package org.djunits.unit;
   
   import org.djunits.unit.unitsystem.UnitSystem;
   
   /**
    * MoneyPerEnergyUnit defines a unit for the cost or benefit per unit of energy, e.g. the cost of electricity per kWh.
    * <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 MoneyPerEnergyUnit extends LinearUnit<MoneyPerEnergyUnit>
  {
      /** */
      private static final long serialVersionUID = 20150905L;
  
      /** The unit of money for the money per energy unit, e.g., EUR. */
      private final MoneyUnit moneyUnit;
  
      /** The unit of energy for the money per energy unit, e.g., kWh. */
      private final EnergyUnit energyUnit;
  
      /** Euro per kWh. */
      public static final MoneyPerEnergyUnit EUR_PER_KILOWATTHOUR;
  
      /** Euro per MWh. */
      public static final MoneyPerEnergyUnit EUR_PER_MEGAWATTHOUR;
  
      /** Euro per MJ. */
      public static final MoneyPerEnergyUnit EUR_PER_MEGAJOULE;
  
      /** US$ per kWh. */
      public static final MoneyPerEnergyUnit USD_PER_KILOWATTHOUR;
  
      /** US$ per MWh. */
      public static final MoneyPerEnergyUnit USD_PER_MEGAWATTHOUR;
  
      /** US$ per MJ. */
      public static final MoneyPerEnergyUnit USD_PER_MEGAJOULE;
  
      /** The standard unit to use. */
      private static MoneyPerEnergyUnit standardMoneyPerEnergyUnit;
  
      static
      {
          EUR_PER_KILOWATTHOUR = new MoneyPerEnergyUnit(MoneyUnit.EUR, EnergyUnit.KILOWATT_HOUR, "EUR/kWh", "\u20AC/kWh");
          EUR_PER_MEGAWATTHOUR = new MoneyPerEnergyUnit(MoneyUnit.EUR, EnergyUnit.MEGAWATT_HOUR, "EUR/MWh", "\u20AC/MWh");
          EUR_PER_MEGAJOULE = new MoneyPerEnergyUnit(MoneyUnit.EUR, EnergyUnit.MEGAJOULE, "EUR/MJ", "\u20AC/MJ");
          USD_PER_KILOWATTHOUR = new MoneyPerEnergyUnit(MoneyUnit.USD, EnergyUnit.KILOWATT_HOUR, "US$/kWh", "US$/kWh");
          USD_PER_MEGAWATTHOUR = new MoneyPerEnergyUnit(MoneyUnit.USD, EnergyUnit.MEGAWATT_HOUR, "US$/MWh", "US$/MWh");
          USD_PER_MEGAJOULE = new MoneyPerEnergyUnit(MoneyUnit.USD, EnergyUnit.MEGAJOULE, "US$/MJ", "US$/MJ");
          standardMoneyPerEnergyUnit = EUR_PER_KILOWATTHOUR;
      }
  
      /**
       * Build a money per energy unit from a money unit and an energy unit.
       * @param moneyUnit MoneyUnit; the unit of money for the money per energy unit, e.g., EUR
       * @param energyUnit EnergyUnit; the unit of energy for the money per energy unit, e.g., kWh
       * @param abbreviationKey String; the key to the locale file for the abbreviation of the unit
       */
      private MoneyPerEnergyUnit(final MoneyUnit moneyUnit, final EnergyUnit energyUnit, final String abbreviationKey)
      {
          super(abbreviationKey, UnitSystem.OTHER, standardMoneyPerEnergyUnit,
                  moneyUnit.getScaleFactor() / energyUnit.getScaleFactor());
          this.moneyUnit = moneyUnit;
          this.energyUnit = energyUnit;
      }
  
      /**
       * Build a user-defined money per energy unit from a money unit and an energy unit.
       * @param moneyUnit MoneyUnit; the unit of money for the money per energy unit, e.g., EUR
       * @param energyUnit EnergyUnit; the unit of energy for the money per energy unit, e.g., kWh
       * @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 MoneyPerEnergyUnit(final MoneyUnit moneyUnit, final EnergyUnit energyUnit, final String name,
              final String abbreviation)
      {
          super(name, abbreviation, UnitSystem.OTHER, standardMoneyPerEnergyUnit,
                  moneyUnit.getScaleFactor() / energyUnit.getScaleFactor());
          this.moneyUnit = moneyUnit;
          this.energyUnit = energyUnit;
      }
  
      /**
       * Build a MoneyPerEnergyUnit with a conversion factor to another MoneyPerEnergyUnit.
       * @param abbreviationKey String; the key to the locale file for the abbreviation of the unit
       * @param referenceUnit MoneyPerEnergyUnit; 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 MoneyPerEnergyUnit(final String abbreviationKey, final MoneyPerEnergyUnit referenceUnit,
              final double scaleFactorToReferenceUnit)
      {
          super(abbreviationKey, UnitSystem.OTHER, referenceUnit, scaleFactorToReferenceUnit);
          this.moneyUnit = referenceUnit.getMoneyUnit();
         this.energyUnit = referenceUnit.getEnergyUnit();
     }
 
     /**
      * Build a user-defined MoneyPerEnergyUnitit with a conversion factor to another MoneyPerEnergyUnit.
      * @param name String; the long name of the unit
      * @param abbreviation String; the abbreviation of the unit
      * @param referenceUnit MoneyPerEnergyUnit; 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 MoneyPerEnergyUnit(final String name, final String abbreviation, final MoneyPerEnergyUnit referenceUnit,
             final double scaleFactorToReferenceUnit)
     {
         super(name, abbreviation, UnitSystem.OTHER, referenceUnit, scaleFactorToReferenceUnit);
         this.moneyUnit = referenceUnit.getMoneyUnit();
         this.energyUnit = referenceUnit.getEnergyUnit();
     }
 
     /**
      * @return moneyUnit
      */
     public final MoneyUnit getMoneyUnit()
     {
         return this.moneyUnit;
     }
 
     /**
      * @return energyUnit
      */
     public final EnergyUnit getEnergyUnit()
     {
         return this.energyUnit;
     }
 
     /**
      * Set the standard MoneyPerEnergyUnit 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
         {
             standardMoneyPerEnergyUnit = new MoneyPerEnergyUnit(standardMoneyUnit, EnergyUnit.KILOWATT_HOUR,
                     standardMoneyUnit.getName() + " per kilowatthour", standardMoneyUnit.getAbbreviation() + "/kWh");
         }
         catch (Exception e)
         {
             // ignore a RunTimeException that indicates that the Unit might already exist
             e = null;
         }
     }
 
     /** {@inheritDoc} */
     @Override
     public final MoneyPerEnergyUnit getStandardUnit()
     {
         return standardMoneyPerEnergyUnit;
     }
 
     /**
      * @return standard MoneyPerEnergyUnit
      */
     public static MoneyPerEnergyUnit getStandardMoneyPerEnergyUnit()
     {
         return standardMoneyPerEnergyUnit;
     }
 
     /** {@inheritDoc} */
     @Override
     public final String getSICoefficientsString()
     {
         return "s2/kgm2";
     }
 
     /** {@inheritDoc} */
     @Override
     public int hashCode()
     {
         final int prime = 31;
         int result = super.hashCode();
         result = prime * result + ((this.energyUnit == null) ? 0 : this.energyUnit.hashCode());
         result = prime * result + ((this.moneyUnit == null) ? 0 : this.moneyUnit.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;
         MoneyPerEnergyUnit other = (MoneyPerEnergyUnit) obj;
         if (this.energyUnit == null)
         {
             if (other.energyUnit != null)
                 return false;
         }
         else if (!this.energyUnit.equals(other.energyUnit))
             return false;
         if (this.moneyUnit == null)
         {
             if (other.moneyUnit != null)
                 return false;
         }
         else if (!this.moneyUnit.equals(other.moneyUnit))
             return false;
         return true;
     }
 
 }