/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2011, QOS.ch. All rights reserved.
    *
    * This program and the accompanying materials are dual-licensed under
    * either the terms of the Eclipse Public License v1.0 as published by
    * the Eclipse Foundation
    *
    *   or (per the licensee's choosing)
   *
   * under the terms of the GNU Lesser General Public License version 2.1
   * as published by the Free Software Foundation.
   */
  package ch.qos.logback.core.joran.spi;
  
  
  import ch.qos.logback.core.spi.ContextAwareBase;
  
  import java.io.File;
  import java.net.URL;
  import java.net.URLDecoder;
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * @author Ceki Gücü
   */
  public class ConfigurationWatchList extends ContextAwareBase {
  
    URL mainURL;
    List<File> fileWatchList = new ArrayList<File>();
    List<Long> lastModifiedList = new ArrayList<Long>();
  
    public void clear() {
      this.mainURL = null;
      lastModifiedList.clear();
      fileWatchList.clear();
    }
  
    /**
     * The mainURL for the configuration file. Null values are allowed.
     * @param mainURL
     */
    public void setMainURL(URL mainURL) {
      // main url can be null
      this.mainURL = mainURL;
      if (mainURL != null)
        addAsFileToWatch(mainURL);
    }
  
    private void addAsFileToWatch(URL url) {
      File file = convertToFile(url);
      if (file != null) {
        fileWatchList.add(file);
        lastModifiedList.add(file.lastModified());
      }
    }
  
    public void addToWatchList(URL url) {
      addAsFileToWatch(url);
    }
  
    public URL getMainURL() {
      return mainURL;
    }
  
    public List<File> getCopyOfFileWatchList() {
      return new ArrayList<File>(fileWatchList);
    }
  
    public boolean changeDetected() {
      int len = fileWatchList.size();
      for (int i = 0; i < len; i++) {
        long lastModified = lastModifiedList.get(i);
        File file = fileWatchList.get(i);
        if (lastModified != file.lastModified()) {
          return true;
        }
      }
      return false;
      //return (lastModified != fileToScan.lastModified() && lastModified != SENTINEL);
    }
  
    @SuppressWarnings("deprecation")
    File convertToFile(URL url) {
      String protocol = url.getProtocol();
      if ("file".equals(protocol)) {
        return new File(URLDecoder.decode(url.getFile()));
      } else {
        addInfo("URL [" + url + "] is not of type file");
        return null;
      }
    }
  
  }