/*
 * File    : TorrentDownloader2Impl.java
 * Created : 27-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.pluginsimpl.local.utils.resourcedownloader;

/**
 * @author parg
 *
 */

import com.aelitis.azureus.core.util.Java15Utils;

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


import javax.net.ssl.*;
import java.net.PasswordAuthentication;
import java.util.Iterator;
import java.util.Map;
import java.util.zip.GZIPInputStream;
import java.util.zip.InflaterInputStream;
import java.util.zip.ZipException;

import org.gudy.azureus2.core3.util.AETemporaryFileHandler;
import org.gudy.azureus2.core3.util.AEThread2;
import org.gudy.azureus2.core3.util.AddressUtils;
import org.gudy.azureus2.core3.util.Constants;
import org.gudy.azureus2.core3.util.Debug;
import org.gudy.azureus2.core3.util.TorrentUtils;
import org.gudy.azureus2.core3.util.UrlUtils;
import org.gudy.azureus2.core3.internat.MessageText;
import org.gudy.azureus2.core3.security.*;
import org.gudy.azureus2.plugins.utils.resourcedownloader.*;

import com.aelitis.azureus.core.util.DeleteFileOnCloseInputStream;

public class 
ResourceDownloaderURLImpl
	extends 	ResourceDownloaderBaseImpl
	implements 	SEPasswordListener
{
	private static final int BUFFER_SIZE = 32768;
  
	private static final int MAX_IN_MEM_READ_SIZE	= 256*1024;
	
	protected URL			original_url;
	protected boolean		auth_supplied;
	protected String		user_name;
	protected String		password;
	
	protected InputStream 	input_stream;
	protected boolean		cancel_download	= false;
	
	protected boolean		download_initiated;
	protected long			size		 	= -2;	// -1 -> unknown
	
	protected boolean       force_no_proxy = false;

	private final String post_data;
	
	public 
	ResourceDownloaderURLImpl(
		ResourceDownloaderBaseImpl	_parent,
		URL							_url )
	{
		this( _parent, _url, false, null, null );
	}
	
	public 
	ResourceDownloaderURLImpl(
		ResourceDownloaderBaseImpl	_parent,
		URL							_url,
		String						_user_name,
		String						_password )
	{
		this( _parent, _url, true, _user_name, _password );
	}
	
	public 
	ResourceDownloaderURLImpl(
		ResourceDownloaderBaseImpl	_parent,
		URL							_url,
		boolean						_auth_supplied,
		String						_user_name,
		String						_password )
	{
		this(_parent, _url, null, _auth_supplied, _user_name, _password);
	}
	
	/**
	 * 
	 * @param _parent
	 * @param _url
	 * @param _data if null, GET will be used, otherwise POST will be used with
	 *              the data supplied
	 * @param _auth_supplied
	 * @param _user_name
	 * @param _password
	 */
	public 
	ResourceDownloaderURLImpl(
		ResourceDownloaderBaseImpl	_parent,
		URL							_url,
		String 						_data,
		boolean						_auth_supplied,
		String						_user_name,
		String						_password )
	{
		super( _parent );
		
		/*
		if ( _url.getHost().equals( "212.159.18.92")){
			try{
				_url = new URL(_url.getProtocol() + "://192.168.0.2:" + _url.getPort() + "/" + _url.getPath());
			}catch( Throwable e ){
				
				e.printStackTrace();
			}
		}
		*/
		
		original_url	= _url;
		post_data 		= _data;
		auth_supplied	= _auth_supplied;
		user_name		= _user_name;
		password		= _password;
	}
	
	protected void setForceNoProxy(boolean force_no_proxy) {
		this.force_no_proxy = force_no_proxy;
	}
	
	protected URL
	getURL()
	{
		return( original_url );
	}
	
	public String
	getName()
	{
		return( original_url.toString());
	}
	
	public long
	getSize()
	
		throws ResourceDownloaderException
	{
			// only every try getting the size once
		
		if ( size == -2 ){
			
			try{
				ResourceDownloaderURLImpl c = (ResourceDownloaderURLImpl)getClone( this );
				
				addReportListener( c );
				
				size = c.getSizeSupport();
				
				setProperties(  c );
				
			}finally{
				
				if ( size == -2 ){
					
					size = -1;
				}
			}
		}
		
		return( size );
	}
	
	protected void
	setSize(
		long	l )
	{
		size	= l;
	}
	
	public void
	setProperty(
		String	name,
		Object	value )
	
		throws ResourceDownloaderException
	{
		setPropertySupport( name, value );
	}
	
	protected long
	getSizeSupport()
	
		throws ResourceDownloaderException
	{
		// System.out.println("ResourceDownloader:getSize - " + getName());
		
		try{
			String	protocol = original_url.getProtocol().toLowerCase();
			
			if ( protocol.equals( "magnet" ) || protocol.equals( "dht" )){
				
				return( -1 );
			}
			
			reportActivity(this, "Getting size of " + original_url );

			try{
				URL	url = new URL( original_url.toString().replaceAll( " ", "%20" ));
			      
				url = AddressUtils.adjustURL( url );

				try{
					if ( auth_supplied ){
	
						SESecurityManager.setPasswordHandler( url, this );
					}
	
					for (int i=0;i<2;i++){
						
						try{
							HttpURLConnection	con;
							
							if ( url.getProtocol().equalsIgnoreCase("https")){
						      	
									// see ConfigurationChecker for SSL client defaults
				
								HttpsURLConnection ssl_con = (HttpsURLConnection)openConnection(url);
				
									// allow for certs that contain IP addresses rather than dns names
				  	
								ssl_con.setHostnameVerifier(
										new HostnameVerifier()
										{
											public boolean
											verify(
													String		host,
													SSLSession	session )
											{
												return( true );
											}
										});
				  	
								con = ssl_con;
				  	
							}else{
				  	
								con = (HttpURLConnection)openConnection(url);
				  	
							}
				  
							con.setRequestMethod( "HEAD" );
							
							con.setRequestProperty("User-Agent", Constants.AZUREUS_NAME + " " + Constants.AZUREUS_VERSION);     
				  
							setRequestProperties( con, false );
							
							con.connect();
				
							int response = con.getResponseCode();
							
							if ((response != HttpURLConnection.HTTP_ACCEPTED) && (response != HttpURLConnection.HTTP_OK)) {
								
								setProperty( "URL_HTTP_Response", new Long( response ));

								throw( new ResourceDownloaderException("Error on connect for '" + trimForDisplay( url ) + "': " + Integer.toString(response) + " " + con.getResponseMessage()));    
							}
															
							getRequestProperties( con );
							
							return( UrlUtils.getContentLength( con ));
							
						}catch( SSLException e ){
							
							if ( i == 0 ){
								
								if ( SESecurityManager.installServerCertificates( url ) != null ){
									
										// certificate has been installed
									
									continue;	// retry with new certificate
								}
							}

							throw( e );
							
						}catch( IOException e ){
							
							if ( i == 0 ){
								
					      		URL retry_url = UrlUtils.getIPV4Fallback( url );
				      			
					      		if ( retry_url != null ){
					      				
					      			url = retry_url;
					      			
					      			continue;
					      		}
							}
							
							throw( e );
						}
					}
					
					throw( new ResourceDownloaderException("Should never get here" ));

				}finally{
					
					if ( auth_supplied ){
					
						SESecurityManager.setPasswordHandler( url, null );
					}
				}
			}catch (java.net.MalformedURLException e){
				
				throw( new ResourceDownloaderException("Exception while parsing URL '" + original_url + "':" + e.getMessage(), e));
				
			}catch (java.net.UnknownHostException e){
				
				throw( new ResourceDownloaderException("Exception while initializing download of '" + trimForDisplay( original_url ) + "': Unknown Host '" + e.getMessage() + "'", e));
				
			}catch (java.io.IOException e ){
				
				throw( new ResourceDownloaderException("I/O Exception while downloading '" + trimForDisplay( original_url )+ "'", e ));
			}
		}catch( Throwable e ){
			
			ResourceDownloaderException	rde;
			
			if ( e instanceof ResourceDownloaderException ){
				
				rde = (ResourceDownloaderException)e;
				
			}else{
				
				Debug.out(e);
				
				rde = new ResourceDownloaderException( "Unexpected error", e );
			}
						
			throw( rde );
		}		
	}
	
	public ResourceDownloaderBaseImpl
	getClone(
		ResourceDownloaderBaseImpl	parent )
	{
		ResourceDownloaderURLImpl c = new ResourceDownloaderURLImpl( parent, original_url, post_data, auth_supplied, user_name, password );
		
		c.setSize( size );
		
		c.setProperties( this );
		c.setForceNoProxy(force_no_proxy);
		
		return( c );
	}

	public void
	asyncDownload()
	{
		final Object	parent_tls = TorrentUtils.getTLS();

		AEThread2	t = 
			new AEThread2( "ResourceDownloader:asyncDownload - " + trimForDisplay( original_url ), true )
			{
				public void
				run()
				{
					Object	child_tls = TorrentUtils.getTLS();
					
					TorrentUtils.setTLS( parent_tls );
					
					try{
						download();
						
					}catch ( ResourceDownloaderException e ){
						
					}finally{
						
						TorrentUtils.setTLS( child_tls );
					}
					
				}
			};
					
		t.start();
	}

	public InputStream
	download()
	
		throws ResourceDownloaderException
	{
		// System.out.println("ResourceDownloader:download - " + getName());
		
		try{
			reportActivity(this, getLogIndent() + "Downloading: " +trimForDisplay(  original_url ));
			
			try{
				this_mon.enter();
				
				if ( download_initiated ){
					
					throw( new ResourceDownloaderException("Download already initiated"));
				}
				
				download_initiated	= true;
				
			}finally{
				
				this_mon.exit();
			}
			
			try{
				URL	url = new URL( original_url.toString().replaceAll( " ", "%20" ));
			      
					// some authentications screw up without an explicit port number here
				
				String	protocol = url.getProtocol().toLowerCase();
				
				if ( url.getPort() == -1 && ! ( protocol.equals( "magnet" ) || protocol.equals( "dht" ))){
					
					int	target_port;
					
					if ( protocol.equals( "http" )){
						
						target_port = 80;
						
					}else{
						
						target_port = 443;
					}
					
					try{
						String str = original_url.toString().replaceAll( " ", "%20" );
					
						int	pos = str.indexOf( "://" );
						
						pos = str.indexOf( "/", pos+4 );
						
							// might not have a trailing "/"
						
						if ( pos == -1 ){
							
							url = new URL( str + ":" + target_port + "/" );
							
						}else{
						
							url = new URL( str.substring(0,pos) + ":" + target_port + str.substring(pos));
						}
												
					}catch( Throwable e ){
						
						Debug.printStackTrace( e );
					}
				}
				
				url = AddressUtils.adjustURL( url );
				
				try{
					if ( auth_supplied ){
						
						SESecurityManager.setPasswordHandler( url, this );
					}

					boolean	use_compression = true;
					
					boolean	follow_redirect = true;
					
redirect_label:
					for (int redirect_loop=0;redirect_loop<2&&follow_redirect; redirect_loop++ ){
						
						follow_redirect = false;
					
						for (int connect_loop=0;connect_loop<2;connect_loop++){
					
							File					temp_file	= null;
	
							try{
								HttpURLConnection	con;
								
								if ( url.getProtocol().equalsIgnoreCase("https")){
							      	
										// see ConfigurationChecker for SSL client defaults
					
									HttpsURLConnection ssl_con = (HttpsURLConnection)openConnection(url);
					
										// allow for certs that contain IP addresses rather than dns names
					  	
									ssl_con.setHostnameVerifier(
											new HostnameVerifier()
											{
												public boolean
												verify(
														String		host,
														SSLSession	session )
												{
													return( true );
												}
											});
					  	
									con = ssl_con;
					  	
								}else{
					  	
									con = (HttpURLConnection)openConnection(url);
					  	
								}
								
								con.setRequestProperty("User-Agent", Constants.AZUREUS_NAME + " " + Constants.AZUREUS_VERSION);     
					  
						 		con.setRequestProperty( "Connection", "close" );
	
						 		if ( use_compression ){
								
						 			con.addRequestProperty( "Accept-Encoding", "gzip" );
						 		}
						 		
								setRequestProperties( con, use_compression );
								
								if ( post_data != null ){
									
									con.setDoOutput(true);
									
									con.setRequestMethod("POST");
									
									OutputStreamWriter wr = new OutputStreamWriter(con.getOutputStream());
									
									wr.write(post_data);
									
									wr.flush();
								}
	
								con.connect();
					
								int response = con.getResponseCode();
													
								if ( 	response == HttpURLConnection.HTTP_MOVED_TEMP ||
										response == HttpURLConnection.HTTP_MOVED_PERM ){
									
										// auto redirect doesn't work from http to https
									
									String	move_to = con.getHeaderField( "location" );
									
									if ( move_to != null && url.getProtocol().equalsIgnoreCase( "http" )){
										
										try{
											URL	move_to_url = new URL( URLDecoder.decode( move_to, "UTF-8" ));
											
											if ( move_to_url.getProtocol().equalsIgnoreCase( "https" )){
												
												url = move_to_url;
												
												follow_redirect = true;
												
												continue redirect_label;
											}
										}catch( Throwable e ){
											
										}
									}
								}
								
								if ( 	response != HttpURLConnection.HTTP_ACCEPTED && 
										response != HttpURLConnection.HTTP_OK ) {
									
									setProperty( "URL_HTTP_Response", new Long( response ));

									throw( new ResourceDownloaderException("Error on connect for '" + trimForDisplay( url ) + "': " + Integer.toString(response) + " " + con.getResponseMessage()));    
								}
									
								getRequestProperties( con );
								
								boolean compressed = false;
								
								try{
									this_mon.enter();
									
									input_stream = con.getInputStream();
									
									String encoding = con.getHeaderField( "content-encoding");
					 				
					 				if ( encoding != null ){
					 					
					 					if ( encoding.equalsIgnoreCase( "gzip"  )){
	
							 				compressed = true;
						 									 					
						 					input_stream = new GZIPInputStream( input_stream );
						 					
					 					}else if ( encoding.equalsIgnoreCase( "deflate" )){
	
					 						compressed = true;
					 						
					 						input_stream = new InflaterInputStream( input_stream );
					 					}
					 				}
								}finally{
									
									this_mon.exit();
								}
								
								ByteArrayOutputStream	baos		= null;
								FileOutputStream		fos			= null;
								
								try{
									byte[] buf = new byte[BUFFER_SIZE];
									
									long	total_read	= 0;
									
										// unfortunately not all servers set content length
									
									/* From Apache's mod_deflate doc:
									 * http://httpd.apache.org/docs/2.0/mod/mod_deflate.html
											Note on Content-Length
	
											If you evaluate the request body yourself, don't trust the
											Content-Length header! The Content-Length header reflects 
											the length of the incoming data from the client and not the
											byte count of the decompressed data stream.
									 */
									long size = compressed ? -1 : UrlUtils.getContentLength( con );					
									
									baos = size>0?new ByteArrayOutputStream(size>MAX_IN_MEM_READ_SIZE?MAX_IN_MEM_READ_SIZE:(int)size):new ByteArrayOutputStream();
									
									while( !cancel_download ){
										
										int read = input_stream.read(buf);
											
										if ( read > 0 ){
										
											if ( total_read > MAX_IN_MEM_READ_SIZE ){
												
												if ( fos == null ){
													
													temp_file = AETemporaryFileHandler.createTempFile();
													
													fos = new FileOutputStream( temp_file );
													
													fos.write( baos.toByteArray());
													
													baos = null;
												}
												
												fos.write( buf, 0, read );
												
											}else{
												
												baos.write(buf, 0, read);
											}
											
											total_read += read;
									        
											informAmountComplete( total_read );
											
											if ( size > 0){
												
												informPercentDone((int)(( 100 * total_read ) / size ));
											}
										}else{
											
											break;
										}
									}
									
										// if we've got a size, make sure we've read all of it
									
									if ( size > 0 && total_read != size ){
										
										if ( total_read > size ){
											
												// this has been seen with UPnP linksys - more data is read than
												// the content-length has us believe is coming (1 byte in fact...)
											
											Debug.outNoStack( "Inconsistent stream length for '" + trimForDisplay( original_url ) + "': expected = " + size + ", actual = " + total_read );
											
										}else{
											
											throw( new IOException( "Premature end of stream" ));
										}
									}
								}finally{
									
									if ( fos != null ){
										
										fos.close();
									}
									
									input_stream.close();
								}
					
								InputStream	res;
								
								if ( temp_file != null ){
								
									res = new DeleteFileOnCloseInputStream( temp_file );
									
									temp_file = null;
									
								}else{
									
									res = new ByteArrayInputStream( baos.toByteArray());
								}
								
								boolean	handed_over = false;
								
								try{
									if ( informComplete( res )){
												
										handed_over = true;
										
										return( res );
									}
								}finally{
								
									if ( !handed_over ){
										
										res.close();
									}
								}
								
								throw( new ResourceDownloaderException("Contents downloaded but rejected: '" + trimForDisplay( original_url ) + "'" ));
		
							}catch( SSLException e ){
								
								if ( connect_loop == 0 ){
									
									if ( SESecurityManager.installServerCertificates( url ) != null ){
										
											// certificate has been installed
										
										continue;	// retry with new certificate
									}
								}
	
								throw( e );
								
							}catch( ZipException e ){
								
								if ( connect_loop == 0 ){
									
									use_compression = false;
									
									continue;
								}
							}catch( IOException e ){
								
								if ( connect_loop == 0 ){
									
									String	msg = e.getMessage();
									
									if ( msg != null ){
										
										msg = msg.toLowerCase( MessageText.LOCALE_ENGLISH );
										
										if ( msg.indexOf( "gzip" ) != -1 ){
								
											use_compression = false;
											
											continue;
										}
									}
															      			
						      		URL retry_url = UrlUtils.getIPV4Fallback( url );
						      			
						      		if ( retry_url != null ){
						      				
						      			url = retry_url;
						      			
						      			continue;
						      		}
								}
								
								throw( e );
								
							}finally{
								
								if ( temp_file != null ){
									
									temp_file.delete();
								}
							}
						}
					}
					
					throw( new ResourceDownloaderException("Should never get here" ));
					
				}finally{
							
					if ( auth_supplied ){
								
						SESecurityManager.setPasswordHandler( url, null );
					}
				}
			}catch (java.net.MalformedURLException e){
				
				throw( new ResourceDownloaderException("Exception while parsing URL '" + trimForDisplay( original_url ) + "':" + e.getMessage(), e));
				
			}catch (java.net.UnknownHostException e){
				
				throw( new ResourceDownloaderException("Exception while initializing download of '" + trimForDisplay( original_url ) + "': Unknown Host '" + e.getMessage() + "'", e));
				
			}catch (java.io.IOException e ){
				
				throw( new ResourceDownloaderException("I/O Exception while downloading '" + trimForDisplay( original_url ) + "'", e ));
			}
		}catch( Throwable e ){
			
			ResourceDownloaderException	rde;
			
			if ( e instanceof ResourceDownloaderException ){
				
				rde = (ResourceDownloaderException)e;
				
			}else{
				Debug.out(e);
				
				rde = new ResourceDownloaderException( "Unexpected error", e );
			}
			
			informFailed(rde);
			
			throw( rde );
		}
	}
	
	public void
	cancel()
	{
		setCancelled();
		
		cancel_download	= true;
		
		try{
			this_mon.enter();
			
			if ( input_stream != null ){
				
				try{
					input_stream.close();
					
				}catch( Throwable e ){
					
				}
			}
		}finally{
			
			this_mon.exit();
		}
		
		informFailed( new ResourceDownloaderCancelledException());
	}
	
	protected void
	setRequestProperties(
		HttpURLConnection		con,
		boolean					use_compression )
	{
		Map properties = getLCKeyProperties();
		
		Iterator	it = properties.entrySet().iterator();
		
		while( it.hasNext()){
			
			Map.Entry entry = (Map.Entry)it.next();
			
			String	key 	= (String)entry.getKey();
			Object	value	= entry.getValue();
			
			if ( key.startsWith( "url_" ) && value instanceof String ){
			
				key = key.substring(4);
				
				if ( key.equals( "accept-encoding" ) && !use_compression ){
					
					//skip
					
				}else{
					
					con.setRequestProperty(key,(String)value);
				}
			}
		}
	}
	
	protected void
	getRequestProperties(
		HttpURLConnection		con )
	{
		try{
			setProperty( ResourceDownloader.PR_STRING_CONTENT_TYPE, con.getContentType() );
			
			setProperty( "URL_URL", con.getURL());
			
			Map	headers = con.getHeaderFields();
			
			Iterator it = headers.entrySet().iterator();
			
			while( it.hasNext()){
				
				Map.Entry	entry = (Map.Entry)it.next();
				
				String	key = (String)entry.getKey();
				Object	val	= entry.getValue();
				
				if ( key != null ){
					
					setProperty( "URL_" + key, val );
				}
			}
			
			setPropertiesSet();
			
		}catch( Throwable e ){
			
			Debug.printStackTrace(e);
		}
	}
	
	public PasswordAuthentication
	getAuthentication(
		String		realm,
		URL			tracker )
	{
		if ( user_name == null || password == null ){
			
			String user_info = tracker.getUserInfo();
			
			if ( user_info == null ){
				
				return( null );
			}
			
			String	user_bit	= user_info;
			String	pw_bit		= "";
			
			int	pos = user_info.indexOf(':');
			
			if ( pos != -1 ){
				
				user_bit	= user_info.substring(0,pos);
				pw_bit		= user_info.substring(pos+1);
			}
			
			return( new PasswordAuthentication( user_bit, pw_bit.toCharArray()));
		}
		
		return( new PasswordAuthentication( user_name, password.toCharArray()));
	}
	
	public void
	setAuthenticationOutcome(
		String		realm,
		URL			tracker,
		boolean		success )
	{
	}
	
	public void
	clearPasswords()
	{
	}
	
	private URLConnection openConnection(URL url) throws IOException {
		if (this.force_no_proxy) {return Java15Utils.openConnectionForceNoProxy(url);}
		else {return url.openConnection();}
	}
	
	protected String
	trimForDisplay(
		URL		url )
	{
		String str = url.toString();
		
		int pos = str.indexOf( '?' );
		
		if ( pos != -1 ){
			
			str = str.substring( 0, pos );
		}
		
		return( str );
	}
}