// Copyright (c) 2007-2009 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:

//

/**

 @file

 @publishedPartner

 @released

*/

#ifndef SYMBIAN_AVAILABILITY_H

#define SYMBIAN_AVAILABILITY_H

#ifdef _DEBUG

// Panic category for "absolutely impossible!" vanilla ASSERT()-type panics from this module

// (if it could happen through user error then you should give it an explicit, documented, category + code)

_LIT(KSpecAssert_ESock_Availabili, "ESock_Availabili");

#endif

namespace ESock

{

/**

Container for availability status. Used by availability plugins to pass availability information into the mesh machine.

*/

class TAvailabilityStatus

	{

public:

	enum

		{

		EUnknownAvailabilityScore = -1,

		EMinAvailabilityScore = 0,

		EMaxAvailabilityScore = 100

		};

	TAvailabilityStatus()

	:	iScore(EUnknownAvailabilityScore)

		{

		}

	TAvailabilityStatus(TInt aScore)

	:	iScore(aScore)

		{

		}

	/**

	@return ETrue if availability is known, EFalse otherwise.

	*/

	TBool IsKnown() const

		{

		return iScore >= EMinAvailabilityScore && iScore <= EMaxAvailabilityScore;

		}

	/**

	@param aScore the availability score. Must be >= EMinAvailabilityScore and <= EMinAvailabilityScore.

	*/

	void SetScore(TInt aScore)

		{

		__ASSERT_DEBUG(aScore >= EMinAvailabilityScore && aScore <= EMaxAvailabilityScore, User::Panic(KSpecAssert_ESock_Availabili, 1));

		iScore = aScore;

		}

	/**

	Set the availability status to unknown

	*/

	void SetUnknown()

		{

		iScore = EUnknownAvailabilityScore;

		}

	/**

	@return the availability score

	*/

	TInt Score() const { return iScore; }

private:

	TInt iScore;

	};

/**

Collection of options used to register to availability notifications

*/

struct TAvailabilitySubscriptionOptions

	{

public:

	/**

	 Subscription option flags:

	 ENotAnyChange    - the client is specifying availability score thresholds he wishes to be notified on crossing;

	 EAnyChange       - the client is interestes in any change in the availability. Only change in calculated score will be reported.

	 EAnyNestedChamge - the client is interested in any change in the availability even if it does not affect the calculated score

	                    e.g.: one of many available access points ceases to be available (and doesn't affect the score calculated against the remaning access points) 

	 */

	enum TChangeScopeFlags

		{

		ENotAnyChange = 0,

		EAnyChange,

		EAnyNestedChange,

		};

	/**

	@param aAnyChange If ETrue, notify on all changes in the calculated availability. If EFalse, use following parameters to decide what to notify on.

	@param aScoreExceeds Notify if availability score exceeds this

	@param aScoreDropsBelow Notify if availability score drops below this

	@param aScoreIncreasesByMoreThan Notify if availability score increased by more than this

	@param aScoreDescreasesByMoreThan Notify if availability score decreased by more than this

	*/

	TAvailabilitySubscriptionOptions(TBool aAnyChange = ETrue,

	                                 TUint aScoreExceeds = 0,

	                                 TUint aScoreDropsBelow = 0,

	                                 TUint aScoreIncreasesByMoreThan = 0,

	                                 TUint aScoreDecreasesByMoreThan = 0)

		iScoreDropsBelow(aScoreDropsBelow),

		iScoreIncreasesByMoreThan(aScoreIncreasesByMoreThan),

		{

		__ASSERT_DEBUG(aScoreExceeds >= TAvailabilityStatus::EMinAvailabilityScore && aScoreExceeds <= TAvailabilityStatus::EMaxAvailabilityScore, User::Panic(KSpecAssert_ESock_Availabili, 2));

		__ASSERT_DEBUG(aScoreDropsBelow >= TAvailabilityStatus::EMinAvailabilityScore && aScoreDropsBelow <= TAvailabilityStatus::EMaxAvailabilityScore, User::Panic(KSpecAssert_ESock_Availabili, 3));

		__ASSERT_DEBUG(aScoreIncreasesByMoreThan >= TAvailabilityStatus::EMinAvailabilityScore && aScoreIncreasesByMoreThan <= TAvailabilityStatus::EMaxAvailabilityScore, User::Panic(KSpecAssert_ESock_Availabili, 4));

		__ASSERT_DEBUG(aScoreDecreasesByMoreThan >= TAvailabilityStatus::EMinAvailabilityScore && aScoreDecreasesByMoreThan <= TAvailabilityStatus::EMaxAvailabilityScore, User::Panic(KSpecAssert_ESock_Availabili, 5));

		}

	/**

	@param aFlags, TChangeScopeFlags describing the subscrption.

	@see TChangeScopeFlags.

	*/

	TAvailabilitySubscriptionOptions(TChangeScopeFlags aFlags)

		iScoreDropsBelow(0),

		iScoreIncreasesByMoreThan(0),

		{

		ASSERT(aFlags != ENotAnyChange); //illegal to ask for thersholds without specifying them.

		}

	/**

	@param aReported Currently reported availability

	@param aNew Newly reported availability

	@return ETrue if the change is one which should be reported

	*/

	TBool IsChangeSignificant(const TAvailabilityStatus& aReported, const TAvailabilityStatus& aNew) const

		{

		__ASSERT_DEBUG(aNew.IsKnown(), User::Panic(KSpecAssert_ESock_Availabili, 6)); //Use only with known availability!

		return ShouldNotifyAnyChange(aReported, aNew)

			|| ShouldNotifyScoreExceeds(aReported, aNew)

			|| ShouldNotifyScoreDropsBelow(aReported, aNew)

			|| ShouldNotifyScoreIncreasesByMoreThan(aReported, aNew)

			|| ShouldNotifyScoreDecreasesByMoreThan(aReported, aNew);

		}

private:

	TBool ShouldNotifyAnyChange(const TAvailabilityStatus& aReported, const TAvailabilityStatus& aNew) const

		{

		return (iFlags == EAnyNestedChange) || 

			   (iFlags == EAnyChange && aNew.Score() != aReported.Score());

		}

	TBool ShouldNotifyScoreExceeds(const TAvailabilityStatus& aReported, const TAvailabilityStatus& aNew) const

		{

		return iScoreExceeds != 0 && aNew.Score() > iScoreExceeds && aReported.Score() <= iScoreExceeds;

		}

	TBool ShouldNotifyScoreDropsBelow(const TAvailabilityStatus& aReported, const TAvailabilityStatus& aNew) const

		{

		return iScoreDropsBelow != 0 && aNew.Score() < iScoreDropsBelow && aReported.Score() >= iScoreDropsBelow;

		}

	TBool ShouldNotifyScoreIncreasesByMoreThan(const TAvailabilityStatus& aReported, const TAvailabilityStatus& aNew) const

		{

		return iScoreIncreasesByMoreThan != 0 && (aNew.Score() - aReported.Score()) > iScoreIncreasesByMoreThan;

		}

	TBool ShouldNotifyScoreDecreasesByMoreThan(const TAvailabilityStatus& aReported, const TAvailabilityStatus& aNew) const

		{

		return iScoreDecreasesByMoreThan != 0 && (aReported.Score() - aNew.Score()) > iScoreDecreasesByMoreThan;

		}

private:

	TUint iScoreExceeds:7;

	TUint iScoreDropsBelow:7;

	TUint iScoreIncreasesByMoreThan:7;

	TUint iScoreDecreasesByMoreThan:7;

	TUint iFlags:4;

	};

} //namespace ESock

#endif // SYMBIAN_AVAILABILITY_H