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

/*

 Copyright (C) 2008 Master IMAFA - Polytech'Nice Sophia - Université de Nice Sophia Antipolis

 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.

*/

#include <ql/experimental/exoticoptions/mceverestengine.hpp>

namespace QuantLib {

    EverestMultiPathPricer::EverestMultiPathPricer(Real notional,

                                                   Real guarantee,

                                                   DiscountFactor discount)

    : notional_(notional), guarantee_(guarantee), discount_(discount) {}

    Real EverestMultiPathPricer::operator()(const MultiPath& multiPath) const {

        Size n = multiPath.pathSize();

        QL_REQUIRE(n>0, "the path cannot be empty");

        Size numAssets = multiPath.assetNumber();

        QL_REQUIRE(numAssets>0, "there must be some paths");

        // We search the yield min

        Real minYield = multiPath[0].back() / multiPath[0].front() - 1.0;

        for (Size j=1; j<numAssets; ++j) {

            Rate yield = multiPath[j].back() / multiPath[j].front() - 1.0;

            minYield = std::min(minYield, yield);

        }

        return (1.0 + minYield + guarantee_) * notional_ * discount_;

    }

}