/*
    *  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.server.config;
  
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.Iterator;
  import java.util.UUID;
  
  import org.apache.directory.api.ldap.model.constants.SchemaConstants;
  import org.apache.directory.api.ldap.model.entry.DefaultEntry;
  import org.apache.directory.api.ldap.model.entry.Entry;
  import org.apache.directory.api.ldap.model.exception.LdapException;
  import org.apache.directory.api.ldap.model.exception.LdapInvalidDnException;
  import org.apache.directory.api.ldap.model.exception.LdapOtherException;
  import org.apache.directory.api.ldap.model.ldif.LdifEntry;
  import org.apache.directory.api.ldap.model.ldif.LdifReader;
  import org.apache.directory.api.ldap.model.name.Dn;
  import org.apache.directory.api.ldap.model.schema.SchemaManager;
  import org.apache.directory.server.core.api.interceptor.context.AddOperationContext;
  import org.apache.directory.server.core.api.interceptor.context.DeleteOperationContext;
  import org.apache.directory.server.core.api.interceptor.context.ModifyOperationContext;
  import org.apache.directory.server.core.api.interceptor.context.MoveAndRenameOperationContext;
  import org.apache.directory.server.core.api.interceptor.context.MoveOperationContext;
  import org.apache.directory.server.core.api.interceptor.context.RenameOperationContext;
  import org.apache.directory.server.core.api.partition.PartitionTxn;
  import org.apache.directory.server.core.partition.ldif.AbstractLdifPartition;
  
  
  /**
   * This class implements a read-only configuration partition.
   *
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class ReadOnlyConfigurationPartition extends AbstractLdifPartition
  {
      /** The input stream */
      private InputStream inputStream;
  
  
      /**
       * Creates a new instance of ReadOnlyConfigurationPartition.
       *
       * @param inputStream
       *      the input stream
       * @param schemaManager
       *      the schema manager
       */
      public ReadOnlyConfigurationPartition( InputStream inputStream, SchemaManager schemaManager )
      {
          super( schemaManager );
          this.inputStream = inputStream;
          id = "config";
  
          try
          {
              suffixDn = new Dn( schemaManager, "ou=config" );
          }
          catch ( LdapInvalidDnException lide )
          {
              // Nothing to do
          }
      }
  
  
      /**
       * {@inheritDoc}
       */
      @Override
      protected void doInit() throws LdapException
      {
          if ( !initialized )
          {
              // Initializing the wrapped partition
              super.doInit();
  
              // Load LDIF entries
              loadLdifEntries();
          }
      }
  
 
     /**
      * Loads the LDIF entries from the input stream.
      * 
      * @throws Exception
      */
     private void loadLdifEntries() throws LdapException
     {
         if ( inputStream != null )
         {
             // Initializing the reader and the entry iterator
             try ( LdifReader reader = new LdifReader( inputStream ) )
             {
                 Iterator<LdifEntry> itr = reader.iterator();
     
                 // Exiting if there's no entry
                 if ( !itr.hasNext() )
                 {
                     return;
                 }
     
                 // Getting the context entry
                 LdifEntry ldifEntry = itr.next();
                 Entry contextEntry = new DefaultEntry( schemaManager, ldifEntry.getEntry() );
     
                 // Checking the context entry
                 if ( suffixDn.equals( contextEntry.getDn() ) )
                 {
                     addMandatoryOpAt( contextEntry );
     
                     super.add( new AddOperationContext( null, contextEntry ) );
                 }
                 else
                 {
                     throw new LdapException( "The given LDIF file doesn't contain the context entry" );
                 }
     
                 // Iterating on all entries
                 while ( itr.hasNext() )
                 {
                     Entry entry = new DefaultEntry( schemaManager, itr.next().getEntry() );
                     addMandatoryOpAt( entry );
     
                     super.add( new AddOperationContext( null, entry ) );
                 }
             }
             catch ( IOException ioe )
             {
                 throw new LdapOtherException( ioe.getMessage(), ioe );
             }
         }
     }
 
 
     /**
      * Adds the CSN and UUID attributes to the entry if they are not present.
      */
     private void addMandatoryOpAt( Entry entry ) throws LdapException
     {
         // entryCSN
         if ( entry.get( SchemaConstants.ENTRY_CSN_AT ) == null )
         {
             entry.add( SchemaConstants.ENTRY_CSN_AT, defaultCSNFactory.newInstance().toString() );
         }
 
         // entryUUID
         if ( entry.get( SchemaConstants.ENTRY_UUID_AT ) == null )
         {
             String uuid = UUID.randomUUID().toString();
             entry.add( SchemaConstants.ENTRY_UUID_AT, uuid );
         }
     }
 
 
     //---------------------------------------------------------------------------------------------
     // Operations
     //---------------------------------------------------------------------------------------------
     /**
      * {@inheritDoc}
      */
     @Override
     public void add( AddOperationContext arg0 ) throws LdapException
     {
         // Does nothing (Read-Only)
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public Entry delete( PartitionTxn partitionTxn, String id ) throws LdapException
     {
         // Does nothing (Read-Only)
         return null;
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public Entry delete( DeleteOperationContext deleteContext ) throws LdapException
     {
         // Does nothing (Read-Only)
         return null;
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void modify( ModifyOperationContext arg0 ) throws LdapException
     {
         // Does nothing (Read-Only)
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void move( MoveOperationContext arg0 ) throws LdapException
     {
         // Does nothing (Read-Only)
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void moveAndRename( MoveAndRenameOperationContext arg0 ) throws LdapException
     {
         // Does nothing (Read-Only)
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void rename( RenameOperationContext arg0 ) throws LdapException
     {
         // Does nothing (Read-Only)
     }
 }