/*
    * 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.util;
  
  import java.io.File;
  import java.util.Collections;
  import java.util.List;
  
  import org.apache.logging.log4j.core.config.Configuration;
  import org.apache.logging.log4j.core.config.ConfigurationListener;
  import org.apache.logging.log4j.core.config.Reconfigurable;
  
  /**
   *
   */
  public class WrappedFileWatcher extends AbstractWatcher implements FileWatcher {
  
      private final FileWatcher watcher;
      private volatile long lastModifiedMillis;
  
      public WrappedFileWatcher(FileWatcher watcher, final Configuration configuration,
          final Reconfigurable reconfigurable, final List<ConfigurationListener> configurationListeners,
          final long lastModifiedMillis) {
          super(configuration, reconfigurable, configurationListeners);
          this.watcher = watcher;
          this.lastModifiedMillis = lastModifiedMillis;
      }
  
  
      public WrappedFileWatcher(FileWatcher watcher) {
          super(null, null, null);
          this.watcher = watcher;
      }
  
      public long getLastModified() {
          return lastModifiedMillis;
      }
  
      @Override
      public void fileModified(File file) {
          watcher.fileModified(file);
      }
  
      @Override
      public boolean isModified() {
          long lastModified = getSource().getFile().lastModified();
          if (lastModifiedMillis != lastModified) {
              lastModifiedMillis = lastModified;
              return true;
          }
          return false;
      }
  
      @Override
      public List<ConfigurationListener> getListeners() {
          if (super.getListeners() != null) {
              return Collections.unmodifiableList(super.getListeners());
          } else {
              return null;
          }
      }
  
      @Override
      public void modified() {
          if (getListeners() != null) {
              super.modified();
          }
          fileModified(getSource().getFile());
          lastModifiedMillis = getSource().getFile().lastModified();
      }
  
      @Override
      public void watching(Source source) {
          lastModifiedMillis = source.getFile().lastModified();
          super.watching(source);
      }
  
      @Override
      public Watcher newWatcher(final Reconfigurable reconfigurable, final List<ConfigurationListener> listeners,
          long lastModifiedMillis) {
          WrappedFileWatcher watcher = new WrappedFileWatcher(this.watcher, getConfiguration(), reconfigurable, listeners,
              lastModifiedMillis);
          if (getSource() != null) {
              watcher.watching(getSource());
          }
         return watcher;
     }
 }