/*
 * File    : TOTorrentXMLDeserialiser.java
 * Created : 14-Oct-2003
 * 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.torrent.impl;

/**
 * @author parg
 *
 */

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

import org.gudy.azureus2.core3.xml.simpleparser.*;

import org.gudy.azureus2.core3.torrent.*;
import org.gudy.azureus2.core3.util.*;
import org.gudy.azureus2.plugins.utils.xml.simpleparser.SimpleXMLParserDocument;
import org.gudy.azureus2.plugins.utils.xml.simpleparser.SimpleXMLParserDocumentAttribute;
import org.gudy.azureus2.plugins.utils.xml.simpleparser.SimpleXMLParserDocumentException;
import org.gudy.azureus2.plugins.utils.xml.simpleparser.SimpleXMLParserDocumentNode;

public class 
TOTorrentXMLDeserialiser 
{
	public
	TOTorrentXMLDeserialiser()
	{
	}
	
	public TOTorrent
	deserialise(
		File		file )
		
		throws TOTorrentException
	{
		try{
			
			SimpleXMLParserDocument	doc = SimpleXMLParserDocumentFactory.create( file );
			
			TOTorrent res = decodeRoot( doc );
					
			return( res );
						
		}catch( SimpleXMLParserDocumentException e ){
					
			throw( new TOTorrentException( "XML Parse Fails: " + e.getMessage(), TOTorrentException.RT_DECODE_FAILS ));
		}
	}
	
	protected TOTorrent
	decodeRoot(
		SimpleXMLParserDocument		doc )
		
		throws TOTorrentException
	{
		String root_name = doc.getName();
				
		if ( root_name.equalsIgnoreCase("TORRENT")){
			
			TOTorrentImpl	torrent = new TOTorrentImpl();
			
			SimpleXMLParserDocumentNode[] kids = doc.getChildren();
			
			URL		announce_url 					= null;
			
			byte[]	torrent_hash = null;
			
			for (int i=0;i<kids.length;i++){
				
				SimpleXMLParserDocumentNode	kid = kids[i];
				
				String	name = kid.getName();
				
				if ( name.equalsIgnoreCase( "ANNOUNCE_URL")){
					
					try{
					
						announce_url = new URL(kid.getValue());
						
					}catch( MalformedURLException e ){
				
						throw( new TOTorrentException( "ANNOUNCE_URL malformed", TOTorrentException.RT_DECODE_FAILS));
					}
					
				}else if ( name.equalsIgnoreCase( "ANNOUNCE_LIST")){
					
					SimpleXMLParserDocumentNode[]	set_nodes = kid.getChildren();
					
					TOTorrentAnnounceURLGroup group = torrent.getAnnounceURLGroup();
					
					TOTorrentAnnounceURLSet[]	sets = new TOTorrentAnnounceURLSet[set_nodes.length];
					
					for (int j=0;j<sets.length;j++){
						
						SimpleXMLParserDocumentNode[]	url_nodes = set_nodes[j].getChildren();
						
						URL[] urls = new URL[url_nodes.length];
						
						for (int k=0;k<urls.length;k++){
							
							try{
					
								urls[k] = new URL(url_nodes[k].getValue());
						
							}catch( MalformedURLException e ){
				
								throw( new TOTorrentException( "ANNOUNCE_LIST malformed", TOTorrentException.RT_DECODE_FAILS));
							}	
						}
						
						sets[j] = group.createAnnounceURLSet( urls );
					}
					
					group.setAnnounceURLSets( sets );
				
				}else if ( name.equalsIgnoreCase( "COMMENT")){
					
					torrent.setComment( readLocalisableString( kid ));
					
				}else if ( name.equalsIgnoreCase( "CREATED_BY")){
					
					torrent.setCreatedBy( readLocalisableString(kid));
					
				}else if ( name.equalsIgnoreCase( "CREATION_DATE")){
										
					torrent.setCreationDate( readGenericLong( kid ).longValue());
						
				}else if ( name.equalsIgnoreCase( "TORRENT_HASH")){
										
					torrent_hash	= readGenericBytes( kid );
						
				}else if ( name.equalsIgnoreCase( "INFO" )){
					
					decodeInfo( kid, torrent );
					
				}else{
					
					mapEntry entry = readGenericMapEntry( kid );
					
					torrent.addAdditionalProperty( entry.name, entry.value );
				}
			}

			if ( announce_url == null ){
				
				throw( new TOTorrentException( "ANNOUNCE_URL missing", TOTorrentException.RT_DECODE_FAILS));
			}
			
			torrent.setAnnounceURL( announce_url );
			
			if ( torrent_hash != null ){
			
				if ( !Arrays.equals( torrent.getHash(), torrent_hash )){
					
					throw( 	new TOTorrentException( "Hash differs - declared TORRENT_HASH and computed hash differ. If this really is the intent (unlikely) then remove the TORRENT_HASH element", 
							TOTorrentException.RT_DECODE_FAILS));
				}
			}
			
			return( torrent );
		}else{
			
			throw( new TOTorrentException( "Invalid root element", TOTorrentException.RT_DECODE_FAILS));
		}
	}
	
	protected void
	decodeInfo(
		SimpleXMLParserDocumentNode		doc,
		TOTorrentImpl					torrent )
		
		throws TOTorrentException
	{
		SimpleXMLParserDocumentNode[] kids = doc.getChildren();
			
		byte[]	torrent_name 	= null;
		long	torrent_length	= 0;
				
		SimpleXMLParserDocumentNode[] file_nodes	= null;

		for (int i=0;i<kids.length;i++){
			
			SimpleXMLParserDocumentNode	kid = kids[i];
				
			String	name = kid.getName();
								
			if ( name.equalsIgnoreCase( "PIECE_LENGTH")){
				
				torrent.setPieceLength( readGenericLong( kid ).longValue());
					
			}else if ( name.equalsIgnoreCase( "LENGTH")){
	
				torrent.setSimpleTorrent( true );
				
				torrent_length =  readGenericLong( kid ).longValue();
				
			}else if ( name.equalsIgnoreCase( "NAME")){
				
				torrent.setName( readLocalisableString( kid ));
				
			}else if ( name.equalsIgnoreCase( "FILES" )){
				
				torrent.setSimpleTorrent( false );
				
				file_nodes = kid.getChildren();
					
			}else if ( name.equalsIgnoreCase( "PIECES" )){
	
				SimpleXMLParserDocumentNode[]	piece_nodes = kid.getChildren();
				
				byte[][]	pieces = new byte[piece_nodes.length][];
				
				for (int j=0;j<pieces.length;j++){
					
					pieces[j] = readGenericBytes( piece_nodes[j] );			
				}
				
				torrent.setPieces( pieces );
				
			}else{
				
				mapEntry entry = readGenericMapEntry( kid );
					
				torrent.addAdditionalInfoProperty( entry.name, entry.value );
			}
		}
		
		if ( torrent.isSimpleTorrent()){
	
			torrent.setFiles( 
				new TOTorrentFileImpl[]{ 
						new TOTorrentFileImpl( 	torrent, 
												0,
												torrent_length,
												new byte[][]{ torrent.getName()})});
		}else{
			
			TOTorrentFileImpl[]	files = new TOTorrentFileImpl[ file_nodes.length ];
			
			long	offset = 0;
			
			for (int j=0;j<files.length;j++){
				
				SimpleXMLParserDocumentNode	file_node = file_nodes[j];
				
				SimpleXMLParserDocumentNode[]	file_entries = file_node.getChildren();
				
				long		file_length	= 0;
				
				boolean		length_entry_found	= false;
				
				byte[][]	path_comps	= null;
				
				Vector	additional_props	= new Vector();
				
				for ( int k=0;k<file_entries.length;k++){
					
					SimpleXMLParserDocumentNode	file_entry = file_entries[k];
					
					String	entry_name = file_entry.getName();
					
					if ( entry_name.equalsIgnoreCase( "LENGTH" )){
				
						file_length = readGenericLong(file_entry).longValue();
				
						length_entry_found = true;
						
					}else if ( entry_name.equalsIgnoreCase( "PATH" )){
						
						SimpleXMLParserDocumentNode[]	path_nodes = file_entry.getChildren();
						
						path_comps = new byte[path_nodes.length][];
						
						for (int n=0;n<path_nodes.length;n++){
							
							path_comps[n] = readLocalisableString( path_nodes[n] );
						}
					}else{
						
						additional_props.addElement( readGenericMapEntry( file_entry ));
					}
				}
				
				if ( (!length_entry_found) || path_comps == null ){

					throw( new TOTorrentException( "FILE element invalid (file length = " + file_length + ")", TOTorrentException.RT_DECODE_FAILS));
				
				}
				
				files[j] = new TOTorrentFileImpl( torrent, offset, file_length, path_comps );
				
				offset += file_length;
				
				for (int k=0;k<additional_props.size();k++){
					
					mapEntry	entry = (mapEntry)additional_props.elementAt(k);
					
					files[j].setAdditionalProperty( entry.name, entry.value );
				}
				
			}
			
			torrent.setFiles( files );
		}
	}
	
	protected mapEntry
	readGenericMapEntry(
		SimpleXMLParserDocumentNode		node ) 
		
		throws TOTorrentException
	{
		if ( !node.getName().equalsIgnoreCase("KEY")){
			
			throw( new TOTorrentException( "Additional property invalid, must be KEY node", TOTorrentException.RT_DECODE_FAILS));				
		}
		
		String 	name = node.getAttribute("name").getValue();
				
		SimpleXMLParserDocumentNode[]	kids = node.getChildren();
		
		if ( kids.length != 1 ){
		
			throw( new TOTorrentException( "Additional property invalid, KEY must have one child", TOTorrentException.RT_DECODE_FAILS));				
		}
		
		String	type = kids[0].getName();
		
		Object  value = readGenericValue( kids[0] );
		
		return( new mapEntry( name, value ));
	}

	protected Object
	readGenericValue(
		SimpleXMLParserDocumentNode	node )
		
		throws TOTorrentException
	{
		String	name = node.getName();
		
		if ( name.equalsIgnoreCase( "BYTES")){
			
			return( readGenericBytes( node ));
					
		}else if ( name.equalsIgnoreCase( "LONG" )){
					
			return( readGenericLong( node ));
					
		}else if ( name.equalsIgnoreCase( "LIST" )){
					
			return( readGenericList( node ));
					
		}else if ( name.equalsIgnoreCase( "MAP" )){
					
			return( readGenericMap( node ));
					
		}else{
					
			throw( new TOTorrentException( "Additional property invalid, sub-key '" + name + "' not recognised", TOTorrentException.RT_DECODE_FAILS));				
		}
	}
	
	protected byte[]
	readGenericBytes(
		SimpleXMLParserDocumentNode node )
		
		throws TOTorrentException
	{
		String value = node.getValue();
		
		byte[]	res = new byte[value.length()/2];
		
		for (int i=0;i<res.length;i++){
			
			res[i] = (byte)Integer.parseInt( value.substring(i*2,i*2+2), 16 );
			
		}
		
		return( res );
		/*
		try{
				
			return( URLDecoder.decode( node.getValue(), Constants.BYTE_ENCODING ).getBytes( Constants.BYTE_ENCODING ));
				
		}catch( UnsupportedEncodingException e ){

			throw( new TOTorrentException( "bytes invalid - unsupported encoding", TOTorrentException.RT_DECODE_FAILS));				
		}
		*/
	}
	
	protected Long
	readGenericLong(
		SimpleXMLParserDocumentNode node )
		
		throws TOTorrentException
	{
		String	value = node.getValue();
		
		try{
			
			return( new Long( value ));
			
		}catch( Throwable e ){
		
			throw( new TOTorrentException( "long value invalid for '" + node.getName() + "'", TOTorrentException.RT_DECODE_FAILS));				
		}
	}
	
	protected Map
	readGenericMap(
		SimpleXMLParserDocumentNode node )
		
		throws TOTorrentException
	{
		Map res = new HashMap();
		
		SimpleXMLParserDocumentNode[]	kids = node.getChildren();
		
		for (int i=0;i<kids.length;i++){
			
			mapEntry	entry = readGenericMapEntry( kids[i] );
			
			res.put( entry.name, entry.value );
		}
		
		return( res );
	}
	
	protected byte[]
	readLocalisableString(
		SimpleXMLParserDocumentNode	kid )
		
		throws TOTorrentException
	{
		SimpleXMLParserDocumentAttribute attr = kid.getAttribute("encoding");
		
		if ( attr == null || attr.getValue().equalsIgnoreCase("bytes")){
		
			return( readGenericBytes( kid ));
		}
		
		try{
		
			return( kid.getValue().getBytes( Constants.DEFAULT_ENCODING ));
			
		}catch( UnsupportedEncodingException e ){

			throw( new TOTorrentException( "bytes invalid - unsupported encoding", TOTorrentException.RT_DECODE_FAILS));				
		}	
	}
	
	protected List
	readGenericList(
		SimpleXMLParserDocumentNode node )
		
		throws TOTorrentException
	{
		List res = new ArrayList();
		
		SimpleXMLParserDocumentNode[]	kids = node.getChildren();
		
		for (int i=0;i<kids.length;i++){
			
			res.add( readGenericValue( kids[i]));
		}
		
		return( res );
	}
	
	protected class
	mapEntry
	{
		String		name;
		Object		value;
		
		mapEntry(
			String	_name,
			Object	_value )
		{
			name	= _name;
			value	= _value;
		}
	}
}
