/**
    * 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.hadoop.hbase.http.log;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.PrintWriter;
  import java.net.URL;
  import java.net.URLConnection;
  import java.util.regex.Pattern;
  
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.commons.logging.impl.Jdk14Logger;
  import org.apache.commons.logging.impl.Log4JLogger;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.classification.InterfaceStability;
  import org.apache.hadoop.hbase.http.HttpServer;
  import org.apache.hadoop.util.ServletUtil;
  
  /**
   * Change log level in runtime.
   */
  @InterfaceStability.Evolving
  public class LogLevel {
    public static final String USAGES = "\nUsage: General options are:\n"
        + "\t[-getlevel <host:httpPort> <name>]\n"
        + "\t[-setlevel <host:httpPort> <name> <level>]\n";
  
    /**
     * A command line implementation
     */
    public static void main(String[] args) {
      if (args.length == 3 && "-getlevel".equals(args[0])) {
        process("http://" + args[1] + "/logLevel?log=" + args[2]);
        return;
      }
      else if (args.length == 4 && "-setlevel".equals(args[0])) {
        process("http://" + args[1] + "/logLevel?log=" + args[2]
                + "&level=" + args[3]);
        return;
      }
  
      System.err.println(USAGES);
      System.exit(-1);
    }
  
    private static void process(String urlstring) {
      try {
        URL url = new URL(urlstring);
        System.out.println("Connecting to " + url);
        URLConnection connection = url.openConnection();
        connection.connect();
  
        BufferedReader in = new BufferedReader(new InputStreamReader(
            connection.getInputStream()));
        for(String line; (line = in.readLine()) != null; )
          if (line.startsWith(MARKER)) {
            System.out.println(TAG.matcher(line).replaceAll(""));
          }
        in.close();
      } catch (IOException ioe) {
        System.err.println("" + ioe);
      }
    }
  
    static final String MARKER = "<!-- OUTPUT -->";
    static final Pattern TAG = Pattern.compile("<[^>]*>");
  
    /**
     * A servlet implementation
     */
    @InterfaceAudience.LimitedPrivate({"HDFS", "MapReduce"})
    @InterfaceStability.Unstable
    public static class Servlet extends HttpServlet {
      private static final long serialVersionUID = 1L;
  
      @Override
     public void doGet(HttpServletRequest request, HttpServletResponse response
         ) throws ServletException, IOException {
 
       // Do the authorization
       if (!HttpServer.hasAdministratorAccess(getServletContext(), request,
           response)) {
         return;
       }
 
       PrintWriter out = ServletUtil.initHTML(response, "Log Level");
       String logName = ServletUtil.getParameter(request, "log");
       String level = ServletUtil.getParameter(request, "level");
 
       if (logName != null) {
         out.println("<br /><hr /><h3>Results</h3>");
         out.println(MARKER
             + "Submitted Log Name: <b>" + logName + "</b><br />");
 
         Log log = LogFactory.getLog(logName);
         out.println(MARKER
             + "Log Class: <b>" + log.getClass().getName() +"</b><br />");
         if (level != null) {
           out.println(MARKER + "Submitted Level: <b>" + level + "</b><br />");
         }
 
         if (log instanceof Log4JLogger) {
           process(((Log4JLogger)log).getLogger(), level, out);
         }
         else if (log instanceof Jdk14Logger) {
           process(((Jdk14Logger)log).getLogger(), level, out);
         }
         else {
           out.println("Sorry, " + log.getClass() + " not supported.<br />");
         }
       }
 
       out.println(FORMS);
       out.println(ServletUtil.HTML_TAIL);
     }
 
     static final String FORMS = "\n<br /><hr /><h3>Get / Set</h3>"
         + "\n<form>Log: <input type='text' size='50' name='log' /> "
         + "<input type='submit' value='Get Log Level' />"
         + "</form>"
         + "\n<form>Log: <input type='text' size='50' name='log' /> "
         + "Level: <input type='text' name='level' /> "
         + "<input type='submit' value='Set Log Level' />"
         + "</form>";
 
     private static void process(org.apache.log4j.Logger log, String level,
         PrintWriter out) throws IOException {
       if (level != null) {
         if (!level.equals(org.apache.log4j.Level.toLevel(level).toString())) {
           out.println(MARKER + "Bad level : <b>" + level + "</b><br />");
         } else {
           log.setLevel(org.apache.log4j.Level.toLevel(level));
           out.println(MARKER + "Setting Level to " + level + " ...<br />");
         }
       }
       out.println(MARKER
           + "Effective level: <b>" + log.getEffectiveLevel() + "</b><br />");
     }
 
     private static void process(java.util.logging.Logger log, String level,
         PrintWriter out) throws IOException {
       if (level != null) {
         log.setLevel(java.util.logging.Level.parse(level));
         out.println(MARKER + "Setting Level to " + level + " ...<br />");
       }
 
       java.util.logging.Level lev;
       for(; (lev = log.getLevel()) == null; log = log.getParent());
       out.println(MARKER + "Effective level: <b>" + lev + "</b><br />");
     }
   }
 }