/*
 * File    : TRTrackerClientUtils.java
 * Created : 29-Feb-2004
 * By      : parg
 * 
 * Azureus - a Java Bittorrent client
 *
 * 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.
 *
 * 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 ( see the LICENSE file ).
 *
 * 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
 */

package org.gudy.azureus2.core3.tracker.util;

/**
 * @author parg
 *
 */

import java.util.*;
import java.net.*;
import java.io.*;

import org.gudy.azureus2.core3.config.*;
import org.gudy.azureus2.core3.tracker.client.impl.TRTrackerAnnouncerImpl;
import org.gudy.azureus2.core3.tracker.client.impl.bt.TRTrackerBTAnnouncerImpl;
import org.gudy.azureus2.core3.tracker.host.TRHost;
import org.gudy.azureus2.core3.util.AENetworkClassifier;
import org.gudy.azureus2.core3.util.AEThread2;
import org.gudy.azureus2.core3.util.Constants;
import org.gudy.azureus2.core3.util.Debug;
import org.gudy.azureus2.core3.util.SystemTime;
import org.gudy.azureus2.core3.util.UrlUtils;

import com.aelitis.azureus.core.networkmanager.admin.NetworkAdmin;
import com.aelitis.azureus.core.networkmanager.admin.NetworkAdminPropertyChangeListener;
import com.aelitis.azureus.core.util.CopyOnWriteList;


public class 
TRTrackerUtils
{
	// author of MakeTorrent has requested we blacklist his site
	// as people keep embedding it as a tracker in torrents

	private static String[]	BLACKLISTED_HOSTS	=  
		{ "krypt.dyndns.org" };

	private static int[]		BLACKLISTED_PORTS	= 
		{ 81 };

	private static String			tracker_ip;
	private static Set<String>		tracker_ip_aliases;
	
	private static Map			override_map;
	
	private static String		bind_ip;
	
	private static String		ports_for_url;
	private static String		ports_for_url_with_crypto;
	
	private static CopyOnWriteList		listeners = new CopyOnWriteList();
	
	private static AEThread2		listener_thread;
	
	static{
		COConfigurationManager.addAndFireParameterListeners(
			new String[]
			{	"Proxy.Data.Enable",
				"Proxy.Data.SOCKS.inform",
				"TCP.Listen.Port.Override",
				"Tracker Client No Port Announce",
				"network.transport.encrypted.use.crypto.port",
				"network.transport.encrypted.require",
				"network.transport.encrypted.fallback.incoming",
				"TCP.Listen.Port",
				"UDP.Listen.Port",
				"HTTP.Data.Listen.Port",
				"HTTP.Data.Listen.Port.Override",
				"HTTP.Data.Listen.Port.Enable",
				"Tracker Client Min Announce Interval"
				},
			new ParameterListener()
			{
				public void 
				parameterChanged(
					String parameterName )
				{
					String	port 				= computePortsForURL( false, true );
			  		String 	port_with_crypto 	= computePortsForURL( true, false );
			  		
			  		if ( ports_for_url != null && ( !ports_for_url.equals( port ))){
			  			
			  			synchronized( listeners ){
			  				
			  					// back off for a bit to prevent multiple config changes from causing
			  					// multiple firings
			  				
			  				if ( listener_thread == null ){
			  					
			  					listener_thread = 
			  						new AEThread2( "TRTrackerUtils:listener", true )
			  						{
			  							public void
			  							run()
			  							{
			  								try{
			  									Thread.sleep(30000);
			  									
			  								}catch( Throwable e ){
			  								}
			  								
			  								synchronized( listeners ){
			  										
			  									listener_thread = null;
			  								}
			  								
			  								for (Iterator it=listeners.iterator();it.hasNext();){
			  									
			  									try{
			  										((TRTrackerUtilsListener)it.next()).announceDetailsChanged();
			  										
			  									}catch( Throwable e ){
			  										
			  										Debug.printStackTrace( e );
			  									}
			  								}
			  							}
			  						};
			  					
			  					listener_thread.start();
			  				}
			  			}
			  		}
			  		
			  		ports_for_url 				= port;
			  		ports_for_url_with_crypto	= port_with_crypto;
				}
			});
	}
			
	private static String
	computePortsForURL(
		boolean	force_crypto,
		boolean	allow_incoming )
	{
		boolean socks_peer_inform	= 	
			COConfigurationManager.getBooleanParameter("Proxy.Data.Enable")&&
			COConfigurationManager.getBooleanParameter("Proxy.Data.SOCKS.inform");
		
				// we currently don't support incoming connections when SOCKs proxying
		
		allow_incoming &= !COConfigurationManager.getBooleanParameter("Tracker Client No Port Announce");
  		
 		int	tcp_port_num;
 		int	udp_port_num;
 		  		
 		if ( allow_incoming ){
 			
	  		if ( socks_peer_inform ){
	  			
	  			tcp_port_num	= 0;
	  			udp_port_num	= 0;
	  		}else{
	  		
	 			tcp_port_num	= COConfigurationManager.getIntParameter( "TCP.Listen.Port" );
	 			udp_port_num	= COConfigurationManager.getIntParameter( "UDP.Listen.Port" );		
	  		}
	  		
	  		String portOverride = COConfigurationManager.getStringParameter("TCP.Listen.Port.Override");
	  		
	  		if(! portOverride.equals("")) {
	  		  
	  			try{
	  				tcp_port_num = Integer.parseInt( portOverride );
	  				
	  			}catch( Throwable e ){
	  				
	  				Debug.printStackTrace(e);
	  			}
	  		}
 		}else{
 			
  			tcp_port_num	= 0;
  			udp_port_num	= 0;
 		}
 		
 		String port = "";
 		
 		if ( force_crypto ){
 			
  			port += "&requirecrypto=1";

 			port += "&port=0&cryptoport=" + tcp_port_num;

 		}else{
 			
	 		boolean require_crypto = COConfigurationManager.getBooleanParameter( "network.transport.encrypted.require");
	 		
	   		if ( require_crypto ){
	  			
	  			port += "&requirecrypto=1";
	  			
	  		}else{
	  			
				port += "&supportcrypto=1"; 
	  		}
	 		  
	 		if ( 	require_crypto &&
	 				(!COConfigurationManager.getBooleanParameter( "network.transport.encrypted.fallback.incoming") ) &&
	 				COConfigurationManager.getBooleanParameter( "network.transport.encrypted.use.crypto.port" )){
	 			
	 			port += "&port=0&cryptoport=" + tcp_port_num;
	 			
	 		}else{
	 
	 			port += "&port=" + tcp_port_num;
	 		}
				
			port += "&azudp=" + udp_port_num;
	 		
	  		  	//  BitComet extension for no incoming connections
	  		
	  		if ( tcp_port_num == 0 ){
	  			
	  			port += "&hide=1";
	  		}	
	  			  		
	  		if ( COConfigurationManager.getBooleanParameter( "HTTP.Data.Listen.Port.Enable" )){
	  			
	  			int	http_port = COConfigurationManager.getIntParameter( "HTTP.Data.Listen.Port.Override" );
	  			
	  			if ( http_port == 0 ){
	  				
	  				http_port = COConfigurationManager.getIntParameter( "HTTP.Data.Listen.Port" );
	  			}
	  			
	  			port += "&azhttp=" + http_port;
	  		}
 		}
 		
 		return( port );
	}
	
	public static String
	getPublicIPOverride()
	{
	    String explicit_ips = COConfigurationManager.getStringParameter( "Override Ip", "" );
	    	    
	   	if ( explicit_ips.length() > 0 ){
	    				  			
			StringTokenizer	tok = new StringTokenizer( explicit_ips, ";" );
					
			while( tok.hasMoreTokens()){
				
				String	this_address = tok.nextToken().trim();
				
				if ( this_address.length() > 0 ){
					
					String	cat = AENetworkClassifier.categoriseAddress( this_address );
					
					if ( cat == AENetworkClassifier.AT_PUBLIC ){
						
						return( this_address );
					}
				}
			}
	   	}
	   	
	   	return( null );
	}
	
	private static Map	az_trackers = COConfigurationManager.getMapParameter( "Tracker Client AZ Instances", new HashMap());
	
	private static Map	udp_probe_results = COConfigurationManager.getMapParameter( "Tracker Client UDP Probe Results", new HashMap());


	static{
	
		COConfigurationManager.addListener(
			new COConfigurationListener()
			{
				public void
				configurationSaved()
				{
					readConfig();
				}
			});
		
		NetworkAdmin.getSingleton().addPropertyChangeListener(
		   	new NetworkAdminPropertyChangeListener()
		   	{
		   		public void
		   		propertyChanged(
		   			String		property )
		   		{
		   			if ( property == NetworkAdmin.PR_DEFAULT_BIND_ADDRESS ){
		   				
		   				readConfig();
		   			}
		   		}
		   	});
		 
		readConfig();
		
	
	}

	static void
	readConfig()
	{
		tracker_ip 	= COConfigurationManager.getStringParameter("Tracker IP", "");
	
		tracker_ip 	= UrlUtils.expandIPV6Host( tracker_ip );
		
		String	aliases = COConfigurationManager.getStringParameter("Tracker IP Aliases", "");
		
		if ( aliases.length() > 0 ){
			
			tracker_ip_aliases = new HashSet<String>();
			
			String[] bits = aliases.split(",");
			
			for (String b: bits ){
				
				b = b.trim();
				
				if ( b.length() > 0 ){
					
					tracker_ip_aliases.add( b );
				}
			}
		}else{
			
			tracker_ip_aliases = null;
		}
		
		String override_ips		= COConfigurationManager.getStringParameter("Override Ip", "");
		
		StringTokenizer	tok = new StringTokenizer( override_ips, ";" );
		
		Map	new_override_map = new HashMap();
		
		while( tok.hasMoreTokens()){
			
			String	ip = tok.nextToken().trim();
			
			if ( ip.length() > 0 ){
				
				new_override_map.put( AENetworkClassifier.categoriseAddress( ip ), ip );
			}
		}
		
		override_map	= new_override_map;
		
		InetAddress bad = NetworkAdmin.getSingleton().getSingleHomedServiceBindAddress();
		
		if ( bad == null || bad.isAnyLocalAddress()){
			
			bind_ip = "";
			
		}else{
		
			bind_ip = bad.getHostAddress();
		}
	}
	
	public static boolean
	isHosting(
		URL		url_in )
	{
		if ( tracker_ip.length() > 0  ){
			
			String host = UrlUtils.expandIPV6Host(url_in.getHost());
			
			boolean	result = host.equalsIgnoreCase( tracker_ip );
			
			if ( !result && tracker_ip_aliases != null ){
			
				result = tracker_ip_aliases.contains( host );
			}
		
			return( result );
			
		}else{
			
			return( false );
		}
	}
	
	public static String
	getTrackerIP()
	{
		return( tracker_ip );
	}
	
	public static boolean
	isTrackerEnabled()
	{
		return( getAnnounceURLs().length > 0 );
	}
	
	public static URL[][]
	getAnnounceURLs()
	{
		String	tracker_host = COConfigurationManager.getStringParameter( "Tracker IP", "" );

		List	urls = new ArrayList();
				
		if ( tracker_host.length() > 0 ){
			
			if ( COConfigurationManager.getBooleanParameter( "Tracker Port Enable")){
										
				int port = COConfigurationManager.getIntParameter("Tracker Port", TRHost.DEFAULT_PORT );
				
				try{
					List	l = new ArrayList();
					
					l.add( new URL( "http://" + UrlUtils.convertIPV6Host( tracker_host ) + ":" + port + "/announce" ));
					
					List	ports = stringToPorts( COConfigurationManager.getStringParameter("Tracker Port Backups" ));
					
					for (int i=0;i<ports.size();i++){
						
						l.add( new URL( "http://" + UrlUtils.convertIPV6Host( tracker_host ) + ":" + ((Integer)ports.get(i)).intValue() + "/announce" ));
					}

					urls.add( l );
					
				}catch( MalformedURLException e ){
					
					Debug.printStackTrace( e );
				}
			}
			
			if ( COConfigurationManager.getBooleanParameter( "Tracker Port SSL Enable")){
				
				int port = COConfigurationManager.getIntParameter("Tracker Port SSL", TRHost.DEFAULT_PORT_SSL );
				
				try{
					List	l = new ArrayList();
					
					l.add( new URL( "https://" + UrlUtils.convertIPV6Host( tracker_host ) + ":" + port + "/announce" ));
					
					List	ports = stringToPorts( COConfigurationManager.getStringParameter("Tracker Port SSL Backups" ));
					
					for (int i=0;i<ports.size();i++){
						
						l.add( new URL( "https://" + UrlUtils.convertIPV6Host( tracker_host ) + ":" + ((Integer)ports.get(i)).intValue() + "/announce" ));
					}

					urls.add( l );
					

				}catch( MalformedURLException e ){
				
					Debug.printStackTrace( e );
				}
			}
			
			if ( COConfigurationManager.getBooleanParameter( "Tracker Port UDP Enable" )){
				
				int port = COConfigurationManager.getIntParameter("Tracker Port", TRHost.DEFAULT_PORT );
				
				boolean	auth = COConfigurationManager.getBooleanParameter( "Tracker Password Enable Torrent" );
					
				try{
					List	l = new ArrayList();
					
					l.add( new URL( "udp://" + UrlUtils.convertIPV6Host( tracker_host ) + ":" + port + "/announce" +
										(auth?"?auth":"" )));
				
					urls.add( l );
					
				}catch( MalformedURLException e ){
				
					Debug.printStackTrace( e );
				}
			}
		}
		
		URL[][]	res = new URL[urls.size()][];
		
		for (int i=0;i<urls.size();i++){
			
			List	l = (List)urls.get(i);
			
			URL[]	u = new URL[l.size()];
			
			l.toArray( u );
			
			res[i] = u;
		}
				
		return( res );		
	}
	
	protected static List
	stringToPorts(
		String	str )
	{
		str = str.replace(',', ';' );
		
		StringTokenizer	tok = new StringTokenizer( str, ";" );
		
		List	res = new ArrayList();
		
		while( tok.hasMoreTokens()){
			
			try{
				res.add( new Integer( tok.nextToken().trim()));
				
			}catch( Throwable e ){
				
				Debug.out("Invalid port entry in '" + str + "'", e);
			}
		}
		
		return( res );
	}
	
	public static URL
	adjustURLForHosting(
		URL		url_in )
	{
		if ( isHosting( url_in )){
					
			String	url = url_in.getProtocol() + "://";
	
			if ( bind_ip.length() < 7 ){
					
					// TODO: this won't work in a pure IPv6 setup
				
				url += "127.0.0.1";
					
			}else{
					
				if ( bind_ip.contains( ":" )){
				
					url += "[" + bind_ip + "]";
					
				}else{
				      url += bind_ip;
				}
			}		
			
			int	port = url_in.getPort();
			
			if ( port != -1 ){
				
				url += ":" + url_in.getPort();
			}
			
			url += url_in.getPath();
			
			String query = url_in.getQuery();
			
			if ( query != null ){
				
				url += "?" + query;
			}
							
			try{
				return( new URL( url ));
				
			}catch( MalformedURLException e ){
				
				Debug.printStackTrace( e );
			}
		}
		
		return( url_in );
	}
	
	public static String
	adjustHostFromHosting(
		String		host_in )
	{
		if ( tracker_ip.length() > 0 ){
				
			String	address_type = AENetworkClassifier.categoriseAddress( host_in );
			
			String	target_ip = (String)override_map.get( address_type );
			
			if ( target_ip == null ){
				
				target_ip	= tracker_ip;
			}
			
			if ( isLoopback( host_in )){
								
				return( target_ip );
			}
		}
		
		return( host_in );
	}
	
	public static boolean
	isLoopback(
		String	host )
	{
		return( 
			host.equals( "127.0.0.1" ) || 
			host.equals( "0:0:0:0:0:0:0:1" ) || host.equals( "::1" ) ||  
			host.equals( bind_ip ));
	}
	
	
	public static void
	checkForBlacklistedURLs(
		URL		url )
	
		throws IOException
	{
		for (int i=0;i<BLACKLISTED_HOSTS.length;i++){
 			
 			if ( 	url.getHost().equalsIgnoreCase( BLACKLISTED_HOSTS[i] ) &&
 					url.getPort() == BLACKLISTED_PORTS[i] ){
 		
 				throw( new IOException( "http://" + BLACKLISTED_HOSTS[i] +
 						":" + BLACKLISTED_PORTS[i] + "/ is not a tracker" ));
 			}
 		}
	}
	
	public static Map
	mergeResponseCache(
		Map		map1,
		Map		map2 )
	{
		return( TRTrackerAnnouncerImpl.mergeResponseCache( map1, map2 ));
	}
		
 	public static String
	getPortsForURL()
  	{
  		return( ports_for_url );
  	}
 	
 	public static String
 	getPortsForURLFullCrypto()
 	{
 		return( ports_for_url_with_crypto );
 	}
 	
 	public static boolean
 	isAZTracker(
 		URL		tracker_url )
 	{
 		String	host = tracker_url.getHost();
 		
 		if ( Constants.isAzureusDomain( host )){
 			
 			return( true );
 		}
 		
 		synchronized( az_trackers ){
 	    	
 	    	return( az_trackers.containsKey( host + ":" + tracker_url.getPort()));
 	    }
 	}
 	
	public static void
 	setAZTracker(
 		URL		tracker_url,
 		boolean	az_tracker )
	{
		String	key = tracker_url.getHost() + ":" + tracker_url.getPort();
				
		synchronized( az_trackers ){
			
			boolean	changed = false;
			
			if ( az_trackers.get( key ) == null ){
			
				if ( az_tracker ){
					
					az_trackers.put( key, new Long( SystemTime.getCurrentTime()));
					
					changed	= true;
				}
			}else{
				
				if ( !az_tracker ){
					
					if ( az_trackers.remove( key ) != null ){
					
						changed = true;
					}
				}
			}
			
			if ( changed ){
				
				COConfigurationManager.setParameter( "Tracker Client AZ Instances", az_trackers );
			}
		}
	}
	
 	public static boolean
 	isUDPProbeOK(
 		URL		tracker_url )
 	{
 		String	host = tracker_url.getHost();
 		
 		if ( Constants.isAzureusDomain( host )){
 			
 			return( false );
 		}
 		
 		synchronized( udp_probe_results ){
 	    	
 	    	return( udp_probe_results.containsKey( host ));
 	    }
 	}
 	
	public static void
 	setUDPProbeResult(
 		URL			tracker_url,
 		boolean		probe_ok )
	{
		String	key = tracker_url.getHost();
				
		synchronized( udp_probe_results ){
			
			boolean	changed = false;
			
			if ( udp_probe_results.get( key ) == null ){
			
				if ( probe_ok ){
					
						// arbitrary max size here just in case something weird happens
					
					if ( udp_probe_results.size() > 512 ){
						
						udp_probe_results.clear();
					}
					
					udp_probe_results.put( key, new Long( SystemTime.getCurrentTime()));
					
					changed	= true;
				}
			}else{
				
				if ( !probe_ok ){
					
					if ( udp_probe_results.remove( key ) != null ){
					
						changed = true;
					}
				}
			}
			
			if ( changed ){
				
				COConfigurationManager.setParameter( "Tracker Client UDP Probe Results", udp_probe_results );
			}
		}
	}
	
	public static void
	addListener(
		TRTrackerUtilsListener	l )
	{
		listeners.add( l );
	}
	
	public static void
	removeListener(
		TRTrackerUtilsListener	l )
	{
		listeners.remove( l );
	}
}
