/*

* Copyright (c) 2003 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:  

*

*/

#ifndef CSIPCONNECTION_H

#define CSIPCONNECTION_H

//  INCLUDES

#include <e32base.h>

#include <in_sock.h>

// FORWARD DECLARATIONS

class CSIP;

class MSIPConnectionObserver;

class CSIPTransactionBase;

class CSIPClientTransaction;

class CSIPServerTransaction;

class MSIPRegistrationContext;

class CSIPRegistrationBinding;

class CRegistrationState;

class CSIPDialog;

class CDialogState;

class CSIPRefresh;

class CSIPMessageElements;

class CSIPRequestElements;

class CSIPResponseElements;

class CSIPClientConnectionObserver;

class CConnectionCallback;

class CSIPClientConnection;

//CONSTANTS

/** SIP minimum value for the expiration in seconds*/

//const TUint KSIPMinExpirationValue=60;

// CLASS DECLARATION

/**

*  Class for monitoring connection's state and sending SIP requests outside

*  the dialog associations.Class must not be used

*  -for sending requests to which received non-failure response creates a dialog

*  -for sending requests that must be sent within SIP dialog

* Note that the user can have only one instance of the class per same IAP-id

*/

class CSIPConnection :

    public CBase

	{

    public:

        /** Connection states */

        enum TState 

            {

            /** Connection initializing */

			EInit=1,

			/** Connection active */

			EActive,

			/** Connection suspended */

			ESuspended,

			/** Connection is inactive */

			EInactive,

			/** Connection is permanently unavailable */

			EUnavailable

            };

    public:  // Constructors and destructor

	    /**

        * Two-phased constructor.

		* @param aSip a handle to the SIP server

		* @param aIapId IAP-id

		* @param aObserver a observer for receiving asynchonous events on this

        *   connection

        * @return New object, ownership is transferred

        */

		IMPORT_C static CSIPConnection*

            NewL(CSIP& aSIP,

				 TUint32 aIapId,

				 MSIPConnectionObserver& aObserver);

	    /**

        * Two-phased constructor.

		* Constructs an object and adds the pointer to the cleanup stack;

		* @param aSip a handle to the SIP server

		* @param aIapId IAP-id

		* @param aObserver a observer for receiving asynchonous events on this

        *   connection

        * @return New object, ownership is transferred

        */

		IMPORT_C static CSIPConnection*

            NewLC(CSIP& aSIP,

				  TUint32 aIapId,

				  MSIPConnectionObserver& aObserver);

		/**

		* Destructor

		*/

		IMPORT_C ~CSIPConnection();

    public: // New functions

        /**

		* Gets current state of the connection        

        * @return current state of the connection

        */

		IMPORT_C TState State() const;

        /**

		* Creates SIP request and sends it to the given destination.

		* The function must not be used with SIP requests that creates

		* SIP dialog associations or must be sent within SIP dialog

		* association.

		* This provokes the Non-invite state machine.

		* This function must be used if the user has created the

		* registration binding.

		* @pre State() == EActive.

		* @pre aContext.IsContextActive()==ETrue

		* @param aElements contains local and remote addresses,

		*		 optional SIP message headers and body.

		*        The ownership is transferred.

		* @param aContext defines outbound proxy to be used. If the user

		*        does not provide from-address it will be constucted using

		*        user's AOR used during the registration.

        * @return SIP client transaction, ownership is transferred

        */

		IMPORT_C CSIPClientTransaction*

            SendRequestL(CSIPRequestElements* aElements,

                         const MSIPRegistrationContext& aContext);

        /**

		* Creates SIP request and sends it to the given destination.

		* The function must not be used with SIP request that creates

		* SIP dialog associations or must be sent within SIP diallog

		* association.

		* This provokes the Non-invite state machine.

		* This function must be used if the user has created the

		* registration binding.

		* @pre State() == EActive.

		* @pre aContext.IsContextActive()==ETrue

		* @param aElements contains local and remote addresses,

		*		 optional SIP message headers and body.

		*        The ownership is transferred.

		* @param aContext defines outbound proxy to be used. If the user

		*        does not provide from-address it will 

		*        be constucted using user's AOR used during the registration.

		* @param aRefresh defines the refresh interval for this transaction.

        * @return SIP client transaction, ownership is transferred

        */

		IMPORT_C CSIPClientTransaction*

            SendRequestL(CSIPRequestElements* aElements,                                        

                         const MSIPRegistrationContext& aContext,

						 CSIPRefresh& aRefresh); 

        /**

		* Creates SIP request and sends it to the given destination.

		* The function must not be used with SIP request that creates SIP

		* diallog associations or must be sent within SIP dialog association.

		* This invokes the Non-invite state machine.

		* @pre State() == EActive.

		* @pre aElements.FromHeader() != 0

		* @param aElements contains local and remote addresses,

		*		 optional SIP message headers and body.

		*        The ownership is transferred.

        * @return SIP client transaction, ownership is transferred

        */

		IMPORT_C CSIPClientTransaction*

            SendRequestL(CSIPRequestElements* aElements);

        /**

		* Creates SIP request and sends it to the given destination.

		* The function must not be used with SIP request that creates SIP

		* dialog associations or must be sent within SIP dialog association.

		* This invokes the Non-invite state machine.

		* @pre State() == EActive.

		* @pre aElements.FromHeader() != 0

		* @param aElements contains local and remote addresses,

		*		 optional SIP message headers and body.

		*        The ownership is transferred.

		* @param aRefresh indicates that transaction will be refreshed

        * @return SIP client transaction, ownership is transferred

        */

		IMPORT_C CSIPClientTransaction*

            SendRequestL(CSIPRequestElements* aElements,

						 CSIPRefresh& aRefresh);

        /**

		* Creates SIP REGISTER request and sends it to the given destination.

		* User must no define any Contact or Expires-headers

		* in the provided elements.

		* @pre State() == EActive

        * @pre aElements != 0

		* @pre aElements->Method().DesC().Length()==0

		* @param aElements contains local and remote addresses, optional SIP

        *        message headers and body. User must not set any expires values

        *        to aElements. The ownership is transferred.

        * @return SIP REGISTER client transaction, ownership is transferred

        */

		IMPORT_C CSIPClientTransaction*

            FetchRegistrationsL(CSIPRequestElements* aElements);

        // Not in real SIP API:

        IMPORT_C void SetState(TState aState);    

		//TODO:SHOULD THIS NEW FUNCTION BE INCLUDED INTO STUB???

		/**

		* Gets Iap-id used for this connection

		* @return Iap-id

		*/

		IMPORT_C TUint32 IapId() const;

		/**

        * Gets SIP server handle

        * @return handle to SIP server, or 0-pointer if SIP server does not

        *	exist any more

        */

        IMPORT_C CSIP* SIP();

		/**

        * Gets SIP server handle

        * @return handle to SIP server, or 0-pointer if SIP server does not

        *	exist any more

        */

        IMPORT_C const CSIP* SIP() const;

		//TODO:ENDS

        /**

		* Incoming request outside dialog has been received.

		*

		* @param aTransaction Server transaction. Ownership is transferred.        

        */

        void IncomingRequestL(CSIPServerTransaction* aTransaction) const;

        /**

        * Gets the local IP address of this CSIPConnection 

        * that is used by the SIP implementation.

        * The user should re-new the call whenever the connection state changes

        * to the CSIPConnection::EActive in order to verify the correctness of

        * the previously retrieved local IP address. The local IP address might

        * be different as a result of the connection state change.

        * @pre State() == CSIPConnection::EActive

        * @param aAddr on return filled with local IP address

        * @leave a system-wide error code

        */ 	                         

	    IMPORT_C void GetLocalAddrL(TInetAddr& aAddr) const;

        /**

		* Incoming request within dialog has been received.

		*

		* @param aTransaction Server transaction. Ownership is transferred.

        * @param aDialogId Identifies the dialog to which the transaction

        *   belongs to.

        */

        void IncomingDialogRequestL(CSIPServerTransaction* aTransaction,

                              		TUint32 aDialogId);

        void IncomingResponseL(CSIPResponseElements* aElements,

                               TUint32 aRequestId) const;

        void IncomingRegistrationResponseL(CSIPResponseElements* aElements,

		                       			   TUint32 aRequestId,

					           			   TUint32 aRegistrationId) const;

        void IncomingRefreshResponseL(CSIPResponseElements* aElements,

		                       		  TUint32 aRequestId,

							   		  TUint32 aRefreshId);

        void ErrorOccured(TInt aError, TUint32 aRequestId) const;

        void RefreshErrorOccured(TInt aError, TUint32 aRefreshId) const;

	    void RegistrationErrorOccured(TInt aError,

                          			  TUint32 aRegistrationId,

                          			  TUint32 aRequestId) const;

		void DialogErrorOccured(TInt aError,

                          		TUint32 aDialogId,

                          		TUint32 aRequestId) const;

        void DialogErrorOccured(TInt aError,

                          		TUint32 aDialogId,

                          		TUint32 aRefreshId,

                          		TUint32 aRequestId) const;

        void ConnectionStateChanged(CSIPConnection::TState aState);

        void InviteCompleted(TUint32 aRequestId) const;

		/**

        * Searches for a transaction with the matching aRequestId.

		* @param aRequestId RequestId associated with the transaction

		* @return Found transaction or NULL if not found. Ownership is not

        *   transferred.

        */

        CSIPTransactionBase* FindTransaction(TUint32 aRequestId) const;

        TInt AddRegistration(CSIPRegistrationBinding* aRegistration);

        void RemoveRegistration(const CSIPRegistrationBinding* aRegistration);

      /**

        * Searches for a registration binding, using aRegistrationId and

        * aRequestId as keys. Registration might not yet have received

        * RegistrationId from SIP client, so the aRequestId may be needed to

        * locate the registration binding.

        * @param aRegistrationId RegistrationId of the registration binding

		* @param aRequestId RequestId of a transaction associated with the

        *   registration

		* @return Found registration binding or NULL if not found.

		*	Ownership is not transferred.

        */

        CSIPRegistrationBinding* FindRegistration(TUint32 aRegistrationId,

                             			   		  TUint32 aRequestId) const;

        TInt AddDialog(CSIPDialog* aDialog);

        void RemoveDialog(const CSIPDialog* aDialog);

        /**

        * Searches for a dialog, using aRequestId as a key.

        * @param aRequestId RequestId of a transaction associated with the

        *   dialog

		* @return Found dialog or NULL if not found. Ownership is not

        *   transferred.

        */

        CSIPDialog* FindDialogByRequestId(TUint32 aRequestId) const;

        /**

		* Informs CSIPConnection that the associated CSIP instance has been

        * deleted. After this the CSIPConnection object can't be used anymore.

		*/

        void CSIPDeleted();

        /**

		* Obtains the initial state for registration state machine.

        *

        * @return Initial registration state, ownership is not transferred

		*/

        CRegistrationState* InitialRegisterStateL() const;

        /**

		* Obtains the initial state for dialog state machine.

        *

        * @return Initial dialog state, ownership is not transferred

		*/

        CDialogState* InitialDialogStateL() const;

        /**

        * Response related to a dialog has been received.

		*

        * @param aElements SIP response elements. Ownership is transferred.

        * @param aRequestId Identifies the transaction

        * @param aDialogId DialogId

        * @param aRefreshId NULL if the response is not related to a refresh,

        *   otherwise the RefreshId. Ownership is not transferred.

		*/

        void IncomingResponseToDialogL(CSIPResponseElements* aElements,

		                               TUint32 aRequestId,

                                       TUint32 aDialogId,

                                       TUint32* aRefreshId);

    private:

        CSIPConnection(CSIP& aSIP,

                       TUint32 aIapId,

                       MSIPConnectionObserver& aObserver);

        void ConstructL();

        /**

        * Send a SIP request.

        *

		* @param aElements SIP headers. Ownership is transferred.

        * @param aRegistrationId If non-NULL, request will use the outbound

        *   proxy and some SIP headers from the registration identified by

        *   aRegistrationId. Ownership is not transferred.

        * @param aRefresh If non-NULL, the request will be refreshed. Otherwise

        *   NULL. Ownership is not transferred.

		* @return New transaction. Ownership is transferred.

        */

        CSIPClientTransaction*

            SendRequestL(CSIPRequestElements* aElements,

                         TUint32* aRegistrationId,

						 CSIPRefresh* aRefresh);

        /**

        * Searches for a refresh and transaction, using aRequestId and

        * aRefreshId as keys.        

		* @param aRequestId RequestId associated with the refreshed transaction

        * @param aRefreshId RefreshId associated with the refresh instance

        * @param aRefresh OUT: if refresh was found, this pointer is set to the

        *   refresh instance. Ownership is not transferred.

        * @param aTransaction OUT: if transaction was found, this pointer is

        *   set to the refreshed client transaction. Ownership is not

        *   transferred.

		* @return ETrue if found, EFalse otherwise

        */

        TBool FindRefresh(TUint32 aRequestId,

                          TUint32 aRefreshId,

                          CSIPRefresh** aRefresh,

                          CSIPClientTransaction** aTransaction) const;

        /**

        * Searches for a registration binding, using aRequestId as a key.

		* @param aRequestId RequestId of a transaction associated with the

        *   registration binding

		* @return Found registration binding or NULL if not found.

		*	Ownership is not transferred.

        */

        CSIPRegistrationBinding* FindRegistration(TUint32 aRequestId) const;

        /**

        * Searches for a dialog, using aDialogId as a key.        

        * @param aDialogId DialogId of the dialog.

		* @return Found dialog or NULL if not found. Ownership is not

        *   transferred.

        */

        CSIPDialog* FindDialog(TUint32 aDialogId) const;

        /**

        * A request has been received with a dialogId, but no matching dialog

        * exists.

		* If the request is NOTIFY, it is stored until a response with the same

        * dialogId is received. Then the response is passed to dialog and after

        * that all the stored NOTIFY are passed to the same dialog.

        * This is needed since NOTIFY can be received before a sent SUBSCRIBE

        * receives a response with dialogId.

		*

        * @param aTransaction Server transaction, ownership is transferred

        * @param aDialogId DialogId

		*/

        void IncomingRequestBeforeDialogExistsL(

                                    CSIPServerTransaction* aTransaction,

                                    TUint32 aDialogId);

        /**

		* Extracts the oldest stored transaction for the dialog identified by

        * aDialogId.

        * @param aDialogId DialogId

        * @return Server transaction or NULL if no transaction is stored for

        *   the dialog. Ownership is transferred.

		*/

        CSIPServerTransaction* GetStoredTransaction(TUint32 aDialogId);

        /**

		* Checks that CSIP is available for use (not NULL). If iSIP is NULL,

        * it means user has deleted a resource needed by CSIPConnection, and

        * this function leaves.

		*/

        void CheckCSipL() const;       

        /**

		* Connection is no longer available. All registrations, dialogs,

        * transactions and refreshes using this connection are terminated, but

        * not deleted.

		*/

        void ConnectionLost();

        //The used CSIP instance. CSIPConnection doesn't own the CSIP.

        //If this pointer is NULL; it means application has deleted the

        //CSIP instance before deleting the CSIPConnection, and this

        //CSIPConnection is now useless.

        CSIP* iSIP;

        //IAP-id of this connection