package org.opentrafficsim.core.unit;
   
   import static org.opentrafficsim.core.unit.unitsystem.UnitSystem.SI_DERIVED;
   
   import org.opentrafficsim.core.unit.unitsystem.UnitSystem;
   
   /**
    * The units of electrical resistance.
    * <p>
   * Copyright (c) 2014 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
   * BSD-style license. See <a href="http://opentrafficsim.org/node/13">OpenTrafficSim License</a>.
   * <p>
   * @version May 15, 2014 <br>
   * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
   */
  public class ElectricalResistanceUnit extends Unit<ElectricalResistanceUnit>
  {
      /** */
      private static final long serialVersionUID = 20140607L;
  
      /** the unit of mass for the electrical resistance unit, e.g., kilogram. */
      private final MassUnit massUnit;
  
      /** the unit of length for the electrical resistance unit, e.g., meters. */
      private final LengthUnit lengthUnit;
  
      /** the unit of electrical current for the electrical resistance unit, e.g., Ampere. */
      private final ElectricalCurrentUnit electricalCurrentUnit;
  
      /** the unit of time for the electrical resistance unit, e.g., second. */
      private final TimeUnit timeUnit;
  
      /** The SI unit for electrical resistance is Ohm. */
      public static final ElectricalResistanceUnit SI;
  
      /** Ohm. */
      public static final ElectricalResistanceUnit OHM;
  
      /** milli-ohm. */
      public static final ElectricalResistanceUnit MILLIOHM;
  
      /** kilo-ohm. */
      public static final ElectricalResistanceUnit KILOOHM;
  
      /** mega-ohm. */
      public static final ElectricalResistanceUnit MEGAOHM;
  
      static
      {
          SI =
                  new ElectricalResistanceUnit(MassUnit.KILOGRAM, LengthUnit.METER, ElectricalCurrentUnit.AMPERE,
                          TimeUnit.SECOND, "ElectricalResistanceUnit.ohm_(name)", "ElectricalResistanceUnit.ohm",
                          SI_DERIVED);
          OHM = SI;
          MILLIOHM =
                  new ElectricalResistanceUnit("ElectricalResistanceUnit.milli_ohm", "ElectricalResistanceUnit.m_ohm",
                          SI_DERIVED, OHM, 0.001);
          KILOOHM =
                  new ElectricalResistanceUnit("ElectricalResistanceUnit.kilo_ohm", "ElectricalResistanceUnit.k_ohm",
                          SI_DERIVED, OHM, 1000.0);
          MEGAOHM =
                  new ElectricalResistanceUnit("ElectricalResistanceUnit.mega_ohm", "ElectricalResistanceUnit.M_ohm",
                          SI_DERIVED, OHM, 1.06);
      }
  
      /**
       * @param massUnit the unit of mass for the electrical resistance unit, e.g., kilogram
       * @param lengthUnit the unit of length for the electrical resistance unit, e.g., meter
       * @param electricalCurrentUnit the unit of electrical current for the electrical resistance unit, e.g., Ampere
       * @param timeUnit the unit of time for the electrical resistance unit, e.g., second
       * @param nameKey the key to the locale file for the long name of the unit
       * @param abbreviationKey the key to the locale file for the abbreviation of the unit
       * @param unitSystem the unit system, e.g. SI or Imperial
       */
      public ElectricalResistanceUnit(final MassUnit massUnit, final LengthUnit lengthUnit,
              final ElectricalCurrentUnit electricalCurrentUnit, final TimeUnit timeUnit, final String nameKey,
              final String abbreviationKey, final UnitSystem unitSystem)
      {
          super(nameKey, abbreviationKey, unitSystem, OHM, massUnit.getConversionFactorToStandardUnit()
                  * lengthUnit.getConversionFactorToStandardUnit()
                  * lengthUnit.getConversionFactorToStandardUnit()
                  / (electricalCurrentUnit.getConversionFactorToStandardUnit()
                          * electricalCurrentUnit.getConversionFactorToStandardUnit() * Math.pow(
                          timeUnit.getConversionFactorToStandardUnit(), 3.0)), true);
          this.massUnit = massUnit;
          this.lengthUnit = lengthUnit;
          this.electricalCurrentUnit = electricalCurrentUnit;
          this.timeUnit = timeUnit;
      }
  
      /**
       * @param electricalPotentialUnit the unit of electrical potential difference for the electrical resistance unit,
       *            e.g., Volt
       * @param electricalCurrentUnit the unit of electrical current for the electrical resistance unit, e.g., Ampere
       * @param nameKey the key to the locale file for the long name of the unit
       * @param abbreviationKey the key to the locale file for the abbreviation of the unit
       * @param unitSystem the unit system, e.g. SI or Imperial
       */
      public ElectricalResistanceUnit(final ElectricalPotentialUnit electricalPotentialUnit,
             final ElectricalCurrentUnit electricalCurrentUnit, final String nameKey, final String abbreviationKey,
             final UnitSystem unitSystem)
     {
         super(nameKey, abbreviationKey, unitSystem, OHM, electricalPotentialUnit.getConversionFactorToStandardUnit()
                 / electricalCurrentUnit.getConversionFactorToStandardUnit(), true);
         this.massUnit = electricalPotentialUnit.getMassUnit();
         this.lengthUnit = electricalPotentialUnit.getLengthUnit();
         this.electricalCurrentUnit = electricalCurrentUnit;
         this.timeUnit = electricalPotentialUnit.getTimeUnit();
     }
 
     /**
      * @param nameKey the key to the locale file for the long name of the unit
      * @param abbreviationKey the key to the locale file for the abbreviation of the unit
      * @param unitSystem the unit system, e.g. SI or Imperial
      * @param referenceUnit the unit to convert to
      * @param conversionFactorToReferenceUnit multiply a value in this unit by the factor to convert to the given
      *            reference unit
      */
     public ElectricalResistanceUnit(final String nameKey, final String abbreviationKey, final UnitSystem unitSystem,
             final ElectricalResistanceUnit referenceUnit, final double conversionFactorToReferenceUnit)
     {
         super(nameKey, abbreviationKey, unitSystem, referenceUnit, conversionFactorToReferenceUnit, true);
         this.massUnit = referenceUnit.getMassUnit();
         this.lengthUnit = referenceUnit.getLengthUnit();
         this.electricalCurrentUnit = referenceUnit.getElectricalCurrentUnit();
         this.timeUnit = referenceUnit.getTimeUnit();
     }
 
     /**
      * @return massUnit
      */
     public final MassUnit getMassUnit()
     {
         return this.massUnit;
     }
 
     /**
      * @return lengthUnit
      */
     public final LengthUnit getLengthUnit()
     {
         return this.lengthUnit;
     }
 
     /**
      * @return electricalCurrentUnit
      */
     public final ElectricalCurrentUnit getElectricalCurrentUnit()
     {
         return this.electricalCurrentUnit;
     }
 
     /**
      * @return timeUnit
      */
     public final TimeUnit getTimeUnit()
     {
         return this.timeUnit;
     }
 
     /** {@inheritDoc} */
     @Override
     public final ElectricalResistanceUnit getStandardUnit()
     {
         return OHM;
     }
 
     /** {@inheritDoc} */
     @Override
     public final String getSICoefficientsString()
     {
         return "kg.m2.s-3.A-2";
     }
 
 }