/*

* Copyright (c) 2006-2007 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:    Provides STUN Client state information.

*

*/

#ifndef MSTUNCLIENTOBSERVER_H

#define MSTUNCLIENTOBSERVER_H

// INCLUDES

#include <e32std.h>

class CSTUNClient;

class CBinding;

/**

 * An observer that must be realized by the client in order to

 * receive notifications about asynchronous STUN events.

 * This class supports also STUN relay usage.

 * 

 * @lib  natfwstunclient.lib

 */

class MSTUNClientObserver

    {

public:

    /**  All STUN/STUN relay binding events */

    enum TSTUNBindingEvent

        {

        /** 

         * A public address was obtained for a CSTUNBinding 

         * or for a CSTUNRelayBinding.

         * The resolved address(es) can be queried from the binding.

         * Those addresses are server reflexive IP address and

         * STUN relay IP address.

         */

        EPublicAddressResolved,

        /** 

         * STUN server rejected the credentials provided that were set with

         * CSTUNClient::SetCredentialsL. Application should obtain valid

         * credentials and then use CSTUNClient::SetCredentialsL.

         */

        ECredentialsRejected,

        EActiveDestinationSet,

        ETCPConnectOk

        };

    /**

     * Indicates that asynchronous initialization of the related

     * CSTUNClient has been completed and it can be used

     * for creating CSTUNBinding(s) or CSTUNRelayBinding(s).

     *

     * @param   aClient the client for which the initialization 

     *          was completed.

     * @param   aCompletionCode value KErrNone indicates that 

     *          the client instance is ready for creating CSTUNBinding(s)

     *          and/or CSTUNRelayBinding(s).

     *          Any other completion code indicates that 

     *          the client instance cannot be used and should be deleted.

     * @return  void

     */

    virtual void STUNClientInitCompleted( 

        const CSTUNClient& aClient, TInt aCompletionCode ) = 0;   

    /**

     * A STUN/STUN Relay binding related event occurred. After this callback

     * the aBinding can be used again by calling its SendRequestL or 

     * AllocateRequestL method.

     *

     * @param   aEvent the STUN/STUN relay binding related event

     * @param   aBinding the STUN binding that is the target for the event.

     * @return  void

     */

    virtual void STUNBindingEventOccurredL( 

        TSTUNBindingEvent aEvent, const CBinding& aBinding ) = 0;

    /**

     * Error occurred during IP address resolution.

     * This callback will also be called if STUNBindingEventOccuredL leaves.

     *

     * @param   aBinding a binding for which the error occured

     * @param   aError error code.

     * @errors  401: Client MUST set long term credentials and try again.

     *              Realm can be read from existing binding through 

     *              RealmFromResponse().

     *          300: Client should use alternate server address,

     *              which can be fetched from binding through 

     *              AlternateServer() -method. After fetching server binding

     *              must be destroyed.

     *          434: Client should use realm with long term credentials.

     *              Realm can be read from existing binding through 

     *              RealmFromResponse().

     *          487: ICE specific error code - role conflict occured.

     * @return  void

     */

    virtual void STUNBindingErrorOccurred( const CBinding& aBinding,

        TInt aError ) = 0;

    };

#endif // MSTUNCLIENTOBSERVER_H