package org.opentrafficsim.road.gtu.lane.perception.headway;
   
   import org.djunits.unit.LengthUnit;
   import org.djunits.value.ValueRuntimeException;
   import org.djunits.value.storage.StorageType;
   import org.djunits.value.vdouble.scalar.Length;
   import org.djunits.value.vdouble.scalar.Speed;
   import org.djunits.value.vdouble.vector.LengthVector;
   import org.djunits.value.vdouble.vector.base.DoubleVector;
  import org.djutils.exceptions.Throw;
  import org.opentrafficsim.core.gtu.GTUException;
  import org.opentrafficsim.road.gtu.lane.LaneBasedGTU;
  import org.opentrafficsim.road.gtu.lane.perception.PerceptionCollectable;
  import org.opentrafficsim.road.network.lane.CrossSectionLink;
  import org.opentrafficsim.road.network.lane.Lane;
  import org.opentrafficsim.road.network.lane.conflict.ConflictPriority;
  import org.opentrafficsim.road.network.lane.conflict.ConflictRule;
  import org.opentrafficsim.road.network.lane.conflict.ConflictType;
  
  /**
   * <p>
   * Copyright (c) 2013-2020 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/current/license.html">OpenTrafficSim License</a>.
   * <p>
   * @version $Revision$, $LastChangedDate$, by $Author$, initial version Jun 2, 2016 <br>
   * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
   * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
   * @author <a href="http://www.transport.citg.tudelft.nl">Wouter Schakel</a>
   */
  public class HeadwayConflict extends AbstractHeadwayLaneBasedObject
  {
  
      /** */
      private static final long serialVersionUID = 20160602L;
  
      /** Conflict type. */
      private final ConflictType conflictType;
  
      /** Conflict priority. */
      private final ConflictPriority conflictPriority;
  
      /** Length of the conflict in the conflicting directions. */
      private final Length conflictingLength;
  
      /**
       * Set of conflicting GTU's <i>completely</i> upstream of the <i>start</i> of the conflict ordered close to far from the
       * start of the conflict. Distance and overlap info concerns the conflict.
       */
      private final PerceptionCollectable<HeadwayGTU, LaneBasedGTU> upstreamConflictingGTUs;
  
      /**
       * Set of conflicting GTU's (partially) downstream of the <i>start</i> of the conflict ordered close to far from the start
       * of conflict. Distance and overlap info concerns the conflict.
       */
      private final PerceptionCollectable<HeadwayGTU, LaneBasedGTU> downstreamConflictingGTUs;
  
      /** Visibility on the conflicting lane within which conflicting vehicles are visible. */
      private final Length conflictingVisibility;
  
      /** Speed limit on the conflicting lane. */
      private final Speed conflictingSpeedLimit;
  
      /** Link of conflicting conflict. */
      private final CrossSectionLink conflictingLink;
  
      /** Stop line on the own lane. */
      private final HeadwayStopLine stopLine;
  
      /** Stop line on the conflicting lane. */
      private final HeadwayStopLine conflictingStopLine;
  
      /** Type of conflict rule. */
      private final Class<? extends ConflictRule> conflictRuleType;
  
      /** Distance of traffic light upstream on conflicting lane. */
      private Length conflictingTrafficLightDistance = null;
  
      /** Whether the conflict is permitted by the traffic light. */
      private boolean permitted = false;
  
      /** Width progression of conflict. */
      private final Width width;
  
      /**
       * Constructor.
       * @param conflictType ConflictType; conflict type
       * @param conflictPriority ConflictPriority; conflict priority
       * @param conflictRuleType Class&lt;? extends ConflictRule&gt;; conflict rule type
       * @param id String; id
       * @param distance Length; distance
       * @param length Length; length of the conflict
       * @param conflictingLength Length; length of the conflict on the conflicting lane
       * @param upstreamConflictingGTUs PerceptionCollectable&lt;HeadwayGTU,LaneBasedGTU&gt;; conflicting GTU's upstream of the
       *            &lt;i&gt;start&lt;/i&gt; of the conflict
       * @param downstreamConflictingGTUs PerceptionCollectable&lt;HeadwayGTU,LaneBasedGTU&gt;; conflicting GTU's downstream of
       *            the &lt;i&gt;start&lt;/i&gt; of the conflict
       * @param conflictingVisibility Length; visibility on the conflicting lane within which conflicting vehicles are visible
       * @param conflictingSpeedLimit Speed; speed limit on the conflicting lane
       * @param conflictingLink CrossSectionLink; conflicting link
      * @param width Width; width progression of conflict
      * @param stopLine HeadwayStopLine; stop line on the own lane
      * @param conflictingStopLine HeadwayStopLine; stop line on the conflicting lane
      * @param lane Lane; the lane
      * @throws GTUException when id is null, or parameters are inconsistent
      */
     @SuppressWarnings("checkstyle:parameternumber")
     public HeadwayConflict(final ConflictType conflictType, final ConflictPriority conflictPriority,
             final Class<? extends ConflictRule> conflictRuleType, final String id, final Length distance, final Length length,
             final Length conflictingLength, final PerceptionCollectable<HeadwayGTU, LaneBasedGTU> upstreamConflictingGTUs,
             final PerceptionCollectable<HeadwayGTU, LaneBasedGTU> downstreamConflictingGTUs, final Length conflictingVisibility,
             final Speed conflictingSpeedLimit, final CrossSectionLink conflictingLink, final Width width,
             final HeadwayStopLinee/perception/headway/HeadwayStopLine.html#HeadwayStopLine">HeadwayStopLine stopLine, final HeadwayStopLine conflictingStopLine, final Lane lane) throws GTUException
     {
         super(ObjectType.CONFLICT, id, distance, length, lane);
         Throw.whenNull(conflictType, "Conflict type may not be null.");
         Throw.whenNull(conflictPriority, "Conflict priority may not be null.");
         Throw.whenNull(conflictRuleType, "Conflict rule type may not be null.");
         Throw.whenNull(id, "Conflict id may not be null.");
         Throw.whenNull(distance, "Conflict distance may not be null.");
         Throw.whenNull(conflictingLength, "Conflict length may not be null.");
         Throw.whenNull(upstreamConflictingGTUs, "Upstreaem conflicting GTU's may not be null.");
         Throw.whenNull(downstreamConflictingGTUs, "Downstream conflicting GTU's may not be null.");
         Throw.whenNull(width, "Width may not be null.");
         Throw.whenNull(conflictingVisibility, "Conflict visibility may not be null.");
         Throw.whenNull(conflictingSpeedLimit, "Conflict speed limit may not be null.");
         this.conflictType = conflictType;
         this.conflictPriority = conflictPriority;
         this.conflictRuleType = conflictRuleType;
         this.conflictingLength = conflictingLength;
         this.upstreamConflictingGTUs = upstreamConflictingGTUs;
         this.downstreamConflictingGTUs = downstreamConflictingGTUs;
         this.conflictingVisibility = conflictingVisibility;
         this.conflictingSpeedLimit = conflictingSpeedLimit;
         this.conflictingLink = conflictingLink;
         this.width = width;
         this.stopLine = stopLine;
         this.conflictingStopLine = conflictingStopLine;
     }
 
     /**
      * Constructor without stop lines.
      * @param conflictType ConflictType; conflict type
      * @param conflictPriority ConflictPriority; conflict priority
      * @param conflictRuleType Class&lt;? extends ConflictRule&gt;; conflict rule type
      * @param id String; id
      * @param distance Length; distance
      * @param length Length; length of the conflict
      * @param conflictingLength Length; length of the conflict on the conflicting lane
      * @param upstreamConflictingGTUs PerceptionCollectable&lt;HeadwayGTU,LaneBasedGTU&gt;; conflicting GTU's upstream of the
      *            &lt;i&gt;start&lt;/i&gt; of the conflict
      * @param downstreamConflictingGTUs PerceptionCollectable&lt;HeadwayGTU,LaneBasedGTU&gt;; conflicting GTU's downstream of
      *            the &lt;i&gt;start&lt;/i&gt; of the conflict
      * @param conflictingVisibility Length; visibility on the conflicting lane within which conflicting vehicles are visible
      * @param conflictingSpeedLimit Speed; speed limit on the conflicting lane
      * @param conflictingLink CrossSectionLink; conflicting link
      * @param width Width; width progression of conflict
      * @param lane Lane; the lane
      * @throws GTUException when id is null, or parameters are inconsistent
      */
     @SuppressWarnings("checkstyle:parameternumber")
     public HeadwayConflict(final ConflictType conflictType, final ConflictPriority conflictPriority,
             final Class<? extends ConflictRule> conflictRuleType, final String id, final Length distance, final Length length,
             final Length conflictingLength, final PerceptionCollectable<HeadwayGTU, LaneBasedGTU> upstreamConflictingGTUs,
             final PerceptionCollectable<HeadwayGTU, LaneBasedGTU> downstreamConflictingGTUs, final Length conflictingVisibility,
             final Speed conflictingSpeedLimit, final CrossSectionLink conflictingLink, final Width width, final Lane lane)
             throws GTUException
     {
         this(conflictType, conflictPriority, conflictRuleType, id, distance, length, conflictingLength, upstreamConflictingGTUs,
                 downstreamConflictingGTUs, conflictingVisibility, conflictingSpeedLimit, conflictingLink, width, null, null,
                 lane);
     }
 
     /**
      * Returns the conflict type.
      * @return conflict type
      */
     public final ConflictType getConflictType()
     {
         return this.conflictType;
     }
 
     /**
      * Returns whether this is a crossing conflict.
      * @return whether this is a crossing conflict
      */
     public final boolean isCrossing()
     {
         return this.conflictType.equals(ConflictType.CROSSING);
     }
 
     /**
      * Returns whether this is a merge conflict.
      * @return whether this is a merge conflict
      */
     public final boolean isMerge()
     {
         return this.conflictType.equals(ConflictType.MERGE);
     }
 
     /**
      * Returns whether this is a split conflict.
      * @return whether this is a split conflict
      */
     public final boolean isSplit()
     {
         return this.conflictType.equals(ConflictType.SPLIT);
     }
 
     /**
      * Returns the conflict priority.
      * @return conflict priority
      */
     public final ConflictPriority getConflictPriority()
     {
         return this.conflictPriority;
     }
 
     /**
      * Returns the length of the conflict on the conflicting lane.
      * @return length of the conflict on the conflicting lane
      */
     public final Length getConflictingLength()
     {
         return this.conflictingLength;
     }
 
     /**
      * Returns a set of conflicting GTU's upstream of the <i>start</i> of the conflict ordered close to far from the conflict.
      * @return set of conflicting GTU's upstream of the <i>start</i> of the conflict ordered close to far from the conflict
      */
     public final PerceptionCollectable<HeadwayGTU, LaneBasedGTU> getUpstreamConflictingGTUs()
     {
         return this.upstreamConflictingGTUs;
     }
 
     /**
      * Returns a set of conflicting GTU's downstream of the <i>start</i> of the conflict ordered close to far from the conflict.
      * Distance is given relative to the <i>end</i> of the conflict, or null for conflicting vehicles on the conflict. In the
      * latter case the overlap is used.
      * @return set of conflicting GTU's downstream of the <i>start</i> of the conflict ordered close to far from the conflict
      */
     public final PerceptionCollectable<HeadwayGTU, LaneBasedGTU> getDownstreamConflictingGTUs()
     {
         return this.downstreamConflictingGTUs;
     }
 
     /**
      * Returns the visibility on the conflicting lane within which conflicting vehicles are visible. All upstream conflicting
      * GTUs have a distance smaller than the visibility. Depending on a limited visibility, a certain (lower) speed may be
      * required while approaching the conflict.
      * @return visibility on the conflicting lane within which conflicting vehicles are visible
      */
     public final Length getConflictingVisibility()
     {
         return this.conflictingVisibility;
     }
 
     /**
      * Returns the speed limit on the conflicting lane.
      * @return speed limit on the conflicting lane
      */
     public final Speed getConflictingSpeedLimit()
     {
         return this.conflictingSpeedLimit;
     }
 
     /**
      * Returns the conflicting link.
      * @return the conflicting link
      */
     public final CrossSectionLink getConflictingLink()
     {
         return this.conflictingLink;
     }
 
     /**
      * Returns the stop line.
      * @return stop line
      */
     public final HeadwayStopLine getStopLine()
     {
         return this.stopLine;
     }
 
     /**
      * Returns the stop line on the conflicting lane.
      * @return stop line
      */
     public final HeadwayStopLine getConflictingStopLine()
     {
         return this.conflictingStopLine;
     }
 
     /**
      * Returns the conflict rule type.
      * @return conflict rule type
      */
     public final Class<? extends ConflictRule> getConflictRuleType()
     {
         return this.conflictRuleType;
     }
 
     /**
      * Returns the distance of a traffic light upstream on the conflicting lane.
      * @return distance of a traffic light upstream on the conflicting lane, or {@code null} if no traffic light
      */
     public final Length getConflictingTrafficLightDistance()
     {
         return this.conflictingTrafficLightDistance;
     }
 
     /**
      * Whether the conflict is permitted by the traffic light.
      * @return whether the conflict is permitted by the traffic light
      */
     public final boolean isPermitted()
     {
         return this.permitted;
     }
 
     /**
      * Set the distance of a traffic light upstream on the conflicting lane.
      * @param trafficLightDistance Length; distance of a traffic light upstream on the conflicting lane.
      * @param permittedConflict boolean; whether the conflict is permitted by the traffic light
      */
     public final void setConflictingTrafficLight(final Length trafficLightDistance, final boolean permittedConflict)
     {
         this.conflictingTrafficLightDistance = trafficLightDistance;
         this.permitted = permittedConflict;
     }
 
     /**
      * Returns the width at the given fraction.
      * @param fraction double; fraction from 0 to 1
      * @return Length; width at the given fraction
      */
     public final Length getWidthAtFraction(final double fraction)
     {
         try
         {
             return this.width.getWidth(fraction);
         }
         catch (ValueRuntimeException exception)
         {
             throw new RuntimeException("Unexpected exception: fraction could not be interpolated.", exception);
         }
     }
 
     /**
      * Width progression of conflict.
      * <p>
      * Copyright (c) 2013-2020 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 $Revision$, $LastChangedDate$, by $Author$, initial version 11 aug. 2018 <br>
      * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
      * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
      * @author <a href="http://www.transport.citg.tudelft.nl">Wouter Schakel</a>
      */
     public static class Width
     {
 
         /** Fractions, from 0 to 1. */
         private final double[] fractions;
 
         /** Vector with widths. */
         private final LengthVector width;
 
         /**
          * @param fractions double[]; fractions, from 0 to 1
          * @param width LengthVector; vector of equal length with widths
          */
         public Width(final double[] fractions, final LengthVector width)
         {
             Throw.whenNull(fractions, "Fractions may not be null.");
             Throw.whenNull(width, "Width may not be null.");
             Throw.when(fractions.length != width.size(), IllegalArgumentException.class,
                     "Array and vector are not of equal length.");
             Throw.when(fractions.length < 2, IllegalArgumentException.class, "Input should at least contain 2 values.");
             Throw.when(fractions[0] != 0.0 || fractions[fractions.length - 1] != 1.0, IllegalArgumentException.class,
                     "Fractions should range from 0 to 1.");
             for (int i = 1; i < fractions.length; i++)
             {
                 Throw.when(fractions[i] <= fractions[i - 1], IllegalArgumentException.class, "Fractions are not increasing.");
             }
             this.fractions = fractions;
             this.width = width;
         }
 
         /**
          * Returns the width at the given fraction.
          * @param fraction double; fraction from 0 to 1
          * @return Length; width at the given fraction
          * @throws ValueRuntimeException when index is out of bounds
          */
         public Length getWidth(final double fraction) throws ValueRuntimeException
         {
             Throw.when(fraction < 0.0 || fraction > 1.0, IllegalArgumentException.class, "Fraction should be between 0 and 1.");
             if (fraction == 1.0)
             {
                 return this.width.get(this.width.size() - 1);
             }
             for (int i = 0; i < this.fractions.length - 1; i++)
             {
                 if (this.fractions[i] <= fraction && this.fractions[i + 1] > fraction)
                 {
                     double r = (fraction - this.fractions[i]) / (this.fractions[i + 1] - this.fractions[i]);
                     return Length.interpolate(this.width.get(i), this.width.get(i + 1), r);
                 }
             }
             throw new RuntimeException("Unexpected exception: fraction could not be interpolated.");
         }
 
         /**
          * Returns a linear width progression.
          * @param startWidth Length; start width
          * @param endWidth Length; end width
          * @return Width; linear width progression
          */
         public static Width linear(final Length startWidth, final Length endWidth)
         {
             Throw.whenNull(startWidth, "Start width may not be null.");
             Throw.whenNull(endWidth, "End width may not be null.");
             try
             {
                 return new Width(new double[] { 0.0, 1.0 },
                         DoubleVector.instantiate(new Length[] { startWidth, endWidth }, LengthUnit.SI, StorageType.DENSE));
             }
             catch (ValueRuntimeException exception)
             {
                 throw new RuntimeException("Unexpected exception: widths could not be put in a vector.", exception);
             }
         }
 
     }
 
     /** {@inheritDoc} */
     @Override
     public final String toString()
     {
         return String.format("Headway %s to object %s of type %s", getDistance(), getId(), getObjectType());
     }
 
 }