/*

* Copyright (c) 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:

*

*/

using System;

using System.Collections.Generic;

using System.Text;

namespace SymbianUtils.BasicTypes

{

    public class SymAddressWithKnownBits : SymAddress

    {

        #region Constructors

        public SymAddressWithKnownBits()

            : this( 0 )

        {

        }

        public SymAddressWithKnownBits( uint aAddress )

            : base( aAddress )

        {

        }

        #endregion

        #region API

        public void SetKnownAddressBits( uint aAddress, int aNumberOfValidBits )

        {

            // First build a bit mask of all the bits which we want to keep

            // from the currently maintained address.

            uint mask = 0;

            for ( int i = 31; i >= aNumberOfValidBits; i-- )

            {

                mask |= (uint) ( 1u << i );

            }

            // aNumberOfValidBits = 0xe

            // mask is 0xffffc000

            // base.Address is 0x802e20ac

            // 11111111 11111111 11000000 00000000 = mask

            // 10000000 00101110 01100110 10101100

            // 10000000 00101110 01000000 00000000

            // Next, we want to apply that mask to the current address

            // in order to prepare for the new values. 

            //

            // I.e. preserve any bits we know but aren't changing, and then

            // clear all other bits that we're about to set below.

            base.Address &= mask;

            // Now we can merge in the new bits

            base.Address |= aAddress;

            // Save how many valid bits of the address we currently have for debugging

            // purposes

            iKnownBits = Math.Max( iKnownBits, aNumberOfValidBits );

            System.Diagnostics.Debug.Assert( iKnownBits >= 0 && iKnownBits <= 32 );

        }

        #endregion

        #region Properties

        public int KnownBits

        {

            get { return iKnownBits; }

            set { iKnownBits = value; }

        }

        public bool IsKnown

        {

            get { return iKnownBits == 32; }

        }

        public bool IsPartial

        {

            get { return iKnownBits > 0; }

        }

        public bool IsUnknown

        {

            get { return iKnownBits == 0; }

        }

        public override string AddressBinary

        {

            get

            {

                string ret = SymBitUtils.BeautifyBits( base.Address, iKnownBits );

                return ret;

            }

        }

        public override string AddressHex

        {

            get

            {

                // Work out how many nibbles we have

                int validNibbles = 0;

                for ( ; validNibbles < iKnownBits; validNibbles += 4 )

                {

                }

                validNibbles /= 4; // Convert bits to nibbles

                int invalidNibbles = 8 - validNibbles;

                StringBuilder text = new StringBuilder();

                text.Append( string.Empty.PadLeft( invalidNibbles, '?' ) );

                text.Append( base.Address.ToString( string.Format( "x{0}", validNibbles ) ) );

                text.Length = Math.Min( 8, text.Length );

                return text.ToString();

            }

        }

        #endregion

        #region Operators

        public static implicit operator uint( SymAddressWithKnownBits aAddress )

        {

            return aAddress.Address;

        }

        #endregion

        #region Internal methods

        #endregion

        #region Data members

        private int iKnownBits = 0;

        #endregion

    }

}