/*
 *
 * (c) Copyright Ascensio System Limited 2010-2018
 *
 * This program is freeware. You can redistribute it and/or modify it under the terms of the GNU 
 * General Public License (GPL) version 3 as published by the Free Software Foundation (https://www.gnu.org/copyleft/gpl.html). 
 * In accordance with Section 7(a) of the GNU GPL its Section 15 shall be amended to the effect that 
 * Ascensio System SIA expressly excludes the warranty of non-infringement of any third-party rights.
 *
 * THIS PROGRAM IS DISTRIBUTED WITHOUT ANY WARRANTY; WITHOUT EVEN THE IMPLIED WARRANTY OF MERCHANTABILITY OR
 * FITNESS FOR A PARTICULAR PURPOSE. For more details, see GNU GPL at https://www.gnu.org/copyleft/gpl.html
 *
 * You can contact Ascensio System SIA by email at sales@onlyoffice.com
 *
 * The interactive user interfaces in modified source and object code versions of ONLYOFFICE must display 
 * Appropriate Legal Notices, as required under Section 5 of the GNU GPL version 3.
 *
 * Pursuant to Section 7 § 3(b) of the GNU GPL you must retain the original ONLYOFFICE logo which contains 
 * relevant author attributions when distributing the software. If the display of the logo in its graphic 
 * form is not reasonably feasible for technical reasons, you must include the words "Powered by ONLYOFFICE" 
 * in every copy of the program you distribute. 
 * Pursuant to Section 7 § 3(e) we decline to grant you any rights under trademark law for use of our trademarks.
 *
*/

namespace ASC.Data.Storage
{
    public class ProgressStream : Stream
    {
        private readonly Stream stream;
        private long length = long.MaxValue;

        public ProgressStream(Stream stream)
        {
            this.stream = stream ?? throw new ArgumentNullException(nameof(stream));
            try
            {
                length = stream.Length;
            }
            catch (Exception) { }
        }

        public override bool CanRead
        {
            get { return stream.CanRead; }
        }

        public override bool CanSeek
        {
            get { return stream.CanSeek; }
        }

        public override bool CanWrite
        {
            get { return stream.CanWrite; }
        }

        public override long Length
        {
            get { return length; }
        }

        public override long Position
        {
            get { return stream.Position; }
            set { stream.Position = value; }
        }

        public event Action<ProgressStream, int> OnReadProgress;

        public void InvokeOnReadProgress(int progress)
        {
            OnReadProgress?.Invoke(this, progress);
        }

        public override void Flush()
        {
            stream.Flush();
        }

        public override long Seek(long offset, SeekOrigin origin)
        {
            return stream.Seek(offset, origin);
        }

        public override void SetLength(long value)
        {
            stream.SetLength(value);
            length = value;
        }

        public override int Read(byte[] buffer, int offset, int count)
        {
            var readed = stream.Read(buffer, offset, count);
            OnReadProgress(this, (int)(stream.Position / (double)length * 100));
            return readed;
        }

        public override void Write(byte[] buffer, int offset, int count)
        {
            stream.Write(buffer, offset, count);
        }
    }
}