/*
 * 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 2008-2009 Sun Microsystems, Inc.
 *      Portions Copyright 2014-2015 ForgeRock AS
 */
package org.opends.server.tasks;

import static org.opends.messages.TaskMessages.*;
import static org.opends.server.util.ServerConstants.*;
import static org.opends.server.util.StaticUtils.*;

import java.util.List;

import org.forgerock.i18n.LocalizableMessage;
import org.forgerock.i18n.slf4j.LocalizedLogger;
import org.forgerock.opendj.ldap.ByteString;
import org.forgerock.opendj.ldap.ResultCode;
import org.opends.server.api.ClientConnection;
import org.opends.server.api.ConnectionHandler;
import org.opends.server.backends.task.Task;
import org.opends.server.backends.task.TaskState;
import org.opends.server.core.DirectoryServer;
import org.opends.server.types.Attribute;
import org.opends.server.types.AttributeType;
import org.opends.server.types.DirectoryException;
import org.opends.server.types.DisconnectReason;
import org.opends.server.types.Entry;
import org.opends.server.types.Operation;
import org.opends.server.types.Privilege;

/**
 * This class provides an implementation of a Directory Server task that can be
 * used to terminate a client connection.
 */
public class DisconnectClientTask extends Task
{
  private static final LocalizedLogger logger = LocalizedLogger.getLoggerForThisClass();

  /** Indicates whether to send a notification message to the client. */
  private boolean notifyClient;

  /** The connection ID for the client connection to terminate. */
  private long connectionID;

  /** The disconnect message to send to the client. */
  private LocalizableMessage disconnectMessage;

  /** {@inheritDoc} */
  @Override
  public LocalizableMessage getDisplayName() {
    return INFO_TASK_DISCONNECT_CLIENT_NAME.get();
  }

  /** {@inheritDoc} */
  @Override
  public void initializeTask() throws DirectoryException
  {
    // If the client connection is available, then make sure the client has the
    // DISCONNECT_CLIENT privilege.
    Operation operation = getOperation();
    if (operation != null)
    {
      ClientConnection conn = operation.getClientConnection();
      if (! conn.hasPrivilege(Privilege.DISCONNECT_CLIENT, operation))
      {
        LocalizableMessage message = ERR_TASK_DISCONNECT_NO_PRIVILEGE.get();
        throw new DirectoryException(ResultCode.INSUFFICIENT_ACCESS_RIGHTS,
                                     message);
      }
    }

    final Entry taskEntry = getTaskEntry();
    connectionID = getConnectionID(taskEntry);
    if (connectionID < 0)
    {
      LocalizableMessage message =
          ERR_TASK_DISCONNECT_NO_CONN_ID.get(ATTR_TASK_DISCONNECT_CONN_ID);
      throw new DirectoryException(ResultCode.CONSTRAINT_VIOLATION, message);
    }

    notifyClient = mustNotifyClient(taskEntry);
    disconnectMessage = getDisconnectMessage(taskEntry);
  }

  private long getConnectionID(Entry taskEntry) throws DirectoryException
  {
    final AttributeType attrType = DirectoryServer.getAttributeTypeOrDefault(ATTR_TASK_DISCONNECT_CONN_ID);
    final List<Attribute> attrList = taskEntry.getAttribute(attrType);
    if (attrList != null)
    {
      for (Attribute a : attrList)
      {
        for (ByteString v : a)
        {
          try
          {
            return Long.parseLong(v.toString());
          }
          catch (Exception e)
          {
            LocalizableMessage message = ERR_TASK_DISCONNECT_INVALID_CONN_ID.get(v);
            throw new DirectoryException(ResultCode.INVALID_ATTRIBUTE_SYNTAX, message, e);
          }
        }
      }
    }
    return -1;
  }

  private boolean mustNotifyClient(Entry taskEntry) throws DirectoryException
  {
    final AttributeType attrType = DirectoryServer.getAttributeTypeOrDefault(ATTR_TASK_DISCONNECT_NOTIFY_CLIENT);
    final List<Attribute> attrList = taskEntry.getAttribute(attrType);
    if (attrList != null)
    {
      for (Attribute a : attrList)
      {
        for (ByteString v : a)
        {
          final String stringValue = toLowerCase(v.toString());
          if ("true".equals(stringValue))
          {
            return true;
          }
          else if ("false".equals(stringValue))
          {
            return false;
          }
          else
          {
            LocalizableMessage message = ERR_TASK_DISCONNECT_INVALID_NOTIFY_CLIENT.get(stringValue);
            throw new DirectoryException(ResultCode.INVALID_ATTRIBUTE_SYNTAX, message);
          }
        }
      }
    }
    return false;
  }

  private LocalizableMessage getDisconnectMessage(Entry taskEntry)
  {
    AttributeType attrType = DirectoryServer.getAttributeTypeOrDefault(ATTR_TASK_DISCONNECT_MESSAGE);
    List<Attribute> attrList = taskEntry.getAttribute(attrType);
    if (attrList != null)
    {
      for (Attribute a : attrList)
      {
        for (ByteString v : a)
        {
          return LocalizableMessage.raw(v.toString());
        }
      }
    }
    return INFO_TASK_DISCONNECT_GENERIC_MESSAGE.get();
  }

  /** {@inheritDoc} */
  @Override
  protected TaskState runTask()
  {
    final ClientConnection clientConnection = getClientConnection();
    if (clientConnection == null)
    {
      logger.error(ERR_TASK_DISCONNECT_NO_SUCH_CONNECTION, connectionID);
      return TaskState.COMPLETED_WITH_ERRORS;
    }

    clientConnection.disconnect(DisconnectReason.ADMIN_DISCONNECT, notifyClient, disconnectMessage);
    return TaskState.COMPLETED_SUCCESSFULLY;
  }

  private ClientConnection getClientConnection()
  {
    for (ConnectionHandler<?> handler : DirectoryServer.getConnectionHandlers())
    {
      for (ClientConnection c : handler.getClientConnections())
      {
        if (c.getConnectionID() == connectionID)
        {
          return c;
        }
      }
    }
    return null;
  }
}