// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using Microsoft.AspNetCore.Http.Features;
using Microsoft.AspNetCore.Internal;
 
namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http;
 
internal sealed class HttpResponseStream : Stream
{
    private readonly HttpResponsePipeWriter _pipeWriter;
    private readonly IHttpBodyControlFeature _bodyControl;
 
    public HttpResponseStream(IHttpBodyControlFeature bodyControl, HttpResponsePipeWriter pipeWriter)
    {
        _bodyControl = bodyControl;
        _pipeWriter = pipeWriter;
    }
 
    public override bool CanSeek => false;
 
    public override bool CanRead => false;
 
    public override bool CanWrite => true;
 
    public override long Length => throw new NotSupportedException();
 
    public override long Position
    {
        get => throw new NotSupportedException();
        set => throw new NotSupportedException();
    }
 
    public override int ReadTimeout
    {
        get => throw new NotSupportedException();
        set => throw new NotSupportedException();
    }
 
    public override int Read(byte[] buffer, int offset, int count)
        => throw new NotSupportedException();
 
    public override Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
      => throw new NotSupportedException();
 
    public override ValueTask<int> ReadAsync(Memory<byte> buffer, CancellationToken cancellationToken)
      => throw new NotSupportedException();
 
    public override void Flush()
    {
        if (!_bodyControl.AllowSynchronousIO)
        {
            throw new InvalidOperationException(CoreStrings.SynchronousWritesDisallowed);
        }
 
        FlushAsync(default).GetAwaiter().GetResult();
    }
 
    public override Task FlushAsync(CancellationToken cancellationToken)
    {
        return _pipeWriter.FlushAsync(cancellationToken).GetAsTask();
    }
 
    public override long Seek(long offset, SeekOrigin origin)
    {
        throw new NotSupportedException();
    }
 
    public override void SetLength(long value)
    {
        throw new NotSupportedException();
    }
    public override void Write(byte[] buffer, int offset, int count)
    {
        if (!_bodyControl.AllowSynchronousIO)
        {
            throw new InvalidOperationException(CoreStrings.SynchronousWritesDisallowed);
        }
 
        WriteAsync(buffer, offset, count, default).GetAwaiter().GetResult();
    }
    public override IAsyncResult BeginWrite(byte[] buffer, int offset, int count, AsyncCallback? callback, object? state)
    {
        return TaskToApm.Begin(WriteAsync(buffer, offset, count), callback, state);
    }
 
    public override void EndWrite(IAsyncResult asyncResult)
    {
        TaskToApm.End(asyncResult);
    }
 
    public override Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
    {
        return _pipeWriter.WriteAsync(new ReadOnlyMemory<byte>(buffer, offset, count), cancellationToken).GetAsTask();
    }
    public override ValueTask WriteAsync(ReadOnlyMemory<byte> source, CancellationToken cancellationToken = default)
    {
        return _pipeWriter.WriteAsync(source, cancellationToken).GetAsValueTask();
    }
}