/*
    * 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.monitoring.jmx;
  
  import java.io.BufferedReader;
  import java.io.File;
  import java.io.FileReader;
  import java.io.IOException;
  import java.io.InputStream;
  
  import org.springframework.util.StringUtils;
  
  import ch.elca.el4j.services.monitoring.notification.CoreNotificationHelper;
  
  /**
   * This MBean adds css information to a given html page.
   *
   * @svnLink $Revision: 4010 $;$Date: 2009-12-01 10:59:54 +0100 (Di, 01. Dez 2009) $;$Author: jonasha $;$URL: https://el4j.svn.sourceforge.net/svnroot/el4j/branches/el4j_3_1/el4j/framework/modules/jmx/src/main/java/ch/elca/el4j/services/monitoring/jmx/CssHtmlParser.java $
   *
   * @author Martin Zeltner (MZE)
   */
  public class CssHtmlParser implements CssHtmlParserMBean {
  	/**
  	 * Contains the stylesheet content to add to html page.
  	 */
  	private String m_stylesheetContent;
  	
  	/**
  	 * Constructor.
  	 *
  	 * @param stylesheetPath
  	 *            Is the path to the needed stylesheet.
  	 * @throws IOException
  	 *             If reading stylesheet makes trouble.
  	 */
  	public CssHtmlParser(String stylesheetPath) throws IOException {
  		StringBuffer sb = new StringBuffer();
  		
  		File stylesheetFile = new File(stylesheetPath);
  		if (stylesheetFile.exists()) {
  			BufferedReader br
  				= new BufferedReader(new FileReader(stylesheetFile));
  			String line = br.readLine();
  			while (StringUtils.hasLength(line)) {
  				sb.append(line);
  				line = br.readLine();
  			}
  			if (br != null) {
  				br.close();
  			}
  			
  		} else {
  			ClassLoader cl = Thread.currentThread().getContextClassLoader();
  			InputStream is = cl.getResourceAsStream(stylesheetPath);
  			if (is != null && is.available() > 0) {
  				int character;
  				while ((character = is.read()) != -1) {
  					sb.append((char) character);
  				}
  			} else {
  				CoreNotificationHelper.notifyMisconfiguration(
  					"Stylesheet '" + stylesheetPath + "' not found.");
  			}
  		}
  		
  		if (!StringUtils.hasText(sb.toString())) {
  			CoreNotificationHelper.notifyMisconfiguration(
  				"Stylesheet '" + stylesheetPath + "' has no content.");
  		}
  		
  		StringBuffer stylesheetContent = new StringBuffer();
  		stylesheetContent.append("<style type=\"text/css\"><!-- ");
  		stylesheetContent.append(sb.toString());
  		stylesheetContent.append(" --></style>");
  		m_stylesheetContent = stylesheetContent.toString();
  	}
  	
  	/**
  	 * {@inheritDoc}
  	 *
  	 * Asks which action should be done for the given request uri string. If
  	 * <code>null</code> is returned the underlying parser takes action.
  	 */
  	public String parseRequest(String s) {
 		return null;
 	}
 
 	/**
 	 * {@inheritDoc}
 	 *
 	 * Adds css content directly before the head end tag in html page. If no
 	 * head end tag exists, no css will be added. The lookup of the head end tag
 	 * is case insensitive.
 	 */
 	public String parsePage(String s) {
 		String answer = s;
 		if (StringUtils.hasText(s)) {
 			int insertionPoint = s.toLowerCase().indexOf("</head>");
 			if (insertionPoint > 0) {
 				StringBuffer sb = new StringBuffer();
 				sb.append(s.substring(0, insertionPoint));
 				sb.append(m_stylesheetContent);
 				sb.append(s.substring(insertionPoint));
 				answer = sb.toString();
 			}
 		}
 		return answer;
 	}
 }