/* this belongs to the WebRaveler package */
package webraveler.vurl;

import java.util.*;


import webraveler.http.HTTPRequest;
import webraveler.http.HTTPResponse;
import webraveler.ravel.Raveler;
import webraveler.ravel.RavelerException;
import webraveler.ravel.RavelerUser;
/**
 * Changes the sequence in which plugins are executed for the given user
 *
 * @author The Web Raveler Development Squad
 * @version 1.0
 */
public class PluginSequenceVURL implements VURL {
	
	/**
	 *
	 */
	public PluginSequenceVURL () {
		
	} // PluginSequenceVURL()
	
	/**
	 * Updates the user's preferences to reflect the given changes in the sequence of plugins.  
	 * Returns a response indicating whether or not the update was successful
	 */
	public HTTPResponse resolveVURL(String username, String query, HTTPRequest request, Raveler ravel) {
		/* Parse the query */
		/* Get the total number of active plugins */
		String pluginNumString;
		int pluginNum;
		int length = query.length();
		pluginNumString = query.substring(length-1,length);
		pluginNum = Integer.parseInt(pluginNumString);
		int equalsIndex;
		int amperIndex=0;
		String pluginName;
		String seqString;
		int seqNum;
		boolean error=false;
		Vector modifiedPlugins = new Vector();
		modifiedPlugins.setSize(pluginNum);
		while ((equalsIndex = query.indexOf('=',amperIndex)) != -1) {
			/* Check if we are past the first part, if so increment the
			 * amperIndex so that we don't include the & in the pluginName */
			if (amperIndex != 0)
				amperIndex++;
			pluginName = query.substring(amperIndex,equalsIndex);
			/* Check if we are at the last part, if so, stop */
			if (pluginName.equals("pluginNum")) 
				break;
			amperIndex = query.indexOf('&',equalsIndex);
			seqString = query.substring(equalsIndex+1,amperIndex);
			seqNum = Integer.parseInt(seqString)-1;
			if (modifiedPlugins.elementAt(seqNum) == null) {
				modifiedPlugins.remove(seqNum);
				modifiedPlugins.insertElementAt(pluginName,seqNum);
			} else {
				System.out.println("Error: Multiple occurences of same sequence number");
				error=true;
				break;
			} //else
		} //while	
		UserConfigVURL userConfig = new UserConfigVURL();
		String message;
		if (error) {
			/* Generate error response */
			message = "<p class='message'>Error in Changing Plugins Sequence</p></body></html>";
		} else {
			/* Get the RavelerUser for the given username */
			RavelerUser user = new RavelerUser();
			try {
				user = ravel.getUser(username);
				/* Set the modified vector to the active plugins vector of the given user */
				user.activePlugins = modifiedPlugins;
				for (Enumeration f = modifiedPlugins.elements() ; f.hasMoreElements() ;) {
					String plugin = (String) f.nextElement();
					System.out.println("PluginSequenceVURL: plugin = '" + plugin + "'");
				} // for
				/* Generate response */
				message = "<p class='message'>The plugins sequence was changed</p>";
			} catch (RavelerException re) {
				message = "<p class='message'>"+re.getMessage()+"</p>";
			} //catch
		} //else
		userConfig.printMessage(message);
		HTTPResponse response = userConfig.resolveVURL(username,query,request,ravel);
		return response;	
	} // resolveVURL

} // class PluginSequenceVURL