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

/*

 Copyright (C) 2008 J. Erik Radmall

 Copyright (C) 2009 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

 <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 unitofmeasureconversion.hpp

    \brief Unit of measure conversion

*/

#ifndef quantlib_unit_of_measure_conversion_hpp

#define quantlib_unit_of_measure_conversion_hpp

#include <ql/experimental/commodities/quantity.hpp>

#include <ql/experimental/commodities/unitofmeasure.hpp>

#include <ql/utilities/null.hpp>

#include <utility>

namespace QuantLib {

    class UnitOfMeasureConversion {

      public:

        enum Type { Direct,  /*!< given directly by the user */

                    Derived  /*!< derived from conversion factors

                                  between other uoms */

        };

        //! \name Constructors

        //@{

        UnitOfMeasureConversion() = default;

        /*! the conversionFactor \f$ r \f$ is given with the

            convention that a unit of the source is worth \f$ r \f$

            units of the target.

        */

        UnitOfMeasureConversion(const CommodityType& commodityType,

                                const UnitOfMeasure& source,

                                const UnitOfMeasure& target,

                                Real conversionFactor);

        //@}

        //! \name Inspectors

        //@{

        //! the source UOM.

        const UnitOfMeasure& source() const;

        //! the target UOM.

        const UnitOfMeasure& target() const;

        //! the commodity type.

        const CommodityType& commodityType() const;

        //! the type

        Type type() const;

        //! the conversion factor

        Real conversionFactor() const;

        const std::string& code() const;

        //@}

        //! \name Utility methods

        //@{

        //! apply the conversion factor to a cash amount

        Quantity convert(const Quantity& quantity) const;

        //! chain two conversion factors

        static UnitOfMeasureConversion chain(const UnitOfMeasureConversion& r1,

                                             const UnitOfMeasureConversion& r2);

        //@}

      protected:

        UnitOfMeasureConversion(const UnitOfMeasureConversion& r1,

                                const UnitOfMeasureConversion& r2);

        struct Data;

        ext::shared_ptr<Data> data_;

        struct Data {

            CommodityType commodityType;

            UnitOfMeasure source, target;

            Real conversionFactor;

            Type type;

            std::string code;

            std::pair<ext::shared_ptr<UnitOfMeasureConversion>,

                      ext::shared_ptr<UnitOfMeasureConversion> >

            conversionFactorChain;

            Data(const CommodityType& commodityType,

                 const UnitOfMeasure& source,

                 const UnitOfMeasure& target,

                 Real conversionFactor,

                 Type type);

            Data(const UnitOfMeasureConversion& r1,

                 const UnitOfMeasureConversion& r2);

        };

    };

    // inline definitions

    inline const CommodityType& UnitOfMeasureConversion::commodityType() const {

        return data_->commodityType;

    }

    inline const UnitOfMeasure& UnitOfMeasureConversion::source() const {

        return data_->source;

    }

    inline const UnitOfMeasure& UnitOfMeasureConversion::target() const {

        return data_->target;

    }

    inline Real UnitOfMeasureConversion::conversionFactor() const {

        return data_->conversionFactor;

    }

    inline UnitOfMeasureConversion::Type UnitOfMeasureConversion::type() const {

        return data_->type;

    }

    inline const std::string& UnitOfMeasureConversion::code() const {

        return data_->code;

    }

}

#endif