package org.opentrafficsim.core.network.factory.xml.units;
   
   import org.djunits.unit.DurationUnit;
   import org.djunits.unit.LengthUnit;
   import org.djunits.unit.PositionUnit;
   import org.djunits.unit.SpeedUnit;
   import org.djunits.unit.TimeUnit;
   import org.djunits.value.vdouble.scalar.Duration;
   import org.djunits.value.vdouble.scalar.Length;
  import org.djunits.value.vdouble.scalar.Position;
  import org.djunits.value.vdouble.scalar.Speed;
  import org.djunits.value.vdouble.scalar.Time;
  import org.opentrafficsim.core.network.NetworkException;
  import org.opentrafficsim.core.units.distributions.ContinuousDistDoubleScalar;
  
  import nl.tudelft.simulation.jstats.distributions.DistBeta;
  import nl.tudelft.simulation.jstats.distributions.DistConstant;
  import nl.tudelft.simulation.jstats.distributions.DistContinuous;
  import nl.tudelft.simulation.jstats.distributions.DistErlang;
  import nl.tudelft.simulation.jstats.distributions.DistExponential;
  import nl.tudelft.simulation.jstats.distributions.DistGamma;
  import nl.tudelft.simulation.jstats.distributions.DistLogNormal;
  import nl.tudelft.simulation.jstats.distributions.DistNormal;
  import nl.tudelft.simulation.jstats.distributions.DistPearson5;
  import nl.tudelft.simulation.jstats.distributions.DistPearson6;
  import nl.tudelft.simulation.jstats.distributions.DistTriangular;
  import nl.tudelft.simulation.jstats.distributions.DistUniform;
  import nl.tudelft.simulation.jstats.distributions.DistWeibull;
  import nl.tudelft.simulation.jstats.streams.MersenneTwister;
  import nl.tudelft.simulation.jstats.streams.StreamInterface;
  
  /**
   * <p>
   * Copyright (c) 2013-2017 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/docs/license.html">OpenTrafficSim License</a>.
   * <p>
   * $LastChangedDate: 2015-07-24 02:58:59 +0200 (Fri, 24 Jul 2015) $, @version $Revision: 1147 $, by $Author: averbraeck $,
   * initial version Jul 23, 2015 <br>
   * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
   */
  public final class Distributions
  {
      /** Utility class. */
      private Distributions()
      {
          // do not instantiate
      }
  
      /** TODO include in GLOBAL tag. */
      private static final StreamInterface STREAM = new MersenneTwister(2L);
  
      /**
       * parse a set of comma-separated values, e.g., <code>10.0, 4, 5.23</code>.
       * @param s the string to parse.
       * @return array of double values.
       */
      private static double[] parseDoubleArgs(final String s)
      {
          String[] ss = s.split(",");
          double[] d = new double[ss.length];
          for (int i = 0; i < ss.length; i++)
          {
              d[i] = Double.parseDouble(ss[i]);
          }
          return d;
      }
  
      /**
       * Parse a continuous distribution.
       * @param ds the name of the distribution, e.g. UNIF.
       * @param args the parameters of the distribution, e.g. {1.0, 2.0}.
       * @return the generated distribution.
       * @throws NetworkException in case distribution unknown or parameter number does not match.
       */
      private static DistContinuous makeDistContinuous(final String ds, final double[] args) throws NetworkException
      {
          try
          {
              switch (ds)
              {
                  case "CONST":
                  case "CONSTANT":
                      return new DistConstant(STREAM, args[0]);
  
                  case "EXPO":
                  case "EXPONENTIAL":
                      return new DistExponential(STREAM, args[0]);
  
                  case "TRIA":
                  case "TRIANGULAR":
                      return new DistTriangular(STREAM, args[0], args[1], args[2]);
  
                  case "NORM":
                  case "NORMAL":
                      return new DistNormal(STREAM, args[0], args[1]);
  
                  case "BETA":
                      return new DistBeta(STREAM, args[0], args[1]);
  
                 case "ERLANG":
                     return new DistErlang(STREAM, (int) args[0], args[1]);
 
                 case "GAMMA":
                     return new DistGamma(STREAM, args[0], args[1]);
 
                 case "LOGN":
                 case "LOGNORMAL":
                     return new DistLogNormal(STREAM, args[0], args[1]);
 
                 case "PEARSON5":
                     return new DistPearson5(STREAM, args[0], args[1]);
 
                 case "PEARSON6":
                     return new DistPearson6(STREAM, args[0], args[1], args[2]);
 
                 case "UNIF":
                 case "UNIFORM":
                     return new DistUniform(STREAM, args[0], args[1]);
 
                 case "WEIB":
                 case "WEIBULL":
                     return new DistWeibull(STREAM, args[0], args[1]);
 
                 default:
                     throw new NetworkException("makeDistContinuous - unknown distribution function " + ds);
             }
         }
         catch (IndexOutOfBoundsException e)
         {
             throw new NetworkException("makeDistContinuous - wrong number of parameters for distribution function " + ds);
         }
     }
 
     /**
      * Parse a relative length distribution, e.g. <code>UNIFORM(1, 3) m</code>.
      * @param s the string to be parsed.
      * @return a typed continuous random distribution.
      * @throws NetworkException in case of a parse error.
      */
     public static ContinuousDistDoubleScalar.Rel<Length, LengthUnit> parseLengthDist(final String s) throws NetworkException
     {
         String[] s1 = s.split("\\(");
         String ds = s1[0];
         String[] s2 = s1[1].split("\\)");
         String unit = LengthUnits.parseLengthUnit(s2[1]);
         double[] args = parseDoubleArgs(s2[0]);
         DistContinuous dist = makeDistContinuous(ds, args);
         return new ContinuousDistDoubleScalar.Rel<Length, LengthUnit>(dist, LengthUnits.LENGTH_UNITS.get(unit));
     }
 
     /**
      * Parse an absolute length distribution, e.g. <code>UNIFORM(1, 3) m</code>.
      * @param s the string to be parsed.
      * @return a typed continuous random distribution.
      * @throws NetworkException in case of a parse error.
      */
     public static ContinuousDistDoubleScalar.Abs<Position, PositionUnit, LengthUnit> parsePositionDist(final String s)
             throws NetworkException
     {
         String[] s1 = s.split("\\(");
         String ds = s1[0];
         String[] s2 = s1[1].split("\\)");
         String unit = LengthUnits.parseLengthUnit(s2[1]);
         double[] args = parseDoubleArgs(s2[0]);
         DistContinuous dist = makeDistContinuous(ds, args);
         return new ContinuousDistDoubleScalar.Abs<Position, PositionUnit, LengthUnit>(dist,
                 PositionUnits.POSITION_UNITS.get(unit));
     }
 
     /**
      * Parse a relative time distribution, e.g. <code>UNIFORM(1, 3) s</code>.
      * @param s the string to be parsed.
      * @return a typed continuous random distribution.
      * @throws NetworkException in case of a parse error.
      */
     public static ContinuousDistDoubleScalar.Rel<Duration, DurationUnit> parseDurationDist(final String s)
             throws NetworkException
     {
         String[] s1 = s.split("\\(");
         String ds = s1[0];
         String[] s2 = s1[1].split("\\)");
         String unit = DurationUnits.parseDurationUnit(s2[1]);
         double[] args = parseDoubleArgs(s2[0]);
         DistContinuous dist = makeDistContinuous(ds, args);
         return new ContinuousDistDoubleScalar.Rel<Duration, DurationUnit>(dist, DurationUnits.DURATION_UNITS.get(unit));
     }
 
     /**
      * Parse an absolute time distribution, e.g. <code>UNIFORM(1, 3) s</code>.
      * @param s the string to be parsed.
      * @return a typed continuous random distribution.
      * @throws NetworkException in case of a parse error.
      */
     public static ContinuousDistDoubleScalar.Abs<Time, TimeUnit, DurationUnit> parseTimeDist(final String s)
             throws NetworkException
     {
         String[] s1 = s.split("\\(");
         String ds = s1[0];
         String[] s2 = s1[1].split("\\)");
         String unit = TimeUnits.parseTimeUnit(s2[1]);
         double[] args = parseDoubleArgs(s2[0]);
         DistContinuous dist = makeDistContinuous(ds, args);
         return new ContinuousDistDoubleScalar.Abs<Time, TimeUnit, DurationUnit>(dist, TimeUnits.TIME_UNITS.get(unit));
     }
 
     /**
      * Parse a relative speed distribution, e.g. <code>TRIANGULAR(80, 90, 110) km/h</code>.
      * @param s the string to be parsed.
      * @return a typed continuous random distribution.
      * @throws NetworkException in case of a parse error.
      */
     public static ContinuousDistDoubleScalar.Rel<Speed, SpeedUnit> parseSpeedDist(final String s) throws NetworkException
     {
         String[] s1 = s.split("\\(");
         String ds = s1[0];
         String[] s2 = s1[1].split("\\)");
         String unit = SpeedUnits.parseSpeedUnit(s2[1]);
         double[] args = parseDoubleArgs(s2[0]);
         DistContinuous dist = makeDistContinuous(ds, args);
         return new ContinuousDistDoubleScalar.Rel<Speed, SpeedUnit>(dist, SpeedUnits.SPEED_UNITS.get(unit));
     }
 
 }