using System;
using System.Threading;
using System.Threading.Tasks;

using FrostFS.Object;

using Grpc.Core;

namespace FrostFS.SDK.ClientV2;

public sealed class RangeReader(AsyncServerStreamingCall<GetRangeResponse> call) : IObjectReader
{
    private bool disposed;

    public AsyncServerStreamingCall<GetRangeResponse> Call { get; private set; } = call;

    public async ValueTask<ReadOnlyMemory<byte>?> ReadChunk(CancellationToken cancellationToken = default)
    {
        if (!await Call.ResponseStream.MoveNext(cancellationToken).ConfigureAwait(false))
            return null;

        var response = Call.ResponseStream.Current;
        Verifier.CheckResponse(response);

        return response.Body.Chunk.Memory;
    }

    public void Dispose()
    {
        if (!disposed)
        {
            Call?.Dispose();
            GC.SuppressFinalize(this);

            disposed = true;
        }
    }
}