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 * 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
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 *      Copyright 2009-2010 Sun Microsystems, Inc.
 */

package org.opends.sdk.schema;



import static com.sun.opends.sdk.messages.Messages.ERR_ATTR_SYNTAX_MR_UNKNOWN_SYNTAX;
import static com.sun.opends.sdk.messages.Messages.WARN_MATCHING_RULE_NOT_IMPLEMENTED;

import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.opends.sdk.*;

import com.sun.opends.sdk.util.Validator;



/**
 * This class defines a data structure for storing and interacting with matching
 * rules, which are used by servers to compare attribute values against
 * assertion values when performing Search and Compare operations. They are also
 * used to identify the value to be added or deleted when modifying entries, and
 * are used when comparing a purported distinguished name with the name of an
 * entry.
 * <p>
 * Matching rule implementations must extend the
 * <code>MatchingRuleImplementation</code> class so they can be used by OpenDS.
 * <p>
 * Where ordered sets of names, or extra properties are provided, the ordering
 * will be preserved when the associated fields are accessed via their getters
 * or via the {@link #toString()} methods.
 */
public final class MatchingRule extends SchemaElement
{
  private final String oid;
  private final List<String> names;
  private final boolean isObsolete;
  private final String syntaxOID;
  private final String definition;
  private MatchingRuleImpl impl;
  private Syntax syntax;
  private Schema schema;



  MatchingRule(final String oid, final List<String> names,
      final String description, final boolean obsolete, final String syntax,
      final Map<String, List<String>> extraProperties, final String definition,
      final MatchingRuleImpl implementation)
  {
    super(description, extraProperties);

    Validator.ensureNotNull(oid, names, description, syntax);
    Validator.ensureNotNull(extraProperties);
    this.oid = oid;
    this.names = names;
    this.isObsolete = obsolete;
    this.syntaxOID = syntax;

    if (definition != null)
    {
      this.definition = definition;
    }
    else
    {
      this.definition = buildDefinition();
    }
    this.impl = implementation;
  }



  /**
   * Get a comparator that can be used to compare the attribute values
   * normalized by this matching rule.
   *
   * @return A comparator that can be used to compare the attribute values
   *         normalized by this matching rule.
   */
  public Comparator<ByteSequence> comparator()
  {
    return impl.comparator(schema);
  }



  /**
   * {@inheritDoc}
   */
  @Override
  public boolean equals(final Object o)
  {
    if (o == null)
    {
      return false;
    }

    if (this == o)
    {
      return true;
    }

    if (!(o instanceof MatchingRule))
    {
      return false;
    }

    return getOID().equals(((MatchingRule) o).getOID());
  }



  /**
   * Returns the normalized form of the provided assertion value, which is best
   * suite for efficiently performing matching operations on that value. The
   * assertion value is guarenteed to be valid against this matching rule's
   * assertion syntax.
   *
   * @param value
   *          The syntax checked assertion value to be normalized.
   * @return The normalized version of the provided assertion value.
   * @throws DecodeException
   *           if the syntax of the value is not valid.
   */
  public Assertion getAssertion(final ByteSequence value)
      throws DecodeException
  {
    return impl.getAssertion(schema, value);
  }



  /**
   * Returns the normalized form of the provided assertion substring values,
   * which is best suite for efficiently performing matching operations on that
   * value.
   *
   * @param subInitial
   *          The normalized substring value fragment that should appear at the
   *          beginning of the target value.
   * @param subAnyElements
   *          The normalized substring value fragments that should appear in the
   *          middle of the target value.
   * @param subFinal
   *          The normalized substring value fragment that should appear at the
   *          end of the target value.
   * @return The normalized version of the provided assertion value.
   * @throws DecodeException
   *           if the syntax of the value is not valid.
   */
  public Assertion getAssertion(final ByteSequence subInitial,
      final List<? extends ByteSequence> subAnyElements,
      final ByteSequence subFinal) throws DecodeException
  {
    return impl.getAssertion(schema, subInitial, subAnyElements, subFinal);
  }



  /**
   * Returns the normalized form of the provided assertion value, which is best
   * suite for efficiently performing greater than or equal ordering matching
   * operations on that value. The assertion value is guarenteed to be valid
   * against this matching rule's assertion syntax.
   *
   * @param value
   *          The syntax checked assertion value to be normalized.
   * @return The normalized version of the provided assertion value.
   * @throws DecodeException
   *           if the syntax of the value is not valid.
   */
  public Assertion getGreaterOrEqualAssertion(final ByteSequence value)
      throws DecodeException
  {
    return impl.getGreaterOrEqualAssertion(schema, value);
  }



  /**
   * Returns the normalized form of the provided assertion value, which is best
   * suite for efficiently performing greater than or equal ordering matching
   * operations on that value. The assertion value is guarenteed to be valid
   * against this matching rule's assertion syntax.
   *
   * @param value
   *          The syntax checked assertion value to be normalized.
   * @return The normalized version of the provided assertion value.
   * @throws DecodeException
   *           if the syntax of the value is not valid.
   */
  public Assertion getLessOrEqualAssertion(final ByteSequence value)
      throws DecodeException
  {
    return impl.getLessOrEqualAssertion(schema, value);
  }



  /**
   * Returns the name or OID for this schema definition. If it has one or more
   * names, then the primary name will be returned. If it does not have any
   * names, then the OID will be returned.
   *
   * @return The name or OID for this schema definition.
   */
  public String getNameOrOID()
  {
    if (names.isEmpty())
    {
      return oid;
    }
    return names.get(0);
  }



  /**
   * Returns an unmodifiable list containing the user-defined names that may be
   * used to reference this schema definition.
   *
   * @return Returns an unmodifiable list containing the user-defined names that
   *         may be used to reference this schema definition.
   */
  public List<String> getNames()
  {
    return names;
  }



  /**
   * Returns the OID for this schema definition.
   *
   * @return The OID for this schema definition.
   */
  public String getOID()
  {

    return oid;
  }



  /**
   * Returns the OID of the assertion value syntax with which this matching rule
   * is associated.
   *
   * @return The OID of the assertion value syntax with which this matching rule
   *         is associated.
   */
  public Syntax getSyntax()
  {
    return syntax;
  }



  /**
   * {@inheritDoc}
   */
  @Override
  public int hashCode()
  {
    return oid.hashCode();
  }



  /**
   * Indicates whether this schema definition has the specified name.
   *
   * @param name
   *          The name for which to make the determination.
   * @return <code>true</code> if the specified name is assigned to this schema
   *         definition, or <code>false</code> if not.
   */
  public boolean hasName(final String name)
  {
    for (final String n : names)
    {
      if (n.equalsIgnoreCase(name))
      {
        return true;
      }
    }
    return false;
  }



  /**
   * Indicates whether this schema definition has the specified name or OID.
   *
   * @param value
   *          The value for which to make the determination.
   * @return <code>true</code> if the provided value matches the OID or one of
   *         the names assigned to this schema definition, or <code>false</code>
   *         if not.
   */
  public boolean hasNameOrOID(final String value)
  {
    return hasName(value) || getOID().equals(value);
  }



  /**
   * Indicates whether this schema definition is declared "obsolete".
   *
   * @return <code>true</code> if this schema definition is declared "obsolete",
   *         or <code>false</code> if not.
   */
  public boolean isObsolete()
  {
    return isObsolete;
  }



  /**
   * Returns the normalized form of the provided attribute value, which is best
   * suite for efficiently performing matching operations on that value.
   *
   * @param value
   *          The attribute value to be normalized.
   * @return The normalized version of the provided attribute value.
   * @throws DecodeException
   *           if the syntax of the value is not valid.
   */
  public ByteString normalizeAttributeValue(final ByteSequence value)
      throws DecodeException
  {
    return impl.normalizeAttributeValue(schema, value);
  }



  /**
   * Returns the string representation of this schema definition in the form
   * specified in RFC 2252.
   *
   * @return The string representation of this schema definition in the form
   *         specified in RFC 2252.
   */
  @Override
  public String toString()
  {
    return definition;
  }



  MatchingRule duplicate()
  {
    return new MatchingRule(oid, names, description, isObsolete, syntaxOID,
        extraProperties, definition, impl);
  }



  @Override
  void toStringContent(final StringBuilder buffer)
  {
    buffer.append(oid);

    if (!names.isEmpty())
    {
      final Iterator<String> iterator = names.iterator();

      final String firstName = iterator.next();
      if (iterator.hasNext())
      {
        buffer.append(" NAME ( '");
        buffer.append(firstName);

        while (iterator.hasNext())
        {
          buffer.append("' '");
          buffer.append(iterator.next());
        }

        buffer.append("' )");
      }
      else
      {
        buffer.append(" NAME '");
        buffer.append(firstName);
        buffer.append("'");
      }
    }

    if (description != null && description.length() > 0)
    {
      buffer.append(" DESC '");
      buffer.append(description);
      buffer.append("'");
    }

    if (isObsolete)
    {
      buffer.append(" OBSOLETE");
    }

    buffer.append(" SYNTAX ");
    buffer.append(syntaxOID);
  }



  @Override
  void validate(final List<LocalizableMessage> warnings, final Schema schema)
      throws SchemaException
  {
    // Try finding an implementation in the core schema
    if (impl == null && Schema.getDefaultSchema().hasMatchingRule(oid))
    {
      impl = Schema.getDefaultSchema().getMatchingRule(oid).impl;
    }
    if (impl == null && Schema.getCoreSchema().hasMatchingRule(oid))
    {
      impl = Schema.getCoreSchema().getMatchingRule(oid).impl;
    }

    if (impl == null)
    {
      impl = Schema.getDefaultMatchingRule().impl;
      final LocalizableMessage message = WARN_MATCHING_RULE_NOT_IMPLEMENTED
          .get(oid, Schema.getDefaultMatchingRule().getOID());
      warnings.add(message);
    }

    try
    {
      // Make sure the specifiec syntax is defined in this schema.
      syntax = schema.getSyntax(syntaxOID);
    }
    catch (final UnknownSchemaElementException e)
    {
      final LocalizableMessage message = ERR_ATTR_SYNTAX_MR_UNKNOWN_SYNTAX.get(
          getNameOrOID(), syntaxOID);
      throw new SchemaException(message, e);
    }

    this.schema = schema;
  }
}