package org.simpleframework.demo.jmx;

import java.util.regex.Matcher;
import java.util.regex.Pattern;


public class WebPageParser implements WebPageParserMBean {

   private final WebObjectIntrospector introspector;
   private final WebConfiguration config;

   public WebPageParser(WebConfiguration config) {
      this(config, null);
   }

   public WebPageParser(WebConfiguration config, WebObjectIntrospector introspector) {
      this.introspector = introspector;
      this.config = config;
   }

   public String parsePage(String page) {
      if (introspector == null) {
         return page;
      }
      if (page == null) {
         return page;
      }
      return replaceData(page);
   }

   public String parseRequest(String request) {
      return null;
   }

   private String replaceData(String source) {
      String result = replaceColor(source);

      if (result != null) {
         return replaceForm(result);
      }
      return source;
   }

   private String replaceColor(String source) {
      String color = config.getColor();

      if (color != null) {
         return replaceMatch(source, ".*(<body).*", "<body bgcolor='" + color + "'");
      }
      return source;
   }

   private String replaceForm(String source) {
      String objectLink = buildObjectReference(source);

      if (objectLink != null) {
         return replaceMatch(source, ".*(<form.*\"/Admin.*Unregister&\".*?</form>).*", objectLink);
      }
      return source;
   }

   private String findObjectName(String source) {
      return findMatch(source, ".*<title>MBean View of .*name=(\\w+).*</title>.*");
   }

   private String findMatch(String source, String expression) {
      Pattern pattern = Pattern.compile(expression, Pattern.DOTALL | Pattern.MULTILINE | Pattern.CASE_INSENSITIVE);
      Matcher matcher = pattern.matcher(source);

      if (matcher.matches()) {
         return matcher.group(1);
      }
      return null;
   }

   private String replaceMatch(String source, String expression, String text) {
      String form = findMatch(source, expression);

      if (form != null) {
         return source.replaceFirst(form, text);
      }
      return source;
   }

   private String buildObjectReference(String source) {
      String objectLink = buildObjectLink(source);

      if (objectLink != null) {
         return String.format("<a href='%s'>Look Inside</a>", objectLink);
      }
      return null;
   }

   private String buildObjectLink(String source) {
      String objectName = findObjectName(source);

      try {
         if (objectName != null) {
            return introspector.getObjectLink(objectName);
         }
      } catch (Exception e) {
         return null;
      }
      return null;
   }
}