/*
    *  Licensed to the Apache Software Foundation (ASF) under one
    *  or more contributor license agreements.  See the NOTICE file
    *  distributed with this work for additional information
    *  regarding copyright ownership.  The ASF licenses this file
    *  to you under the Apache License, Version 2.0 (the
    *  "License"); you may not use this file except in compliance
    *  with the License.  You may obtain a copy of the License at
    *  
   *    http://www.apache.org/licenses/LICENSE-2.0
   *  
   *  Unless required by applicable law or agreed to in writing,
   *  software distributed under the License is distributed on an
   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   *  KIND, either express or implied.  See the License for the
   *  specific language governing permissions and limitations
   *  under the License. 
   *  
   */
  package org.apache.directory.api.ldap.model.schema;
  
  
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.directory.api.i18n.I18n;
  
  
  /**
   * A dITStructureRule definition. A dITStructureRules is a rule governing the
   * structure of the DIT by specifying a permitted superior to subordinate entry
   * relationship. A structure rule relates a nameForm, and therefore a STRUCTURAL
   * objectClass, to superior dITStructureRules. This permits entries of the
   * STRUCTURAL objectClass identified by the nameForm to exist in the DIT as
   * subordinates to entries governed by the indicated superior dITStructureRules.
   * Hence dITStructureRules only apply to structural object classes.
   * <p>
   * According to ldapbis [MODELS]:
   * </p>
   * 
   * <pre>
   *  DIT structure rule descriptions are written according to the ABNF:
   *  
   *    DITStructureRuleDescription = LPAREN WSP
   *        ruleid                    ; rule identifier
   *        [ SP &quot;NAME&quot; SP qdescrs ]  ; short names (descriptors)
   *        [ SP &quot;DESC&quot; SP qdstring ] ; description
   *        [ SP &quot;OBSOLETE&quot; ]         ; not active
   *        SP &quot;FORM&quot; SP oid          ; NameForm
   *        [ SP &quot;SUP&quot; ruleids ]      ; superior rules
   *        extensions WSP RPAREN     ; extensions
   * 
   *    ruleids = ruleid / ( LPAREN WSP ruleidlist WSP RPAREN )
   * 
   *    ruleidlist = ruleid *( SP ruleid )
   * 
   *    ruleid = number
   * 
   *  where:
   *    [ruleid] is the rule identifier of this DIT structure rule;
   *    NAME [qdescrs] are short names (descriptors) identifying this DIT
   *        structure rule;
   *    DESC [qdstring] is a short descriptive string;
   *    OBSOLETE indicates this DIT structure rule use is not active;
   *    FORM is specifies the name form associated with this DIT structure
   *        rule;
   *    SUP identifies superior rules (by rule id); and
   *    [extensions] describe extensions.
   *  
   *  If no superior rules are identified, the DIT structure rule applies
   *  to an autonomous administrative point (e.g. the root vertex of the
   *  subtree controlled by the subschema) [X.501].
   * </pre>
   * 
   * @see <a href="http://www.faqs.org/rfcs/rfc2252.html">RFC2252 Section 6.33</a>
   * @see <a
   *      href="http://www.ietf.org/internet-drafts/draft-ietf-ldapbis-models-11.txt">ldapbis
   *      [MODELS]</a>
   * @see DescriptionUtils#getDescription(DitStructureRule)
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class DitStructureRule extends AbstractSchemaObject
  {
      /** The mandatory serialVersionUID */
      public static final long serialVersionUID = 1L;
  
      /** The rule ID. A DSR does not have an OID */
      private int ruleId;
  
      /** The associated NameForm */
      private String form;
  
      /** The list of superiors rules */
      private List<Integer> superRules;
  
  
      /**
       * Creates a new instance of DitStructureRule
       */
     public DitStructureRule( int ruleId )
     {
         super( SchemaObjectType.DIT_STRUCTURE_RULE, null );
         this.ruleId = ruleId;
         form = null;
         superRules = new ArrayList<Integer>();
     }
 
 
     /**
      *  @return The associated NameForm's OID
      */
     public String getForm()
     {
         return form;
     }
 
 
     /**
      * Sets the associated NameForm's OID
      *
      * @param form The NameForm's OID
      */
     public void setForm( String form )
     {
         if ( locked )
         {
             throw new UnsupportedOperationException( I18n.err( I18n.ERR_04441, getName() ) );
         }
 
         if ( !isReadOnly )
         {
             this.form = form;
         }
     }
 
 
     /**
      * @return The Rule ID
      */
     public int getRuleId()
     {
         return ruleId;
     }
 
 
     /**
      * Sets the rule identifier of this DIT structure rule;
      *
      * @param ruleId the rule identifier of this DIT structure rule;
      */
     public void setRuleId( int ruleId )
     {
         if ( locked )
         {
             throw new UnsupportedOperationException( I18n.err( I18n.ERR_04441, getName() ) );
         }
 
         if ( !isReadOnly )
         {
             this.ruleId = ruleId;
         }
     }
 
 
     /**
      * @return The list of superiors RuleIDs
      */
     public List<Integer> getSuperRules()
     {
         return superRules;
     }
 
 
     /**
      * Sets the list of superior RuleIds
      * 
      * @param superRules the list of superior RuleIds
      */
     public void setSuperRules( List<Integer> superRules )
     {
         if ( locked )
         {
             throw new UnsupportedOperationException( I18n.err( I18n.ERR_04441, getName() ) );
         }
 
         if ( !isReadOnly )
         {
             this.superRules = superRules;
         }
     }
 
 
     /**
      * Adds a new superior RuleId
      *
      * @param superRule The superior RuleID to add
      */
     public void addSuperRule( Integer superRule )
     {
         if ( locked )
         {
             throw new UnsupportedOperationException( I18n.err( I18n.ERR_04441, getName() ) );
         }
 
         superRules.add( superRule );
     }
 
 
     /**
      * The DIT structure rule does not have an OID
      * 
      * {@inheritDoc}
      */
     @Override
     public String getOid()
     {
         // We cannot throw exception here. E.g. SchemaObjectWrapper will try to use this in hashcode.
         return null;
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public String toString()
     {
         return SchemaObjectRenderer.OPEN_LDAP_SCHEMA_RENDERER.render( this );
     }
 
 
     /**
      * {@inheritDoc}
      */
     public DitStructureRule copy()
     {
         DitStructureRule copy = new DitStructureRule( ruleId );
 
         // Copy the SchemaObject common data
         copy.copy( this );
 
         // Copy the Superiors rules
         copy.superRules = new ArrayList<Integer>();
 
         // Copy the form
         copy.form = form;
 
         for ( int superRule : superRules )
         {
             copy.superRules.add( superRule );
         }
 
         return copy;
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public boolean equals( Object o )
     {
         if ( !super.equals( o ) )
         {
             return false;
         }
 
         if ( !( o instanceof DitStructureRule ) )
         {
             return false;
         }
 
         @SuppressWarnings("unused")
         DitStructureRule that = ( DitStructureRule ) o;
 
         // TODO : complete the test
         return true;
     }
 
 
     /**
      * {@inheritDoc}
      */
     public void clear()
     {
         // Clear the common elements
         super.clear();
 
         // Clear the references
         superRules.clear();
     }
 }