/*

* 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;

using SymbianUtils.BasicTypes;

using SymbianStructuresLib.Arm;

using SymbianStructuresLib.Arm.Exceptions;

using SymbianETMLib.Common.Types;

using SymbianETMLib.Common.Packets;

namespace SymbianETMLib.Common.State

{

    public class ETMDecodeStateISync : ETMDecodeState

    {

        #region Constructors

        public ETMDecodeStateISync( ETMStateData aManager )

            : base( aManager )

        {

            iContextIdBytesRequired = aManager.Config.ContextIDSize;

            iBytesRemaining = iContextIdBytesRequired;

        }

        #endregion

        #region API

        public override ETMDecodeState HandleByte( SymByte aByte )

        {

            ETMDecodeState nextState = this;

            //

            switch ( iState )

            {

            case TState.EStateHeader:

                if ( base.StateData.Config.ContextIDSize != 0 )

                {

                    iState = TState.EStateContextId;

                }

                else

                {

                    iState = TState.EStateInformation;

                }

                break;

            case TState.EStateContextId:

                OnContextByte( aByte );

                break;

            case TState.EStateInformation:

                OnInformationByte( aByte );

                break;

            case TState.EStateAddress:

                OnAddress( aByte );

                break;

            default:

            case TState.EStateIdle:

                System.Diagnostics.Debug.Assert( false );

                break;

            }

            //

            if ( iState == TState.EStateIdle )

            {

                nextState = new ETMDecodeStateSynchronized( base.StateData );

            }

            //

            return nextState;

        }

        #endregion

        #region Properties

        #endregion

        #region Internal enumerations

        private enum TState

        {

            EStateHeader = 0,

            EStateContextId,

            EStateInformation,

            EStateAddress,

            EStateIdle

        }

        #endregion

        #region Internal methods

        private void OnContextByte( SymByte aByte )

        {

            int byteNumber = iContextIdBytesRequired - iBytesRemaining;

            uint val = aByte.LShift( byteNumber * 8 );

            iContextId |= val;

            if ( --iBytesRemaining == 0 )

            {

                base.StateData.SetContextID( iContextId );

                iState = TState.EStateInformation;

            }

        }

        private void OnInformationByte( SymByte aByte )

        {

            iInformationByte = new ETMPcktISyncInformation( aByte );

            iState = TState.EStateAddress;

            // We're expecting 4 address bytes to follow.

            iBytesRemaining = 4;

        }

        private void OnAddress( SymByte aByte )

        {

            int byteNumber = 4 - iBytesRemaining;

            uint val = aByte.LShift( byteNumber * 8 );

            iAddress |= val;

            if ( --iBytesRemaining == 0 )

            {

                // Save for tracing purposes

                SymAddress originalAddress = new SymAddress( base.StateData.CurrentAddress.Address );

                TArmInstructionSet originalInstructionSet = base.StateData.CurrentInstructionSet;

                // Set new branch address

                TArmInstructionSet newInstructionSet = iInformationByte.InstructionSet;

                uint address = iAddress;

                if ( ( address & 0x1 ) == 0x1 )

                {

                    // We branched to THUMB, hence change of instruction set...

                    address &= 0xFFFFFFFE;

                    newInstructionSet = TArmInstructionSet.ETHUMB;

                }

                // Store address etc - always 32 bit full address during I-SYNC

                base.StateData.CurrentInstructionSet = newInstructionSet;

                base.StateData.SetKnownAddressBits( address, 32, TETMBranchType.EBranchExplicit );

                // And output debug trace...

                Trace( originalAddress, originalInstructionSet, base.StateData.CurrentAddress, newInstructionSet );

                // We're done

                iState = TState.EStateIdle;

            }

        }

        private void Trace( SymAddress aOriginalAddress, TArmInstructionSet aOriginalISet, SymAddress aNewAddress, TArmInstructionSet aNewISet )

        {

            System.Diagnostics.Debug.Assert( base.StateData.LastBranch.IsKnown );

            //

            StringBuilder lines = new StringBuilder();

            lines.AppendLine( "   I-SYNC" );

            lines.AppendLine( string.Format( "       from: {0} 0x{1:x8} {2}", ETMDecodeState.MakeInstructionSetPrefix( aOriginalISet ), aOriginalAddress, StateData.Engine.LookUpSymbol( aOriginalAddress ) ) );

            lines.AppendLine( string.Format( "         to: {0} 0x{1:x8} {2}", ETMDecodeState.MakeInstructionSetPrefix( aNewISet ), aNewAddress, StateData.Engine.LookUpSymbol( aNewAddress ) ) );

            //

            base.Trace( lines.ToString() );

        }

        #endregion

        #region From System.Object

        #endregion

        #region Data members

        private readonly int iContextIdBytesRequired;

        private TState iState = TState.EStateHeader;

        private uint iContextId = 0;

        private uint iAddress = 0;

        private int iBytesRemaining = 0;

        private ETMPcktISyncInformation iInformationByte = null;

        #endregion

    }

}