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;
      }
  }