using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Threading.Tasks.Dataflow;
using OpenSSL.Core;
using OpenSSL.Crypto;


namespace Pithos.Network
{
    //public class MD5BlockCalculator:IDisposable
    //{
    //    private MessageDigestContext _hasher ;

    //    private ActionBlock<Tuple<long, byte[],int>>  _actionBlock;

    //    private long _currentBlock = 0;

    //    public MD5BlockCalculator(int capacity)
    //    {
    //        var opt = new ExecutionDataflowBlockOptions { BoundedCapacity = capacity };
    //        _actionBlock = new ActionBlock<Tuple<long, byte[], int>>(t => ProcessBlock(t), opt);
    //        _hasher = new MessageDigestContext(MessageDigest.CreateByName("md5"));
    //        _hasher.Init();
    //    }

    //    public MD5BlockCalculator()
    //    {
    //        _actionBlock = new ActionBlock<Tuple<long, byte[], int>>(t => ProcessBlock(t));
    //        _hasher = new MessageDigestContext(MessageDigest.CreateByName("md5"));
    //        _hasher.Init();
    //    }

    //    private void ProcessBlock(Tuple<long,byte[],int> tuple)
    //    {
    //        if (tuple.Item1 == _currentBlock)
    //        {
    //            var size = tuple.Item3;

    //            var buffer= tuple.Item2;
    //            if (size == buffer.Length)
    //            {
    //                _hasher.Update(buffer);
    //            }
    //            else
    //            {
    //                var block = new byte[size];
    //                Buffer.BlockCopy(buffer, 0, block, 0, size);
    //                _hasher.Update(block);
    //            }
    //            Interlocked.Increment(ref _currentBlock);
    //        }
    //        else
    //        {
    //            _actionBlock.Post(tuple);
    //        }
    //    }

    //    public void PostBlock(long blockIndex,byte[] buffer,int size)
    //    {
    //        _actionBlock.Post(Tuple.Create(blockIndex, buffer, size));
    //    }

    //    public async Task<string> GetHash()
    //    {
    //        _actionBlock.Complete();
    //        await _actionBlock.Completion;
    //        Debug.Assert(_actionBlock.InputCount == 0);
    //        var hashBytes=_hasher.DigestFinal();
    //        var hash=hashBytes.ToHashString();
    //        return hash;
    //    }

    //    public void Dispose()
    //    {
    //        Dispose(true);
    //        GC.SuppressFinalize(this);
    //    }

    //    protected virtual void Dispose(bool disposing)
    //    {
    //        if (disposing && _hasher!=null)
    //            _hasher.Dispose();
    //        _hasher = null;            
    //    }
    //}
}