/*
 * 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 2009-2010 Sun Microsystems, Inc.
 */

package org.opends.guitools.controlpanel.util;

import java.util.HashSet;
import java.util.List;
import java.util.Set;

import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.SearchControls;
import javax.naming.directory.SearchResult;
import javax.naming.ldap.InitialLdapContext;

import org.opends.guitools.controlpanel.browser.BrowserController;
import org.opends.guitools.controlpanel.datamodel.CustomSearchResult;
import org.opends.server.config.ConfigConstants;
import org.opends.server.config.ConfigException;
import org.opends.server.schema.AttributeTypeSyntax;
import org.opends.server.schema.ObjectClassSyntax;
import org.opends.server.types.AttributeType;
import org.opends.server.types.ByteStringBuilder;
import org.opends.server.types.DirectoryException;
import org.opends.server.types.InitializationException;
import org.opends.server.types.ObjectClass;
import org.opends.server.types.Schema;

/**
 * Class used to retrieve the schema from the schema files.
 *
 */
public class RemoteSchemaLoader extends SchemaLoader
{
  private Schema schema;

  /**
   * Constructor.
   *
   */
  public RemoteSchemaLoader()
  {
    super();
  }

  /**
   * Reads the schema.
   * @param ctx the connection to be used to load the schema.
   * @throws NamingException if an error occurs reading the schema.
   * @throws DirectoryException if an error occurs parsing the schema.
   * @throws InitializationException if an error occurs finding the base
   * schema.
   * @throws ConfigException if an error occurs loading the configuration
   * required to use the schema classes.
   */
  public void readSchema(InitialLdapContext ctx) throws NamingException,
  DirectoryException, InitializationException, ConfigException
  {
    SearchControls searchControls = new SearchControls();
    searchControls.setSearchScope(SearchControls.OBJECT_SCOPE);
    String[] schemaAttrs =
    {
        ConfigConstants.ATTR_OBJECTCLASSES_LC,
        ConfigConstants.ATTR_ATTRIBUTE_TYPES_LC
    };
    searchControls.setReturningAttributes(schemaAttrs);
    String filter = BrowserController.ALL_OBJECTS_FILTER;
    NamingEnumeration<SearchResult> srs =
      ctx.search(ConfigConstants.DN_DEFAULT_SCHEMA_ROOT,
          filter,
          searchControls);
    SearchResult sr = null;
    try
    {
      while (srs.hasMore())
      {
        sr = srs.next();
      }
    }
    finally
    {
      srs.close();
    }
    CustomSearchResult csr = new CustomSearchResult(sr,
        ConfigConstants.DN_DEFAULT_SCHEMA_ROOT);

    schema = getBaseSchema();

    List<Object> attrs =
      csr.getAttributeValues(ConfigConstants.ATTR_ATTRIBUTE_TYPES_LC);
    Set<String> remainingAttrs = new HashSet<String>();
    for (Object o : attrs)
    {
      remainingAttrs.add((String)o);
    }

    while (!remainingAttrs.isEmpty())
    {
      DirectoryException lastException = null;
      boolean oneRegistered = false;
      Set<String> registeredAttrs = new HashSet<String>();
      for (String attrDefinition : remainingAttrs)
      {
        ByteStringBuilder sb = new ByteStringBuilder();
        sb.append(attrDefinition);
        try
        {
          AttributeType attrType =
            AttributeTypeSyntax.decodeAttributeType(sb, schema, false);
          schema.registerAttributeType(attrType, true);
          oneRegistered = true;
          registeredAttrs.add(attrDefinition);
        }
        catch (DirectoryException de)
        {
          lastException = de;
        }
      }
      if (!oneRegistered)
      {
        throw lastException;
      }
      remainingAttrs.removeAll(registeredAttrs);
    }

    List<Object> objectClasses =
      csr.getAttributeValues(ConfigConstants.ATTR_OBJECTCLASSES_LC);

    Set<String> remainingOcs = new HashSet<String>();
    for (Object o : objectClasses)
    {
      remainingOcs.add((String)o);
    }

    while (!remainingOcs.isEmpty())
    {
      DirectoryException lastException = null;
      boolean oneRegistered = false;
      Set<String> registeredOcs = new HashSet<String>();
      for (String ocDefinition : remainingOcs)
      {
        ByteStringBuilder sb = new ByteStringBuilder();
        sb.append(ocDefinition);
        try
        {
          ObjectClass oc =
            ObjectClassSyntax.decodeObjectClass(sb, schema, false);
          schema.registerObjectClass(oc, true);
          oneRegistered = true;
          registeredOcs.add(ocDefinition);
        }
        catch (DirectoryException de)
        {
          lastException = de;
        }
      }
      if (!oneRegistered)
      {
        throw lastException;
      }
      remainingOcs.removeAll(registeredOcs);
    }
  }

  /**
   * Returns the schema that was read.
   * @return the schema that was read.
   */
  @Override
  public Schema getSchema()
  {
    return schema;
  }
}