/*
    *  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.codec.search;
  
  
  import java.nio.BufferOverflowException;
  import java.nio.ByteBuffer;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.directory.api.asn1.EncoderException;
  import org.apache.directory.api.asn1.ber.tlv.BerValue;
  import org.apache.directory.api.asn1.ber.tlv.TLV;
  import org.apache.directory.api.asn1.ber.tlv.UniversalTag;
  import org.apache.directory.api.i18n.I18n;
  import org.apache.directory.api.ldap.codec.api.LdapConstants;
  import org.apache.directory.api.util.Strings;
  
  
  /**
   * A Object that stores the substring filter. 
   * 
   * A substring filter follow this
   * grammar : 
   * 
   * substring = attr "=" ( ([initial] any [final] | 
   *                        (initial [any] [final) | 
   *                        ([initial] [any] final) ) 
   *                       
   * initial = value 
   * any = "*" *(value "*")
   * final = value
   * 
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class SubstringFilter extends Filter
  {
      /** The substring filter type (an attributeDescription) */
      private String type;
  
      /**
       * This member is used to control the length of the three parts of the
       * substring filter
       */
      private int substringsLength;
  
      /** The initial filter */
      private String initialSubstrings;
  
      /** The any filter. It's a list of LdapString */
      private List<String> anySubstrings = new ArrayList<String>( 1 );
  
      /** The final filter */
      private String finalSubstrings;
  
      /** Temporary storage for substringsFilter length */
      private int substringsFilterLength;
  
      /** Temporary storage for substringsFilter sequence length */
      private int substringsFilterSequenceLength;
  
  
      // ~ Methods
      // ------------------------------------------------------------------------------------
  
      /**
       * The constructor. We will create the 'any' subsring arraylist with only
       * one element.
       */
      public SubstringFilter( int tlvId )
      {
          super( tlvId );
      }
  
  
      /**
       * The constructor. We will create the 'any' subsring arraylist with only
       * one element.
       */
      public SubstringFilter()
      {
          super();
     }
 
 
     /**
      * Get the internal substrings
      * 
      * @return Returns the anySubstrings.
      */
     public List<String> getAnySubstrings()
     {
         return anySubstrings;
     }
 
 
     /**
      * Add a internal substring
      * 
      * @param any The anySubstrings to set.
      */
     public void addAnySubstrings( String any )
     {
         this.anySubstrings.add( any );
     }
 
 
     /**
      * Get the final substring
      * 
      * @return Returns the finalSubstrings.
      */
     public String getFinalSubstrings()
     {
         return finalSubstrings;
     }
 
 
     /**
      * Set the final substring
      * 
      * @param finalSubstrings The finalSubstrings to set.
      */
     public void setFinalSubstrings( String finalSubstrings )
     {
         this.finalSubstrings = finalSubstrings;
     }
 
 
     /**
      * Get the initial substring
      * 
      * @return Returns the initialSubstrings.
      */
     public String getInitialSubstrings()
     {
         return initialSubstrings;
     }
 
 
     /**
      * Set the initial substring
      * 
      * @param initialSubstrings The initialSubstrings to set.
      */
     public void setInitialSubstrings( String initialSubstrings )
     {
         this.initialSubstrings = initialSubstrings;
     }
 
 
     /**
      * Get the attribute
      * 
      * @return Returns the type.
      */
     public String getType()
     {
         return type;
     }
 
 
     /**
      * Set the attribute to match
      * 
      * @param type The type to set.
      */
     public void setType( String type )
     {
         this.type = type;
     }
 
 
     /**
      * @return Returns the substringsLength.
      */
     public int getSubstringsLength()
     {
         return substringsLength;
     }
 
 
     /**
      * @param substringsLength The substringsLength to set.
      */
     public void setSubstringsLength( int substringsLength )
     {
         this.substringsLength = substringsLength;
     }
 
 
     /**
      * Compute the SubstringFilter length 
      * 
      * SubstringFilter : 
      * 0xA4 L1 
      *   | 
      *   +--> 0x04 L2 type 
      *   +--> 0x30 L3 
      *          | 
      *         [+--> 0x80 L4 initial] 
      *         [+--> 0x81 L5-1 any] 
      *         [+--> 0x81 L5-2 any] 
      *         [+--> ... 
      *         [+--> 0x81 L5-i any] 
      *         [+--> ... 
      *         [+--> 0x81 L5-n any] 
      *         [+--> 0x82 L6 final]
      */
     public int computeLength()
     {
         // The type
         int typeLength = Strings.getBytesUtf8( type ).length;
 
         substringsFilterLength = 1 + TLV.getNbBytes( typeLength ) + typeLength;
         substringsFilterSequenceLength = 0;
 
         if ( initialSubstrings != null )
         {
             int initialLength = Strings.getBytesUtf8( initialSubstrings ).length;
             substringsFilterSequenceLength += 1 + TLV.getNbBytes( initialLength )
                 + initialLength;
         }
 
         if ( anySubstrings != null )
         {
             for ( String any : anySubstrings )
             {
                 int anyLength = Strings.getBytesUtf8( any ).length;
                 substringsFilterSequenceLength += 1 + TLV.getNbBytes( anyLength ) + anyLength;
             }
         }
 
         if ( finalSubstrings != null )
         {
             int finalLength = Strings.getBytesUtf8( finalSubstrings ).length;
             substringsFilterSequenceLength += 1 + TLV.getNbBytes( finalLength )
                 + finalLength;
         }
 
         substringsFilterLength += 1 + TLV.getNbBytes( substringsFilterSequenceLength )
             + substringsFilterSequenceLength;
 
         return 1 + TLV.getNbBytes( substringsFilterLength ) + substringsFilterLength;
     }
 
 
     /**
      * Encode the Substrings Filter to a PDU. 
      * 
      * Substrings Filter :
      * 
      * 0xA4 LL 
      * 0x30 LL substringsFilter
      *   0x04 LL type
      *   0x30 LL substrings sequence
      *    |  0x80 LL initial
      *    | /  [0x81 LL any]* 
      *    |/   [0x82 LL final]
      *    +--[0x81 LL any]+
      *     \   [0x82 LL final]
      *      \
      *       0x82 LL final
      * 
      * @param buffer The buffer where to put the PDU
      * @return The PDU.
      */
     public ByteBuffer encode( ByteBuffer buffer ) throws EncoderException
     {
         if ( buffer == null )
         {
             throw new EncoderException( I18n.err( I18n.ERR_04023 ) );
         }
 
         try
         {
             // The SubstringFilter Tag
             buffer.put( ( byte ) LdapConstants.SUBSTRINGS_FILTER_TAG );
             buffer.put( TLV.getBytes( substringsFilterLength ) );
 
             // The type
             BerValue.encode( buffer, type.getBytes() );
 
             // The SubstringSequenceFilter Tag
             buffer.put( UniversalTag.SEQUENCE.getValue() );
             buffer.put( TLV.getBytes( substringsFilterSequenceLength ) );
 
             if ( ( initialSubstrings == null ) && ( ( anySubstrings == null ) || ( anySubstrings.size() == 0 ) )
                 && ( finalSubstrings == null ) )
             {
                 throw new EncoderException( I18n.err( I18n.ERR_04058 ) );
             }
 
             // The initial substring
             if ( initialSubstrings != null )
             {
                 byte[] initialBytes = Strings.getBytesUtf8( initialSubstrings );
                 buffer.put( ( byte ) LdapConstants.SUBSTRINGS_FILTER_INITIAL_TAG );
                 buffer.put( TLV.getBytes( initialBytes.length ) );
                 buffer.put( initialBytes );
             }
 
             // The any substrings
             if ( anySubstrings != null )
             {
                 for ( String any : anySubstrings )
                 {
                     byte[] anyBytes = Strings.getBytesUtf8( any );
                     buffer.put( ( byte ) LdapConstants.SUBSTRINGS_FILTER_ANY_TAG );
                     buffer.put( TLV.getBytes( anyBytes.length ) );
                     buffer.put( anyBytes );
                 }
             }
 
             // The final substring
             if ( finalSubstrings != null )
             {
                 byte[] finalBytes = Strings.getBytesUtf8( finalSubstrings );
                 buffer.put( ( byte ) LdapConstants.SUBSTRINGS_FILTER_FINAL_TAG );
                 buffer.put( TLV.getBytes( finalBytes.length ) );
                 buffer.put( finalBytes );
             }
         }
         catch ( BufferOverflowException boe )
         {
             throw new EncoderException( I18n.err( I18n.ERR_04005 ) );
         }
 
         return buffer;
     }
 
 
     /**
      * Return a string compliant with RFC 2254 representing a Substring filter
      * 
      * @return The substring filter string
      */
     public String toString()
     {
 
         StringBuffer sb = new StringBuffer();
 
         if ( initialSubstrings != null )
         {
             sb.append( initialSubstrings );
         }
 
         sb.append( '*' );
 
         if ( anySubstrings != null )
         {
             for ( String any : anySubstrings )
             {
                 sb.append( any ).append( '*' );
             }
         }
 
         if ( finalSubstrings != null )
         {
             sb.append( finalSubstrings );
         }
 
         return sb.toString();
     }
 }