/*
    * Copyright 2015 Apache Software Foundation.
    *
    * Licensed 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.lookup;
  
  import java.net.URI;
  import java.net.URISyntaxException;
  
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.LoggerContext;
  import org.apache.logging.log4j.core.config.plugins.Plugin;
  import org.apache.logging.log4j.core.impl.ContextAnchor;
  import org.apache.logging.log4j.status.StatusLogger;
  
  /**
   * Lookup properties of Log4j
   */
  @Plugin(name = "log4j", category = StrLookup.CATEGORY)
  public class Log4jLookup extends AbstractLookup {
  
      public final static String KEY_CONFIG_LOCATION = "configLocation";
      public final static String KEY_CONFIG_PARENT_LOCATION = "configParentLocation";
  
      private static final org.apache.logging.log4j.Logger LOGGER = StatusLogger.getLogger();
  
      private static String asPath(final URI uri) {
          if (uri.getScheme() == null || uri.getScheme().equals("file")) {
              return uri.getPath();
          }
          return uri.toString();
      }
  
      private static URI getParent(final URI uri) throws URISyntaxException {
          final String s = uri.toString();
          final int offset = s.lastIndexOf('/');
          if (offset > -1) {
              return new URI(s.substring(0, offset));
          }
          return new URI("../");
      }
  
      @Override
      public String lookup(final LogEvent event, final String key) {
          final LoggerContext ctx = ContextAnchor.THREAD_CONTEXT.get();
          if (ctx == null) {
              return null;
          }
  
          switch (key) {
          case KEY_CONFIG_LOCATION:
              return asPath(ctx.getConfigLocation());
  
          case KEY_CONFIG_PARENT_LOCATION:
              try {
                  return asPath(getParent(ctx.getConfigLocation()));
              } catch (final URISyntaxException use) {
                  LOGGER.error(use);
                  return null;
              }
  
          default:
              return null;
          }
      }
  }