package org.opentrafficsim.core.gtu;
   
   import java.awt.Color;
   
   import org.djunits.unit.DurationUnit;
   import org.djunits.unit.TimeUnit;
   import org.djunits.value.vdouble.scalar.Acceleration;
   import org.djunits.value.vdouble.scalar.Duration;
   import org.djunits.value.vdouble.scalar.Length;
  import org.djunits.value.vdouble.scalar.Speed;
  import org.djunits.value.vdouble.scalar.Time;
  import org.opentrafficsim.core.dsol.OTSDEVSSimulatorInterface;
  import org.opentrafficsim.core.dsol.OTSSimTimeDouble;
  import org.opentrafficsim.core.geometry.OTSGeometryException;
  import org.opentrafficsim.core.geometry.OTSLine3D;
  import org.opentrafficsim.core.geometry.OTSPoint3D;
  import org.opentrafficsim.core.gtu.animation.IDGTUColorer;
  import org.opentrafficsim.core.gtu.behavioralcharacteristics.ParameterException;
  import org.opentrafficsim.core.gtu.plan.operational.OperationalPlan;
  import org.opentrafficsim.core.gtu.plan.operational.OperationalPlanBuilder;
  import org.opentrafficsim.core.gtu.plan.operational.OperationalPlanException;
  import org.opentrafficsim.core.gtu.plan.strategical.StrategicalPlanner;
  import org.opentrafficsim.core.gtu.plan.tactical.TacticalPlanner;
  import org.opentrafficsim.core.idgenerator.IdGenerator;
  import org.opentrafficsim.core.network.NetworkException;
  import org.opentrafficsim.core.perception.PerceivableContext;
  
  import nl.tudelft.simulation.dsol.SimRuntimeException;
  import nl.tudelft.simulation.dsol.formalisms.eventscheduling.SimEvent;
  import nl.tudelft.simulation.event.EventProducer;
  import nl.tudelft.simulation.language.Throw;
  import nl.tudelft.simulation.language.d3.DirectedPoint;
  
  /**
   * Implements the basic functionalities of any GTU: the ability to move on 3D-space according to a plan.
   * <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>
   * @version $Revision: 3570 $, $LastChangedDate: 2017-04-29 12:51:08 +0200 (Sat, 29 Apr 2017) $, by $Author: averbraeck $,
   *          initial version Oct 22, 2014 <br>
   * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
   * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
   */
  public abstract class AbstractGTU extends EventProducer implements GTU
  {
      /** */
      private static final long serialVersionUID = 20140822L;
  
      /** The id of the GTU. */
      private final String id;
  
      /** unique number of the GTU. */
      private final int uniqueNumber;
  
      /** the unique number counter. */
      private static int staticUNIQUENUMBER = 0;
  
      /** The type of GTU, e.g. TruckType, CarType, BusType. */
      private final GTUType gtuType;
  
      /** The simulator to schedule activities on. */
      private final OTSDEVSSimulatorInterface simulator;
  
      /** The maximum acceleration. */
      private Acceleration maximumAcceleration;
  
      /** The maximum deceleration, stored as a negative number. */
      private Acceleration maximumDeceleration;
  
      /**
       * The odometer which measures how much distance have we covered between instantiation and the last completed operational
       * plan. In order to get a complete odometer reading, the progress of the current plan execution has to be added to this
       * value.
       */
      private Length odometer;
  
      /** The strategical planner that can instantiate tactical planners to determine mid-term decisions. */
      private StrategicalPlanner strategicalPlanner;
  
      /** The tactical planner that can generate an operational plan. */
      private TacticalPlanner tacticalPlanner = null;
  
      /** The current operational plan, which provides a short-term movement over time. */
      private OperationalPlan operationalPlan = null;
  
      /** The next move event as scheduled on the simulator, can be used for interrupting the current move. */
      private SimEvent<OTSSimTimeDouble> nextMoveEvent;
  
      /** The model in which this GTU is registered. */
      private PerceivableContext perceivableContext;
  
      /** Turn indicator status. */
      private TurnIndicatorStatus turnIndicatorStatus = TurnIndicatorStatus.NOTPRESENT;
  
      /** Is this GTU destroyed? */
      private boolean destroyed = false;
  
      /** The cached base color. */
     private Color baseColor = null;
 
     /** aligned or not. */
     // TODO: should be indicated with a Parameter
     public static boolean ALIGNED = true;
 
     /** aligned schedule count. */
     // TODO: can be removed after testing period
     public static int ALIGN_COUNT = 0;
 
     /**
      * @param id String; the id of the GTU
      * @param gtuType GTUType; the type of GTU, e.g. TruckType, CarType, BusType
      * @param simulator OTSDEVSSimulatorInterface; the simulator to schedule plan changes on
      * @param perceivableContext PerceivableContext; the perceivable context in which this GTU will be registered
      * @throws GTUException when the preconditions of the constructor are not met
      */
     @SuppressWarnings("checkstyle:parameternumber")
     public AbstractGTU(final String id, final GTUType gtuType, final OTSDEVSSimulatorInterface simulator,
             final PerceivableContext perceivableContext) throws GTUException
     {
         Throw.when(id == null, GTUException.class, "id is null");
         Throw.when(gtuType == null, GTUException.class, "gtuType is null");
         Throw.when(gtuType.equals(GTUType.NONE), GTUException.class, "gtuType of an actual GTU cannot be GTUType.NONE");
         Throw.when(gtuType.equals(GTUType.ALL), GTUException.class, "gtuType of an actual GTU cannot be GTUType.ALL");
         Throw.when(perceivableContext == null, GTUException.class, "perceivableContext is null for GTU with id %s", id);
         Throw.when(perceivableContext.containsGtuId(id), GTUException.class,
                 "GTU with id %s already registered in perceivableContext %s", id, perceivableContext.getId());
         Throw.when(simulator == null, GTUException.class, "simulator is null for GTU with id %s", id);
 
         this.id = id;
         this.uniqueNumber = ++staticUNIQUENUMBER;
         this.gtuType = gtuType;
         this.simulator = simulator;
         this.odometer = Length.ZERO;
         this.perceivableContext = perceivableContext;
         this.perceivableContext.addGTU(this);
     }
 
     /**
      * @param idGenerator IdGenerator; the generator that will produce a unique id of the GTU
      * @param gtuType GTUType; the type of GTU, e.g. TruckType, CarType, BusType
      * @param simulator OTSDEVSSimulatorInterface; the simulator to schedule plan changes on
      * @param perceivableContext PerceivableContext; the perceivable context in which this GTU will be registered
      * @throws GTUException when the preconditions of the constructor are not met
      */
     @SuppressWarnings("checkstyle:parameternumber")
     public AbstractGTU(final IdGenerator idGenerator, final GTUType gtuType, final OTSDEVSSimulatorInterface simulator,
             final PerceivableContext perceivableContext) throws GTUException
     {
         this(generateId(idGenerator), gtuType, simulator, perceivableContext);
     }
 
     /**
      * Initialize the GTU at a location and speed, and give it a mission to fulfill through the strategical planner.
      * @param strategicalPlanner StrategicalPlanner; the strategical planner responsible for the overall 'mission' of the GTU,
      *            usually indicating where it needs to go. It operates by instantiating tactical planners to do the work.
      * @param initialLocation DirectedPoint; the initial location (and direction) of the GTU
      * @param initialSpeed Speed; the initial speed of the GTU
      * @throws SimRuntimeException when scheduling after the first move fails
      * @throws GTUException when the preconditions of the parameters are not met or when the construction of the original
      *             waiting path fails
      */
     @SuppressWarnings({ "checkstyle:hiddenfield", "hiding", "checkstyle:designforextension" })
     public void init(final StrategicalPlanner strategicalPlanner, final DirectedPoint initialLocation, final Speed initialSpeed)
             throws SimRuntimeException, GTUException
     {
         Throw.when(strategicalPlanner == null, GTUException.class, "strategicalPlanner is null for GTU with id %s", this.id);
         Throw.whenNull(initialLocation, "Initial location of GTU cannot be null");
         Throw.when(Double.isNaN(initialLocation.x) || Double.isNaN(initialLocation.y) || Double.isNaN(initialLocation.z),
                 GTUException.class, "initialLocation %s invalid for GTU with id %s", initialLocation, this.id);
         Throw.when(initialSpeed == null, GTUException.class, "initialSpeed is null for GTU with id %s", this.id);
         Throw.when(!getId().equals(strategicalPlanner.getGtu().getId()), GTUException.class,
                 "GTU %s is initialized with a strategical planner for GTU %s", getId(), strategicalPlanner.getGtu().getId());
 
         this.strategicalPlanner = strategicalPlanner;
         Time now = this.simulator.getSimulatorTime().getTime();
 
         // Give the GTU a 1 micrometer long operational plan, or a stand-still plan, so the first move will work
         DirectedPoint p = initialLocation;
         try
         {
             if (initialSpeed.si < OperationalPlan.DRIFTING_SPEED_SI)
             {
                 this.operationalPlan = new OperationalPlan(this, p, now, new Duration(1E-6, DurationUnit.SECOND));
             }
             else
             {
                 OTSPoint3D p2 = new OTSPoint3D(p.x + 1E-6 * Math.cos(p.getRotZ()), p.y + 1E-6 * Math.sin(p.getRotZ()), p.z);
                 OTSLine3D path = new OTSLine3D(new OTSPoint3D(p), p2);
                 this.operationalPlan = OperationalPlanBuilder.buildConstantSpeedPlan(this, path, now, initialSpeed);
             }
 
             fireTimedEvent(GTU.INIT_EVENT, new Object[] { getId(), initialLocation, getLength(), getWidth(), getBaseColor() },
                     now);
 
             // and do the real move
             move(initialLocation);
         }
         catch (OperationalPlanException | OTSGeometryException | NetworkException | ParameterException exception)
         {
             throw new GTUException("Failed to create OperationalPlan for GTU " + this.id, exception);
         }
     }
 
     /**
      * Generate an id, but check first that we have a valid IdGenerator.
      * @param idGenerator IdGenerator; the generator that will produce a unique id of the GTU
      * @return a (hopefully unique) Id of the GTU
      * @throws GTUException when the idGenerator is null
      */
     private static String generateId(final IdGenerator idGenerator) throws GTUException
     {
         Throw.when(idGenerator == null, GTUException.class, "AbstractGTU.<init>: idGenerator is null");
         return idGenerator.nextId();
     }
 
     /**
      * Destructor. Don't forget to call with super.destroy() from any override to avoid memory leaks in the network.
      */
     @Override
     @SuppressWarnings("checkstyle:designforextension")
     public void destroy()
     {
         fireTimedEvent(GTU.DESTROY_EVENT, new Object[] { getId(), getLocation(), getOdometer() },
                 this.simulator.getSimulatorTime());
 
         // cancel the next move
         if (this.nextMoveEvent != null)
         {
             this.simulator.cancelEvent(this.nextMoveEvent);
             this.nextMoveEvent = null;
         }
 
         this.perceivableContext.removeGTU(this);
         this.destroyed = true;
     }
 
     /**
      * Move from the current location according to an operational plan to a location that will bring us nearer to reaching the
      * location provided by the strategical planner. <br>
      * This method can be overridden to carry out specific behavior during the execution of the plan (e.g., scheduling of
      * triggers, entering or leaving lanes, etc.). Please bear in mind that the call to super.move() is essential, and that one
      * has to take care to handle the situation that the plan gets interrupted.
      * @param fromLocation the last known location (initial location, or end location of the previous operational plan)
      * @throws SimRuntimeException when scheduling of the next move fails
      * @throws OperationalPlanException when there is a problem creating a good path for the GTU
      * @throws GTUException when there is a problem with the state of the GTU when planning a path
      * @throws NetworkException in case of a problem with the network, e.g., a dead end where it is not expected
      * @throws ParameterException in there is a parameter problem
      */
     @SuppressWarnings("checkstyle:designforextension")
     protected void move(final DirectedPoint fromLocation)
             throws SimRuntimeException, OperationalPlanException, GTUException, NetworkException, ParameterException
     {
         Time now = this.simulator.getSimulatorTime().getTime();
 
         // Add the odometer distance from the currently running operational plan.
         // Because a plan can be interrupted, we explicitly calculate the covered distance till 'now'
         Length currentOdometer;
         if (this.operationalPlan != null)
         {
             currentOdometer = this.odometer.plus(this.operationalPlan.getTraveledDistance(now));
         }
         else
         {
             currentOdometer = this.odometer;
         }
 
         // Do we have an operational plan?
         // TODO discuss when a new tactical planner may be needed
         if (this.tacticalPlanner == null)
         {
             // Tell the strategical planner to provide a tactical planner
             this.tacticalPlanner = this.strategicalPlanner.generateTacticalPlanner();
         }
         this.operationalPlan = this.tacticalPlanner.generateOperationalPlan(now, fromLocation);
         this.odometer = currentOdometer;
         if (getOperationalPlan().getAcceleration(Duration.ZERO).si < -10
                 && getOperationalPlan().getSpeed(Duration.ZERO).si > 2.5)
         {
             System.err.println("(getOperationalPlan().getAcceleration(Duration.ZERO).si < -10)");
             // this.tacticalPlanner.generateOperationalPlan(now, fromLocation);
         }
 
         if (ALIGNED && this.operationalPlan.getTotalDuration().si == 0.5)
         {
             // schedule the next move at exactly 0.5 seconds on the clock
             // store the event, so it can be cancelled in case the plan has to be interrupted and changed halfway
             double tNext = Math.floor(2.0 * now.si + 1.0) / 2.0;
             DirectedPoint p = (tNext - now.si < 0.5) ? this.operationalPlan.getEndLocation()
                     : this.operationalPlan.getLocation(new Duration(tNext - now.si, DurationUnit.SI));
             this.nextMoveEvent = new SimEvent<>(new OTSSimTimeDouble(new Time(tNext, TimeUnit.BASE)), this, this, "move",
                     new Object[] { p });
             ALIGN_COUNT++;
         }
         else
         {
             // schedule the next move at the end of the current operational plan
             // store the event, so it can be cancelled in case the plan has to be interrupted and changed halfway
             this.nextMoveEvent = new SimEvent<>(new OTSSimTimeDouble(now.plus(this.operationalPlan.getTotalDuration())), this,
                     this, "move", new Object[] { this.operationalPlan.getEndLocation() });
         }
         this.simulator.scheduleEvent(this.nextMoveEvent);
 
         fireTimedEvent(GTU.MOVE_EVENT,
                 new Object[] { getId(), fromLocation, getSpeed(), getAcceleration(), getTurnIndicatorStatus(), getOdometer() },
                 this.simulator.getSimulatorTime());
     }
 
     /**
      * Interrupt the move and ask for a new plan. This method can be overridden to carry out the bookkeeping needed when the
      * current plan gets interrupted.
      * @throws OperationalPlanException when there was a problem retrieving the location from the running plan
      * @throws SimRuntimeException when scheduling of the next move fails
      * @throws OperationalPlanException when there is a problem creating a good path for the GTU
      * @throws GTUException when there is a problem with the state of the GTU when planning a path
      * @throws NetworkException in case of a problem with the network, e.g., unreachability of a certain point
      * @throws ParameterException when there is a problem with a parameter
      */
     @SuppressWarnings("checkstyle:designforextension")
     protected void interruptMove()
             throws SimRuntimeException, OperationalPlanException, GTUException, NetworkException, ParameterException
     {
         this.simulator.cancelEvent(this.nextMoveEvent);
         move(this.operationalPlan.getLocation(this.simulator.getSimulatorTime().getTime()));
     }
 
     /** {@inheritDoc} */
     @Override
     public final String getId()
     {
         return this.id;
     }
 
     /** {@inheritDoc} */
     @SuppressWarnings("checkstyle:designforextension")
     @Override
     public GTUType getGTUType()
     {
         return this.gtuType;
     }
 
     /** {@inheritDoc} */
     @Override
     public final RelativePosition getReference()
     {
         return RelativePosition.REFERENCE_POSITION;
     }
 
     /**
      * @return simulator the simulator to schedule plan changes on
      */
     @Override
     public final OTSDEVSSimulatorInterface getSimulator()
     {
         return this.simulator;
     }
 
     /**
      * @return strategicalPlanner the planner responsible for the overall 'mission' of the GTU, usually indicating where it
      *         needs to go. It operates by instantiating tactical planners to do the work.
      */
     @Override
     @SuppressWarnings("checkstyle:designforextension")
     public StrategicalPlanner getStrategicalPlanner()
     {
         return this.strategicalPlanner;
     }
 
     /**
      * @return tacticalPlanner the tactical planner that can generate an operational plan
      */
     @Override
     @SuppressWarnings("checkstyle:designforextension")
     public TacticalPlanner getTacticalPlanner()
     {
         // TODO discuss when a new tactical planner may be needed
         if (null == this.tacticalPlanner)
         {
             this.tacticalPlanner = this.strategicalPlanner.generateTacticalPlanner();
         }
         return this.tacticalPlanner;
     }
 
     /**
      * @return operationalPlan the current operational plan, which provides a short-term movement over time
      */
     @Override
     public final OperationalPlan getOperationalPlan()
     {
         return this.operationalPlan;
     }
 
     /** {@inheritDoc} */
     @Override
     public final Length getOdometer()
     {
         if (this.operationalPlan == null)
         {
             return this.odometer;
         }
         try
         {
             return this.odometer.plus(this.operationalPlan.getTraveledDistance(this.simulator.getSimulatorTime().getTime()));
         }
         catch (OperationalPlanException ope)
         {
             return this.odometer;
         }
     }
 
     /** {@inheritDoc} */
     @Override
     public final Speed getSpeed()
     {
         if (this.operationalPlan == null)
         {
             return Speed.ZERO;
         }
         try
         {
             return this.operationalPlan.getSpeed(this.simulator.getSimulatorTime().getTime());
         }
         catch (OperationalPlanException ope)
         {
             // this should not happen at all...
             System.err.println("t = " + this.simulator.getSimulatorTime().getTime());
             System.err.println("op.validity = " + this.operationalPlan.getEndTime());
             throw new RuntimeException("getSpeed() could not derive a valid speed for the current operationalPlan", ope);
         }
     }
 
     /** {@inheritDoc} */
     @Override
     public final Acceleration getAcceleration()
     {
         if (this.operationalPlan == null)
         {
             return Acceleration.ZERO;
         }
         try
         {
             return this.operationalPlan.getAcceleration(this.simulator.getSimulatorTime().getTime());
         }
         catch (OperationalPlanException ope)
         {
             // this should not happen at all...
             throw new RuntimeException(
                     "getAcceleration() could not derive a valid acceleration for the current operationalPlan", ope);
         }
     }
 
     /**
      * @return maximumAcceleration
      */
     @Override
     public final Acceleration getMaximumAcceleration()
     {
         return this.maximumAcceleration;
     }
 
     /**
      * @param maximumAcceleration set maximumAcceleration
      */
     public final void setMaximumAcceleration(final Acceleration maximumAcceleration)
     {
         if (maximumAcceleration.le(Acceleration.ZERO))
         {
             throw new RuntimeException("Maximum acceleration of GTU " + this.id + " set to value <= 0");
         }
         this.maximumAcceleration = maximumAcceleration;
     }
 
     /**
      * @return maximumDeceleration
      */
     @Override
     public final Acceleration getMaximumDeceleration()
     {
         return this.maximumDeceleration;
     }
 
     /**
      * @param maximumDeceleration set maximumDeceleration, stored as a negative number
      */
     public final void setMaximumDeceleration(final Acceleration maximumDeceleration)
     {
         if (maximumDeceleration.ge(Acceleration.ZERO))
         {
             throw new RuntimeException("Maximum deceleration of GTU " + this.id + " set to value >= 0");
         }
         this.maximumDeceleration = maximumDeceleration;
     }
 
     /** cache time. */
     private Time cacheLocationTime = new Time(Double.NaN, TimeUnit.BASE);
 
     /** caced position at time. */
     private DirectedPoint cacheLocation = null;
 
     /** {@inheritDoc} */
     @Override
     @SuppressWarnings("checkstyle:designforextension")
     public DirectedPoint getLocation()
     {
         if (this.operationalPlan == null)
         {
             System.err.println(
                     "No operational plan for GTU " + this.id + " at t=" + this.getSimulator().getSimulatorTime().getTime());
             return new DirectedPoint(0, 0, 0);
         }
         try
         {
             // cache
             if (this.cacheLocationTime.si != this.simulator.getSimulatorTime().getTime().si)
             {
                 this.cacheLocationTime = this.simulator.getSimulatorTime().getTime();
                 this.cacheLocation = this.operationalPlan.getLocation(this.cacheLocationTime);
             }
             return this.cacheLocation;
         }
         catch (OperationalPlanException exception)
         {
             return new DirectedPoint(0, 0, 0);
         }
     }
 
     /** {@inheritDoc} */
     @Override
     public final TurnIndicatorStatus getTurnIndicatorStatus()
     {
         return this.turnIndicatorStatus;
     }
 
     /** {@inheritDoc} */
     @Override
     public final void setTurnIndicatorStatus(final TurnIndicatorStatus turnIndicatorStatus)
     {
         this.turnIndicatorStatus = turnIndicatorStatus;
     }
 
     /** {@inheritDoc} */
     @Override
     @SuppressWarnings("checkstyle:designforextension")
     public Color getBaseColor()
     {
         if (this.baseColor == null)
         {
             this.baseColor = IDGTUColorer.LEGEND.get(this.uniqueNumber % IDGTUColorer.LEGEND.size()).getColor();
         }
         return this.baseColor;
     }
 
     /**
      * @return whether the GTU is destroyed, for the animation.
      */
     public final boolean isDestroyed()
     {
         return this.destroyed;
     }
 
     /**
      * @return perceivableContext
      */
     public final PerceivableContext getPerceivableContext()
     {
         return this.perceivableContext;
     }
 
     /** {@inheritDoc} */
     @Override
     @SuppressWarnings("designforextension")
     public int hashCode()
     {
         final int prime = 31;
         int result = 1;
         result = prime * result + ((this.id == null) ? 0 : this.id.hashCode());
         result = prime * result + this.uniqueNumber;
         return result;
     }
 
     /** {@inheritDoc} */
     @Override
     @SuppressWarnings({ "designforextension", "needbraces" })
     public boolean equals(final Object obj)
     {
         if (this == obj)
             return true;
         if (obj == null)
             return false;
         if (getClass() != obj.getClass())
             return false;
         AbstractGTU other = (AbstractGTU) obj;
         if (this.id == null)
         {
             if (other.id != null)
                 return false;
         }
         else if (!this.id.equals(other.id))
             return false;
         if (this.uniqueNumber != other.uniqueNumber)
             return false;
         return true;
     }
 
 }