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

 import java.io.IOException;

 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.parser.login.LoginStage;

 import org.jscsi.parser.login.LoginStatus;

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

 import org.jscsi.target.settings.SettingsException;

 import org.jscsi.target.settings.TextParameter;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 /**

  * A {@link TargetLoginStage} sub-class representing Login Operational (Parameter) Negotiation Stages.

  * 

  * @author Andreas Ergenzinger

  */

 public final class LoginOperationalParameterNegotiationStage extends TargetLoginStage {

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

     /**

      * The constructor.

      * 

      * @param targetLoginPhase the login phase this stage is a part of.

      */

     public LoginOperationalParameterNegotiationStage (TargetLoginPhase targetLoginPhase) {

         super(targetLoginPhase, LoginStage.LOGIN_OPERATIONAL_NEGOTIATION);

     }

     @Override

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

         LOGGER.debug("Entering LOPN Stage");

         BasicHeaderSegment bhs = pdu.getBasicHeaderSegment();

         initiatorTaskTag = bhs.getInitiatorTaskTag();

         String keyValuePairProposal = receivePduSequence(pdu);

         // negotiate parameters, leave if unsuccessful

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

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

         if (!negotiator.negotiate(session.getTargetServer(), stageNumber, connection.isLeadingConnection(), ((TargetLoginPhase) targetPhase).getFirstPduAndSetToFalse(), requestKeyValuePairs, responseKeyValuePairs)) {

             // negotiation failure, no exception

             sendRejectPdu(LoginStatus.INITIATOR_ERROR);

             // nextStageNumber = null;//no change

             return;

         }

         // print request and response key value pairs if debugging

         if (LOGGER.isDebugEnabled()) {

             final StringBuilder sb = new StringBuilder();

             sb.append("request: ");

             for (String s : requestKeyValuePairs) {

                 sb.append("\n  ");

                 sb.append(s);

             }

             sb.append("\nresponse: ");

             for (String s : responseKeyValuePairs) {

                 sb.append("\n  ");

                 sb.append(s);

             }

             LOGGER.debug(sb.toString());

         }

         // make sure that initiator wants to proceed to FFP, leave if it does

         // not

         if (requestedNextStageNumber != LoginStage.FULL_FEATURE_PHASE) {

             sendRejectPdu(LoginStatus.INITIATOR_ERROR);

             throw new InternetSCSIException();

         }

         // concatenate key-value pairs to null char-separated string

         final String keyValuePairReply = TextParameter.concatenateKeyValuePairs(responseKeyValuePairs);

         // send reply, finish negotiation, and return successfully

         sendPduSequence(keyValuePairReply, LoginStage.FULL_FEATURE_PHASE);

         negotiator.finishNegotiation(true);

         nextStageNumber = LoginStage.FULL_FEATURE_PHASE;

     }

 }