/***************************************************************************
 *   Copyright (c) 2009 Jürgen Riegel <FreeCAD@juergen-riegel.net>         *
 *                                                                         *
 *   This file is part of the FreeCAD CAx development system.              *
 *                                                                         *
 *   This library is free software; you can redistribute it and/or         *
 *   modify it under the terms of the GNU Library General Public           *
 *   License as published by the Free Software Foundation; either          *
 *   version 2 of the License, or (at your option) any later version.      *
 *                                                                         *
 *   This library  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         *
 *   GNU Library General Public License for more details.                  *
 *                                                                         *
 *   You should have received a copy of the GNU Library General Public     *
 *   License along with this library; see the file COPYING.LIB. If not,    *
 *   write to the Free Software Foundation, Inc., 59 Temple Place,         *
 *   Suite 330, Boston, MA  02111-1307, USA                                *
 *                                                                         *
 ***************************************************************************/

#ifndef BASE_UNITSSCHEMA_H
#define BASE_UNITSSCHEMA_H

#include <string>
#include <Base/Quantity.h>

namespace Base
{

/** Units systems */
enum class UnitSystem
{
    SI1 = 0,             /** internal (mm,kg,s) SI system
                            (http://en.wikipedia.org/wiki/International_System_of_Units) */
    SI2 = 1,             /** MKS (m,kg,s) SI system */
    Imperial1 = 2,       /** the Imperial system (http://en.wikipedia.org/wiki/Imperial_units) */
    ImperialDecimal = 3, /** Imperial with length in inch only */
    Centimeters = 4,     /** All lengths in centimeters, areas and volumes in square/cubic meters */
    ImperialBuilding = 5, /** All lengths in feet + inches + fractions */
    MmMin = 6, /** Lengths in mm, Speed in mm/min. Angle in degrees. Useful for small parts & CNC */
    ImperialCivil = 7,       /** Lengths in ft, Speed in ft/s. Used in Civil Eng in North America */
    FemMilliMeterNewton = 8, /** Lengths in mm, Mass in t, TimeSpan in s, thus force is in N */
    MeterDecimal = 9,        /** Lengths in metres always */
    NumUnitSystemTypes       // must be the last item!
};


/** The UnitSchema class
 * The subclasses of this class define the stuff for a
 * certain units schema.
 */
class UnitsSchema
{
public:
    UnitsSchema() = default;
    UnitsSchema(const UnitsSchema&) = default;
    UnitsSchema(UnitsSchema&&) = default;
    UnitsSchema& operator=(const UnitsSchema&) = default;
    UnitsSchema& operator=(UnitsSchema&&) = default;
    virtual ~UnitsSchema() = default;
    /** Gets called if this schema gets activated.
     * Here it's theoretically possible that you can change the static factors
     * for certain units (e.g. mi = 1,8km instead of mi=1.6km).
     */
    virtual void setSchemaUnits()
    {}
    /// If you use setSchemaUnits() you also have to impment this method to undo your changes!
    virtual void resetSchemaUnits()
    {}

    /// This method translates the quantity in a string as the user may expect it.
    virtual std::string
    schemaTranslate(const Base::Quantity& quant, double& factor, std::string& unitString) = 0;

    std::string
    toLocale(const Base::Quantity& quant, double factor, const std::string& unitString) const;

    // return true if this schema uses multiple units for length (ex. Ft/In)
    virtual bool isMultiUnitLength() const
    {
        return false;
    }

    // return true if this schema uses multiple units for angles (ex. DMS)
    virtual bool isMultiUnitAngle() const
    {
        return false;
    }

    // return the basic length unit for this schema
    virtual std::string getBasicLengthUnit() const
    {
        return {"mm"};
    }
};

}  // namespace Base

#endif  // BASE_UNITSSCHEMA_H