package org.opentrafficsim.core.unit;
   
   import static org.opentrafficsim.core.unit.unitsystem.UnitSystem.IMPERIAL;
   import static org.opentrafficsim.core.unit.unitsystem.UnitSystem.SI_DERIVED;
   
   import org.opentrafficsim.core.unit.unitsystem.UnitSystem;
   
   /**
    * The mass flow rate is the mass of a substance which passes through a given surface per unit of time (wikipedia).
   * <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 FlowMassUnit extends Unit<FlowMassUnit>
  {
      /** */
      private static final long serialVersionUID = 20140607L;
  
      /** the unit of mass for the flow unit, e.g., kilogram. */
      private final MassUnit massUnit;
  
      /** the unit of time for the flow unit, e.g., second. */
      private final TimeUnit timeUnit;
  
      /** The SI unit for mass flow rate is kg/s. */
      public static final FlowMassUnit SI;
  
      /** kg/s. */
      public static final FlowMassUnit KILOGRAM_PER_SECOND;
  
      /** lb/s. */
      public static final FlowMassUnit POUND_PER_SECOND;
  
      static
      {
          SI =
                  new FlowMassUnit(MassUnit.KILOGRAM, TimeUnit.SECOND, "FlowMassUnit.kilogram_per_second",
                          "FlowMassUnit.kg/s", SI_DERIVED);
          KILOGRAM_PER_SECOND = SI;
          POUND_PER_SECOND =
                  new FlowMassUnit(MassUnit.POUND, TimeUnit.SECOND, "FlowMassUnit.pound_per_second", "FlowMassUnit.lb/s",
                          IMPERIAL);
      }
  
      /**
       * Create a flow-massunit based on mass and time.
       * @param massUnit the unit of mass for the flow unit, e.g., kilogram
       * @param timeUnit the unit of time for the flow 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 FlowMassUnit(final MassUnit massUnit, final TimeUnit timeUnit, final String nameKey,
              final String abbreviationKey, final UnitSystem unitSystem)
      {
          super(nameKey, abbreviationKey, unitSystem, KILOGRAM_PER_SECOND, massUnit.getConversionFactorToStandardUnit()
                  / timeUnit.getConversionFactorToStandardUnit(), true);
          this.massUnit = massUnit;
          this.timeUnit = timeUnit;
      }
  
      /**
       * Create a flow-massunit based on another flow-massunit.
       * @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 FlowMassUnit(final String nameKey, final String abbreviationKey, final UnitSystem unitSystem,
              final FlowMassUnit referenceUnit, final double conversionFactorToReferenceUnit)
      {
          super(nameKey, abbreviationKey, unitSystem, referenceUnit, conversionFactorToReferenceUnit, true);
          this.massUnit = referenceUnit.getMassUnit();
          this.timeUnit = referenceUnit.getTimeUnit();
      }
  
      /**
       * @return massUnit
       */
      public final MassUnit getMassUnit()
      {
          return this.massUnit;
      }
  
      /**
       * @return timeUnit
       */
      public final TimeUnit getTimeUnit()
      {
          return this.timeUnit;
      }
  
      /** {@inheritDoc} */
      @Override
     public final FlowMassUnit getStandardUnit()
     {
         return KILOGRAM_PER_SECOND;
     }
 
     /** {@inheritDoc} */
     @Override
     public final String getSICoefficientsString()
     {
         return "kg/s";
     }
 
 }