/*
    * EL4J, the Extension Library for the J2EE, adds incremental enhancements to
    * the spring framework, http://el4j.sf.net
    * Copyright (C) 2005 by ELCA Informatique SA, Av. de la Harpe 22-24,
    * 1000 Lausanne, Switzerland, http://www.elca.ch
    *
    * EL4J is published under the GNU Lesser General Public License (LGPL)
    * Version 2.1. See http://www.gnu.org/licenses/
    *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
   * GNU Lesser General Public License for more details.
   *
   * For alternative licensing, please contact info@elca.ch
   */
  
  package ch.elca.el4j.services.statistics.light;
  
  import java.text.MessageFormat;
  
  import javax.management.MBeanServer;
  import javax.management.ObjectName;
  
  import org.springframework.beans.factory.DisposableBean;
  import org.springframework.beans.factory.InitializingBean;
  
  import ch.elca.el4j.services.monitoring.jmx.display.DisplayManager;
  import ch.elca.el4j.services.monitoring.jmx.display.HtmlDisplayManager;
  import ch.elca.el4j.services.monitoring.jmx.display.HtmlTabulator;
  import ch.elca.el4j.services.monitoring.jmx.display.Section;
  
  import com.jamonapi.MonitorFactory;
  
  /**
   * This class is a JMX proxy for JAMon performance measurements.
   *
   * @svnLink $Revision: 3880 $;$Date: 2009-08-04 15:17:52 +0200 (Di, 04. Aug 2009) $;$Author: swismer $;$URL: https://el4j.svn.sourceforge.net/svnroot/el4j/branches/el4j_3_1/el4j/framework/modules/light_statistics/jmx/src/main/java/ch/elca/el4j/services/statistics/light/LightStatisticsReporter.java $
   *
   * @author Andreas Bur (ABU)
   */
  public class LightStatisticsReporter
  		implements LightStatisticsReporterMBean, InitializingBean,
  		DisposableBean {
  
  	/** The address that points to this class. */
  	public static final String NAME = "Performance:key=lightStatisticsReporter";
  	
  	/** The measurements' captions. */
  	private static String[] CAPTIONS = {
  		"Target", "Hits", "Avg",
  		"Total", "StdDev", "LastValue",
  		"Min", "Max", "Active",
  		"AvgActive", "MaxActive", "FirstAccess",
  		"LastAccess", "Enabled", "Primary", "HasListeners"
  	};
  	
  	
  	/** Foramt string used to render responses. */
  	private String m_formatString;
  	
  	/** The MBean server where this class is registered in. */
  	private MBeanServer m_server;
  	
  	/** Whether class names are printed fully qualified or not. */
  	private boolean m_fullyQualified = false;
  	
  	/**
  	 * {@inheritDoc}
  	 */
  	public String getFormatString() {
  		return m_formatString;
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void setFormatString(String formatString) {
  		this.m_formatString = formatString;
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public boolean isFullyQualified() {
  		return m_fullyQualified;
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void setFullyQualified(boolean fullyQualified) {
  		this.m_fullyQualified = fullyQualified;
  	}
  
  	/**
  	 * @return Retruns the MBean server instance where this instance is
  	 * retistered in.
  	 */
 	public MBeanServer getServer() {
 		return m_server;
 	}
 
 	/**
 	 * Sets the MBean server where this instance has to register.
 	 * @param beanServer The MBean server to set.
 	 */
 	public void setServer(MBeanServer beanServer) {
 		m_server = beanServer;
 	}
 	
 	/**
 	 * {@inheritDoc}
 	 */
 	public void resetMonitor() {
 		MonitorFactory.reset();
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	public void enableMonitor() {
 		MonitorFactory.setEnabled(true);
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	public void disableMonitor() {
 		MonitorFactory.setEnabled(false);
 	}
 	
 	/**
 	 * {@inheritDoc}
 	 */
 	public String[] getData() {
 		Object[][] dataAsObj = MonitorFactory.getRootMonitor().getBasicData();
 		
 		if (dataAsObj == null) {
 			return new String[]  {" "};
 		}
 		
 		// make simple conversion to String[][]
 		String[][] data;
 		data = new String[dataAsObj.length][];
 		for (int i = 0; i < dataAsObj.length; i++) {
 			String[] line = new String[dataAsObj[i].length];
 			for (int j = 0; j < dataAsObj[i].length; j++) {
 				line[j] = (dataAsObj[i][j]).toString();
 			}
 			data[i] = line;
 		}
 		
 		
 		String[] paddedCaptions = new String[CAPTIONS.length];
 		String[] result = new String[data.length + 1];
 		MessageFormat format = new MessageFormat(m_formatString);
 		
 		int[] lengths = prepareData(data);
 		
 		// pad header
 		for (int i = 0; i < CAPTIONS.length; i++) {
 			paddedCaptions[i] = padString(CAPTIONS[i], lengths[i]);
 		}
 		
 		// format header
 		result[0] = format.format(paddedCaptions);
 		
 		
 		if (data[0].length >= CAPTIONS.length) {
 			// pad data
 			for (int i = 0; i < data.length; i++) {
 				for (int j = 0; j < CAPTIONS.length; j++) {
 					data[i][j] = padString(data[i][j], lengths[j]);
 				}
 			}
 			
 			// format data
 			for (int i = 0; i < data.length; i++) {
 				result[i + 1] = format.format(data[i]);
 			}
 		}
 		
 		return result;
 	}
 	
 	/**
 	 * Converts class names, removes blank characters and computes the number
 	 * of chars in the widest line.
 	 * @param data The measurement data.
 	 * @return The number of chars in the widest row for each column of the
 	 * data.
 	 */
 	protected int[] prepareData(String[][] data) {
 		int[] lengths = new int[CAPTIONS.length];
 		
 		for (int i = 0; i < CAPTIONS.length; i++) {
 			lengths[i] = CAPTIONS[i].length();
 		}
 		
 		// no measurements taken
 		if (data[0].length == 1) {
 			return lengths;
 		}
 		
 		// convert class names
 		for (int j = 0; j < data.length; j++) {
 			data[j][0] = convertClassName(data[j][0]);
 			int len = data[j][0].length();
 			if (len > lengths[0]) {
 				lengths[0] = len;
 			}
 		}
 		
 		for (int i = 1; i < CAPTIONS.length; i++) {
 			for (int j = 0; j < data.length; j++) {
 				// remove &nbsp
 				data[j][i] = data[j][i].replaceAll("&nbsp", " ");
 				
 				// compute length
 				int len = data[j][i].length();
 				if (len > lengths[i]) {
 					lengths[i] = len;
 				}
 			}
 		}
 		return lengths;
 	}
 	
 	/**
 	 * Pads the given string to the requested lengths using <code>_</code>.
 	 * @param s The string to pad.
 	 * @param len The final length of the padded string.
 	 * @return The padded string.
 	 */
 	private String padString(String s, int len) {
 		StringBuffer buffer = new StringBuffer(s);
 		for (int i = s.length(); i < len; i++) {
 			buffer.append("_");
 		}
 		return buffer.toString();
 	}
 	
 	/**
 	 * Formats a class name in demanded representation, fully qualified or just
 	 * <code>ClassName.MethodName</code>.
 	 * @param className
 	 *      The fully qualified class name with method name appended.
 	 * @return The string in demanded representation.
 	 */
 	private String convertClassName(String className) {
 		if (m_fullyQualified) {
 			return className;
 			
 		} else {
 			int pos = className.lastIndexOf('.');
 			String fqClassName = className.substring(0, pos);
 			pos = fqClassName.lastIndexOf('.');
 			return className.substring(pos + 1);
 		}
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	public void afterPropertiesSet() throws Exception {
 		if (m_server == null) {
 			throw new IllegalStateException("m_beanServer has not been set!");
 		}
 		
 		m_server.registerMBean(this, new ObjectName(NAME));
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	public void destroy() throws Exception {
 		if (m_server != null) {
 			m_server.unregisterMBean(new ObjectName(NAME));
 		}
 	}
 	
 	/** {@inheritDoc} */
 	public String report() {
 		DisplayManager manager = new HtmlDisplayManager();
 		manager.setTitle("Light Statistics");
 		Section section = new Section("Light Statistics");
 		HtmlTabulator table = new HtmlTabulator(CAPTIONS);
 		Object[][] data = MonitorFactory.getRootMonitor().getBasicData();
 		
 		if (data == null) {
 			section.addWarning("No data.");
 			manager.addSection(section);
 			return manager.getPage();
 		}
 		
 		for (Object[] row : data) {
 			String[] thisRow = new String[row.length];
 			for (int i = 0; i < row.length; i++) {
 				thisRow[i] = row[i].toString();
 			}
 			table.addRow(thisRow);
 		}
 		section.add(table.tabulate());
 		manager.addSection(section);
 		
 		return manager.getPage();
 	}
 }