/*

* 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 System.IO;

using SymbianUtils;

using SymbianUtils.Streams;

using SymbianImageLib.Common.Header;

using SymbianStructuresLib.Compression.Common;

namespace SymbianImageLib.Common.Streams

{

    internal class SIStream : DisposableObject

    {

        #region Enumerations

        public enum TOwnershipType

        {

            EOwned = 0,

            EOwnedExternally

        }

        #endregion

        #region Constructors

        public SIStream()

            : this( null, TOwnershipType.EOwned )

        {

        }

        public SIStream( Stream aStream )

            : this( aStream, TOwnershipType.EOwned )

        {

        }

        public SIStream( Stream aStream, TOwnershipType aType )

        {

            SwitchStream( aStream, aType );

        }

        #endregion

        #region Framework API

        public virtual bool InRange( long aPosition )

        {

            bool ret = ( aPosition >= 0 && aPosition < this.Length );

            return ret;

        }

        public virtual void Seek( long aPosition, SeekOrigin aOrigin )

        {

            iStream.Seek( aPosition, aOrigin );

        }

        public virtual int Read( byte[] aBuffer, int aOffset, int aCount )

        {

            int ret = iStream.Read( aBuffer, aOffset, aCount );

            return ret;

        }

        public virtual void Write( byte[] aBuffer )

        {

            Write( aBuffer, 0, aBuffer.Length );

        }

        public virtual void Write( SIStream aFrom, int aCount )

        {

            Write( (Stream) aFrom, aCount );

        }

        public virtual void Write( Stream aFrom, int aCount )

        {

            byte[] temp = new byte[ aCount ];

            int ret = aFrom.Read( temp, 0, aCount );

            if ( ret != aCount )

            {

                throw new Exception( "Unable to read required number of bytes from stream" );

            }

            Write( temp, 0, aCount );

        }

        public virtual void Write( byte[] aBuffer, int aOffset, int aCount )

        {

            iStream.Write( aBuffer, aOffset, aCount );

        }

        #endregion

        #region API

        public void SwitchStream( Stream aStream, TOwnershipType aType )

        {

            if ( iStream != null )

            {

                if ( iOwnership == TOwnershipType.EOwned )

                {

                    iStream.Dispose();

                    iStream = null;

                    iLength = 0;

                }

            }

            //

            iStream = aStream;

            iOwnership = aType;

            //

            if ( iStream != null )

            {

                // Cache this because calling it is very expensive.

                iLength = iStream.Length;

            }

        }

        public void Close()

        {

            base.Dispose();

        }

        public void Seek( long aPosition )

        {

            Seek( aPosition, SeekOrigin.Begin );

        }

        public SymbianStreamReaderLE CreateReader()

        {

            return SymbianStreamReaderLE.New( iStream );

        }

        public SymbianStreamReaderLE CreateReader( SymbianStreamReaderLE.TCloseOperation aCloseOperation )

        {

            return SymbianStreamReaderLE.New( iStream, aCloseOperation );

        }

        #endregion

        #region Properties

        public long Length

        {

            get { return iLength; }

        }

        #endregion

        #region Operators

        public static explicit operator Stream( SIStream aStream )

        {

            return aStream.InternalStream;

        }

        #endregion

        #region Internal methods

        protected Stream InternalStream

        {

            get { return iStream; }

        }

        #endregion

        #region Data members

        private Stream iStream = null;

        private TOwnershipType iOwnership = TOwnershipType.EOwned;

        private long iLength = 0;

        #endregion

    }

}