using System.Buffers;

namespace NBConfigBuilder;

public enum MemoryStreamBufferSource
{
    None = 0,
    Pack = 1,
    UnPack = 2,
}

public sealed class MemoryStreamBuffer : MemoryStream, IBufferWriter<byte>
{
    public MemoryStreamBufferSource MemoryStreamBufferSource;

    public MemoryStreamBuffer()
    {
    }

    public MemoryStreamBuffer(MemoryStreamBufferSource memoryStreamBufferSource, int capacity) : base(capacity)
    {
        MemoryStreamBufferSource = memoryStreamBufferSource;
    }

    public MemoryStreamBuffer(byte[] buffer) : base(buffer)
    {
    }

    public void Advance(int count)
    {
        if (count < 0)
        {
            throw new ArgumentOutOfRangeException(nameof(count), count, "The value of 'count' cannot be negative.");
        }

        var newLength = Position + count;

        if (newLength != Length)
        {
            SetLength(newLength);
        }

        Position = newLength;
    }

    public Memory<byte> GetMemory(int sizeHint = 0)
    {
        if (sizeHint < 0)
        {
            throw new ArgumentOutOfRangeException(nameof(sizeHint), sizeHint,
                "The value of 'count' cannot be negative.");
        }

        if (Length - Position <= sizeHint)
        {
            SetLength(Position + sizeHint);
        }

        return new Memory<byte>(GetBuffer(), (int)Position, (int)(Length - Position));
    }

    public Span<byte> GetSpan(int sizeHint = 0)
    {
        if (sizeHint < 0)
        {
            throw new ArgumentOutOfRangeException(nameof(sizeHint), sizeHint,
                "The value of 'count' cannot be negative.");
        }

        if (Length - Position <= sizeHint)
        {
            SetLength(Position + sizeHint);
        }

        return new Span<byte>(GetBuffer(), (int)Position, (int)(Length - Position));
    }
}