/*
 * 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 legal-notices/CDDLv1_0.txt
 * or http://forgerock.org/license/CDDLv1.0.html.
 * 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 legal-notices/CDDLv1_0.txt.
 * 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 2014 ForgeRock AS.
 */
package org.opends.server.backends;

import java.util.Collections;
import java.util.Set;

import org.forgerock.i18n.slf4j.LocalizedLogger;
import org.forgerock.opendj.config.server.ConfigException;
import org.forgerock.opendj.ldap.ConditionResult;
import org.forgerock.opendj.ldap.ResultCode;
import org.forgerock.util.Reject;
import org.opends.server.admin.Configuration;
import org.opends.server.api.Backend;
import org.opends.server.core.AddOperation;
import org.opends.server.core.DeleteOperation;
import org.opends.server.core.DirectoryServer;
import org.opends.server.core.ModifyDNOperation;
import org.opends.server.core.ModifyOperation;
import org.opends.server.core.SearchOperation;
import org.opends.server.types.AttributeType;
import org.opends.server.types.BackupConfig;
import org.opends.server.types.BackupDirectory;
import org.opends.server.types.CanceledOperationException;
import org.opends.server.types.DN;
import org.opends.server.types.DirectoryException;
import org.opends.server.types.Entry;
import org.opends.server.types.IndexType;
import org.opends.server.types.InitializationException;
import org.opends.server.types.LDIFExportConfig;
import org.opends.server.types.LDIFImportConfig;
import org.opends.server.types.LDIFImportResult;
import org.opends.server.types.RestoreConfig;

import static org.opends.messages.BackendMessages.*;
import static org.opends.server.util.StaticUtils.*;

/**
 * An abstract backend that can be subclassed to plug-in different storage engines.
 *
 * @param <C>
 *          the type of the BackendCfg for the current backend
 */
public abstract class PluggableStorageBackend<C extends Configuration> extends Backend<C>
{
  private static final LocalizedLogger logger = LocalizedLogger.getLoggerForThisClass();

  /** The set of base DNs for this backend. */
  private DN[] baseDNs;

  /** {@inheritDoc} */
  @Override
  public void configureBackend(final Configuration cfg) throws ConfigException
  {
    Reject.ifNull(cfg);
  }

  /** {@inheritDoc} */
  @Override
  public void initializeBackend() throws InitializationException
  {
    for (DN baseDN : this.baseDNs)
    {
      try
      {
        DirectoryServer.registerBaseDN(baseDN, this, true);
      }
      catch (final Exception e)
      {
        throw new InitializationException(ERR_BACKEND_CANNOT_REGISTER_BASEDN.get(baseDN, getExceptionMessage(e)), e);
      }
    }
  }

  /** {@inheritDoc} */
  @Override
  public void finalizeBackend()
  {
    super.finalizeBackend();

    for (DN baseDN : this.baseDNs)
    {
      try
      {
        DirectoryServer.deregisterBaseDN(baseDN);
      }
      catch (final DirectoryException e)
      {
        logger.traceException(e);
      }
    }
  }

  /** {@inheritDoc} */
  @Override
  public DN[] getBaseDNs()
  {
    return baseDNs;
  }

  /** {@inheritDoc} */
  @Override
  public void preloadEntryCache() throws UnsupportedOperationException
  {
    throw new RuntimeException("Not implemented");
  }

  /** {@inheritDoc} */
  @Override
  public boolean isLocal()
  {
    return true;
  }

  /** {@inheritDoc} */
  @Override
  public boolean isIndexed(final AttributeType attributeType, final IndexType indexType)
  {
    throw new RuntimeException("Not implemented");
  }

  /** {@inheritDoc} */
  @Override
  public Entry getEntry(final DN entryDN) throws DirectoryException
  {
    if (entryDN == null)
    {
      throw new DirectoryException(DirectoryServer.getServerErrorResultCode(),
          ERR_BACKEND_GET_ENTRY_NULL.get(getBackendID()));
    }
    throw new RuntimeException("Not implemented");
  }

  /** {@inheritDoc} */
  @Override
  public ConditionResult hasSubordinates(final DN entryDN) throws DirectoryException
  {
    long ret = numSubordinates(entryDN, false);
    if (ret < 0)
    {
      return ConditionResult.UNDEFINED;
    }
    return ConditionResult.valueOf(ret != 0);
  }

  /** {@inheritDoc} */
  @Override
  public long numSubordinates(final DN entryDN, final boolean subtree) throws DirectoryException
  {
    throw new RuntimeException("Not implemented");
  }

  /** {@inheritDoc} */
  @Override
  public void addEntry(Entry entry, AddOperation addOperation) throws DirectoryException, CanceledOperationException
  {
    throw new DirectoryException(ResultCode.UNWILLING_TO_PERFORM,
        ERR_BACKEND_ADD_NOT_SUPPORTED.get(String.valueOf(entry.getName()), getBackendID()));
  }

  /** {@inheritDoc} */
  @Override
  public void deleteEntry(DN entryDN, DeleteOperation deleteOperation) throws DirectoryException,
      CanceledOperationException
  {
    throw new DirectoryException(ResultCode.UNWILLING_TO_PERFORM,
        ERR_BACKEND_DELETE_NOT_SUPPORTED.get(String.valueOf(entryDN), getBackendID()));
  }

  /** {@inheritDoc} */
  @Override
  public void replaceEntry(Entry oldEntry, Entry newEntry, ModifyOperation modifyOperation) throws DirectoryException,
      CanceledOperationException
  {
    throw new DirectoryException(ResultCode.UNWILLING_TO_PERFORM,
        ERR_BACKEND_MODIFY_NOT_SUPPORTED.get(String.valueOf(newEntry.getName()), getBackendID()));
  }

  /** {@inheritDoc} */
  @Override
  public void renameEntry(DN currentDN, Entry entry, ModifyDNOperation modifyDNOperation) throws DirectoryException,
      CanceledOperationException
  {
    throw new DirectoryException(ResultCode.UNWILLING_TO_PERFORM,
        ERR_BACKEND_MODIFY_DN_NOT_SUPPORTED.get(String.valueOf(currentDN), getBackendID()));
  }

  /** {@inheritDoc} */
  @Override
  public void search(final SearchOperation searchOperation) throws DirectoryException
  {
    throw new RuntimeException("Not implemented");
  }

  /** {@inheritDoc} */
  @Override
  public Set<String> getSupportedControls()
  {
    return Collections.emptySet();
  }

  /** {@inheritDoc} */
  @Override
  public Set<String> getSupportedFeatures()
  {
    return Collections.emptySet();
  }

  /** {@inheritDoc} */
  @Override
  public boolean supportsLDIFExport()
  {
    return false;
  }

  /** {@inheritDoc} */
  @Override
  public void exportLDIF(final LDIFExportConfig exportConfig) throws DirectoryException
  {
    throw new DirectoryException(ResultCode.UNWILLING_TO_PERFORM,
        ERR_BACKEND_IMPORT_AND_EXPORT_NOT_SUPPORTED.get(getBackendID()));
  }

  /** {@inheritDoc} */
  @Override
  public boolean supportsLDIFImport()
  {
    return false;
  }

  /** {@inheritDoc} */
  @Override
  public LDIFImportResult importLDIF(LDIFImportConfig importConfig) throws DirectoryException
  {
    throw new DirectoryException(ResultCode.UNWILLING_TO_PERFORM,
        ERR_BACKEND_IMPORT_AND_EXPORT_NOT_SUPPORTED.get(getBackendID()));
  }

  /** {@inheritDoc} */
  @Override
  public boolean supportsBackup()
  {
    throw new RuntimeException("Not implemented");
  }

  /** {@inheritDoc} */
  @Override
  public boolean supportsBackup(BackupConfig backupConfig, StringBuilder unsupportedReason)
  {
    throw new RuntimeException("Not implemented");
  }

  /** {@inheritDoc} */
  @Override
  public void createBackup(BackupConfig backupConfig) throws DirectoryException
  {
    throw new DirectoryException(ResultCode.UNWILLING_TO_PERFORM,
        ERR_BACKEND_BACKUP_AND_RESTORE_NOT_SUPPORTED.get(getBackendID()));
  }

  /** {@inheritDoc} */
  @Override
  public void removeBackup(BackupDirectory backupDirectory, String backupID) throws DirectoryException
  {
    throw new DirectoryException(ResultCode.UNWILLING_TO_PERFORM,
        ERR_BACKEND_BACKUP_AND_RESTORE_NOT_SUPPORTED.get(getBackendID()));
  }

  /** {@inheritDoc} */
  @Override
  public boolean supportsRestore()
  {
    throw new RuntimeException("Not implemented");
  }

  /** {@inheritDoc} */
  @Override
  public void restoreBackup(RestoreConfig restoreConfig) throws DirectoryException
  {
    throw new DirectoryException(ResultCode.UNWILLING_TO_PERFORM,
        ERR_BACKEND_BACKUP_AND_RESTORE_NOT_SUPPORTED.get(getBackendID()));
  }

  /** {@inheritDoc} */
  @Override
  public long getEntryCount()
  {
    throw new RuntimeException("Not implemented");
  }

}