package org.openslx.satellitedaemon.filetransfer;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.List;

import org.apache.log4j.Logger;
import org.apache.thrift.TException;
import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.protocol.TProtocol;
import org.apache.thrift.transport.TFramedTransport;
import org.apache.thrift.transport.TSocket;
import org.apache.thrift.transport.TTransport;
import org.apache.thrift.transport.TTransportException;
import org.openslx.encryption.AsymEncryptionHandler;
import org.openslx.imagemaster.crcchecker.CrcFile;
import org.openslx.imagemaster.thrift.iface.AuthenticationException;
import org.openslx.imagemaster.thrift.iface.AuthorizationError;
import org.openslx.imagemaster.thrift.iface.AuthorizationException;
import org.openslx.imagemaster.thrift.iface.DownloadData;
import org.openslx.imagemaster.thrift.iface.ImageData;
import org.openslx.imagemaster.thrift.iface.ImageDataError;
import org.openslx.imagemaster.thrift.iface.ImageDataException;
import org.openslx.imagemaster.thrift.iface.ImageServer;
import org.openslx.imagemaster.thrift.iface.ServerSessionData;
import org.openslx.imagemaster.thrift.iface.UploadData;
import org.openslx.imagemaster.thrift.iface.UploadError;
import org.openslx.imagemaster.thrift.iface.UploadException;
import org.openslx.imagemaster.thrift.iface.UserInfo;
import org.openslx.satellitedaemon.Globals;
import org.openslx.satellitedaemon.Identity;
import org.openslx.satellitedaemon.db.DbImage;
import org.openslx.satellitedaemon.db.DbImage.Status;

/***********************************************************************************************/
/**
 * Handles the authentication with the Satellite Server and sends the
 * FILTRANSFERCredentials, which are necessary for the upload of the image.
 */
public class ThriftConnection
{
	private static ThreadLocal<ImageServer.Client> client = new ThreadLocal<ImageServer.Client>();
	private static ServerSessionData sSD = null;
	private static Logger log = Logger.getLogger( ThriftConnection.class );
	private static CrcFile crc = null;

	/***********************************************************************************************/
	/**
	 * Method for getting UploadeInfos
	 * 
	 * when the CRCsum need to be transfered. The method calls getConnection()
	 * to check if the connection is ok and to get the ServerSessionData. If
	 * connection is ok, it calls submitImage with CRCsum in List<Integer>.
	 * 
	 * @return returns 'null' if there is a problem.
	 */
	public static UploadData getUploadInfos( ImageData imDat, String path )
	{
		ImageServer.Client theClient = null;
		String crcPath = path.concat( ".crc" );
		theClient = getConnection();
		if ( theClient == null ) {
			log.error( "Client was null!" );
			return null;
		}
		List<Integer> crcSums = null;
		try {
			crc = new CrcFile( crcPath );
			log.info( "Made CRCFile from " + crcPath );
			log.info( "crc.getCrcSums( ).size = " + crc.getCrcSums().size() );
			crcSums = crc.getCrcSums();
		} catch ( FileNotFoundException e ) {
			log.debug( "crcFile " + crcPath + " not found." );
		} catch ( IOException e ) {
			log.error( "IOException", e );
		}
		try {
			return theClient.submitImage( sSD.sessionId, imDat, crcSums );
		} catch ( AuthorizationException e ) {
			if ( e.number == AuthorizationError.NOT_AUTHENTICATED ) {
				log.warn( "Suddenly nut authenticated anymore.", e );
			} else if ( e.number == AuthorizationError.NO_PERMISSION ) {
				log.error( "No permission for uploading.", e );
				// TODO: add error message into database.
			} else {
				log.warn( "Unknown authorization error.", e );
			}
		} catch ( ImageDataException e ) {
			if ( e.number == ImageDataError.INVALID_DATA ) {
				log.warn( "Data for image not valid", e );
				// TODO: add e.message into DB;
			} else {
				log.warn( "ImageDataException", e );
			}
		} catch ( UploadException e ) {
			if ( e.number == UploadError.BROKEN_BLOCK ) {
				// A Block was transmitted 20 times unsuccessfully.
				// TODO: Mark the Image as corrupted.
			} else if ( e.number == UploadError.INVALID_CRC ) {
				// The CRC sum contained errors
				if ( crc != null && !crc.isValid() )
					crc.delete();
			} else {
				e.printStackTrace();
			}
		} catch ( TException e ) {
			log.error( "TException", e );
		}
		return null;
	}

	/***********************************************************************************************/
	/**
	 * Method for getting DonwloadInfos. Calls getConnection if client was null.
	 * You need to specify all Blocks you want to have in an List.
	 * 
	 * @return returns 'null' if there is a problem.
	 */
	public static DownloadData getDownloadInfos( DbImage imDat )
	{
		ImageServer.Client theClient = null;

		theClient = getConnection();
		if ( theClient == null ) {
			log.error( "Client was null!" );
			return null;
		}

		try {
			return theClient.getImage( sSD.sessionId, imDat.guid );
		} catch ( ImageDataException e ) {
			log.debug( "In catch - blog of thrift connection" );
			if ( e.isSetNumber()
					&& e.getNumber().equals( ImageDataError.INVALID_DATA ) ) {
				// Data in the db is not valid
				// TODO: add e.message into DB;
			} else if ( e.getNumber().equals( ImageDataError.UNKNOWN_IMAGE ) ) {
				// The image requested is not known.
				// TODO: change field image_syncMode, so the image is not asked
				// for again.
				// For now just changed status of image. Currently no
				// possibility for creating new useful state in DB. (Offenburg)
				log.info( "Image not known. For skipping next time, mark as only_local." );
				imDat.updateStatus( Status.only_local );
				// Plus add a note in some way to mark as unknown by Server
			} else {
				e.printStackTrace();
			}
		} catch ( AuthorizationException e ) {
			if ( e.isSetNumber()
					&& e.getNumber().equals(
							AuthorizationError.NOT_AUTHENTICATED ) ) {
				log.error( "Not authenticated. SessionID is not valid.", e );
				// SessionID is not valid
				// TODO: Code for new SSID
			} else if ( e.getNumber().equals( AuthorizationError.NO_PERMISSION ) ) {
				log.error( "No permission error.", e );
				// TODO: add e.message into database.
			} else {
				e.printStackTrace();
			}
		} catch ( TException e ) {
			log.error( "TException", e );
		}
		return null;
	}

	/***********************************************************************************************/
	/**
	 * This method checks if there is already a working connection. If not,
	 * newClient() establishes one. Also it does the Authentication if not done
	 * yet.
	 * 
	 * @return returns the client if successful.
	 */
	private static ImageServer.Client getConnection()
	{
		ImageServer.Client theClient = client.get();
		boolean isAuthenticated;

		if ( theClient == null ) {
			// There is no client instance for this thread, create a new one
			log.info( "No existing client for this thread. Making a new client ..." );
			theClient = newClient();
			isAuthenticated = false;
			if ( theClient == null ) {
				log.debug( "The client was null after newClient()" );
				return null;
			}
		} else {
			// There is a client instance for this thread, see if it's still usable and authenticated
			try {
				isAuthenticated = theClient.isServerAuthenticated( sSD.sessionId );
				log.debug( "Existing client is " + ( isAuthenticated ? "still" : "not" ) + " authenticated." );
			} catch ( TException x ) {
				theClient = newClient();
				if ( theClient == null ) {
					log.warn( "Masterserver connection fail" );
					return null;
				}
				log.debug( "Existing client was not connected anymore." );
				isAuthenticated = false;
			}
		}

		if ( !isAuthenticated ) {
			try {
				ByteBuffer tmpBuffer = theClient
						.startServerAuthentication( Identity
								.getOrganizationName() );
				byte[] toEncrypt = new byte[ tmpBuffer.remaining() ];
				tmpBuffer.get( toEncrypt );
				AsymEncryptionHandler aeh = new AsymEncryptionHandler(
						Identity.getPrivateKey() );

				byte[] byteArray = aeh.encryptMessage( toEncrypt );
				sSD = theClient.serverAuthenticate(
						Identity.getOrganizationName(),
						ByteBuffer.wrap( byteArray ) );
			} catch ( AuthenticationException e ) {
				log.error( "ThriftConnection: AuthenticationException: Server Authetication was not sucessful.", e );
				return null;
			} catch ( TException e ) {
				log.error( "ThriftConnection: TException: Server Authetication was not sucessful.", e );
				return null;
			}
			log.info( "is Authenticated." );

		}
		return theClient;
	}

	/***********************************************************************************************/
	/**
	 * Method for creating a new Client for Thrift communication.
	 * 
	 * @throws IOException
	 */
	private static ImageServer.Client newClient()
	{
		final ImageServer.Client newClient;
		try {
			TTransport transport = new TFramedTransport( new TSocket(
					Globals.getMasterserverHost(), Globals.getThriftPort() ) );
			transport.open();
			TProtocol protocol = new TBinaryProtocol( transport );
			newClient = new ImageServer.Client( protocol );
			log.debug( "ThriftConnection: Made a new Client" );
		} catch ( TTransportException e ) {
			log.error( "Transport could not be opened. Couldn't create new client.", e );
			return null;
		}
		client.set( newClient );
		return newClient;
	}

	/**
	 * Publish new user to master-server, which insert it to his db.
	 * @param userInfo
	 * @return true, if successful.
	 */
	public static boolean publishUser( UserInfo userInfo )
	{
		ImageServer.Client theClient = null;
		theClient = getConnection();
		if ( theClient == null ) {
			log.error( "Client was null!" );
			return false;
		}
		try {
			return theClient.publishUser( sSD.sessionId, userInfo );
		} catch ( AuthorizationException e ) {
			log.error( "AutorizationException", e );
		} catch ( TException e ) {
			log.error( "TException", e );
		}
		return false;
	}

	/**
	 * Register new, by master unknown satellite - server with organizationId,
	 * ipAddress and key - information.
	 * @param organizationId
	 * @param ipAddress
	 * @param modulus
	 * @param exponent
	 * @return true, if successful. 
	 */
	public static boolean registerSatellite( String organizationId, String ipAddress, String modulus, String exponent )
	{
		ImageServer.Client theClient = null;
		theClient = getConnection();
		// No check for valid connection. --> not needed, because this satellite is not known yet by master.
		try {
			return theClient.registerSatellite( organizationId, ipAddress, modulus, exponent );
		} catch ( TException e ) {
			log.error( "TException", e );
			return false;
		}
	}
	
	/**
	 * Update in master - DB existing satellite - ipAddress.
	 * @param ipAddress
	 * @return true, if successful.
	 */
	public static boolean updateSatelliteAddress(String ipAddress) {
		ImageServer.Client theClient = null;
		theClient = getConnection();
		if ( theClient == null) {
			log.error( "Client was null!" );
			return false;
		}
		try {
			return theClient.updateSatelliteAddress( sSD.sessionId, ipAddress );
		} catch ( TException e ) {
			log.error( "TException", e );
			return false;
		}
	}
}