/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership. The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License. You may obtain a copy of the License at
    * 
   *      http://www.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.river.discovery;
  
  import java.io.IOException;
  import java.util.Arrays;
  import net.jini.core.lookup.ServiceID;
  import net.jini.io.UnsupportedConstraintException;
  
  /**
   * Class representing the values in a multicast announcement.
   *
   * @author Sun Microsystems, Inc.
   * @since 2.0
   */
  public class MulticastAnnouncement {
  
      /** The announcement sequence number. */
      private final long sequenceNumber;
      /** The lookup service host. */
      private final String host;
      /** The lookup service listen port. */
      private final int port;
      /** The lookup service member groups. */
      private final String[] groups;
      /** The lookup service ID. */
      private final ServiceID serviceID;
  
      /**
       * Creates a new <code>MulticastAnnouncement</code> instance containing the
       * given values.  The <code>groups</code> array is copied; a
       * <code>null</code> value is considered equivalent to an empty array.
       *
       * @param sequenceNumber the announcement sequence number
       * @param host the lookup service host
       * @param port the lookup service listen port
       * @param groups the lookup service member groups
       * @param serviceID the lookup service ID
       * @throws NullPointerException if <code>host</code> or
       * <code>serviceID</code> is <code>null</code>, or if <code>groups</code>
       * contains <code>null</code>
       * @throws IllegalArgumentException if <code>port</code> is out of range
       */
      public MulticastAnnouncement(   long sequenceNumber,
  				    String host,
  				    int port,
  				    String[] groups,
  				    ServiceID serviceID)
      {
  	this(sequenceNumber, host, port, groups, serviceID,
  		check(host, port, groups, serviceID));
      }
      
      private static boolean check(String host,
  				 int port,
  				 String[] groups,
  				 ServiceID serviceID)
      {
  	groups = (groups != null) ? groups : new String[0];
  	if (host == null || 
  	    serviceID == null ||
  	    Arrays.asList(groups).contains(null))
  	{
  	    throw new NullPointerException();
  	}
  	if (port < 0 || port > 0xFFFF) {
  	    throw new IllegalArgumentException("port out of range: " + port);
  	}
  	return true;
      }
      
      private MulticastAnnouncement(  long sequenceNumber,
  				    String host,
  				    int port,
  				    String[] groups,
  				    ServiceID serviceID,
  				    boolean check)
      {
  	this.sequenceNumber = sequenceNumber;
  	this.host = host;
  	this.port = port;
  	this.groups = groups.clone();
  	this.serviceID = serviceID;
     }
 
     /**
      * Returns the announcement sequence number.
      *
      * @return the announcement sequence number
      */
     public long getSequenceNumber() {
 	return sequenceNumber;
     }
 
     /**
      * Returns the lookup service host name.
      *
      * @return the lookup service host name
      */
     public String getHost() {
 	return host;
     }
 
     /**
      * Returns the lookup service listen port.
      *
      * @return the lookup service listen port
      */
     public int getPort() {
 	return port;
     }
 
     /**
      * Returns the member groups of the lookup service.
      *
      * @return the member groups of the lookup service
      */
     public String[] getGroups() {
 	return groups.clone();
     }
 
     /**
      * Returns the service ID of the lookup service.
      *
      * @return the service ID of the lookup service
      */
     public ServiceID getServiceID() {
 	return serviceID;
     }
     
     /**
      * Checks if the constraints whose checking was delayed when this instance
      * was decoded, if any, are satisfied. If the instance was not decoded,
      * but directly constructed, this method does nothing.
      * @throws UnsupportedConstraintException if unable to satisfy the specified
      * constraints
      * @throws SecurityException if the given constraints cannot be satisfied
      * due to insufficient caller permissions
      * @throws IOException if an error occurs in interpreting the data
      */
     public void checkConstraints() throws IOException {
         // do nothing by default
     }
     
     /**
      * Returns a string representation of this announcement.
      *
      * @return a string representation of this announcement
      */
     @Override
     public String toString() {
 	StringBuilder sb = new StringBuilder(120);
 	sb.append("MulticastAnnouncement[").append(sequenceNumber).append(",")
 	    .append(host).append(":").append(port).append(",")
 	    .append(Arrays.asList(groups)).append(",")
 	    .append(serviceID).append("]");
 	return sb.toString();
     }
 }