/*
    * 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.config;
  
  import org.apache.logging.log4j.Level;
  import org.apache.logging.log4j.Logger;
  import org.apache.logging.log4j.core.Filter;
  import org.apache.logging.log4j.core.config.plugins.Plugin;
  import org.apache.logging.log4j.core.config.plugins.PluginAliases;
  import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
  import org.apache.logging.log4j.core.config.plugins.PluginElement;
  import org.apache.logging.log4j.core.config.plugins.PluginFactory;
  import org.apache.logging.log4j.status.StatusLogger;
  
  /**
   * An Appender reference.
   */
  @Plugin(name = "AppenderRef", category = Node.CATEGORY, printObject = true)
  @PluginAliases("appender-ref")
  public final class AppenderRef {
      private static final Logger LOGGER = StatusLogger.getLogger();
  
      private final String ref;
      private final Level level;
      private final Filter filter;
  
      private AppenderRef(final String ref, final Level level, final Filter filter) {
          this.ref = ref;
          this.level = level;
          this.filter = filter;
      }
  
      public String getRef() {
          return ref;
      }
  
      public Level getLevel() {
          return level;
      }
  
      public Filter getFilter() {
          return filter;
      }
  
      @Override
      public String toString() {
          return ref;
      }
  
      /**
       * Create an Appender reference.
       * @param ref The name of the Appender.
       * @param level The Level to filter against.
       * @param filter The filter(s) to use.
       * @return The name of the Appender.
       */
      @PluginFactory
      public static AppenderRef createAppenderRef(
              @PluginAttribute("ref") final String ref,
              @PluginAttribute("level") final Level level,
              @PluginElement("Filter") final Filter filter) {
  
          if (ref == null) {
              LOGGER.error("Appender references must contain a reference");
              return null;
          }
          return new AppenderRef(ref, level, filter);
      }
  }