/*
    * 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.plugins.visitors;
  
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.config.Configuration;
  import org.apache.logging.log4j.core.config.Node;
  import org.apache.logging.log4j.core.config.plugins.PluginValue;
  import org.apache.logging.log4j.util.StringBuilders;
  import org.apache.logging.log4j.util.Strings;
  
  /**
   * PluginVisitor implementation for {@link PluginValue}.
   */
  public class PluginValueVisitor extends AbstractPluginVisitor<PluginValue> {
      public PluginValueVisitor() {
          super(PluginValue.class);
      }
  
      @Override
      public Object visit(final Configuration configuration, final Node node, final LogEvent event,
              final StringBuilder log) {
          final String name = this.annotation.value();
          final String elementValue = node.getValue();
          final String attributeValue = node.getAttributes().get("value");
          String rawValue = null; // if neither is specified, return null (LOG4J2-1313)
          if (Strings.isNotEmpty(elementValue)) {
              if (Strings.isNotEmpty(attributeValue)) {
                  LOGGER.error("Configuration contains {} with both attribute value ({}) AND element" +
                                  " value ({}). Please specify only one value. Using the element value.",
                          node.getName(), attributeValue, elementValue);
              }
              rawValue = elementValue;
          } else {
              rawValue = removeAttributeValue(node.getAttributes(), "value");
          }
          final String value = this.substitutor.replace(event, rawValue);
          StringBuilders.appendKeyDqValue(log, name, value);
          return value;
      }
  }