package org.opentrafficsim.road.gtu.lane.plan.operational;
   
   import java.io.Serializable;
   
   import org.djunits.value.vdouble.scalar.Acceleration;
   import org.djunits.value.vdouble.scalar.Length;
   import org.opentrafficsim.core.gtu.GTU;
   import org.opentrafficsim.core.gtu.GTUException;
   import org.opentrafficsim.core.gtu.TurnIndicatorIntent;
  import org.opentrafficsim.core.gtu.TurnIndicatorStatus;
  import org.opentrafficsim.core.network.LateralDirectionality;
  
  import nl.tudelft.simulation.language.Throw;
  
  /**
   * Simplified plan containing only an acceleration value and possible lane change direction.
   * <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/current/license.html">OpenTrafficSim License</a>.
   * <p>
   * @version $Revision$, $LastChangedDate$, by $Author$, initial version Jul 26, 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 SimpleOperationalPlan implements Serializable
  {
  
      /** */
      private static final long serialVersionUID = 20160811L;
  
      /** Acceleration. */
      private Acceleration acceleration;
  
      /** Lane change direction. */
      private final LateralDirectionality laneChangeDirection;
  
      /** Indicator intent. */
      private TurnIndicatorIntent indicatorIntent = TurnIndicatorIntent.NONE;
  
      /** Distance to object causing turn indicator intent. */
      private Length indicatorObjectDistance = null;
  
      /**
       * @param acceleration acceleration
       */
      public SimpleOperationalPlan(final Acceleration acceleration)
      {
          this(acceleration, LateralDirectionality.NONE);
      }
  
      /**
       * @param acceleration acceleration
       * @param laneChangeDirection lane change direction, may be {@code null}.
       */
      public SimpleOperationalPlan(final Acceleration acceleration, final LateralDirectionality laneChangeDirection)
      {
          Throw.whenNull(acceleration, "Acceleration may not be null.");
          Throw.whenNull(laneChangeDirection, "Lane change direction may not be null.");
          checkAcceleration(acceleration);
          this.acceleration = acceleration;
          this.laneChangeDirection = laneChangeDirection;
      }
  
      /**
       * @return acceleration.
       */
      public final Acceleration getAcceleration()
      {
          return this.acceleration;
      }
  
      /**
       * @return if lane change.
       */
      public final boolean isLaneChange()
      {
          return this.laneChangeDirection != LateralDirectionality.NONE;
      }
  
      /**
       * @return laneChangeDirection, may be NONE if no lane change.
       */
      public final LateralDirectionality getLaneChangeDirection()
      {
          return this.laneChangeDirection;
      }
  
      /**
       * Set minimum of current and given acceleration.
       * @param a acceleration to set if lower than current acceleration
       */
      public final void minimizeAcceleration(final Acceleration a)
      {
          checkAcceleration(a);
          this.acceleration = Acceleration.min(this.acceleration, a);
      }
  
     /**
      * Check acceleration level.
      * @param a acceleration
      */
     private void checkAcceleration(final Acceleration a)
     {
         if (a.equals(Acceleration.NEGATIVE_INFINITY) || a.equals(Acceleration.NEG_MAXVALUE))
         {
             throw new RuntimeException("Model has calcalated a negative infinite or negative max value acceleration.");
         }
     }
 
     /**
      * @return indicatorIntent.
      */
     public final TurnIndicatorIntent getIndicatorIntent()
     {
         return this.indicatorIntent;
     }
 
     /**
      * Set left indicator intent. Any intent given with distance overrules this intent.
      */
     public final void setIndicatorIntentLeft()
     {
         if (this.indicatorObjectDistance != null)
         {
             return;
         }
         if (this.indicatorIntent.isRight())
         {
             this.indicatorIntent = TurnIndicatorIntent.CONFLICTING;
         }
         else
         {
             this.indicatorIntent = TurnIndicatorIntent.LEFT;
         }
     }
 
     /**
      * Set right indicator intent. Any intent given with distance overrules this intent.
      */
     public final void setIndicatorIntentRight()
     {
         if (this.indicatorObjectDistance != null)
         {
             return;
         }
         if (this.indicatorIntent.isLeft())
         {
             this.indicatorIntent = TurnIndicatorIntent.CONFLICTING;
         }
         else
         {
             this.indicatorIntent = TurnIndicatorIntent.RIGHT;
         }
     }
 
     /**
      * Set left indicator intent. Intent with smallest provided distance has priority.
      * @param distance distance to object pertaining to the turn indicator intent
      */
     public final void setIndicatorIntentLeft(final Length distance)
     {
         if (compareAndIgnore(distance))
         {
             return;
         }
         if (this.indicatorIntent.isRight())
         {
             this.indicatorIntent = TurnIndicatorIntent.CONFLICTING;
         }
         else
         {
             this.indicatorIntent = TurnIndicatorIntent.LEFT;
         }
 
     }
 
     /**
      * Set right indicator intent. Intent with smallest provided distance has priority.
      * @param distance distance to object pertaining to the turn indicator intent
      */
     public final void setIndicatorIntentRight(final Length distance)
     {
         if (compareAndIgnore(distance))
         {
             return;
         }
         if (this.indicatorIntent.isLeft())
         {
             this.indicatorIntent = TurnIndicatorIntent.CONFLICTING;
         }
         else
         {
             this.indicatorIntent = TurnIndicatorIntent.RIGHT;
         }
     }
 
     /**
      * Compares distances and returns whether the given distance (and intent) can be ignored.
      * @param distance distance to object of intent
      * @return whether the given distance can be ignored
      */
     private boolean compareAndIgnore(final Length distance)
     {
         if (this.indicatorObjectDistance != null)
         {
             if (this.indicatorObjectDistance.lt(distance))
             {
                 // disregard input; the intent from larger distance
                 return true;
             }
             if (this.indicatorObjectDistance.gt(distance))
             {
                 // disregard existing; the intent from larger distance
                 this.indicatorIntent = TurnIndicatorIntent.NONE; // prevents a set to CONFLICTING
             }
         }
         else
         {
             // disregard existing; the intent without distance
             this.indicatorIntent = TurnIndicatorIntent.NONE; // prevents a set to CONFLICTING
         }
         return false;
     }
 
     /** {@inheritDoc} */
     @Override
     @SuppressWarnings("checkstyle:designforextension")
     public String toString()
     {
         return "SimpleOperationalPlan [Acceleration=" + this.acceleration + ", change=" + this.laneChangeDirection
                 + ", indicator intent=" + this.indicatorIntent + "]";
     }
 
     /**
      * @param gtu GTU to set the indicator on
      * @throws GTUException if GTU does not support the indicator
      */
     public void setTurnIndicator(final GTU gtu) throws GTUException
     {
         if (this.indicatorIntent.isLeft())
         {
             gtu.setTurnIndicatorStatus(TurnIndicatorStatus.LEFT);
         }
         else if (this.indicatorIntent.isRight())
         {
             gtu.setTurnIndicatorStatus(TurnIndicatorStatus.RIGHT);
         }
         else
         {
             gtu.setTurnIndicatorStatus(TurnIndicatorStatus.NONE);
         }
     }
 
 }