/*
    *  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
    *  
   *    https://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.syntaxCheckers;
  
  
  import org.apache.directory.api.i18n.I18n;
  import org.apache.directory.api.ldap.model.constants.SchemaConstants;
  import org.apache.directory.api.ldap.model.schema.SyntaxChecker;
  import org.apache.directory.api.util.Strings;
  
  
  /**
   * A SyntaxChecker which verifies that a value is a NisNetGroupTriple according to 
   * RFC 2307 :
   * <pre>
   * nisnetgrouptriple = "(" hostname "," username "," domainname ")"
   *      hostname          = "" / "-" / keystring
   *      username          = "" / "-" / keystring
   *      domainname        = "" / "-" / keystring
   * </pre>
   * 
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  @SuppressWarnings("serial")
  public final class NisNetgroupTripleSyntaxChecker extends SyntaxChecker
  {
      /**
       * A static instance of NisNetGroupTripleChecker
       */
      public static final NisNetgroupTripleSyntaxChecker INSTANCE = 
          new NisNetgroupTripleSyntaxChecker( SchemaConstants.NIS_NETGROUP_TRIPLE_SYNTAX );
      
      /**
       * A static Builder for this class
       */
      public static final class Builder extends SCBuilder<NisNetgroupTripleSyntaxChecker>
      {
          /**
           * The Builder constructor
           */
          private Builder()
          {
              super( SchemaConstants.NIS_NETGROUP_TRIPLE_SYNTAX );
          }
          
          
          /**
           * Create a new instance of NisNetgroupTripleSyntaxChecker
           * @return A new instance of NisNetgroupTripleSyntaxChecker
           */
          @Override
          public NisNetgroupTripleSyntaxChecker build()
          {
              return new NisNetgroupTripleSyntaxChecker( oid );
          }
      }
  
      
      /**
       * Creates a new instance of NisNetgroupTripleSyntaxChecker.
       * 
       * @param oid The OID to use for this SyntaxChecker
       */
      private NisNetgroupTripleSyntaxChecker( String oid )
      {
          super( oid );
      }
  
      
      /**
       * @return An instance of the Builder for this class
       */
      public static Builder builder()
      {
          return new Builder();
      }
      
      
      private int parseKeyString( String strValue, int pos )
      {
          char c = strValue.charAt( pos );
          
         // The end of the keyString
         if ( ( c == ',' ) || ( c == ')' ) )
         {
             return pos;
         }
         
         // We must have a first alphabetic char
         if ( Character.isUpperCase( c ) || Character.isLowerCase( c ) )
         {
             pos++;
         }
         else
         {
             return -1;
         }
         
         try 
         { 
             c = strValue.charAt( pos );
             
             while ( ( c != ',' ) && ( c != ')' ) )
             {
                 if ( Character.isUpperCase( c ) || Character.isLowerCase( c ) || Character.isDigit( c )
                     || ( c == '-' ) || ( c == ';' ) || ( c == '_' ) )
                 {
                     pos++;
                 }
                 else
                 {
                     return -1;
                 }
 
                 c = strValue.charAt( pos );
             }
             
             return pos;
         }
         catch ( IndexOutOfBoundsException ioobe )
         {
             return -1;
         }
     }
     
 
     /**
      * {@inheritDoc}
      */
     @Override
     public boolean isValidSyntax( Object value )
     {
         String strValue;
 
         if ( value == null )
         {
             if ( LOG.isDebugEnabled() )
             {
                 LOG.debug( I18n.err( I18n.ERR_13210_SYNTAX_INVALID, "null" ) );
             }
             
             return false;
         }
 
         if ( value instanceof String )
         {
             strValue = ( String ) value;
         }
         else if ( value instanceof byte[] )
         {
             strValue = Strings.utf8ToString( ( byte[] ) value );
         }
         else
         {
             strValue = value.toString();
         }
 
         // The  nisNetGroup must at least contain a '(', 2 ',' and a ')'
         if ( strValue.length() < 4 )
         {
             if ( LOG.isDebugEnabled() )
             {
                 LOG.debug( I18n.err( I18n.ERR_13210_SYNTAX_INVALID, value ) );
             }
             
             return false;
         }
 
         // The hostname
         int pos = parseKeyString( strValue, 1 );
         
         if ( pos == -1 )
         {
             if ( LOG.isDebugEnabled() )
             {
                 LOG.debug( I18n.err( I18n.ERR_13210_SYNTAX_INVALID, value ) );
             }
             
             return false;
         }
         
         if ( strValue.charAt( pos ) != ',' )
         {
             if ( LOG.isDebugEnabled() )
             {
                 LOG.debug( I18n.err( I18n.ERR_13210_SYNTAX_INVALID, value ) );
             }
             
             return false;
         }
         else
         {
             pos++;
         }
 
         // The username
         pos = parseKeyString( strValue, pos );
         
         if ( pos == -1 )
         {
             if ( LOG.isDebugEnabled() )
             {
                 LOG.debug( I18n.err( I18n.ERR_13210_SYNTAX_INVALID, value ) );
             }
             
             return false;
         }
         
         if ( strValue.charAt( pos ) != ',' )
         {
             if ( LOG.isDebugEnabled() )
             {
                 LOG.debug( I18n.err( I18n.ERR_13210_SYNTAX_INVALID, value ) );
             }
             
             return false;
         }
         else
         {
             pos++;
         }
 
         // The domainname
         pos = parseKeyString( strValue, pos );
         
         if ( pos == -1 )
         {
             if ( LOG.isDebugEnabled() )
             {
                 LOG.debug( I18n.err( I18n.ERR_13210_SYNTAX_INVALID, value ) );
             }
             
             return false;
         }
         
         if ( strValue.charAt( pos ) != ')' )
         {
             if ( LOG.isDebugEnabled() )
             {
                 LOG.debug( I18n.err( I18n.ERR_13210_SYNTAX_INVALID, value ) );
             }
             
             return false;
         }
 
         return true;
     }
 }