/*
 * 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 2009 Sun Microsystems, Inc.
 */
package org.opends.sdk.schema;



import org.opends.sdk.*;

import com.sun.opends.sdk.util.StaticUtils;
import com.sun.opends.sdk.util.SubstringReader;



/**
 * This class defines the objectIdentifierMatch matching rule defined in
 * X.520 and referenced in RFC 2252. This expects to work on OIDs and
 * will match either an attribute/objectclass name or a numeric OID.
 * NOTE: This matching rule requires a schema to lookup object
 * identifiers in the descriptor form.
 */
final class ObjectIdentifierEqualityMatchingRuleImpl extends
    AbstractMatchingRuleImpl
{
  static class OIDAssertion implements Assertion
  {
    private final String oid;



    OIDAssertion(String oid)
    {
      this.oid = oid;
    }



    public ConditionResult matches(ByteSequence attributeValue)
    {
      final String attrStr = attributeValue.toString();

      // We should have normalized all values to OIDs. If not, we know
      // the descriptor form is not valid in the schema.
      if (attrStr.length() == 0
          || !StaticUtils.isDigit(attrStr.charAt(0)))
      {
        return ConditionResult.UNDEFINED;
      }
      if (oid.length() == 0 || !StaticUtils.isDigit(oid.charAt(0)))
      {
        return ConditionResult.UNDEFINED;
      }

      return attrStr.equals(oid) ? ConditionResult.TRUE
          : ConditionResult.FALSE;
    }
  }



  static String resolveNames(Schema schema, String oid)
  {
    if (!StaticUtils.isDigit(oid.charAt(0)))
    {
      // Do an best effort attempt to normalize names to OIDs.

      String schemaName = null;

      if (schema.hasAttributeType(oid))
      {
        schemaName = schema.getAttributeType(oid).getOID();
      }

      if (schemaName == null)
      {
        if (schema.hasDITContentRule(oid))
        {
          schemaName =
              schema.getDITContentRule(oid).getStructuralClass()
                  .getOID();
        }
      }

      if (schemaName == null)
      {
        if (schema.hasSyntax(oid))
        {
          schemaName = schema.getSyntax(oid).getOID();
        }
      }

      if (schemaName == null)
      {
        if (schema.hasObjectClass(oid))
        {
          schemaName = schema.getObjectClass(oid).getOID();
        }
      }

      if (schemaName == null)
      {
        if (schema.hasMatchingRule(oid))
        {
          schemaName = schema.getMatchingRule(oid).getOID();
        }
      }

      if (schemaName == null)
      {
        if (schema.hasMatchingRuleUse(oid))
        {
          schemaName =
              schema.getMatchingRuleUse(oid).getMatchingRule().getOID();
        }
      }

      if (schemaName == null)
      {
        if (schema.hasNameForm(oid))
        {
          schemaName = schema.getNameForm(oid).getOID();
        }
      }

      if (schemaName != null)
      {
        return schemaName;
      }
      else
      {
        return StaticUtils.toLowerCase(oid);
      }
    }
    return oid;
  }



  @Override
  public Assertion getAssertion(Schema schema, ByteSequence value)
      throws DecodeException
  {
    final String definition = value.toString();
    final SubstringReader reader = new SubstringReader(definition);
    final String normalized =
        resolveNames(schema, SchemaUtils.readOID(reader));

    return new OIDAssertion(normalized);
  }



  public ByteString normalizeAttributeValue(Schema schema,
      ByteSequence value) throws DecodeException
  {
    final String definition = value.toString();
    final SubstringReader reader = new SubstringReader(definition);
    final String normalized =
        resolveNames(schema, SchemaUtils.readOID(reader));
    return ByteString.valueOf(normalized);
  }
}