/* 
 *	Jeti, a Java Jabber client, Copyright (C) 2007 E.S. de Boer  
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *	For questions, comments etc, 
 *	use the website at http://jeti.jabberstudio.org
 */

//created on Mar 11, 2007
package nu.fw.jeti.backend;

import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.net.URL;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.Attributes;
import org.xml.sax.helpers.DefaultHandler;

import nu.fw.jeti.events.DiscoveryListener;
import nu.fw.jeti.jabber.Backend;
import nu.fw.jeti.jabber.JID;
import nu.fw.jeti.jabber.elements.DiscoItem;
import nu.fw.jeti.jabber.elements.DiscoveryInfo;
import nu.fw.jeti.jabber.elements.DiscoveryItem;
import nu.fw.jeti.jabber.elements.IQDiscoInfo;
import nu.fw.jeti.jabber.elements.IQXCaps;
import nu.fw.jeti.jabber.handlers.IQDiscoInfoHandler;
import nu.fw.jeti.util.Log;
import nu.fw.jeti.util.PreferencesHandler;


public class CapabilitiesCache implements DiscoveryListener {
	private Map capabilities;
	private Map cache;
	private Backend backend;

	
	public CapabilitiesCache(Backend backend)
	{
		this.backend = backend;
		capabilities = new HashMap();
		cache = new HashMap();
	}
	
	public void setCapability(JID jid, IQXCaps caps){
		String cap = caps.getNode() + "#" + caps.getVer();
		addCap(jid, cap);
		if(caps.getExt() != null){
			String[] extensions = caps.getExt().split(" ");
			for (int i = 0; i < extensions.length; i++) {
				cap = caps.getNode() +"#"+ extensions[i];
				addCap(jid, cap);
			}
		}
	}

	private void addCap(JID jid, String cap) {
		if(cache.containsKey(cap)){
			getJIDCapabilities(jid).addCapabilities((IQDiscoInfo)cache.get(cap));
		}
		else {
			backend.getInfo(jid, cap, this);
		}
	}


	private Capabilities getJIDCapabilities(JID jid) {
		Capabilities jidCapabilities = null;
		if(capabilities.containsKey(jid)){
			jidCapabilities = (Capabilities) capabilities.get(jid);
		}
		else {
			jidCapabilities = new Capabilities();
			capabilities.put(jid,jidCapabilities);
		}
		return jidCapabilities;
	}
	
	public void discoveryInfoResult(JID jid, DiscoveryInfo info){
		if(!info.hasFeatures())return;
		IQDiscoInfo disco = (IQDiscoInfo)info;
		cache.put(disco.getNode(), disco);
		getJIDCapabilities(jid).addCapabilities(disco);
	}
	
	public void discoveryItemResult(JID jid, DiscoveryItem item){}
	
	
	/**
	 * Has JID jid capability capability
	 * @param jid
	 * @param capability
	 */
	public boolean hasCapability(JID jid, String capability){
		return getJIDCapabilities(jid).hasCapability(capability);
	}	
	
	public void save()
	{
		StringBuffer xml = new StringBuffer();
		xml.append("<?xml version='1.0'?>");
		xml.append("<queries>");
		for (Iterator iter = cache.values().iterator(); iter.hasNext();) {
			
			((IQDiscoInfo)iter.next()).appendToXML(xml);
			xml.append("\n");
		}
		xml.append("</queries>");
		System.out.println(xml.toString());
		try
		{
			BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(
					new FileOutputStream(Start.path + "capabilitiesCache.xml"), "UTF8"));
			writer.write(xml.toString());
			writer.close();
		}
		catch (IOException ex2)
		{
			ex2.printStackTrace();
		}
	}
	
	static class DiscoInfoHandler extends DefaultHandler
    {
         private Map queries;
         private IQDiscoInfoHandler discoHandler;
	
        public DiscoInfoHandler(Map queries)
        {
            this.queries = queries;
            discoHandler = new IQDiscoInfoHandler();
        }
	    
        public void startElement(String uri, String localName, String qName, Attributes attr) 
        {
        	if(qName.equals("queries")); //do nothing top level
        	else if(qName.equals("query"))	
            {
                discoHandler.startHandling(attr);
            }
            else discoHandler.startElement(qName, attr);
        }
        
        public void endElement(String uri, String localName, String qName){
        	if(qName.equals("query")){
	        	IQDiscoInfo info = (IQDiscoInfo) discoHandler.build();
	        	queries.put(info.getNode(),info);
        	}
        }
	}
	
}