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

 import static org.jscsi.target.storage.IStorageModule.VIRTUAL_BLOCK_SIZE;

 import java.io.IOException;

 import java.security.DigestException;

 import org.jscsi.exception.InternetSCSIException;

 import org.jscsi.parser.BasicHeaderSegment;

 import org.jscsi.parser.ProtocolDataUnit;

 import org.jscsi.parser.scsi.SCSICommandParser;

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

 import org.jscsi.target.scsi.cdb.ReadCapacity10Cdb;

 import org.jscsi.target.scsi.cdb.ReadCapacity16Cdb;

 import org.jscsi.target.scsi.cdb.ReadCapacityCdb;

 import org.jscsi.target.scsi.cdb.ScsiOperationCode;

 import org.jscsi.target.scsi.readCapacity.ReadCapacity10ParameterData;

 import org.jscsi.target.scsi.readCapacity.ReadCapacity16ParameterData;

 import org.jscsi.target.scsi.readCapacity.ReadCapacityParameterData;

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

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

 import org.jscsi.target.settings.SettingsException;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 public final class ReadCapacityStage extends TargetFullFeatureStage {

     private static final Logger LOGGER = LoggerFactory.getLogger(ReadCapacityStage.class);

     public ReadCapacityStage (final TargetFullFeaturePhase targetFullFeaturePhase) {

         super(targetFullFeaturePhase);

     }

     @Override

     public void execute (ProtocolDataUnit pdu) throws IOException , InterruptedException , InternetSCSIException , DigestException , SettingsException {

         // find out the type of READ CAPACITY command ((10) or (16))

         final BasicHeaderSegment bhs = pdu.getBasicHeaderSegment();

         final SCSICommandParser parser = (SCSICommandParser) bhs.getParser();

         final ScsiOperationCode opCode = ScsiOperationCode.valueOf(parser.getCDB().get(0));

         ReadCapacityCdb cdb;

         if (opCode == ScsiOperationCode.READ_CAPACITY_10)

             cdb = new ReadCapacity10Cdb(parser.getCDB());

         else if (opCode == ScsiOperationCode.READ_CAPACITY_16)

             cdb = new ReadCapacity16Cdb(parser.getCDB());

         else {

             // programmer error, we should not be here, close the connection

             throw new InternetSCSIException("wrong SCSI Operation Code " + opCode + " in ReadCapacityStage");

         }

         /*

          * Everything is fine, carry on. The PMI bit of the command descriptor block is ignored, since there is no way

          * to know if "substantial vendor specific delay in data transfer may be encountered" after the address in the

          * LOGICAL BLOCK ADDRESS field. Therefore we always try to return the whole length of the storage medium.

          */

         // make sure that the LOGICAL BLOCK ADDRESS field is valid and send

         // appropriate response

         if (session.getStorageModule().checkBounds(cdb.getLogicalBlockAddress(), 0) != 0) {

             // invalid, log error, send error PDU, and return

             LOGGER.error("encountered " + cdb.getClass() + " in ReadCapacityStage with " + "LOGICAL BLOCK ADDRESS = " + cdb.getLogicalBlockAddress());

             final FieldPointerSenseKeySpecificData fp = new FieldPointerSenseKeySpecificData(true,// senseKeySpecificDataValid

             true,// commandData (i.e. invalid field in CDB)

             false,// bitPointerValid

             0,// bitPointer, reserved since invalid

             0);// fieldPointer to the SCSI OpCode field

             final FieldPointerSenseKeySpecificData[] fpArray = new FieldPointerSenseKeySpecificData[] { fp };

             final ProtocolDataUnit responsePdu = createFixedFormatErrorPdu(fpArray,// senseKeySpecificData

                     AdditionalSenseCodeAndQualifier.LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE,// additionalSenseCodeAndQualifier

                     bhs.getInitiatorTaskTag(),// initiatorTaskTag

                     parser.getExpectedDataTransferLength());// expectedDataTransferLength

             connection.sendPdu(responsePdu);

             return;

         } else {

             // send PDU with requested READ CAPACITY parameter data

             ReadCapacityParameterData parameterData;

             if (cdb instanceof ReadCapacity10Cdb)

                 parameterData = new ReadCapacity10ParameterData(session.getStorageModule().getSizeInBlocks(),// returnedLogicalBlockAddress

                 VIRTUAL_BLOCK_SIZE);// logicalBlockLengthInBytes

             else

                 parameterData = new ReadCapacity16ParameterData(session.getStorageModule().getSizeInBlocks(),// returnedLogicalBlockAddress

                 VIRTUAL_BLOCK_SIZE);// logicalBlockLengthInBytes

             sendResponse(bhs.getInitiatorTaskTag(),// initiatorTaskTag,

                     parser.getExpectedDataTransferLength(),// expectedDataTransferLength,

                     parameterData);// responseData

         }

     }

 }