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

/*
 Copyright (C) 2004 Neil Firth
 Copyright (C) 2000, 2001, 2002, 2003 RiskMap srl
 Copyright (C) 2007 StatPro Italia srl

 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/instruments/multiassetoption.hpp>
#include <ql/processes/stochasticprocessarray.hpp>
#include <ql/termstructures/volatilities/blackconstantvol.hpp>
#include <ql/math/solvers1d/brent.hpp>

namespace QuantLib {

    MultiAssetOption::MultiAssetOption(
        const boost::shared_ptr<StochasticProcess>& process,
        const boost::shared_ptr<Payoff>& payoff,
        const boost::shared_ptr<Exercise>& exercise,
        const boost::shared_ptr<PricingEngine>& engine)
    : Option(payoff, exercise, engine), stochasticProcess_(process) {
        registerWith(stochasticProcess_);
    }

    bool MultiAssetOption::isExpired() const {
        return exercise_->lastDate() < Settings::instance().evaluationDate();
    }

    Real MultiAssetOption::delta() const {
        calculate();
        QL_REQUIRE(delta_ != Null<Real>(), "delta not provided");
        return delta_;
    }

    Real MultiAssetOption::gamma() const {
        calculate();
        QL_REQUIRE(gamma_ != Null<Real>(), "gamma not provided");
        return gamma_;
    }

    Real MultiAssetOption::theta() const {
        calculate();
        QL_REQUIRE(theta_ != Null<Real>(), "theta not provided");
        return theta_;
    }

    Real MultiAssetOption::vega() const {
        calculate();
        QL_REQUIRE(vega_ != Null<Real>(), "vega not provided");
        return vega_;
    }

    Real MultiAssetOption::rho() const {
        calculate();
        QL_REQUIRE(rho_ != Null<Real>(), "rho not provided");
        return rho_;
    }

    Real MultiAssetOption::dividendRho() const {
        calculate();
        QL_REQUIRE(dividendRho_ != Null<Real>(), "dividend rho not provided");
        return dividendRho_;
    }

    void MultiAssetOption::setupExpired() const {
        NPV_ = delta_ = gamma_ = theta_ =
            vega_ = rho_ = dividendRho_ =  0.0;
    }

    void MultiAssetOption::setupArguments(
                                       PricingEngine::arguments* args) const {
        MultiAssetOption::arguments* arguments =
            dynamic_cast<MultiAssetOption::arguments*>(args);
        QL_REQUIRE(arguments != 0, "wrong argument type");

        arguments->payoff = payoff_;
        arguments->stochasticProcess = stochasticProcess_;
        arguments->exercise = exercise_;

        Size n = exercise_->dates().size();
        arguments->stoppingTimes.clear();
        arguments->stoppingTimes.reserve(n);
        for (Size i=0; i<n; ++i) {
            arguments->stoppingTimes.push_back(
                               stochasticProcess_->time(exercise_->date(i)));
        }
    }

    void MultiAssetOption::fetchResults(const PricingEngine::results* r) const {
        Option::fetchResults(r);
        const Greeks* results = dynamic_cast<const Greeks*>(r);
        QL_ENSURE(results != 0,
                  "no greeks returned from pricing engine");
        delta_          = results->delta;
        gamma_          = results->gamma;
        theta_          = results->theta;
        vega_           = results->vega;
        rho_            = results->rho;
        dividendRho_    = results->dividendRho;
    }


    void MultiAssetOption::arguments::validate() const {

        Option::arguments::validate();

        QL_REQUIRE(stochasticProcess, "no process given");
    }

}