namespace Voxel
{
    public class ChunkMesh
    {
        public int X;
        public int Y;
        private byte[] _packedData;
        public int Size = 0;

        public ChunkMesh(int x, int y)
        {
            _packedData = Array.Empty<byte>();
            X = x;
            Y = y;
        }

        public void SetFaces(List<FaceData> faces)
        {
            Size = faces.Count;
            _packedData = PackFaces(faces);
        }

        private static byte[] PackFaces(List<FaceData> faces)
        {
            const int BYTES_PER_FACE = 4;
            int totalFaces = faces.Count;
            var result = new byte[faces.Count * BYTES_PER_FACE];

            for (int i = 0; i < totalFaces; i++)
            {
                var face = faces[i];
                uint packed = face._data;
                int offset = i * 4;

                // Write little-endian (important!)
                result[offset] = (byte)(packed);
                result[offset + 1] = (byte)(packed >> 8);
                result[offset + 2] = (byte)(packed >> 16);
                result[offset + 3] = (byte)(packed >> 24);
            }

            return result;
        }

        public byte[] GetPackedData() => _packedData;
    }
}