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.ModeSense6Cdb;

 import org.jscsi.target.scsi.modeSense.CachingModePage;

 import org.jscsi.target.scsi.modeSense.HeaderType;

 import org.jscsi.target.scsi.modeSense.InformationExceptionsControlModePage;

 import org.jscsi.target.scsi.modeSense.ModePage;

 import org.jscsi.target.scsi.modeSense.ModePageCode;

 import org.jscsi.target.scsi.modeSense.ModeParameterList;

 import org.jscsi.target.scsi.modeSense.ModeParameterListBuilder;

 import org.jscsi.target.scsi.modeSense.ShortLogicalBlockDescriptor;

 import org.jscsi.target.settings.SettingsException;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 /**

  * A stage for processing <code>MODE SENSE (6)</code> SCSI commands.

  * 

  * @author Andreas Ergenzinger

  */

 public final class ModeSenseStage extends TargetFullFeatureStage {

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

     public ModeSenseStage (TargetFullFeaturePhase targetFullFeaturePhase) {

         super(targetFullFeaturePhase);

     }

     @Override

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

         final BasicHeaderSegment bhs = pdu.getBasicHeaderSegment();

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

         final ModeSense6Cdb cdb = new ModeSense6Cdb(parser.getCDB());

         if (LOGGER.isDebugEnabled()) {

             LOGGER.debug(Boolean.toString(cdb.getDisableBlockDescriptors()));

             LOGGER.debug(cdb.getPageControl().toString());

             LOGGER.debug(Integer.toString(cdb.getPageCode()));

             LOGGER.debug(Integer.toString(cdb.getSubpageCode()));

             LOGGER.debug("cdb.getAllocationLength() = " + cdb.getAllocationLength());

             // LOGGER.debug(cdb.getModePage());

         }

         // final PageControl pageControl = cdb.getPageControl();//see 8 lines

         // below

         final ModePageCode modePageCode = cdb.getModePage();

         // ModeParameterList and ModeParameterListBuilder common to

         // all supported ModePage requests

         ModePage[] modePages = null;

         if (modePageCode == ModePageCode.INFORMATIONAL_EXCEPTIONS_CONTROL_MODE_PAGE) {

             // TODO this should to be made dynamic wrt. cdb.getPageControl();

             modePages = new ModePage[] { getInformationExceptionsControlModePage() };

         } else if (modePageCode == ModePageCode.CACHING_MODE_PAGE) {

             modePages = new ModePage[] { getCachingModePage() };

         } else if (modePageCode == ModePageCode.RETURN_ALL_MODE_PAGES_ONLY) {

             modePages = new ModePage[] { getInformationExceptionsControlModePage(), getCachingModePage() };

         }// else modeParameterList stays null

         // create and send response PDU

         if (modePages != null) {

             // create ModeParameterList

             final ModeParameterListBuilder builder = new ModeParameterListBuilder(HeaderType.MODE_PARAMETER_HEADER_6);

             builder.setLogicalBlockDescriptors(new ShortLogicalBlockDescriptor(session.getStorageModule().getSizeInBlocks(),// numberOfLogicalBlocks

             VIRTUAL_BLOCK_SIZE));// logicalBlockLength

             builder.setModePages(modePages);

             ModeParameterList modeParameterList = ModeParameterList.build(builder);

             // send response

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

                     parser.getExpectedDataTransferLength(),// expectedDataTransferLength,

                     modeParameterList);// responseData

         } else {

             /*

              * The initiator has requested a mode sense page which the jSCSI Target cannot provide. This could be

              * answered with an Illegal field in CDB message but, there is no good way to identify the exact field at

              * fault.

              */

             throw new InternetSCSIException();

         }

     }

     private static final InformationExceptionsControlModePage getInformationExceptionsControlModePage () {

         return new InformationExceptionsControlModePage(false,// parametersSaveable

         false,// performance

         false,// enableBackgroundFunction

         false,// enableWarning

         true,// disableExceptionControl

         false,// test

         false,// logErrors

         0x0,// methodOfReportingInformationalExceptionConditions

         0,// intervalTimer

         0);// reportCount

     }

     private static final CachingModePage getCachingModePage () {

         return new CachingModePage(false,// parametersSaveable

         false,// initiatorControl

         true,// abortPrefetch

         false,// cachingAnalysisPermitted

         false,// discontinuity

         true,// sizeEnable

         false,// writebackCacheEnable

         false,// multiplicationFactor

         true,// readCacheDisable

         0x0,// demandReadRetentionPriority

         0x0,// writeRetentionPriority

         0,// disablePrefetchTransferLength

         0,// minimumPrefetch

         65535,// maximumPrefetch

         65535,// maximumPrefetchCeiling

         true,// forceSequentialWrite

         false,// logicalBlockCacheSegmentSize

         false,// disableReadAhead

         false,// nonVolatileCacheDisabled

         20,// numberOfCacheSegments

         0);// cacheSegmentSize

     }

     public boolean canHandle (final ProtocolDataUnit pdu) {

         final BasicHeaderSegment bhs = pdu.getBasicHeaderSegment();

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

         final ModeSense6Cdb cdb = new ModeSense6Cdb(parser.getCDB());

         final ModePageCode modePageCode = cdb.getModePage();

         if (modePageCode == ModePageCode.INFORMATIONAL_EXCEPTIONS_CONTROL_MODE_PAGE) {

             return true;

         } else if (modePageCode == ModePageCode.CACHING_MODE_PAGE) {

             return true;

         } else if (modePageCode == ModePageCode.RETURN_ALL_MODE_PAGES_ONLY) {

             return true;

         } else {

             return false;

         }

     }

 }