/*

* 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.IO;

using System.Collections.Generic;

using System.Text;

using System.Text.RegularExpressions;

using SymbianUtils.DataBuffer.Entry;

using SymbianUtils.Range;

namespace SymbianUtils.DataBuffer

{

    public class DataBuffer : IEnumerable<byte>

    {

        #region Constructors

        public DataBuffer()

		{

		}

		#endregion

		#region API

        public void Add( byte aByte )

        {

            uint address = 0;

            //

            if ( Count > 0 )

            {

                address = ( Last.Address - AddressOffset ) + 1;

            }

            //

            DataBufferByte entry = new DataBufferByte( aByte, address );

            Add( entry );

        }

        public void Add( IEnumerable<byte> aBytes )

        {

            foreach ( byte b in aBytes )

            {

                Add( b );

            }

        }

        public void Add( uint aDWord )

        {

            // Make 4 bytes

            byte b0 = (byte) (( aDWord & 0x000000FF ) >> 00);

            byte b1 = (byte) (( aDWord & 0x0000FF00 ) >> 08);

            byte b2 = (byte) (( aDWord & 0x00FF0000 ) >> 16);

            byte b3 = (byte) (( aDWord & 0xFF000000 ) >> 24);

            //

            Add( b0 );

            Add( b1 );

            Add( b2 );

            Add( b3 );

        }

        public void Add( DataBufferByte aEntry )

        {

            aEntry.Buffer = this;

            iData.Add( aEntry );

        }

        public void Set( DataBuffer aCopyFrom )

        {

            iAddressOffset = aCopyFrom.AddressOffset;

            iData = aCopyFrom.iData;

        }

        public void Save( Stream aStream )

        {

            byte[] bytes = this;

            aStream.Write( bytes, 0, bytes.Length );

        }

        public void Read( Stream aStream )

        {

        }

        public void Read( Stream aStream, int aOffset, int aLength )

        {

            byte[] bytes = new byte[ aLength ];

            aStream.Seek( aOffset, SeekOrigin.Begin );

            aStream.Read( bytes, 0, bytes.Length );

            Add( bytes );

        }

        public void Clear()

        {

            iData.Clear();

            iAddressOffset = 0;

        }

        public byte[] ToArray()

        {

            List<byte> ret = new List<byte>( iData.Count + 1 );

            //

            int count = iData.Count;

            for ( int i = 0; i < count; i++ )

            {

                ret.Add( iData[ i ].Byte );

            }

            //

            return ret.ToArray();

        }

        #endregion

		#region Properties

        public int Count

        {

            get { return iData.Count; }

        }

        public uint AddressOffset

        {

            get { return iAddressOffset; }

            set { iAddressOffset = value; }

        }

        public DataBufferByte First

        {

            get

            {

                DataBufferByte ret = new DataBufferByte( 0, 0 );

                //

                if ( Count > 0 )

                {

                    ret = iData[ 0 ];

                }

                //

                return ret;

            }

        }

        public DataBufferByte Last

        {

            get

            {

                DataBufferByte ret = new DataBufferByte( 0, 0 );

                //

                if ( Count > 0 )

                {

                    ret = iData[ Count - 1 ];

                }

                //

                return ret;

            }

        }

        public AddressRange Range

        {

            get

            {

                AddressRange ret = new AddressRange();

                if ( First != null )

                {

                    ret.Min = First.Address;

                }

                if ( Last != null )

                {

                    ret.Max = Last.Address;

                }

                return ret;

            }

        }

        public DataBufferUint this[ uint aAddress ]

        {

            get

            {

                DataBufferUint ret = new DataBufferUint( 0, aAddress );

                //

                foreach ( DataBufferUint uintEntry in GetUintEnumerator() )

                {

                    if ( uintEntry.Address == aAddress )

                    {

                        ret = uintEntry;

                        break;

                    }

                }

                //

                return ret;

            }

        }

		#endregion

        #region Enumerator API

        public IEnumerable<DataBufferUint> GetUintEnumerator()

        {

            // This iterator works from the bottom of the stack

            // upwards, just like Symbian OS/ARM stack allocation

            //

            //

            // Count = 12

            //

            // [0123][4567][89AB]

            //

            int count = iData.Count;

            //

            for ( int i = count - 4; i >= 0; i -= 4 )

            {

                DataBufferByte e0 = iData[ i + 0 ];

                DataBufferByte e1 = iData[ i + 1 ];

                DataBufferByte e2 = iData[ i + 2 ];

                DataBufferByte e3 = iData[ i + 3 ];

                //

                uint value = Combine( e0, e1, e2, e3 );

                DataBufferUint ret = new DataBufferUint( value, e0.Address );

                yield return ret;

            }

        }

        public IEnumerable<DataBufferByte> GetByteEnumerator()

        {

            int count = iData.Count;

            for ( int i = count - 1; i >= 0; i-- )

            {

                DataBufferByte entry = iData[ i ];

                yield return entry;

            }

        }

        #endregion

        #region From IEnumerable<byte>

        public IEnumerator<byte> GetEnumerator()

        {

            foreach ( DataBufferByte b in iData )

            {

                yield return b.Byte;

            }

        }

        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()

        {

            foreach ( DataBufferByte b in iData )

            {

                yield return b.Byte;

            }

        }

        #endregion

        #region Operators

        public static implicit operator byte[]( DataBuffer aBuffer )

        {

            byte[] ret = aBuffer.ToArray();

            return ret;

        }

        #endregion

        #region Internal methods

        private List<byte> GetRawBytes()

        {

            List<byte> ret = new List<byte>( iData.Count + 1 );

            //

            foreach ( DataBufferByte b in iData )

            {

                ret.Add( b.Byte );

            }

            //

            return ret;

        }

        private uint Combine( params DataBufferByte[] aItems )

        {

            if ( aItems.Length != 4 )

            {

                throw new ArgumentException( "Expected 4 items" );

            }

            //

            uint ret =

                ( (uint) aItems[ 0 ].Byte )       +

                ( (uint) aItems[ 1 ].Byte <<  8 ) +

                ( (uint) aItems[ 2 ].Byte << 16 ) +

                ( (uint) aItems[ 3 ].Byte << 24 )

                ;

            return ret;

        }

		#endregion

        #region From System.Object

        public override string ToString()

        {

            string ret = string.Empty;

            //

            List<byte> rawBytes = GetRawBytes();

            if ( rawBytes.Count > 0 )

            {

                DataBufferByte firstByte = First;

                uint startingAddress = firstByte.Address;

                //

                ret = SymbianUtils.Utilities.RawByteUtility.ConvertDataToText( rawBytes, true, ref startingAddress );

            }

            //

            return ret;

        }

        #endregion

        #region Data members

        private uint iAddressOffset = 0;

        private List<DataBufferByte> iData = new List<DataBufferByte>();

        #endregion

    }

}