package org.jscsi.target.scsi.cdb;

 import java.nio.ByteBuffer;

 import org.jscsi.target.scsi.inquiry.PageCode;

 import org.jscsi.target.scsi.inquiry.PageCode.VitalProductDataPageName;

 import org.jscsi.target.scsi.inquiry.SupportedVpdPages;

 import org.jscsi.target.util.BitManip;

 import org.jscsi.target.util.ReadWrite;

 /**

  * This class represents Command Descriptor Blocks for the <code>INQUIRY</code> SCSI command.

  * 

  * @author Andreas Ergenzinger

  */

 public class InquiryCDB extends CommandDescriptorBlock {

     /**

      * An enable vital product data (EVPD) bit set to one specifies that the device server shall return the vital

      * product data specified by the PAGE CODE field.

      * <p>

      * If the EVPD bit is set to zero, the device server shall return the standard INQUIRY data. If the PAGE CODE field

      * is not set to zero when the EVPD bit is set to zero, the command shall be terminated with CHECK CONDITION status,

      * with the sense key set to ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD IN CDB.

      */

     private final boolean enableVitalProductData;

     /**

      * The ALLOCATION LENGTH field specifies the maximum number of bytes that an application client has allocated in the

      * Data-In Buffer. An allocation length of zero specifies that no data shall be transferred. This condition shall

      * not be considered as an error. The device server shall terminate transfers to the Data-In Buffer when the number

      * of bytes specified by the ALLOCATION LENGTH field have been transferred or when all available data have been

      * transferred, whichever is less.

      * <p>

      * The allocation length is used to limit the maximum amount of variable length data (e.g., mode data, log data,

      * diagnostic data) returned to an application client. If the information being transferred to the Data-In Buffer

      * includes fields containing counts of the number of bytes in some or all of the data, then the contents of these

      * fields shall not be altered to reflect the truncation, if any, that results from an insufficient ALLOCATION

      * LENGTH value, unless the standard that describes the Data-In Buffer format states otherwise.

      * <p>

      * If the amount of information to be transferred exceeds the maximum value that the ALLOCATION LENGTH field is

      * capable of specifying, the device server shall transfer no data and terminate the command with CHECK CONDITION

      * status, with the sense key set to ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD IN CDB.

      * <p>

      * If EVPD is set to zero, the allocation length should be at least five, so that the ADDITIONAL LENGTH field in the

      * parameter data is returned. If EVPD is set to one, the allocation length should be should be at least four, so

      * that the PAGE LENGTH field in the parameter data is returned.

      */

     private final int allocationLength;

     /**

      * When the EVPD bit is set to one, the PAGE CODE field specifies which page of vital product data information the

      * device server shall return.

      */

     private final PageCode pageCode;

     public InquiryCDB (ByteBuffer buffer) {

         super(buffer);

         // EVPD

         enableVitalProductData = BitManip.getBit(buffer.get(1),// byte

                 0);// bit number

         // page code

         pageCode = new PageCode(buffer.get(2));

         // allocation length

         allocationLength = ReadWrite.readTwoByteInt(buffer, 3);

         final VitalProductDataPageName vpdpn = pageCode.getVitalProductDataPageName();

         if (enableVitalProductData) {

             if (!SupportedVpdPages.vpdPageCodeSupported(vpdpn)) addIllegalFieldPointer(2);// page code not supported

         } else {

             /*

              * If the PAGE CODE field is not set to zero when the EVPD bit is set to zero, the command shall be

              * terminated with CHECK CONDITION status, with the sense key set to ILLEGAL REQUEST, and the additional

              * sense code set to INVALID FIELD IN CDB.

              */

             if (vpdpn != VitalProductDataPageName.SUPPORTED_VPD_PAGES) addIllegalFieldPointer(2);// value should be 0x00

         }

     }

     public boolean getEnableVitalProductData () {

         return enableVitalProductData;

     }

     public PageCode getPageCode () {

         return pageCode;

     }

     public int getAllocationLength () {

         return allocationLength;

     }

 }