package org.opentrafficsim.sim0mq.publisher;
   
   import org.djutils.exceptions.Throw;
   import org.djutils.metadata.MetaData;
   
   /**
    * Common code for most implementations of TranceiverInterface.
    * <p>
    * Copyright (c) 2020-2024 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
   * BSD-style license. See <a href="https://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
   * </p>
   * @author <a href="https://github.com/averbraeck">Alexander Verbraeck</a>
   * @author <a href="https://tudelft.nl/staff/p.knoppers-1">Peter Knoppers</a>
   * @author <a href="https://github.com/wjschakel">Wouter Schakel</a>
   */
  public abstract class AbstractTransceiver implements TransceiverInterface
  {
      /** The address field descriptors. */
      private final MetaData addressFields;
  
      /** The result field descriptors. */
      private final MetaData resultFields;
  
      /** The id of the AbstractTransceiver. */
      private final String id;
  
      /**
       * Construct a new AbstractTransceiver.
       * @param id String; the id of the new AbstractTransceiver
       * @param addressFields MetaData; description of the elements of an address that the <code>get</code> method of this
       *            AbstractTransceiver can handle
       * @param resultFields MetaData; description of the result of the <code>get</code> method
       */
      public AbstractTransceiver(final String id, final MetaData addressFields, final MetaData resultFields)
      {
          Throw.whenNull(id, "id may not be null");
          Throw.whenNull(addressFields, "addressFieldDescriptors may not be null");
          Throw.whenNull(resultFields, "resultFieldDescriptors may not be null");
          this.id = id;
          this.addressFields = addressFields;
          this.resultFields = resultFields;
      }
  
      /** {@inheritDoc} */
      @Override
      public final String getId()
      {
          return this.id;
      }
  
      /** {@inheritDoc} */
      @Override
      public final MetaData getAddressFields()
      {
          return this.addressFields;
      }
  
      /** {@inheritDoc} */
      @Override
      public final MetaData getResultFields()
      {
          return this.resultFields;
      }
  
      /**
       * Verify the composition of an Object[].
       * @param metaData MetaData; the expected composition
       * @param address Object[]; the object array that must be verified
       * @return String; null if metaData is OK; descriptive text on error
       */
      public static String verifyMetaData(final MetaData metaData, final Object[] address)
      {
          if (metaData.size() == 0 && (address == null || address.length == 0))
          {
              return null;
          }
          if (metaData.equals(MetaData.NO_META_DATA)) // anything goes
          {
              return null;
          }
          if (null == address)
          {
              return ("Address may not be null");
          }
          if (address.length != metaData.size())
          {
              return String.format("Address for %s has wrong length (expected %d address element%s, got %d address element%s)",
                      metaData.getName(), metaData.size(), metaData.size() != 1 ? "s" : "", address.length,
                      address.length != 1 ? "s" : "");
          }
          for (int index = 0; index < address.length; index++)
          {
              Object object = address[index];
              if ((null != object) && (!(metaData.getObjectClass(index).isAssignableFrom(object.getClass()))))
              {
                  return String.format("objectArray[%d] (%s) cannot be used for %s", index, address[index],
                          metaData.getObjectClass(index).getName());
              }
          }
         return null;
     }
 
     /** {@inheritDoc} */
     @Override
     public String toString()
     {
         return "AbstractTransceiver [id=" + this.id + ", addressFields=" + this.addressFields + ", resultFields="
                 + this.resultFields + "]";
     }
 
 }