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

/*

 Copyright (C) 2012 Peter Caspers

 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

 <https://www.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.

*/

/*! \file fdmtimedepdirichletboundary.cpp

*/

#include <ql/methods/finitedifferences/meshers/fdmmesher.hpp>

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

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

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

#include <algorithm>

#include <utility>

namespace QuantLib {

    FdmTimeDepDirichletBoundary::FdmTimeDepDirichletBoundary(

        const ext::shared_ptr<FdmMesher>& mesher,

        std::function<Real(Real)> valueOnBoundary,

        Size direction,

        Side side)

    : indices_(FdmIndicesOnBoundary(mesher->layout(), direction, side).getIndices()),

      valueOnBoundary_(std::move(valueOnBoundary)), values_(indices_.size()) {}

    FdmTimeDepDirichletBoundary::FdmTimeDepDirichletBoundary(

        const ext::shared_ptr<FdmMesher>& mesher,

        std::function<Array(Real)> valuesOnBoundary,

        Size direction,

        Side side)

    : indices_(FdmIndicesOnBoundary(mesher->layout(), direction, side).getIndices()),

      valuesOnBoundary_(std::move(valuesOnBoundary)), values_(indices_.size()) {}

    void FdmTimeDepDirichletBoundary::setTime(Time t) {

        if (valueOnBoundary_) {

            std::fill(values_.begin(), values_.end(), valueOnBoundary_(t));

        } else if (valuesOnBoundary_) {

            values_ = valuesOnBoundary_(t);

        } else {

            QL_FAIL("no boundary values defined");

        }

    }

    void FdmTimeDepDirichletBoundary::applyAfterApplying(array_type& a) const {

        QL_REQUIRE(indices_.size() == values_.size(),

                   "values on boundary size (" << values_.size()

                   << ") does not match hypersurface size ("

                   << indices_.size() << ")");

        for (auto iter = indices_.begin(); iter != indices_.end(); ++iter) {

            a[*iter] = values_[iter - indices_.begin()];

        }

    }

    void FdmTimeDepDirichletBoundary::applyAfterSolving(array_type& a) const {

        this->applyAfterApplying(a);

    }

}