MoneyPerVolumeUnit

package org.djunits.unit;

import org.djunits.unit.unitsystem.UnitSystem;

/**
 * MoneyPerVolumeUnit defines a unit for the cost or benefit per volume, e.g. the cost of a gallon of fuel.
 * <p>
 * Copyright (c) 2015-2019 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
 * BSD-style license. See <a href="http://djunits.org/docs/license.html">DJUNITS License</a>.
 * <p>
 * $LastChangedDate: 2019-03-02 19:06:46 +0100 (Sat, 02 Mar 2019) $, @version $Revision: 342 $, by $Author: averbraeck $,
 * initial version Sep 5, 2015 <br>
 * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
 */
public class MoneyPerVolumeUnit extends LinearUnit<MoneyPerVolumeUnit>
{
    /** */
    private static final long serialVersionUID = 20150905L;

    /** The unit of money for the money per volume unit, e.g., EUR. */
    private final MoneyUnit moneyUnit;

    /** The unit of volume for the money per volume unit, e.g., liter. */
    private final VolumeUnit volumeUnit;

    /** Euro per cubic meter. */
    public static final MoneyPerVolumeUnit EUR_PER_CUBIC_METER;

    /** Euro per liter. */
    public static final MoneyPerVolumeUnit EUR_PER_LITER;

    /** US$ per gallon (US). */
    public static final MoneyPerVolumeUnit USD_PER_GALLON_US_FLUID;

    /** US$ per ounce (US). */
    public static final MoneyPerVolumeUnit USD_PER_OUNCE_US_FLUID;

    /** The standard unit to use. */
    private static MoneyPerVolumeUnit standardMoneyPerVolumeUnit;

    static
    {
        EUR_PER_CUBIC_METER =
                new MoneyPerVolumeUnit(MoneyUnit.EUR, VolumeUnit.CUBIC_METER, "EUR per cubic meter", "\u20AC/m^3");
        EUR_PER_LITER = new MoneyPerVolumeUnit(MoneyUnit.EUR, VolumeUnit.LITER, "EUR per liter", "\u20AC/l");
        USD_PER_GALLON_US_FLUID =
                new MoneyPerVolumeUnit(MoneyUnit.USD, VolumeUnit.GALLON_US_FLUID, "USD per gallon (US)", "US$/gallon");
        USD_PER_OUNCE_US_FLUID =
                new MoneyPerVolumeUnit(MoneyUnit.USD, VolumeUnit.OUNCE_US_FLUID, "USD per ounce (US)", "US$/ounce");
        standardMoneyPerVolumeUnit = EUR_PER_CUBIC_METER;
    }

    /**
     * Build a money per volume unit from a money unit and an volume unit.
     * @param moneyUnit MoneyUnit; the unit of money for the money per volume unit, e.g., EUR
     * @param volumeUnit VolumeUnit; the unit of volume for the money per volume unit, e.g., m^3
     * @param abbreviationKey String; the key to the locale file for the abbreviation of the unit
     */
    private MoneyPerVolumeUnit(final MoneyUnit moneyUnit, final VolumeUnit volumeUnit, final String abbreviationKey)
    {
        super(abbreviationKey, UnitSystem.OTHER, standardMoneyPerVolumeUnit,
                moneyUnit.getScaleFactor() / volumeUnit.getScaleFactor());
        this.moneyUnit = moneyUnit;
        this.volumeUnit = volumeUnit;
    }

    /**
     * Build a user-defined money per volume unit from a money unit and an volume unit.
     * @param moneyUnit MoneyUnit; the unit of money for the money per volume unit, e.g., EUR
     * @param volumeUnit VolumeUnit; the unit of volume for the money per volume unit, e.g., m^3
     * @param name String; the key to the locale file for the long name of the unit
     * @param abbreviation String; the key to the locale file for the abbreviation of the unit
     */
    public MoneyPerVolumeUnit(final MoneyUnit moneyUnit, final VolumeUnit volumeUnit, final String name,
            final String abbreviation)
    {
        super(name, abbreviation, UnitSystem.OTHER, standardMoneyPerVolumeUnit,
                moneyUnit.getScaleFactor() / volumeUnit.getScaleFactor());
        this.moneyUnit = moneyUnit;
        this.volumeUnit = volumeUnit;
    }

    /**
     * Build a MoneyPerVolumeUnit unit based on another MoneyPerVolumeUnit.
     * @param abbreviationKey String; the key to the locale file for the abbreviation of the unit
     * @param referenceUnit MoneyPerVolumeUnit; the unit to convert to
     * @param scaleFactorToReferenceUnit double; multiply a value in this unit by the factor to convert to the given reference
     *            unit
     */
    private MoneyPerVolumeUnit(final String abbreviationKey, final MoneyPerVolumeUnit referenceUnit,
            final double scaleFactorToReferenceUnit)
    {
        super(abbreviationKey, UnitSystem.OTHER, referenceUnit, scaleFactorToReferenceUnit);
        this.moneyUnit = referenceUnit.getMoneyUnit();
        this.volumeUnit = referenceUnit.getVolumeUnit();
    }

    /**
     * Build a user-defined MoneyPerVolumeUnit with a conversion factor to another MoneyPerVolumeUnit.
     * @param name String; the long name of the unit
     * @param abbreviation String; the abbreviation of the unit
     * @param referenceUnit MoneyPerVolumeUnit; the unit to convert to
     * @param scaleFactorToReferenceUnit double; multiply a value in this unit by the factor to convert to the given reference
     *            unit
     */
    public MoneyPerVolumeUnit(final String name, final String abbreviation, final MoneyPerVolumeUnit referenceUnit,
            final double scaleFactorToReferenceUnit)
    {
        super(name, abbreviation, UnitSystem.OTHER, referenceUnit, scaleFactorToReferenceUnit);
        this.moneyUnit = referenceUnit.getMoneyUnit();
        this.volumeUnit = referenceUnit.getVolumeUnit();
    }

    /**
     * @return moneyUnit
     */
    public final MoneyUnit getMoneyUnit()
    {
        return this.moneyUnit;
    }

    /**
     * @return volumeUnit
     */
    public final VolumeUnit getVolumeUnit()
    {
        return this.volumeUnit;
    }

    /**
     * Set the standard MoneyPerVolumeUnit in case the standard MoneyUnit changes, as the standard money unit is flexible.
     * @param standardMoneyUnit MoneyUnit; the new standard money unit.
     */
    protected static void setStandardUnit(final MoneyUnit standardMoneyUnit)
    {
        try
        {
            standardMoneyPerVolumeUnit = new MoneyPerVolumeUnit(standardMoneyUnit, VolumeUnit.CUBIC_METER,
                    standardMoneyUnit.getName() + " per cubic meter", standardMoneyUnit.getAbbreviation() + "/m^3");
        }
        catch (Exception e)
        {
            // ignore a RunTimeException that indicates that the Unit might already exist
            e = null;
        }
    }

    /** {@inheritDoc} */
    @Override
    public final MoneyPerVolumeUnit getStandardUnit()
    {
        return standardMoneyPerVolumeUnit;
    }

    /**
     * @return standard MoneyPerVolumeUnit
     */
    public static MoneyPerVolumeUnit getStandardMoneyPerVolumeUnit()
    {
        return standardMoneyPerVolumeUnit;
    }

    /** {@inheritDoc} */
    @Override
    public final String getSICoefficientsString()
    {
        return "1/m3";
    }

    /** {@inheritDoc} */
    @Override
    public int hashCode()
    {
        final int prime = 31;
        int result = super.hashCode();
        result = prime * result + ((this.moneyUnit == null) ? 0 : this.moneyUnit.hashCode());
        result = prime * result + ((this.volumeUnit == null) ? 0 : this.volumeUnit.hashCode());
        return result;
    }

    /** {@inheritDoc} */
    @SuppressWarnings("checkstyle:needbraces")
    @Override
    public boolean equals(final Object obj)
    {
        if (this == obj)
            return true;
        if (!super.equals(obj))
            return false;
        if (getClass() != obj.getClass())
            return false;
        MoneyPerVolumeUnit other = (MoneyPerVolumeUnit) obj;
        if (this.moneyUnit == null)
        {
            if (other.moneyUnit != null)
                return false;
        }
        else if (!this.moneyUnit.equals(other.moneyUnit))
            return false;
        if (this.volumeUnit == null)
        {
            if (other.volumeUnit != null)
                return false;
        }
        else if (!this.volumeUnit.equals(other.volumeUnit))
            return false;
        return true;
    }

}