/*
 * 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]
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 * CDDL HEADER END
 *
 *
 *      Copyright 2009 Sun Microsystems, Inc.
 */

package org.opends.sdk.schema;



import static com.sun.opends.sdk.messages.Messages.*;

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(String oid, List<String> names, String description,
      boolean obsolete, String syntax,
      Map<String, List<String>> extraProperties, String definition,
      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);
  }



  /**
   * Retrieves 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(ByteSequence value)
      throws DecodeException
  {
    return impl.getAssertion(schema, value);
  }



  /**
   * Retrieves 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(ByteSequence subInitial,
      List<? extends ByteSequence> subAnyElements, ByteSequence subFinal)
      throws DecodeException
  {
    return impl.getAssertion(schema, subInitial, subAnyElements,
        subFinal);
  }



  /**
   * Retrieves 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(ByteSequence value)
      throws DecodeException
  {
    return impl.getGreaterOrEqualAssertion(schema, value);
  }



  /**
   * Retrieves 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(ByteSequence value)
      throws DecodeException
  {
    return impl.getLessOrEqualAssertion(schema, value);
  }



  /**
   * Retrieves 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);
  }



  /**
   * Retrieves an iterable over the set of user-defined names that may
   * be used to reference this schema definition.
   *
   * @return Returns an iterable over the set of user-defined names that
   *         may be used to reference this schema definition.
   */
  public Iterable<String> getNames()
  {
    return names;
  }



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

    return oid;
  }



  /**
   * Retrieves 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;
  }



  @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(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(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;
  }



  /**
   * Retrieves 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(ByteSequence value)
      throws DecodeException
  {
    return impl.normalizeAttributeValue(schema, value);
  }



  /**
   * Retrieves 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(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(List<LocalizableMessage> warnings, 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;
  }
}