package org.opentrafficsim.sim0mq.publisher;
   
   import org.djunits.Throw;
   import org.djutils.immutablecollections.ImmutableSet;
   import org.djutils.metadata.MetaData;
   import org.djutils.metadata.ObjectDescriptor;
   import org.djutils.serialization.SerializationException;
   import org.opentrafficsim.base.Identifiable;
   import org.opentrafficsim.core.network.OTSNetwork;
  import org.sim0mq.Sim0MQException;
  
  /**
   * Common code for id transceivers that use an empty address.
   * <p>
   * Copyright (c) 2020-2020 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>
   * @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 abstract class AbstractIdTransceiver extends AbstractTransceiver
  {
      /** The network. */
      private final OTSNetwork network;
  
      /**
       * Construct a GTUIdTransceiver.
       * @param network OTSNetwork; the OTS network
       * @param id String; name of the IdTransceiver
       */
      public AbstractIdTransceiver(final OTSNetwork network, final String id)
      {
          super(id, new MetaData("No address", "empty address", new ObjectDescriptor[0]),
                  new MetaData("No address", "empty address", new ObjectDescriptor[] { new ObjectDescriptor("String array",
                          "String array filled with all currently valid GTU ids", String[].class) }));
          Throw.whenNull(network, "Network may not be null");
          this.network = network;
      }
  
      /**
       * Retrieve the set of names of objects that can be individually subscribed to.
       * @return Set&lt;?&gt;; the set of names of objects whose that can be subscribed to. Each object in this set should
       *         implement <code>Identifiable</code>
       */
      abstract ImmutableSet<?> getSet();
  
      /** {@inheritDoc} */
      @Override
      public final Object[] get(final Object[] address, final ReturnWrapper returnWrapper)
              throws Sim0MQException, SerializationException
      {
          String bad = verifyMetaData(getAddressFields(), address);
          if (bad != null)
          {
              returnWrapper.nack(bad);
              return null;
          }
          ImmutableSet<?> set = getSet();
          Object[] result = new Object[set.size()];
          int nextIndex = 0;
          for (Object object : set)
          {
              result[nextIndex++] = ((Identifiable) object).getId();
          }
          return result;
      }
  
      /**
       * Retrieve the network.
       * @return OTSNetwork; the network
       */
      final OTSNetwork getNetwork()
      {
          return this.network;
      }
  
  }