/* 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 user's prefences for the plugin
 *
 * @author The Web Raveler Development Squad
 * @version 1.0
 */
public class PluginChangePref implements VURL {
	String pluginName;
	Hashtable specialChars;
	
	/**
	 * Constructs a PluginChangePref given the name of the plugin
	 *
	 * @param pluginName a String containing the name of the plugin
	 */
	public PluginChangePref (String pluginName) {
		this.pluginName = pluginName;
		specialChars = new Hashtable();
		setupSpecialChars();
	} // PluginChangePref()
	
	/**
	 * Updates the user's preferences for the plugin
	 */
	public HTTPResponse resolveVURL(String username, String query, HTTPRequest request, Raveler ravel) {
		/* Generate response */
		String responseString = new String("");
		responseString += "<html><head>" + Raveler.ravelerCSS;
		responseString += "<title>"+pluginName+" Configuration</title></head><body>";
		responseString += "<p class='level1'>"+pluginName+" Configuration</p>";
		/* Get the RavelerUser associated with the given username */
		RavelerUser user = new RavelerUser();
		try {
			user = ravel.getUser(username);
			/* Parse query string */
			int equalsIndex;
			int amperIndex=0;
			String name;
			String value;
			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++;
				name = query.substring(amperIndex,equalsIndex);
				amperIndex = query.indexOf("&",equalsIndex);
				/* Check if we are at the last part, if so, set the amperIndex
				* to the length of the query */
				if (amperIndex == -1) 
					amperIndex = query.length();
				value = query.substring(equalsIndex+1,amperIndex);
				value = handleSpecialChars(value);
				user.modifyAttribute(pluginName,name,value);
			} // while
			responseString += "<p class='Message'>Preferences changed</p>";
		} catch (RavelerException re) {
			responseString += "<p class='message'>"+re.getMessage()+"</p>";
		}
		responseString += "</body></html>";
		return new HTTPResponse("HTTP/1.0",200,"OK",responseString.getBytes(),new Hashtable());	
	} // resolveVURL
	
	/** 
	 * Converts the encoded special characters in the query string to their original form
	 *
	 * @param value a string to be decoded
	 * @return a String with the decoded value
	 */
	public String handleSpecialChars(String value) {
		int percentIndex=0;
		while ((percentIndex= value.indexOf('%',percentIndex)) != -1) {
			String encod = value.substring(percentIndex,percentIndex+3);
			if (specialChars.containsKey(encod)) {
				String unencod = (String) specialChars.get(encod);
				value = value.substring(0,percentIndex)+unencod+value.substring(percentIndex+3,value.length());
			} //if
			percentIndex++;
		} //while
		/* Change all + to spaces */
		value = value.replace('+',' ');
		return value;
	} //handleSpecialChars(String)
	
	/**
	 * Sets up the hash table of special characters and their equivalent encoding
	 */
	public void setupSpecialChars() {
		/* Put the special characters and their encoding in hash */
		specialChars.put("%22"," ");
		specialChars.put("%5B","[");
		specialChars.put("%5D","]");
		specialChars.put("%7B","{");
		specialChars.put("%7D","}");
		specialChars.put("%26","&");
		specialChars.put("%3C","<");
		specialChars.put("%3E",">");
		specialChars.put("%2B","+");
		specialChars.put("%5C","\\");
		specialChars.put("%2F","/");
		specialChars.put("%28","(");
		specialChars.put("%29",")");
		specialChars.put("%3F","?");
		specialChars.put("%24","$");
		specialChars.put("%5E","^");
		specialChars.put("%25","%");
		specialChars.put("%3A",":");
		specialChars.put("%3D","=");
		specialChars.put("%21","!");
		specialChars.put("%40","@");
		specialChars.put("%23","#");
		specialChars.put("%3B",";");
		specialChars.put("%27","'");
		specialChars.put("%22","\"");
		specialChars.put("%2C",",");
		specialChars.put("%7E","~");
	}

} // class PluginChangePref