package org.opentrafficsim.core.unit;
   
   import static org.opentrafficsim.core.unit.unitsystem.UnitSystem.CGS;
   import static org.opentrafficsim.core.unit.unitsystem.UnitSystem.IMPERIAL;
   import static org.opentrafficsim.core.unit.unitsystem.UnitSystem.MTS;
   import static org.opentrafficsim.core.unit.unitsystem.UnitSystem.OTHER;
   import static org.opentrafficsim.core.unit.unitsystem.UnitSystem.SI_DERIVED;
   
   import org.opentrafficsim.core.unit.unitsystem.UnitSystem;
  
  /**
   * The units of force.
   * <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 ForceUnit extends Unit<ForceUnit>
  {
      /** */
      private static final long serialVersionUID = 20140607L;
  
      /** the unit of mass for the force unit, e.g., kilogram. */
      private final MassUnit massUnit;
  
      /** the unit of length for the force unit, e.g., length. */
      private final LengthUnit lengthUnit;
  
      /** the unit of time for the force unit, e.g., second. */
      private final TimeUnit timeUnit;
  
      /** The SI unit for force is Newton. */
      public static final ForceUnit SI;
  
      /** Newton. */
      public static final ForceUnit NEWTON;
  
      /** Dyne. */
      public static final ForceUnit DYNE;
  
      /** kilogram-force. */
      public static final ForceUnit KILOGRAM_FORCE;
  
      /** ounce-force. */
      public static final ForceUnit OUNCE_FORCE;
  
      /** pound-force. */
      public static final ForceUnit POUND_FORCE;
  
      /** ton-force. */
      public static final ForceUnit TON_FORCE;
  
      /** sthene. */
      public static final ForceUnit STHENE;
  
      static
      {
          SI =
                  new ForceUnit(MassUnit.KILOGRAM, LengthUnit.METER, TimeUnit.SECOND, "ForceUnit.newton", "ForceUnit.N",
                          SI_DERIVED);
          NEWTON = SI;
          DYNE =
                  new ForceUnit(MassUnit.GRAM, LengthUnit.CENTIMETER, TimeUnit.SECOND, "ForceUnit.dyne", "ForceUnit.dyn",
                          CGS);
          KILOGRAM_FORCE =
                  new ForceUnit(MassUnit.KILOGRAM, AccelerationUnit.STANDARD_GRAVITY, "ForceUnit.kilogram-force",
                          "ForceUnit.kgf", OTHER);
          OUNCE_FORCE =
                  new ForceUnit(MassUnit.OUNCE, AccelerationUnit.STANDARD_GRAVITY, "ForceUnit.ounce-force",
                          "ForceUnit.ozf", IMPERIAL);
          POUND_FORCE =
                  new ForceUnit(MassUnit.POUND, AccelerationUnit.STANDARD_GRAVITY, "ForceUnit.pound-force",
                          "ForceUnit.lbf", IMPERIAL);
          TON_FORCE =
                  new ForceUnit(MassUnit.TON_SHORT, AccelerationUnit.STANDARD_GRAVITY, "ForceUnit.ton-force",
                          "ForceUnit.tnf", IMPERIAL);
          STHENE =
                  new ForceUnit(MassUnit.TON_METRIC, AccelerationUnit.METER_PER_SECOND_2, "ForceUnit.sthene",
                          "ForceUnit.sn", MTS);
      }
  
      /**
       * Build a standard unit.
       * @param massUnit the unit of mass for the force unit, e.g., kilogram
       * @param lengthUnit the unit of length for the force unit, e.g., meter
       * @param timeUnit the unit of time for the force 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 ForceUnit(final MassUnit massUnit, final LengthUnit lengthUnit, final TimeUnit timeUnit,
              final String nameKey, final String abbreviationKey, final UnitSystem unitSystem)
      {
          super(nameKey, abbreviationKey, unitSystem, NEWTON, massUnit.getConversionFactorToStandardUnit()
                  * lengthUnit.getConversionFactorToStandardUnit()
                  / (timeUnit.getConversionFactorToStandardUnit() * timeUnit.getConversionFactorToStandardUnit()), true);
          this.massUnit = massUnit;
         this.lengthUnit = lengthUnit;
         this.timeUnit = timeUnit;
     }
 
     /**
      * Build a unit with a conversion factor to another unit.
      * @param massUnit the unit of mass for the force unit, e.g., kilogram
      * @param accelerationUnit the unit of acceleration for the force unit, e.g., m/s^2
      * @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 ForceUnit(final MassUnit massUnit, final AccelerationUnit accelerationUnit, final String nameKey,
             final String abbreviationKey, final UnitSystem unitSystem)
     {
         super(nameKey, abbreviationKey, unitSystem, NEWTON, massUnit.getConversionFactorToStandardUnit()
                 * accelerationUnit.getConversionFactorToStandardUnit(), true);
         this.massUnit = massUnit;
         this.lengthUnit = accelerationUnit.getLengthUnit();
         this.timeUnit = accelerationUnit.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 ForceUnit(final String nameKey, final String abbreviationKey, final UnitSystem unitSystem,
             final ForceUnit referenceUnit, final double conversionFactorToReferenceUnit)
     {
         super(nameKey, abbreviationKey, unitSystem, referenceUnit, conversionFactorToReferenceUnit, true);
         this.massUnit = referenceUnit.getMassUnit();
         this.lengthUnit = referenceUnit.getLengthUnit();
         this.timeUnit = referenceUnit.getTimeUnit();
     }
 
     /**
      * @return massUnit
      */
     public final MassUnit getMassUnit()
     {
         return this.massUnit;
     }
 
     /**
      * @return lengthUnit
      */
     public final LengthUnit getLengthUnit()
     {
         return this.lengthUnit;
     }
 
     /**
      * @return timeUnit
      */
     public final TimeUnit getTimeUnit()
     {
         return this.timeUnit;
     }
 
     /** {@inheritDoc} */
     @Override
     public final ForceUnit getStandardUnit()
     {
         return NEWTON;
     }
 
     /** {@inheritDoc} */
     @Override
     public final String getSICoefficientsString()
     {
         return "kgm/s2";
     }
 
 }