/*

* 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.Text;

using System.Threading;

using System.Collections;

using SymbianUtils.Tracer;

namespace SymbianUtils

{

	public abstract class AsyncTextReaderBase : AsyncReaderBase

	{

		#region Constructors

		protected AsyncTextReaderBase()

            : this( null )

		{

		}

        protected AsyncTextReaderBase( ITracer aTracer )

            : base( aTracer )

        {

        }

        #endregion

        #region Properties

        protected bool TrimLine

        {

            get { return iTrimLine; }

            set { iTrimLine = value; }

        }

        #endregion

        #region Read handlers

        protected virtual bool ContinueProcessing()

		{

			return false;

		}

		protected virtual bool ImmediateAbort()

		{

			return false;

		}

		protected virtual void HandleReadLine( string aLine )

		{

		}

		#endregion

		#region Framework API

		protected abstract string ProvideReadLine();

        protected virtual void OnProgressChanged( int aProgress )

        {

            NotifyEvent( TEvent.EReadingProgress );

        }

		#endregion

        #region Internal constants

        private const int KProgressCheckGranularity = 500;

        #endregion

        #region Internal methods

        protected override void PerformOperation()

		{

			bool forcedContinue = false;

			bool immediateAbort = false;

			string line;

			//

			lock( this )

			{

				line = ProvideReadLine();

				forcedContinue = ContinueProcessing();

				immediateAbort = ImmediateAbort();

			}

            System.DateTime tenPercentTime = DateTime.Now;

            int newProgress = 0;

            int oldProgress = 0;

            int progressTracker = 0;

			while ( ( line != null || forcedContinue ) && !immediateAbort )

			{

                if ( line != null && TrimLine )

				{

					line = line.Trim();

				}

				//

				lock( this )

				{

					HandleReadLine( line );

				}

				//

				lock( this )

				{

                    if ( progressTracker == KProgressCheckGranularity )

                    {

                        newProgress = Progress;

                        progressTracker = 0;

                    }

                    ++progressTracker;

				}

                if ( newProgress != oldProgress )

                {

#if DEBUG

                    if ( newProgress > 0 && ( newProgress % 10 ) == 0 )

                    {

                        System.DateTime now = DateTime.Now;

                        long intermediateTickDuration = ( ( now.Ticks - tenPercentTime.Ticks ) / 100 );

                        System.Diagnostics.Debug.WriteLine( newProgress.ToString( "d2" ) + " % COMPLETE - " + intermediateTickDuration.ToString( "d12" ) );

                        tenPercentTime = now;

                    }

#endif

                    OnProgressChanged( newProgress );

                    oldProgress = newProgress;

                }

                //

				lock( this )

				{

					line = ProvideReadLine();

                    forcedContinue = ContinueProcessing();

                    immediateAbort = ImmediateAbort();

                }

			}

            System.DateTime endTime = DateTime.Now;

            long tickDuration = ( ( endTime.Ticks - iOperationStartTime.Ticks ) / 100 );

            System.Diagnostics.Debug.WriteLine( "TEXT READ COMPLETE - " + tickDuration.ToString( "d12" ) );

        }

		#endregion

        #region Data members

        private bool iTrimLine = true;

        #endregion

    }

}