/*
 *   Copyright (C) 2007-2009 Petri Damstén <damu@iki.fi>
 *   Copyright (C) 2014 John Layt <jlayt@kde.org>
 *
 *   This program 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, or
 *   (at your option) any later version.
 *
 *   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
 *   GNU General Public License for more details
 *
 *   You should have received a copy of the GNU Library General Public
 *   License along with this program; if not, write to the
 *   Free Software Foundation, Inc.,
 *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#ifndef KUNITCONVERSION_VALUE_H
#define KUNITCONVERSION_VALUE_H

#include "kunitconversion/kunitconversion_export.h"

#include "unit.h"

#include <QString>
#include <QSharedDataPointer>

class QVariant;

namespace KUnitConversion
{

class ValuePrivate;

/**
 * @short Class to hold a value in a unit of measurement
 *
 * @since 4.4
 *
 * This is a class to hold a value in a unit of measurement.
 *
 * @b license GNU-LGPL v.2 or later
 *
 * @see Converter, Unit, UnitCategory
 *
 * @author Petri Damstén <damu@iki.fi>
 * @author John Layt <jlayt@kde.org>
 */

class KUNITCONVERSION_EXPORT Value
{
public:
    /**
     * Creates a null value.
     */
    Value();
    /**
     * Creates a value with a unit instance
     */
    Value(qreal number, const Unit &unit);
    /**
     * Creates a value with a unit (as a string).
     */
    Value(qreal number, const QString &unitString);
    /**
     * Creates a value with a unit (as a enum value).
     */
    Value(qreal number, UnitId unitId);
    /**
     * Creates a value based on a QVariant (calling toReal() on it) with a unit (as a string).
     */
    Value(const QVariant &number, const QString &unitString);

    /**
     * Copy constructor, copy @p other to this.
     **/
    Value(const Value &other);

    /**
     * Destroys this Value instance
     */
    ~Value();

    /**
     * Assignment operator, assign @p other to this.
     **/
    Value &operator=(const Value &other);

#ifdef Q_COMPILER_RVALUE_REFS
    /**
     * Move-assigns @p other to this Value instance, transferring the
     * ownership of the managed pointer to this instance.
     **/
    Value &operator=(Value &&other) { swap(other); return *this; }
#endif

    /**
     * Swaps this Value with @p other. This function is very fast and never fails.
     **/
    void swap(Value &other) { d.swap(other.d); }

    /**
     * @return @c true if this Value is equal to the @p other Value.
     **/
    bool operator==(const Value &other) const;

    /**
     * @return @c true if this Value is not equal to the @p other Value.
     **/
    bool operator!=(const Value &other) const;

    /**
     * @return returns true if this Value is null
     **/
    bool isNull() const;

    /**
     * Check if value is valid.
     *
     * @return True if value is valid
     **/
    bool isValid() const;

    /**
     * Number part of the value
     **/
    qreal number() const;

    /**
     * Unit part of the value
     **/
    Unit unit() const;

    /**
     * Convert value to a string
     * @param fieldWidth width of the formatted field, padded by spaces.
     *                   Positive value aligns right, negative aligns left
     * @param format type of floating point formatting, like in QString::arg
     * @param precision number of digits after the decimal separator
     * @param fillChar the character used to fill up the empty places when
     *                 field width is greater than argument width
     * @return value as a string
     **/
    QString toString(int fieldWidth = 0, char format = 'g', int precision = -1,
                     const QChar &fillChar = QLatin1Char(' ')) const;

    /**
     * Convert value to a string with symbol
     * @param fieldWidth width of the formatted field, padded by spaces.
     *                   Positive value aligns right, negative aligns left
     * @param format type of floating point formatting, like in QString::arg
     * @param precision number of digits after the decimal separator
     * @param fillChar the character used to fill up the empty places when
     *                 field width is greater than argument width
     * @return value as a string
     **/
    QString toSymbolString(int fieldWidth = 0, char format = 'g', int precision = -1,
                           const QChar &fillChar = QLatin1Char(' ')) const;

    /**
     * rounds value to decimal count
     * @param decimals decimal count.
     **/
    Value &round(uint decimals);

    /**
    * convert to another unit
    **/
    Value convertTo(const Unit &unit) const;

    /**
    * convert to another unit
    **/
    Value convertTo(UnitId unit) const;

    /**
    * convert to another unit
    **/
    Value convertTo(const QString &unit) const;

private:
    QSharedDataPointer<ValuePrivate> d;
};

} // KUnitConversion namespace

#endif
