/*
    * 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.logging.log4j.core.net;
  
  import java.io.OutputStream;
  import java.io.Serializable;
  import java.net.InetAddress;
  import java.net.UnknownHostException;
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.logging.log4j.core.Layout;
  import org.apache.logging.log4j.core.appender.ManagerFactory;
  import org.apache.logging.log4j.util.Strings;
  
  /**
   * Socket Manager for UDP connections.
   */
  public class DatagramSocketManager extends AbstractSocketManager {
  
      private static final DatagramSocketManagerFactory FACTORY = new DatagramSocketManagerFactory();
  
      /**
       * The Constructor.
       * @param name The unique name of the connection.
       * @param os The OutputStream.
       * @param inetAddress
       * @param host The host to connect to.
       * @param port The port on the host.
       * @param layout The layout
       */
      protected DatagramSocketManager(final String name, final OutputStream os, final InetAddress inetAddress, final String host,
                  final int port, final Layout<? extends Serializable> layout) {
          super(name, os, inetAddress, host, port, layout);
      }
  
      /**
       * Obtain a SocketManager.
       * @param host The host to connect to.
       * @param port The port on the host.
       * @param layout The layout.
       * @return A DatagramSocketManager.
       */
      public static DatagramSocketManager getSocketManager(final String host, final int port, final Layout<? extends Serializable> layout) {
          if (Strings.isEmpty(host)) {
              throw new IllegalArgumentException("A host name is required");
          }
          if (port <= 0) {
              throw new IllegalArgumentException("A port value is required");
          }
          return (DatagramSocketManager) getManager("UDP:" + host + ':' + port, new FactoryData(host, port, layout),
              FACTORY);
      }
  
      /**
       * Gets this DatagramSocketManager's content format. Specified by:
       * <ul>
       * <li>Key: "protocol" Value: "udp"</li>
       * <li>Key: "direction" Value: "out"</li>
       * </ul>
       * 
       * @return Map of content format keys supporting DatagramSocketManager
       */
      @Override
      public Map<String, String> getContentFormat() {
          final Map<String, String> result = new HashMap<String, String>(super.getContentFormat());
          result.put("protocol", "udp");
          result.put("direction", "out");
          return result;
      }
  
      /**
       * Data for the factory.
       */
      private static class FactoryData {
          private final String host;
          private final int port;
          private final Layout<? extends Serializable> layout;
  
          public FactoryData(final String host, final int port, final Layout<? extends Serializable> layout) {
              this.host = host;
              this.port = port;
              this.layout = layout;
          }
      }
 
     /**
      * Factory to create the DatagramSocketManager.
      */
     private static class DatagramSocketManagerFactory implements ManagerFactory<DatagramSocketManager, FactoryData> {
 
         @Override
         public DatagramSocketManager createManager(final String name, final FactoryData data) {
             InetAddress inetAddress;
             try {
                 inetAddress = InetAddress.getByName(data.host);
             } catch (final UnknownHostException ex) {
                 LOGGER.error("Could not find address of " + data.host, ex);
                 return null;
             }
             final OutputStream os = new DatagramOutputStream(data.host, data.port, data.layout.getHeader(),
                     data.layout.getFooter());
             return new DatagramSocketManager(name, os, inetAddress, data.host, data.port, data.layout);
         }
     }
 }