/***********************************************************
Copyright (C) 2004 VeriSign, Inc.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

http://www.verisign.com/nds/naming/namestore/techdocs.html
***********************************************************/
package com.verisign.epp.framework;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.verisign.epp.codec.domain.EPPDomainCheckCmd;
import com.verisign.epp.codec.domain.EPPDomainCreateCmd;
import com.verisign.epp.codec.domain.EPPDomainDeleteCmd;
import com.verisign.epp.codec.domain.EPPDomainInfoCmd;
import com.verisign.epp.codec.domain.EPPDomainMapFactory;
import com.verisign.epp.codec.domain.EPPDomainRenewCmd;
import com.verisign.epp.codec.domain.EPPDomainTransferCmd;
import com.verisign.epp.codec.domain.EPPDomainUpdateCmd;
// EPP Imports
import com.verisign.epp.codec.gen.EPPCodecException;
import com.verisign.epp.codec.gen.EPPFactory;
import com.verisign.epp.codec.gen.EPPMessage;

/**
 * The <code>EPPDomainHandler</code> class provides an interface for handling
 * EPP Domain Commands in a Server implementation. EPPEvents are handled by the
 * handleEvent() method here and routed to the appropriate abstract member
 * function. Subclasses should override the abstract methods to define the
 * desired behavior of a particular command when it is received. A subclassed
 * instance of <code>EPPDomainHandler</code> should be registered with the
 * <code>EPPDispatcher</code> so that EEPEvents related to the Domain Mapping
 * will be handled there. <br>
 * <br>
 *
 * @author $Author: jim $
 * @version $Revision: 1.2 $
 *
 * @see EPPEventHandler
 * @see EPPEvent
 */
public abstract class EPPDomainHandler implements EPPEventHandler {
  /** The Namespace that this handler supports. In this case, domain. */
  private static final String NS = EPPDomainMapFactory.NS;

  /** Category for logging */
  private static Logger cat = LoggerFactory.getLogger(EPPDomainHandler.class);

  /**
   * Construct an instance of <code>EPPDomainHandler</code>
   */
  /**
   * Whenever an EPPDomainHandler instance is created load the corresponsding
   * Map Factory into the Codec
   */
  public EPPDomainHandler() {
    try {
      EPPFactory.getInstance().addMapFactory(EPPDomainMapFactory.class.getName());
    }
    catch (EPPCodecException e) {
      cat.error("Couldn't load the Map Factory associated with the Domain Mapping", e);
      System.exit(1);
    }
  }

  /**
   * Returns the Namespace that this handler supports. In this case, domain.
   *
   * @return String The Namespace that this handler supports
   */
  public final String getNamespace() {
    return NS;
  }

  /**
   * This method receives an <code>EPPEvent</code> and routes it to the
   * appropriate abstract method.
   *
   * @param aEvent
   *           An <code>EPPEvent</code> that contains the
   *           <code>EPPCommand</code>
   * @param aData
   *           Any data that a Server needs to send to this
   *           <code>EPPContactHandler</code> instance
   *
   * @return DOCUMENT ME!
   *
   * @exception EPPEventException
   *               Thrown if an unrecognized <code>EPPEvent</code> is received
   */
  public final EPPEventResponse handleEvent(EPPEvent aEvent, Object aData) throws EPPEventException {
    try {
      this.preHandleEvent(aEvent, aData);
    }
    catch (EPPHandleEventException e) {
      return new EPPEventResponse(e.getResponse());
    }

    EPPMessage message = aEvent.getMessage();
    EPPEventResponse response;

    if (message instanceof EPPDomainCreateCmd) {
      response = doDomainCreate(aEvent, aData);
    }
    else if (message instanceof EPPDomainDeleteCmd) {
      response = doDomainDelete(aEvent, aData);
    }
    else if (message instanceof EPPDomainInfoCmd) {
      response = doDomainInfo(aEvent, aData);
    }
    else if (message instanceof EPPDomainCheckCmd) {
      response = doDomainCheck(aEvent, aData);
    }
    else if (message instanceof EPPDomainRenewCmd) {
      response = doDomainRenew(aEvent, aData);
    }
    else if (message instanceof EPPDomainTransferCmd) {
      response = doDomainTransfer(aEvent, aData);
    }
    else if (message instanceof EPPDomainUpdateCmd) {
      response = doDomainUpdate(aEvent, aData);
    }
    else {
      throw new EPPEventException("In EPPDomainHandler an event was sent that is not supported");
    }

    try {
      this.postHandleEvent(aEvent, aData);
    }
    catch (EPPHandleEventException e) {
      return new EPPEventResponse(e.getResponse());
    }

    return response;
  }

  /**
   * Handles any common behavior that all domain commands need to execute
   * before they execute their command specific behavior. The default
   * implementation does nothing.
   *
   * @param aEvent
   *           The <code>EPPEvent</code> that is being handled
   * @param aData
   *           Any data that a Server needs to send to this
   *           <code>EPPDomainHandler</code>
   *
   * @exception EPPHandleEventException
   *               Thrown if an error condition occurs. It must contain an
   *               <code>EPPEventResponse</code>
   */
  protected void preHandleEvent(EPPEvent aEvent, Object aData) throws EPPHandleEventException {
  }

  /**
   * Handles any common behavior that all domain commands need to execute after
   * they execute their command specific behavior. The default implementation
   * does nothing
   *
   * @param aEvent
   *           The <code>EPPEvent</code> that is being handled
   * @param aData
   *           Any data that a Server needs to send to this
   *           <code>EPPDomainHandler</code>
   *
   * @exception EPPHandleEventException
   *               Thrown if an error condition occurs. It must contain an
   *               <code>EPPEventResponse</code>
   */
  protected void postHandleEvent(EPPEvent aEvent, Object aData) throws EPPHandleEventException {
  }

  /**
   * Invoked when a Domain Create command is received. Subclasses should define
   * the behavior when a Domain Create command is received.
   *
   * @param aEvent
   *           The <code>EPPEvent</code> that is being handled
   * @param aData
   *           Any data that a Server needs to send to this
   *           <code>EPPDomainHandler</code>
   *
   * @return EPPEventResponse The response that should be sent back to the
   *         client.
   */
  protected abstract EPPEventResponse doDomainCreate(EPPEvent aEvent, Object aData);

  /**
   * Invoked when a Domain Delete command is received. Subclasses should define
   * the behavior when a Domain Delete command is received.
   *
   * @param aEvent
   *           The <code>EPPEvent</code> that is being handled
   * @param aData
   *           Any data that a Server needs to send to this
   *           <code>EPPDomaindHandler</code>
   *
   * @return EPPEventResponse The response that should be sent back to the
   *         client.
   */
  protected abstract EPPEventResponse doDomainDelete(EPPEvent aEvent, Object aData);

  /**
   * Invoked when a Domain Info command is received. Subclasses should define
   * the behavior when a Domain Info command is received.
   *
   * @param aEvent
   *           The <code>EPPEvent</code> that is being handled
   * @param aData
   *           Any data that a Server needs to send to this
   *           <code>EPPDomaindHandler</code>
   *
   * @return EPPEventResponse The response that should be sent back to the
   *         client.
   */
  protected abstract EPPEventResponse doDomainInfo(EPPEvent aEvent, Object aData);

  /**
   * Invoked when a Domain Check command is received. Subclasses should define
   * the behavior when a Domain Check command is received.
   *
   * @param aEvent
   *           The <code>EPPEvent</code> that is being handled
   * @param aData
   *           Any data that a Server needs to send to this
   *           <code>EPPDomaindHandler</code>
   *
   * @return EPPEventResponse The response that should be sent back to the
   *         client.
   */
  protected abstract EPPEventResponse doDomainCheck(EPPEvent aEvent, Object aData);

  /**
   * Invoked when a Domain Renew command is received. Subclasses should define
   * the behavior when a Domain Renew command is received.
   *
   * @param aEvent
   *           The <code>EPPEvent</code> that is being handled
   * @param aData
   *           Any data that a Server needs to send to this
   *           <code>EPPDomaindHandler</code>
   *
   * @return EPPEventResponse The response that should be sent back to the
   *         client.
   */
  protected abstract EPPEventResponse doDomainRenew(EPPEvent aEvent, Object aData);

  /**
   * Invoked when a Domain Transfer command is received. Subclasses should
   * define the behavior when a Domain Transfer command is received.
   *
   * @param aEvent
   *           The <code>EPPEvent</code> that is being handled
   * @param aData
   *           Any data that a Server needs to send to this
   *           <code>EPPDomaindHandler</code>
   *
   * @return EPPEventResponse The response that should be sent back to the
   *         client.
   */
  protected abstract EPPEventResponse doDomainTransfer(EPPEvent aEvent, Object aData);

  /**
   * Invoked when a Domain Update command is received. Subclasses should define
   * the behavior when a Domain Update command is received.
   *
   * @param aEvent
   *           The <code>EPPEvent</code> that is being handled
   * @param aData
   *           Any data that a Server needs to send to this
   *           <code>EPPDomaindHandler</code>
   *
   * @return EPPEventResponse The response that should be sent back to the
   *         client.
   */
  protected abstract EPPEventResponse doDomainUpdate(EPPEvent aEvent, Object aData);
}
