/*
    * Licensed under the GPL License. You may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *   https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
    *
    * THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
    * WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
    * PURPOSE.
   */
  package psiprobe.controllers.threads;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  import java.util.TreeMap;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.catalina.Context;
  import org.springframework.beans.factory.annotation.Value;
  import org.springframework.stereotype.Controller;
  import org.springframework.web.bind.annotation.RequestMapping;
  import org.springframework.web.servlet.ModelAndView;
  
  import psiprobe.controllers.AbstractTomcatContainerController;
  import psiprobe.model.java.ThreadModel;
  import psiprobe.tools.Instruments;
  
  /**
   * The Class ListThreadsController.
   */
  @Controller
  public class ListThreadsController extends AbstractTomcatContainerController {
  
    @RequestMapping(path = "/th_impl1.htm")
    @Override
    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response)
        throws Exception {
      return super.handleRequest(request, response);
    }
  
    @Override
    protected ModelAndView handleRequestInternal(HttpServletRequest request,
        HttpServletResponse response) throws Exception {
  
      /*
       * Create a list of webapp classloaders. This will help us to associate threads with
       * applications.
       */
      List<Context> contexts = getContainerWrapper().getTomcatContainer().findContexts();
      Map<String, String> classLoaderMap = new TreeMap<>();
      for (Context context : contexts) {
        if (context.getLoader() != null && context.getLoader().getClassLoader() != null) {
          classLoaderMap.put(toUid(context.getLoader().getClassLoader()), context.getName());
        }
      }
  
      return new ModelAndView(getViewName(), "threads", enumerateThreads(classLoaderMap));
    }
  
    /**
     * Enumerate threads.
     *
     * @param classLoaderMap the class loader map
     *
     * @return the list
     */
    private List<ThreadModel> enumerateThreads(final Map<String, String> classLoaderMap) {
  
      // get top ThreadGroup
      ThreadGroup masterGroup = Thread.currentThread().getThreadGroup();
      while (masterGroup.getParent() != null) {
        masterGroup = masterGroup.getParent();
      }
  
      // enumerate all Threads starting from top
      List<ThreadModel> threadList = new ArrayList<>();
  
      Thread[] threads = new Thread[masterGroup.activeCount()];
      int numThreads = masterGroup.enumerate(threads);
  
      for (int i = 0; i < numThreads; i++) {
        ThreadModel threadModel = new ThreadModel();
        threadModel.setThreadClass(threads[i].getClass().getName());
        threadModel.setName(threads[i].getName());
        threadModel.setPriority(threads[i].getPriority());
        threadModel.setDaemon(threads[i].isDaemon());
        threadModel.setInterrupted(threads[i].isInterrupted());
        if (threads[i].getThreadGroup() != null) {
          threadModel.setGroupName(threads[i].getThreadGroup().getName());
        }
        Object target = Instruments.getField(threads[i], "target");
        if (target != null) {
          threadModel.setRunnableClassName(target.getClass().getName());
        }
  
        ClassLoader cl = threads[i].getContextClassLoader();
       if (cl != null) {
         if (classLoaderMap != null) {
           threadModel.setAppName(classLoaderMap.get(toUid(cl)));
         }
         threadModel.setClassLoader(toUid(cl));
       }
       threadList.add(threadModel);
     }
     return threadList;
   }
 
   /**
    * To uid.
    *
    * @param obj the obj
    *
    * @return the string
    */
   private static String toUid(Object obj) {
     return obj.getClass().getName() + "@" + obj.hashCode();
   }
 
   @Value("threads")
   @Override
   public void setViewName(String viewName) {
     super.setViewName(viewName);
   }
 
 }