package org.openslx.imagemaster.ftp;

import java.io.File;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;

import org.apache.ftpserver.FtpServer;
import org.apache.ftpserver.FtpServerFactory;
import org.apache.ftpserver.ftplet.Authority;
import org.apache.ftpserver.ftplet.FtpException;
import org.apache.ftpserver.ftplet.Ftplet;
import org.apache.ftpserver.ftplet.UserManager;
import org.apache.ftpserver.impl.FtpIoSession;
import org.apache.ftpserver.listener.Listener;
import org.apache.ftpserver.listener.ListenerFactory;
import org.apache.ftpserver.ssl.SslConfigurationFactory;
import org.apache.ftpserver.usermanager.PropertiesUserManagerFactory;
import org.apache.ftpserver.usermanager.SaltedPasswordEncryptor;
import org.apache.ftpserver.usermanager.impl.BaseUser;
import org.apache.ftpserver.usermanager.impl.WritePermission;
import org.apache.log4j.Logger;
import org.openslx.imagemaster.Globals;
import org.openslx.imagemaster.Globals.PropString;
import org.openslx.imagemaster.thrift.iface.FtpCredentials;
import org.openslx.imagemaster.util.RandomString;

public class MasterFtpServer implements Runnable
{
	private static Logger log = Logger.getLogger( MasterFtpServer.class );
	private FtpServer server;
	private UserManager userManager;
	private Listener listener;
	// key: ftpUsername, value: createTime
	public final HashMap<String, Long> users = new HashMap<>();
	private boolean ini = false;

	public void init( int port )
	{
		if ( ini )
			return;

		FtpServerFactory serverFactory = new FtpServerFactory();
		ListenerFactory factory = new ListenerFactory();

		// config ssl
		SslConfigurationFactory sslConfigFactory = new SslConfigurationFactory();
		sslConfigFactory.setKeystoreFile( new File( Globals.getPropertyString( PropString.KEYSTOREFILE ) ) );
		sslConfigFactory.setKeyAlias( Globals.getPropertyString( PropString.KEYSTOREALIAS ) );
		sslConfigFactory.setKeystorePassword( Globals.getPropertyString( PropString.KEYSTOREPASSWORD ) );

		// set the port of the listener
		factory.setPort( port );
		factory.setSslConfiguration( sslConfigFactory.createSslConfiguration() );
		factory.setImplicitSsl( true );

		// replace the default listener
		listener = factory.createListener();
		serverFactory.addListener( "default", listener );

		// create user manager
		PropertiesUserManagerFactory userManagerFactory = new PropertiesUserManagerFactory();
		File userFile = new File( "src/main/properties/ftp.properties" );
		userManagerFactory.setFile( userFile );
		userManagerFactory.setPasswordEncryptor( new SaltedPasswordEncryptor() );
		userManager = userManagerFactory.createUserManager();
		serverFactory.setUserManager( userManager );

		// add the Ftplet
		HashMap<String, Ftplet> map = new HashMap<String, Ftplet>();
		map.put( "Ftplet1", new MasterFtplet() );
		serverFactory.setFtplets( map );

		// start the server
		server = serverFactory.createServer();
		ini = true;
	}

	public FtpCredentials addUser( final String serverSessionId )
	{
		FtpCredentials ftpCredentials = null;

		String generatedUser = RandomString.generate( 10, false );
		String generatedPass = RandomString.generate( 16, true );

		String dir = Globals.getPropertyString( Globals.PropString.FTPBASEDIR ) + "/"
				+ generatedUser + "/";

		if ( !new File( dir ).mkdir() ) {
			return ftpCredentials;
		}

		BaseUser user = new BaseUser();
		user.setName( generatedUser );
		user.setPassword( generatedPass );
		user.setHomeDirectory( dir );

		List<Authority> authorities = new ArrayList<Authority>();
		authorities.add( new WritePermission() );
		user.setAuthorities( authorities );

		try {
			userManager.save( user );
			ftpCredentials = new FtpCredentials( generatedUser, generatedPass );
			synchronized ( users ) {
				users.put( ftpCredentials.username, System.currentTimeMillis());
			}
		} catch ( FtpException e ) {
		}

		log.info( "Generated user/pass: " + generatedUser + "\t"
				+ generatedPass + "\n with home dir: " + dir );

		return ftpCredentials;
	}

	public boolean removeUser( final String username )
	{
		if ( !users.containsKey( username ) )
			return false;

		try {
			// first find active session and close it
			Iterator<FtpIoSession> iter = listener.getActiveSessions().iterator();
			while (iter.hasNext()) {
				FtpIoSession session = (FtpIoSession) iter.next();
				if (session.getUser() == null) continue;
				if (session.getUser().getName() == username) {
					session.close();
				}
			}
			// afterwards delete user
			userManager.delete( username );
			// remove user from map (cache)
			synchronized ( users ) {
				users.remove( username );
			}
			return true;
		} catch ( FtpException e ) {
			return false;
		}
	}

	@Override
	public void run()
	{
		try {
			//if (!ini) throw new Exception("FTP server needs to be initalized.");
			log.info( "Starting FTP Sever" );
			server.start();
		} catch ( FtpException e1 ) {
			e1.printStackTrace();
		}
	}
}