package com.ecyrd.jspwiki.plugin;

import com.ecyrd.jspwiki.WikiContext;
import com.ecyrd.jspwiki.WikiPage;

import java.text.SimpleDateFormat;

import java.util.Date;
import java.util.Map;

/**
 * This simple plugin displays the date and time when the plugin was
 * last modified.
 *
 * Usage:
 * <PRE>
 *   [{INSERT DateModifiedPlugin}]
 * </PRE>
 *
 * Optional parameter: <b>format</b> - specifies the format to use
 * when stringinizing the date.
 *
 * @author <a href="mailto:vovansim@hotmail.com">vovan</a>
 * @version 1.0
 */
public class DateModifiedPlugin implements WikiPlugin {

  /**
   * The default date format, a-la CurrentTimePlugin.
   */
  public static final String DEFAULT_FORMAT = "HH:mm:ss dd-MMM-yyyy zzzz";

  /**
   * Executes the plugin and spits out the date as a result.
   *
   * @param context a <code>WikiContext</code> value
   * @param params a <code>Map</code> value
   * @return a <code>String</code> value
   * @exception PluginException if an error occurs
   */
  public String execute(WikiContext context, Map params)
	throws PluginException {

	//Get the format that we want to use for the date.
	String formatString = (String) params.get("format");

	//See if the parameter was present.
	if(formatString == null) {
	  formatString = DEFAULT_FORMAT;
	}

	try {
	  //Create a formatter for the date:
	  SimpleDateFormat fmt = new SimpleDateFormat(formatString);

	  //Get the date when the page was last modified:
	  Date d = context.getPage().getLastModified();

	  //Check that the date is actually present:
	  if (d == null) {
		return "Never";
	  } else {
		return fmt.format(d);
	  }
	}
	catch(IllegalArgumentException e) {
	  throw new PluginException("You specified bad format: " + e.getMessage());
	}
  }
}