/*
 * 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
 *
 *
 *      Copyright 2006-2008 Sun Microsystems, Inc.
 */
package org.opends.server.schema;



import static org.opends.server.schema.SchemaConstants.*;
import static org.opends.server.util.StaticUtils.*;

import java.util.Collection;
import java.util.Collections;

import org.opends.server.api.EqualityMatchingRule;
import org.opends.server.types.ByteSequence;
import org.opends.server.types.ByteString;
import org.opends.server.types.DirectoryException;



/**
 * This class implements the telephoneNumberMatch matching rule defined in X.520
 * and referenced in RFC 2252.  Note that although the specification calls for a
 * very rigorous format, this is widely ignored so this matching will compare
 * only numeric digits and strip out everything else.
 */
class TelephoneNumberEqualityMatchingRule
       extends EqualityMatchingRule
{
  /**
   * Creates a new instance of this telephoneNumberMatch matching rule.
   */
  public TelephoneNumberEqualityMatchingRule()
  {
    super();
  }



  /**
   * {@inheritDoc}
   */
  @Override
  public Collection<String> getAllNames()
  {
    return Collections.singleton(getName());
  }



  /**
   * 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.
   */
  @Override
  public String getName()
  {
    return EMR_TELEPHONE_NAME;
  }



  /**
   * Retrieves the OID for this matching rule.
   *
   * @return  The OID for this matching rule.
   */
  @Override
  public String getOID()
  {
    return EMR_TELEPHONE_OID;
  }



  /**
   * Retrieves the description for this matching rule.
   *
   * @return  The description for this matching rule, or <CODE>null</CODE> if
   *          there is none.
   */
  @Override
  public String 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.
   */
  @Override
  public String getSyntaxOID()
  {
    return SYNTAX_TELEPHONE_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.
   */
  @Override
  public ByteString normalizeValue(ByteSequence value)
         throws DirectoryException
  {
    String valueString = value.toString();
    int    valueLength = valueString.length();
    StringBuilder buffer = new StringBuilder(valueLength);


    // Iterate through the characters in the value and filter out everything
    // that isn't a digit.
    for (int i=0; i < valueLength; i++)
    {
      char c = valueString.charAt(i);
      if (isDigit(c))
      {
        buffer.append(c);
      }
    }


    return ByteString.valueOf(buffer.toString());
  }
}