/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE
 * or https://OpenDS.dev.java.net/OpenDS.LICENSE.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE.  If applicable,
 * add the following below this CDDL HEADER, with the fields enclosed
 * by brackets "[]" replaced with your own identifying * information:
 *      Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 *
 *
 *      Portions Copyright 2006 Sun Microsystems, Inc.
 */
package org.opends.server.schema;



import org.opends.server.api.OrderingMatchingRule;
import org.opends.server.config.ConfigEntry;
import org.opends.server.config.ConfigException;
import org.opends.server.core.DirectoryException;
import org.opends.server.core.InitializationException;
import org.opends.server.protocols.asn1.ASN1OctetString;
import org.opends.server.types.ByteString;

import static org.opends.server.loggers.Debug.*;
import static org.opends.server.messages.MessageHandler.*;
import static org.opends.server.messages.SchemaMessages.*;
import static org.opends.server.schema.SchemaConstants.*;
import static org.opends.server.util.StaticUtils.*;



/**
 * This class defines the octetStringOrderingMatch matching rule defined in
 * X.520.  This will be the default ordering matching rule for the binary and
 * octet string syntaxes.
 */
public class OctetStringOrderingMatchingRule
       extends OrderingMatchingRule
{
  /**
   * The fully-qualified name of this class for debugging purposes.
   */
  private static final String CLASS_NAME =
       "org.opends.server.schema.OctetStringOrderingMatchingRule";



  /**
   * The serial version identifier required to satisfy the compiler because this
   * class implements the <CODE>java.io.Serializable</CODE> interface.  This
   * value was generated using the <CODE>serialver</CODE> command-line utility
   * included with the Java SDK.
   */
  private static final long serialVersionUID = 3832343819704649155L;



  /**
   * Creates a new instance of this octetStringOrderingMatch matching rule.
   */
  public OctetStringOrderingMatchingRule()
  {
    super();

    assert debugConstructor(CLASS_NAME);
  }



  /**
   * Initializes this matching rule based on the information in the provided
   * configuration entry.
   *
   * @param  configEntry  The configuration entry that contains the information
   *                      to use to initialize this matching rule.
   *
   * @throws  ConfigException  If an unrecoverable problem arises in the
   *                           process of performing the initialization.
   *
   * @throws  InitializationException  If a problem that is not
   *                                   configuration-related occurs during
   *                                   initialization.
   */
  public void initializeMatchingRule(ConfigEntry configEntry)
         throws ConfigException, InitializationException
  {
    assert debugEnter(CLASS_NAME, "initializeMatchingRule",
                      String.valueOf(configEntry));

    // No initialization is required.
  }



  /**
   * Retrieves the common name for this matching rule.
   *
   * @return  The common name for this matching rule, or <CODE>null</CODE> if
   * it does not have a name.
   */
  public String getName()
  {
    assert debugEnter(CLASS_NAME, "getName");

    return OMR_OCTET_STRING_NAME;
  }



  /**
   * Retrieves the OID for this matching rule.
   *
   * @return  The OID for this matching rule.
   */
  public String getOID()
  {
    assert debugEnter(CLASS_NAME, "getOID");

    return OMR_OCTET_STRING_OID;
  }



  /**
   * Retrieves the description for this matching rule.
   *
   * @return  The description for this matching rule, or <CODE>null</CODE> if
   *          there is none.
   */
  public String getDescription()
  {
    assert debugEnter(CLASS_NAME, "getDescription");

    // There is no standard description for this matching rule.
    return null;
  }



  /**
   * Retrieves the OID of the syntax with which this matching rule is
   * associated.
   *
   * @return  The OID of the syntax with which this matching rule is associated.
   */
  public String getSyntaxOID()
  {
    assert debugEnter(CLASS_NAME, "getSyntaxOID");

    return SYNTAX_OCTET_STRING_OID;
  }



  /**
   * Retrieves the normalized form of the provided value, which is best suited
   * for efficiently performing matching operations on that value.
   *
   * @param  value  The value to be normalized.
   *
   * @return  The normalized version of the provided value.
   *
   * @throws  DirectoryException  If the provided value is invalid according to
   *                              the associated attribute syntax.
   */
  public ByteString normalizeValue(ByteString value)
         throws DirectoryException
  {
    assert debugEnter(CLASS_NAME, "normalizeValue", String.valueOf(value));

    return new ASN1OctetString(value.value());
  }



  /**
   * Compares the first value to the second and returns a value that indicates
   * their relative order.
   *
   * @param  value1  The normalized form of the first value to compare.
   * @param  value2  The normalized form of the second value to compare.
   *
   * @return  A negative integer if <CODE>value1</CODE> should come before
   *          <CODE>value2</CODE> in ascending order, a positive integer if
   *          <CODE>value1</CODE> should come after <CODE>value2</CODE> in
   *          ascending order, or zero if there is no difference between the
   *          values with regard to ordering.
   */
  public int compareValues(ByteString value1, ByteString value2)
  {
    assert debugEnter(CLASS_NAME, "compareValues", String.valueOf(value1),
                      String.valueOf(value2));

    return compare(value1.value(), value2.value());
  }



  /**
   * Compares the contents of the provided byte arrays to determine their
   * relative order.
   *
   * @param  b1  The first byte array to use in the comparison.
   * @param  b2  The second byte array to use in the comparison.
   *
   * @return  A negative integer if <CODE>b1</CODE> should come before
   *          <CODE>b2</CODE> in ascending order, a positive integer if
   *          <CODE>b1</CODE> should come after <CODE>b2</CODE> in ascending
   *          order, or zero if there is no difference between the values with
   *          regard to ordering.
   */
  public int compare(byte[] b1, byte[] b2)
  {
    assert debugEnter(CLASS_NAME, "compareValues", String.valueOf(b1),
                      String.valueOf(b2));

    int minLength = Math.min(b1.length, b2.length);

    for (int i=0; i < minLength; i++)
    {
      if (b1[i] == b2[i])
      {
        continue;
      }
      else if (b1[i] < b2[i])
      {
        return -1;
      }
      else if (b1[i] > b2[i])
      {
        return 1;
      }
    }

    if (b1.length == b2.length)
    {
      return 0;
    }
    else if (b1.length < b2.length)
    {
      return -1;
    }
    else
    {
      return 1;
    }
  }
}