// ThreadStatFrame.java
// $Id: ThreadStatFrame.java,v 1.5 1998/03/18 10:13:38 bmahe Exp $
// (c) COPYRIGHT MIT and INRIA, 1996.
// Please first read the full copyright statement in file COPYRIGHT.html

package org.w3c.jigsaw.status ;

import java.util.Hashtable ;

import org.w3c.tools.resources.*;
import org.w3c.www.http.*;
import org.w3c.jigsaw.http.* ;
import org.w3c.jigsaw.frames.*;
import org.w3c.jigsaw.html.HtmlGenerator ;

/**
 * The server thread status.
 * This ought to be the client status, it will shortly (FIXME). It should uses
 * a two frame display, one listing the clients, and the other one listing per
 * client informations.
 * <p>By the Way, this uses the nasty refresh stuff from netscape. It should
 * perhaps be a servlet.
 */

public class ThreadStatFrame extends HTTPFrame {
  protected static Integer REFRESH_DEFAULT = new Integer(5) ;

  /**
   * Attribute index - Our refresh interval.
   */
  protected static int ATTR_REFRESH = -1 ;
    
  static {
    Attribute a   = null ;
    Class     cls = null ;
    try {
      cls = Class.forName("org.w3c.jigsaw.status.ThreadStatFrame");
    } catch (Exception ex) {
      ex.printStackTrace() ;
      System.exit(1) ;
    }
    // The refresh interval attribute:
    a = new IntegerAttribute("refresh"
			     , new Integer(5)
			     , Attribute.EDITABLE) ;
    ATTR_REFRESH = AttributeRegistry.registerAttribute(cls, a) ;
  }

  Runtime runtime = null ;

  public void registerResource(FramedResource resource) {
    super.registerOtherResource(resource);
  }

  /**
   * Dump the currenr threads into an HTML page.
   * @param request The request we are to reply to.
   */

  public Reply listThreads (Request request) {
    // enumerate all thread, and return a full thread listing:
    int    tcount   = Thread.activeCount() ;
    HtmlGenerator g = new HtmlGenerator ("Thread status") ;
    g.meta ("Refresh", getValue(ATTR_REFRESH, REFRESH_DEFAULT).toString());
    addStyleSheet(g);
    // Dump thread informations:
    Thread tarray[] = new Thread[tcount] ;
    Thread.enumerate (tarray) ;
    g.append ("<h1>Thread dump</h1>") ;
    g.append ("<ul>") ;
    String rname = getResource().getIdentifier();
    for (int i = 0 ; i < tcount ; i++) {
      String name = tarray[i].getName() ;
      g.append ("<li>"
		+ "<a href=\""+rname+"?" + name + "\">" + name + "</a>"
		+ (tarray[i].isDaemon() ? "D " : "  ")
		+ (tarray[i].isAlive()  ? "R " : "  ")) ;
    }
    g.append ("</ul>") ;
    // Dark features:
    g.append ("<p>To kill a thread, add a <b>?</b><em>thread-name</em> "
	      + "to the current URL.</p>") ;
    // Add global java process informations:
    g.append ("<h2>Misc informations</h2>") ;
    g.append ("<p>Total free memory: " + runtime.freeMemory());
    g.append ("<p>Toal memory      : " + runtime.totalMemory()) ;
    g.close() ;
    // Reply back:
    Reply  reply = request.makeReply(HTTP.OK) ;
    reply.setStream (g) ;
    return reply ;
  }

  protected Reply dumpThread (Request request) 
    throws HTTPException
  {
    // enumerate all thread, and return a full thread listing:
    int    tcount   = Thread.activeCount() ;
    Thread tarray[] = new Thread[tcount] ;
    Thread.enumerate (tarray) ;
    // Find ZE thread
    String tname   = request.getQueryString () ;
    Thread queried = null ;
    for (int i = 0 ; i < tcount ; i++) {
      if ( tarray[i].getName().equals (tname) ) {
	queried = tarray[i] ;
	break ;
      }
    }
    if ( queried == null ) {
      Reply reply = request.makeReply(HTTP.NOT_FOUND);
      reply.setContent ("Thread " + tname + " not found.") ;
      return reply ;
    } 
    // Default to killing the thread, which will trigger a stack dump:
    queried.stop () ;
    return listThreads (request) ;
  }
		
  /**
   * Get the threads.
   * If a search string is present, kill the indicated thread, otherwise
   * list the currently running threads.
   * @param request The request to handle.
   * @exception HTTPException If processing the request failed.
   */
     
  public Reply get (Request request) 
    throws HTTPException
  {
    if ( request.hasQueryString() ) {
      return dumpThread (request) ;
    } else {
      return listThreads (request) ;
    }
  }

  /**
   * Initialize the thread lister.
   * Just get a pointer to our runtime object.
   * @param values The default attribute values.
   */

  public void initialize(Object values[]) {
    super.initialize(values) ;
    runtime = Runtime.getRuntime() ;
  }
    
}