package org.jscsi.target.connection.stage.fullfeature;

 import java.io.IOException;

 import java.nio.ByteBuffer;

 import org.jscsi.exception.InternetSCSIException;

 import org.jscsi.parser.ProtocolDataUnit;

 import org.jscsi.parser.scsi.SCSIResponseParser;

 import org.jscsi.parser.scsi.SCSIStatus;

 import org.jscsi.target.connection.TargetPduFactory;

 import org.jscsi.target.connection.phase.TargetFullFeaturePhase;

 import org.jscsi.target.connection.stage.TargetStage;

 import org.jscsi.target.scsi.IResponseData;

 import org.jscsi.target.scsi.ScsiResponseDataSegment;

 import org.jscsi.target.scsi.sense.AdditionalSenseBytes;

 import org.jscsi.target.scsi.sense.AdditionalSenseCodeAndQualifier;

 import org.jscsi.target.scsi.sense.ErrorType;

 import org.jscsi.target.scsi.sense.FixedFormatSenseData;

 import org.jscsi.target.scsi.sense.SenseKey;

 import org.jscsi.target.scsi.sense.information.FourByteInformation;

 import org.jscsi.target.scsi.sense.senseDataDescriptor.senseKeySpecific.FieldPointerSenseKeySpecificData;

 /**

  * This class is an abstract super-class for stages of the {@link TargetFullFeaturePhase}.

  * 

  * @see TargetStage

  * @author Andreas Ergenzinger

  */

 public abstract class TargetFullFeatureStage extends TargetStage {

     /**

      * The abstract constructor.

      * 

      * @param targetFullFeaturePhase

      *            the phase this stage is a part of

      */

     public TargetFullFeatureStage(TargetFullFeaturePhase targetFullFeaturePhase) {

         super(targetFullFeaturePhase);

     }

     /**

      * Creates a PDU with {@link FixedFormatSenseData} that must be sent to the initiator after receiving a

      * Command

      * Descriptor Block with an illegal field.

      * 

      * @param senseKeySpecificData

      *            contains a list of all illegal fields

      * @param additionalSenseCodeAndQualifier

      *            provides more specific information about the cause of the check condition

      * @param initiatorTaskTag

      *            used by the initiator to identify the task

      * @param expectedDataTransferLength

      *            the amount of payload data expected by the initiator (i.e. allocated buffer

      *            space)

      * @return the error PDU

      */

     protected static final ProtocolDataUnit createFixedFormatErrorPdu(

         final FieldPointerSenseKeySpecificData[] senseKeySpecificData,

         final AdditionalSenseCodeAndQualifier additionalSenseCodeAndQualifier, final int initiatorTaskTag,

         final int expectedDataTransferLength) {

         // create the whole sense data

         FixedFormatSenseData senseData = new FixedFormatSenseData(false,// valid

             ErrorType.CURRENT,// error type

             false,// file mark

             false,// end of medium

             false,// incorrect length indicator

             SenseKey.ILLEGAL_REQUEST,// sense key

             new FourByteInformation(),// information

             new FourByteInformation(),// command specific information

             additionalSenseCodeAndQualifier,// additional sense code and

                                             // qualifier

             (byte)0,// field replaceable unit code

             senseKeySpecificData[0],// sense key specific data, only report

                                     // first problem

             new AdditionalSenseBytes());// additional sense bytes

         // keep only the part of the sense data that will be sent

         final ScsiResponseDataSegment dataSegment =

             new ScsiResponseDataSegment(senseData, expectedDataTransferLength);

         final int senseDataSize = senseData.size();

         // calculate residuals and flags

         final int residualCount = Math.abs(expectedDataTransferLength - senseDataSize);

         final boolean residualOverflow = expectedDataTransferLength < senseDataSize;

         final boolean residualUnderflow = expectedDataTransferLength > senseDataSize;

         // create and return PDU

         return TargetPduFactory.createSCSIResponsePdu(false,// bidirectionalReadResidualOverflow

             false,// bidirectionalReadResidualUnderflow

             residualOverflow,// residualOverflow

             residualUnderflow,// residualUnderflow,

             SCSIResponseParser.ServiceResponse.COMMAND_COMPLETED_AT_TARGET,// response,

             SCSIStatus.CHECK_CONDITION,// status,

             initiatorTaskTag,// initiatorTaskTag,

             0,// snackTag

             0,// expectedDataSequenceNumber

             0,// bidirectionalReadResidualCount

             residualCount,// residualCount

             dataSegment);// data segment

     }

     /**

      * Creates a PDU with {@link FixedFormatSenseData} that must be sent to the initiator after receiving a

      * Command

      * Descriptor Block with an illegal field, which requires the the additional sense code

      * {@link AdditionalSenseCodeAndQualifier#INVALID_FIELD_IN_CDB}.

      * 

      * @param senseKeySpecificData

      *            contains a list of all illegal fields

      * @param initiatorTaskTag

      *            used by the initiator to identify the task

      * @param expectedDataTransferLength

      *            the amount of payload data expected by the initiator (i.e. allocated buffer

      *            space)

      * @return the error PDU

      */

     protected static final ProtocolDataUnit createFixedFormatErrorPdu(

         final FieldPointerSenseKeySpecificData[] senseKeySpecificData, final int initiatorTaskTag,

         final int expectedDataTransferLength) {

         return createFixedFormatErrorPdu(senseKeySpecificData,

             AdditionalSenseCodeAndQualifier.INVALID_FIELD_IN_CDB, initiatorTaskTag,

             expectedDataTransferLength);

     }

     /**

      * Creates a SCSI Response PDU with a length zero data segment. Objects created with this method can be

      * used as

      * replies in task terminating with {@link SCSIStatus#GOOD} which do not require additional data to be

      * transfered,

      * or for creating follow-up PDU with {@link SCSIStatus#CHECK_CONDITION} status sent after Data-In PDUs

      * with sense

      * data.

      * 

      * @param status

      *            the SCSI status of the task

      * @param initiatorTaskTag

      *            used by the initiator to identify the task

      * @param expectedDataTransferLength

      *            total amount of payload data in bytes expected by the initiator

      * @param responseDataSize

      *            actual amount of payload data in bytes sent by the target

      * @return the SCSI Response PDU

      */

     protected static final ProtocolDataUnit createScsiResponsePdu(final SCSIStatus status,

         final int initiatorTaskTag, final int expectedDataTransferLength, final int responseDataSize) {

         // calculate residuals and flags

         final int residualCount = Math.abs(expectedDataTransferLength - responseDataSize);

         final boolean residualOverflow = expectedDataTransferLength < responseDataSize;

         final boolean residualUnderflow = expectedDataTransferLength > responseDataSize;

         return TargetPduFactory.createSCSIResponsePdu(false,// bidirectionalReadResidualOverflow

             false,// bidirectionalReadResidualUnderflow

             residualOverflow,// residualOverflow,

             residualUnderflow,// residualUnderflow,

             SCSIResponseParser.ServiceResponse.COMMAND_COMPLETED_AT_TARGET,// response

             status,// status

             initiatorTaskTag,// initiatorTaskTag

             0,// snackTag

             0,// expectedDataSequenceNumber

             0,// bidirectionalReadResidualCount

             residualCount,// residualCount

             ScsiResponseDataSegment.EMPTY_DATA_SEGMENT);// data segment

     }

     /**

      * Sends a two byte sequence of a Data-In and a SCSI Response PDU with the specified <i>responseData</i>

      * payload to

      * the initiator.

      * 

      * @param initiatorTaskTag

      *            used by the initiator to identify the task

      * @param expectedDataTransferLength

      *            the total amount of payload data in bytes expected by the initiator

      *            <p>

      *            The method might throw exceptions during PDU serialization and sending.

      * @param responseData

      *            the data requested by the initiator

      * @throws InterruptedException

      * @throws IOException

      * @throws InternetSCSIException

      */

     protected final void sendResponse(final int initiatorTaskTag, final int expectedDataTransferLength,

         final IResponseData responseData) throws InterruptedException, IOException, InternetSCSIException {

         // serialize all response data

         final ByteBuffer fullBuffer = ByteBuffer.allocate(responseData.size());

         responseData.serialize(fullBuffer, 0);

         // copy fullBuffer to buffer with size trimmed to

         // expectedDataTransferLength

         ByteBuffer trimmedBuffer;

         if (fullBuffer.capacity() <= expectedDataTransferLength) {

             // no trimming

             trimmedBuffer = fullBuffer;

         } else {

             trimmedBuffer = ByteBuffer.allocate(expectedDataTransferLength);

             trimmedBuffer.put(fullBuffer.array(),// source array

                 0,// offset in source

                 expectedDataTransferLength);// length

         }

         // coompute residual count and associated flags

         final boolean residualOverflow = expectedDataTransferLength < fullBuffer.capacity();

         final boolean residualUnderflow = expectedDataTransferLength > fullBuffer.capacity();

         final int residualCount = Math.abs(expectedDataTransferLength - fullBuffer.capacity());

         // create and send PDU

         ProtocolDataUnit pdu = TargetPduFactory.createDataInPdu(true,// finalFlag

             false,// acknowledgeFlag always false

             residualOverflow,// residualOverflowFlag x

             residualUnderflow,// residualUnderflowFlag x

             true,// statusFlag

             SCSIStatus.GOOD,// status, reserved

             0,// logicalUnitNumber reserved

             initiatorTaskTag,// initiatorTaskTag

             -1,// targetTransferTag reserved

             0,// dataSequenceNumber

             0,// bufferOffset

             residualCount,// residualCount x

             trimmedBuffer);// dataSegment

         connection.sendPdu(pdu);

         //        VirtualBox was not working with the success message sent via ScsiResponse ..

         //        Deactivated this method and set the data-in pdu up to take over the success

         //        notification.

         //        pdu = TargetPduFactory.createSCSIResponsePdu(false,// bidirectionalReadResidualOverflow

         //            false,// bidirectionalReadResidualUnderflow

         //            residualOverflow,// residualOverflow

         //            residualUnderflow,// residualUnderflow

         //            ServiceResponse.COMMAND_COMPLETED_AT_TARGET,// response

         //            SCSIStatus.GOOD,// status

         //            initiatorTaskTag, 0,// snackTag, reserved

         //            0,// expectedDataSequenceNumber

         //            0,// bidirectionalReadResidualCount

         //            residualCount,// residualCount

         //            ScsiResponseDataSegment.EMPTY_DATA_SEGMENT);// scsiResponseDataSegment

         //

         //        connection.sendPdu(pdu);

     }

 }