// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Diagnostics;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
 
namespace System.Net.Http
{
    internal sealed partial class HttpConnection : IDisposable
    {
        private abstract class HttpContentWriteStream : HttpContentStream
        {
            public long BytesWritten { get; protected set; }
 
            public HttpContentWriteStream(HttpConnection connection) : base(connection) =>
                Debug.Assert(connection != null);
 
            public sealed override bool CanRead => false;
            public sealed override bool CanWrite => _connection != null;
 
            public sealed override void Flush() =>
                _connection?.Flush();
 
            public sealed override Task FlushAsync(CancellationToken ignored)
            {
                HttpConnection? connection = _connection;
                return connection != null ?
                    connection.FlushAsync(async: true).AsTask() :
                    default!;
            }
 
            public sealed override int Read(Span<byte> buffer) => throw new NotSupportedException();
 
            public sealed override ValueTask<int> ReadAsync(Memory<byte> buffer, CancellationToken cancellationToken) => throw new NotSupportedException();
 
            public sealed override Task CopyToAsync(Stream destination, int bufferSize, CancellationToken cancellationToken) => throw new NotSupportedException();
 
            public abstract Task FinishAsync(bool async);
        }
    }
}