/*

  * This software is licensed under the Apache License, Version 2.0

  * (the "License") agreement; 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 net.admin4j.ui.servlets;

 import java.io.IOException;

 import java.util.ArrayList;

 import java.util.Arrays;

 import java.util.Collections;

 import java.util.HashMap;

 import java.util.List;

 import java.util.Map;

 import java.util.StringTokenizer;

 import javax.servlet.ServletConfig;

 import javax.servlet.ServletException;

 import javax.servlet.http.HttpServletRequest;

 import javax.servlet.http.HttpServletResponse;

 import net.admin4j.config.Admin4JConfiguration;

 import net.admin4j.deps.commons.beanutils.BeanComparator;

 import net.admin4j.deps.commons.collections.comparators.ComparatorChain;

 import net.admin4j.deps.commons.collections.comparators.ReverseComparator;

 import net.admin4j.deps.commons.lang3.StringUtils;

 import net.admin4j.entity.ExecutionPoint;

 import net.admin4j.hotspot.ExecutionTracker;

 import net.admin4j.hotspot.HotSpotUtils;

 import net.admin4j.util.ServletUtils;

 /**

  * Will display execution statistics and allow users to see programatic hot spots

  * in real time.

  * 

  * <p>Init parameters for this servlet are as follows:</p>

  * <li>sleep.interval.millis -- Optional.  Default 30000 (30 sec).  Amount of time in millis monitor will sleep between checks.</li>

  * @author D. Ashmore

  * @since 1.0

  */

 public class HotSpotDisplayServlet extends AdminDisplayServlet {

     private static final String DISPLAY_OPTION_TOP_50 = "Top 50";

     private static final String DISPLAY_OPTION_TOP_25 = "Top 25";

     private static final String DISPLAY_OPTION_TOP_10 = "Top 10";

     private static final String DISPLAY_OPTION_ALL = "All";

     private static final long serialVersionUID = 2757696314660986019L;

     public static final Integer DEFAULT_SLEEP_INTERGER_MILLIS=30000;

     private Integer sleepIntervalInMillis = DEFAULT_SLEEP_INTERGER_MILLIS;

     public static final String PUBLIC_HANDLE="hotSpot";

     /* (non-Javadoc)

      * @see javax.servlet.GenericServlet#init(javax.servlet.ServletConfig)

      */

     @Override

     public void init(ServletConfig config) throws ServletException {

         super.init(config);

         // Take the sleep interval meant specifically for HotSpot first.

         String sleepIntervalMillisStr = ServletUtils.getConfigurationSetting(

                 new String[]{PUBLIC_HANDLE + ".sleep.interval.millis", 

                         "sleep.interval.millis"}, config);

         if ( !StringUtils.isEmpty(sleepIntervalMillisStr) ) {

             try {

                 sleepIntervalInMillis = Integer.parseInt(sleepIntervalMillisStr);

             } catch (NumberFormatException e) {

                 this.logger.error("Invalid Sleep Interval provided.  Default used.  value="+sleepIntervalMillisStr, e);

                 sleepIntervalInMillis = DEFAULT_SLEEP_INTERGER_MILLIS;

             }

         }

         else if ( Admin4JConfiguration.getHotSpotSleepIntervalMillis() != null ) {

             sleepIntervalInMillis = Admin4JConfiguration.getHotSpotSleepIntervalMillis();

         }

         ExecutionTracker.startTracking(sleepIntervalInMillis);

     }

     @SuppressWarnings("unchecked")

     @Override

     protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

         if ( !StringUtils.isEmpty(request.getParameter("Reset"))) {

             ExecutionTracker.reset();

         }

         String selectedDisplayOption = DISPLAY_OPTION_ALL;

         if ( !StringUtils.isEmpty(request.getParameter("displayOption"))) {

             selectedDisplayOption = request.getParameter("displayOption");

         }

         Map<StackTraceElement, ExecutionPoint> fullExecutionMap = ExecutionTracker.getExecutionMap();

         Map<StackTraceElement, ExecutionPoint> executionMap = ExecutionTracker.getHotSpotMap();

         Map<StackTraceElement, ExecutionPoint> blockedExecutionMap = ExecutionTracker.getBlockedExecutionMap();

         displayHotSpotPage(request, response, selectedDisplayOption,

                 fullExecutionMap, executionMap, blockedExecutionMap);

     }

     protected void displayHotSpotPage(HttpServletRequest request,

             HttpServletResponse response, String selectedDisplayOption,

             Map<StackTraceElement, ExecutionPoint> fullExecutionMap,

             Map<StackTraceElement, ExecutionPoint> executionMap,

             Map<StackTraceElement, ExecutionPoint> blockedExecutionMap)

             throws IOException {

         ExecutionPoint displayedExecutionPoint = null;

         if ( !StringUtils.isEmpty(request.getParameter("DisplayClass"))) {

             StringTokenizer epStrTok = new StringTokenizer(request.getParameter("DisplayClass"), ":");

             String className = epStrTok.nextToken();

             String methodName = epStrTok.nextToken();

             String fileName = epStrTok.nextToken();

             displayedExecutionPoint = fullExecutionMap.get(new StackTraceElement(className, methodName, fileName, 0));

         }

         List<String> displayOptionList = new ArrayList<String>();

         displayOptionList.add(DISPLAY_OPTION_ALL);

         displayOptionList.add(DISPLAY_OPTION_TOP_10);

         displayOptionList.add(DISPLAY_OPTION_TOP_25);

         displayOptionList.add(DISPLAY_OPTION_TOP_50);

         List<ExecutionPoint> pointList = new ArrayList<ExecutionPoint>();

         pointList.addAll(executionMap.values());

         ComparatorChain comparator = new ComparatorChain();

         comparator.addComparator(new ReverseComparator(new BeanComparator("nbrExecutions")));

         comparator.addComparator(new BeanComparator("stackTraceElement.className"));

         comparator.addComparator(new BeanComparator("stackTraceElement.methodName"));

         comparator.addComparator(new BeanComparator("stackTraceElement.lineNumber"));

         Collections.sort(pointList, comparator);

         if ( !selectedDisplayOption.equals(DISPLAY_OPTION_ALL)) {

             int top = 50;

             if (selectedDisplayOption.equals(DISPLAY_OPTION_TOP_25)) {

                 top = 25;

             }

             if (selectedDisplayOption.equals(DISPLAY_OPTION_TOP_10)) {

                 top = 10;

             }

             while (pointList.size() > top) {

                 pointList.remove(top);

             }

         }

         List<ExecutionPoint> blockedPointList = new ArrayList<ExecutionPoint>();

         blockedPointList.addAll(blockedExecutionMap.values());

         comparator = new ComparatorChain();

         comparator.addComparator(new ReverseComparator(new BeanComparator("nbrBlockedExecutions")));

         comparator.addComparator(new BeanComparator("stackTraceElement.className"));

         comparator.addComparator(new BeanComparator("stackTraceElement.methodName"));

         comparator.addComparator(new BeanComparator("stackTraceElement.lineNumber"));

         Collections.sort(blockedPointList, comparator);

         Map<String,Object> variableMap = new HashMap<String,Object>();

         variableMap.put("displayOptionList", displayOptionList);

         variableMap.put("executionPointList", pointList);

         variableMap.put("blockedExecutionPointList", blockedPointList);

         if (displayedExecutionPoint != null) {

             variableMap.put("displayedExecutionPointList", Arrays.asList(displayedExecutionPoint));

         }

         variableMap.put("selectedDisplayOption", selectedDisplayOption);

         variableMap.put("hotSpotUtils", new HotSpotUtils(fullExecutionMap));

         displayFreeMarkerPage(request, response, "hotSpotServletDisplay.ftl", variableMap);

     }

     /* (non-Javadoc)

      * @see net.admin4j.ui.servlets.Admin4JServlet#getServletLabel()

      */

     @Override

     public String getServletLabel() {

         return "HotSpot Display";

     }

     /**

      * Just here to support unit testing.

      * @return

      */

     protected Integer getSleepIntervalInMillis() {

         return sleepIntervalInMillis;

     }

 }