package org.jscsi.target.settings.entry;

 import org.jscsi.target.TargetServer;

 import org.jscsi.target.settings.KeySet;

 import org.jscsi.target.settings.NegotiationStatus;

 import org.jscsi.target.settings.NegotiationType;

 import org.jscsi.target.settings.TextParameter;

 /**

  * This {@link Entry} sub-class is used for managing and negotiation String parameters. The <i>value</i> part of the

  * corresponding <i>key-value</i> pairs can be made up of one or several comma-separated strings.

  * <p>

  * The default or negotiated value can be accessed via the {@link #getStringValue()} method.

  * 

  * @see Entry

  * @author Andreas Ergenzinger

  */

 public final class StringEntry extends Entry {

     /**

      * Contains all values supported by the jSCSI Target.

      */

     private final String[] supportedValues;

     /**

      * The {@link StringEntry} constructor.

      * 

      * @param keySet contains all relevant keys

      * @param negotiationType declared or negotiated

      * @param use determines under which circumstances the parameter may be negotiated

      * @param negotiationStatus indicates whether there is a default value or if the parameter must be negotiated

      * @param supportedValues all values supported by the jSCSI Target

      * @param defaultValue the default value or <code>null</code>

      */

     public StringEntry (final KeySet keySet, final NegotiationType negotiationType, final Use use, final NegotiationStatus negotiationStatus, final String[] supportedValues, final Object defaultValue) {

         super(keySet, negotiationType, use, negotiationStatus, defaultValue);

         this.supportedValues = supportedValues;

     }

     @Override

     protected boolean inProtocolValueRange (Object values) {

         // receives a String array

         // (size of array has already been checked in parseOffer(...))

         final String[] vals = (String[]) values;

         // check for illegal characters

         for (String s : vals)

             if (!TextParameter.checkTextValueFormat(s)) return false;

         return true;

     }

     @Override

     protected Object parseOffer (TargetServer target, String values) {

         // receives a comma-separated list of string values (or a single value)

         // enforce that declaration consists of exactly one value

         final String[] split = TextParameter.splitValues(values);

         if (negotiationType == NegotiationType.DECLARED && split.length > 1) return null;// protocol error

         return split;

     }

     @Override

     protected void processDeclaration (Object values) {

         // receives a String array or length 1

         value = ((String[]) values)[0];

     }

     @Override

     protected String processNegotiation (Object values) {

         // receives a String array

         final String[] requestedValues = (String[]) values;

         final String[] commonValues = TextParameter.intersect(supportedValues, requestedValues);

         // reject if no commonly supported values

         if (commonValues.length == 0) return null;

         // otherwise, save and return negotiation result

         value = commonValues[0];

         return commonValues[0];

     }

     @Override

     public String getStringValue () {

         return (String) value;

     }

     @Override

     public Entry copy () {

         final StringEntry e = new StringEntry(keySet, negotiationType, use, negotiationStatus, supportedValues, (String) value);

         e.alreadyNegotiated = this.alreadyNegotiated;

         return e;

     }

 }