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

 import java.io.IOException;

 import java.nio.ByteBuffer;

 import java.security.DigestException;

 import java.util.List;

 import java.util.Vector;

 import org.jscsi.exception.InternetSCSIException;

 import org.jscsi.parser.BasicHeaderSegment;

 import org.jscsi.parser.ProtocolDataUnit;

 import org.jscsi.target.connection.TargetPduFactory;

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

 import org.jscsi.target.settings.SettingsException;

 import org.jscsi.target.settings.TextKeyword;

 import org.jscsi.target.settings.TextParameter;

 import org.jscsi.target.util.ReadWrite;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 /**

  * A stage for processing requests by the initiator for a list of all targets available through the iSCSI portal and for

  * negotiating connection parameters in the full feature phase.

  * <p>

  * That latter functionality is currently not implemented.

  * 

  * @author Andreas Ergenzinger

  */

 public final class TextNegotiationStage extends TargetFullFeatureStage {

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

     public TextNegotiationStage (TargetFullFeaturePhase targetFullFeaturePhase) {

         super(targetFullFeaturePhase);

     }

     @Override

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

         final BasicHeaderSegment bhs = pdu.getBasicHeaderSegment();

         final int initiatorTaskTag = bhs.getInitiatorTaskTag();

         final String textRequest = new String(pdu.getDataSegment().array());

         LOGGER.debug("text request: " + textRequest);

         ByteBuffer replyDataSegment = null;// for later

         // tokenize key-value pairs

         final List<String> requestKeyValuePairs = TextParameter.tokenizeKeyValuePairs(textRequest);

         final List<String> responseKeyValuePairs = new Vector<String>();

         // process SendTargets command

         if (requestKeyValuePairs != null) {

             // A SendTargets command consists of a single Text request PDU. This

             // PDU contains exactly one text key and value.

             String sendTargetsValue = null;

             if (requestKeyValuePairs.size() == 1) sendTargetsValue = TextParameter.getSuffix(requestKeyValuePairs.get(0),// string

                     TextKeyword.SEND_TARGETS + TextKeyword.EQUALS);// prefix

             if (sendTargetsValue != null) {

                 // initiator wants target information

                 /*

                  * ALL must be supported in discovery session and must not be supported in operational session.

                  * <name-of-this-target> must be supported in discovery session (and it does no harm to support it in

                  * the operational session). <nothing> must be supported in the operational session and will only return

                  * info on the target the initiator is connected to, this means no info is returned in discovery

                  * session. outcome table | discovery |operational| ---------------+-----------+-----------| ALL | TN +

                  * TA | fail | ---------------+-----------+-----------| <this target> | TA | TA |

                  * ---------------+-----------+-----------| <other target> | fail | fail |

                  * ---------------+-----------+-----------| <nothing> | fail | TA | TN stands for TargetName, TA for

                  * TargetAddress "fail" means no text response.

                  */

                 final boolean normal = session.isNormalSession();

                 final boolean sendTargetName = // see upper table

                 !normal && sendTargetsValue.equals(TextKeyword.ALL);

                 final boolean sendTargetAddress = // see upper table

                 (!normal && sendTargetsValue.equals(TextKeyword.ALL)) || (session.getTargetServer().isValidTargetName(sendTargetsValue)) || (normal && sendTargetsValue.length() == 0);

                 /*

                  * A target record consists of a TargetName key-value pair followed by one or more TargetAddress

                  * key-value pairs for that TargetName. (table above takes precedence to these definitions)

                  */

                 // add TargetName

                 if (sendTargetName) {

                     for (String curTargetName : session.getTargetServer().getTargetNames()) {

                         responseKeyValuePairs.add(TextParameter.toKeyValuePair(TextKeyword.TARGET_NAME, curTargetName));

                         // add TargetAddress

                         if (sendTargetAddress) responseKeyValuePairs.add(TextParameter.toKeyValuePair(TextKeyword.TARGET_ADDRESS, session.getTargetServer().getConfig().getTargetAddress() + // domain

                         TextKeyword.COLON + // :

                         session.getTargetServer().getConfig().getPort() + // port

                         TextKeyword.COMMA + // ,

                         session.getTargetServer().getConfig().getTargetPortalGroupTag())); // groupTag)

                     }

                 } else {

                     // We're here if they sent us a target name and are asking for the address (I think)

                     if (sendTargetAddress) responseKeyValuePairs.add(TextParameter.toKeyValuePair(TextKeyword.TARGET_ADDRESS, session.getTargetServer().getConfig().getTargetAddress() + // domain

                     TextKeyword.COLON + // :

                     session.getTargetServer().getConfig().getPort() + // port

                     TextKeyword.COMMA + // ,

                     session.getTargetServer().getConfig().getTargetPortalGroupTag())); // groupTag)

                 }

             } else {

                 // initiator wants to negotiate or declare parameters

                 // TODO

             }

             // concatenate and serialize reply

             final String replyString = TextParameter.concatenateKeyValuePairs(responseKeyValuePairs);

             LOGGER.debug("text negotiation stage reply: " + replyString);

             replyDataSegment = ReadWrite.stringToTextDataSegments(replyString, settings.getMaxRecvDataSegmentLength())[0];// definitely

                                                                                                                           // fits

                                                                                                                           // into

                                                                                                                           // one

                                                                                                                           // data

                                                                                                                           // segment

         }

         // send reply

         final ProtocolDataUnit responsePdu = TargetPduFactory.createTextResponsePdu(true,// finalFlag

                 false,// continueFlag

                 0,// logicalUnitNumber

                 initiatorTaskTag, 0xffffffff,// targetTransferTag

                 replyDataSegment);// dataSegment

         connection.sendPdu(responsePdu);

     }

 }