/*

* Copyright (c) 2003-2009 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:

* Name          : SdpAttributeField.h

* Part of       : SDP Codec

* Interface     : SDK API, SDP Codec API

* Version       : 1.0

*

*/

#ifndef CSDPATTRIBUTEFIELD_H

#define CSDPATTRIBUTEFIELD_H

//  INCLUDES

#include <e32base.h>

#include <stringpool.h>

#include "sdpcodecstringconstants.h"

// FORWARD DECLARATIONS

class RReadStream;

class RWriteStream;

class CSdpFmtAttributeField;

class CSdpAttributeFieldPtrs;

// CLASS DECLARATION

/**

 *  @publishedAll

 *  @released

 *

 *	This class encapsulates the attribute field of Session Description Protocol

 *	for media and session level attributes. Media format/payload type level

 *  attributes are supported by the CSdpFmtAttributeField class. 

 * 

 *	The normative reference for correct formatting and values is

 *	draft-ietf-mmusic-sdp-new-14 unless specified otherwise in

 *  member documentation. The implementation supports this normative

 *  reference, but does not enforce it fully. 

 *

 *  @lib sdpcodec.lib

 */

class CSdpAttributeField : public CBase

	{

    public:     // Constructors and destructor

        /**

         *	Constructs a new attribute field.

		 *			 

         *	@param aText A string containing a correctly 

         *         formatted field value terminated by a CRLF.

         *	@return a new instance.

         */

		IMPORT_C static CSdpAttributeField* DecodeL( const TDesC8& aText );

        /**

         *	Constructs a new attribute field and adds the pointer to the 

         *  cleanup stack.

		 *		 

         *	@param aTest A string containing a correctly 

         *         formatted field value terminated by a CRLF.

         *	@return a new instance.

         */

		IMPORT_C static CSdpAttributeField* DecodeLC( const TDesC8& aText );

        /**

         *	Constructs a new attribute field. 

		 *

         *	@param aAttribute The attribute name. It can be a pre-

         *         defined name in the SDP string pool or defined by the 

         *         client.

         *	@param aValue A valid attribute value or an empty 

         *         descriptor to omit the value part.

         *	@return a new instance.

		 */

		IMPORT_C static CSdpAttributeField* NewL(

            RStringF aAttribute, const TDesC8& aValue );

        /**

         *	Constructs a new attribute field and adds the pointer to the 

         *  cleanup stack. 

		 *

         *	@param aAttribute The attribute name. It can be a pre-defined 

         *         name in the SDP string pool or defined by the client.

         *	@param aValue A valid attribute value or an empty 

         *         descriptor to omit the value part.

         *	@return a new instance.

		 */

		IMPORT_C static CSdpAttributeField* NewLC(

            RStringF aAttribute, const TDesC8& aValue );

 		/**

		 *	Deletes the resources held by the instance.

		 */

		IMPORT_C ~CSdpAttributeField();

    public:     // New functions

    	/**

		 *	Outputs the field formatted according to SDP syntax and including

		 *  the terminating CRLF.

		 * 

		 *	@param aStream Stream used for output. On return the 

         *         stream includes correctly formatted attribute field.

		 */

		IMPORT_C void EncodeL( RWriteStream& aStream ) const;

		/**

		 *	Creates a new instance that is equal to the target.

		 *

		 *	@return a new instance.

		 */

		IMPORT_C CSdpAttributeField* CloneL() const;

		/**	

		 *	Compares this instance to another for equality.

		 *

		 *	@param aObj: The instance to compare to.

		 *	@return ETrue if equal, EFalse if not.

		 */

		IMPORT_C TBool operator == ( const CSdpAttributeField& aObj ) const;

		/**

		 *	Gets the attribute name.

		 *	

		 *	@return	The attribute name. The name can be pre-defined 

         *          name in the SDP string table or defined by the client.

		 */

		IMPORT_C RStringF Attribute() const;

		/**

		 *	Gets the attribute.

		 *

 		 *	@return	The value or an empty descriptor if there is no value part.

		 */

		IMPORT_C const TDesC8& Value() const;

		/**

		 *	Sets the attribute and attribute value.

		 *

         *	@param aAttribute A valid attribute name. It can be a 

         *         pre-defined name in the SDP string pool or 

         *         defined by the client.

         *	@param aValue A valid attribute value or an empty 

         *         descriptor to omit the value part.

		 *  @leave KErrSdpCodecAttributeField if the attribute part is not 

		 *         pre-defined EAttributeFmtp or EAttributeRtpmap.

		 */

		IMPORT_C void SetL( RStringF aAttribute, const TDesC8& aValue );

		/**

 		 *	Assigns attribute to the format level attribute.

 		 *  In the final output the attribute will placed after format level

		 *  attribute.

 		 *

 		 *	@param aFmtAttribute A format level 

 		 *         attribute this attribute is assigned to.

 		 */

 		IMPORT_C void AssignTo(const CSdpFmtAttributeField& aFmtAttribute);

		/**

		 *	Test if the attribute belongs to the given format level attribute.

		 *  Note, that the check can be true for the media level paremeter if

		 *  it appears after the last format level attribute.

		 *

		 *	@param  aFmtAttribute: A format level 

		 *          attribute this attribute belongs to.

		 *	@return	ETrue if attribute belongs to the format level attribute, 

		 *          EFalse otherwise.

		 */

		IMPORT_C TBool BelongsTo(const CSdpFmtAttributeField& aFmtAttribute) const;

    public:     // Internal to codec

        /**

         *  Externalizes the object to stream

         *

         *  @param aStream Stream where the object's state will be stored

         */

		void ExternalizeL( RWriteStream& aStream ) const;

        /**

         *  Creates object from the stream data

         *

         *  @param aStream Stream where the object's state will be read

         *  @return Initialized object

         */

        static CSdpAttributeField* InternalizeL( RReadStream& aStream );

        /**

         *  Informs if the attribute belongs to any format level attribute.

         *

         *  @return ETrue if attribute belongs to any format level 

		 *			attribute, EFalse otherwise.

         */

        TBool IsFmtAttribute();

	private:    // Constructors

        /**

         *  Constructor

         */

		CSdpAttributeField();

        /**

         *  Second phase constructor

         *

         *  @param aText Text string ending to LF character

         */

        void ConstructL( const TDesC8& aText );

        /**

         *  Second phase constructor

         *

         *  @param aAttribute Attribute identifier

         *  @param aValue Value of the attribute of KNullDesC8

         */

        void ConstructL( RStringF aAttribute, const TDesC8& aValue );

    private:    // Internal

        /**

         *  Verifies that attribute is valid property attribute and initializes

         *  the member variables of class accordingly

         *

         *  @param aAttribute Attribute in descriptor

         */

        void FormatProperyAttributeL( const TDesC8& aAttribute );

        /**

         *  Verifies that attribute is valid value attribute and initializes

         *  the member variables of class accordingly

         *

         *  @param aArray Array of the attributes

         */

        void FormatValueAttributeL( const TDesC8& aAttribute,

                                    const TDesC8& aValue );

        /**

         *  Verifies that the value is valid for the attribute

         *

         *  @param aAttribute The attribute

         *  @param aArray Array containing the values (and attribute)

         */

        void VerifyValueAttributeL( SdpCodecStringConstants::TStrings aString,

                                    const TDesC8& aValue );

        /**

         *  Forms attribute and value strings out of the token array

         *  and pushes both (aAttribute & aValue) into cleanup stack

         *

         *  @param aArray Token array

         *  @param aAttribute Attribute string (in cleanup stack)

         *  @param aValue Value string (in cleanup stack)

         */

        void CreateAttributeAndValueStringsLC( RArray<TPtrC8>& aArray,

                                               HBufC8*& aAttribute,

                                               HBufC8*& aValue );

        /**

         *  Checks if the value is among the valid orient attributes

         *

         *  @param aValue Value string

         */

        void CheckValidOrientL( const TDesC8& aValue );

        /**

         *  Checks if the value is valid language attribute as

         *  specified in RFC 3066

         *

         *  @param aValue Value string

         */

        void CheckValidLangStrL( const TDesC8& aValue );

        /**

         *  Checks if the value is valid framerate attribute

         *

         *  @param aValue Value string

         */

        void CheckValidFrameRateL( const TDesC8& aValue );

        /**

         *  Checks if the value is among valid uri value for control attribute

         *

         *  @param aValue Value string

         */       

        void CheckValidControlL( const TDesC8& aValue );

        /**

         *  Checks if the value is valid value for group attribute as

         *  specified in RFC 3388

         *

         *  @param aValue Value string

         */       

        void CheckValidGroupL( const TDesC8& aValue );

        /**

         *  Checks if the value is valid value for des attribute as

         *  specified in RFC 3312

         *

         *  @param aValue Value string

         */       

        void CheckValidDesL( const TDesC8& aValue );

        /**

         *  Checks if the value is valid value for curr and conf attribute as

         *  specified in RFC 3312

         *

         *  @param aValue Value string

         */       

        void CheckValidCurrAndConfL( const TDesC8& aValue );

        /**

         *  Checks if value is included in the list of predefined values

         *

         *  @param aItemsCount Predefined values count

         *  @param aValuesList List of predefined values

         *  @param aValue Value string

         */       

        void ValidValueInListL( TInt aItemsCount, 

                                const TText8* const aValuesList[], 

                                const TDesC8& aValue );

        /**

         *  Checks if the value is valid value for range attribute as

         *  specified in RFC 2326

         *

         *  @param aValue Value string

         */       

        void CheckValidRangeL( const TDesC8& aValue );

        /**

         *  Checks if the value is valid rtpmap string

         *

         *  @param aValue Value string

         */   

        void CheckValidRtpmapL( const TDesC8& aValue );

        /**

         *  Checks if the value is valid fmtp string

         *

         *  @param aValue Value string

         */   

        void CheckValidFmtpL( const TDesC8& aValue );

        /**

         *  Set attribute and values. Attribute is not one of predefined ones.

         *

         *  @param aAttribute Attribute string (in cleanup stack)

         *  @param aValue Value string

         */   

        void SetNotPredefinedAttributeL( const TDesC8& aAttribute, 

                                         const TDesC8& aValue );

        void CreateAttributeFieldPtrsL();

        inline CSdpAttributeFieldPtrs& AttributeFieldPtrs();      

        inline const CSdpAttributeFieldPtrs& AttributeFieldPtrs() const;

		void __DbgTestInvariant() const;

    private:    // Data

        // String pool

        RStringPool iPool;

        // Attribute name

        RStringF iAttribute;

        // Flag indicating if the attribute is a property attribute

        TBool iPropertyAttribute;

        // Value field

        HBufC8* iValue;

	};

#endif // CSDPATTRIBUTEFIELD_H