using BlazorApp.Models.Canopen;
using BlazorApp.Models.Canopen.Eds;
namespace BlazorApp.Models.Canopen.Eds
{
    public class EdsDeviceDecoder : ICanopenDeviceDecoder
    {
        private readonly EdsDevice _device;

        public int NodeId => _device.NodeId;

        public EdsDeviceDecoder(EdsDevice device)
        {
            _device = device;
        }

        public string DecodeTpdo(int pdoIndex, byte[] data, byte length)
        {
            if (!_device.Tpdos.TryGetValue(pdoIndex, out var tpdo))
                return "-";

            var results = new List<string>();

            foreach (var obj in tpdo.Objects)
            {
                ulong raw = ReadBits(data, obj.BitOffset, obj.BitLength);
                double value = raw * obj.Factor;

                results.Add($"{obj.Name}: {value:F2} {obj.Unit}");
            }

            return string.Join(" | ", results);
        }

        private static ulong ReadBits(byte[] data, int bitOffset, int bitLength)
        {
            ulong value = 0;
            int byteOffset = bitOffset / 8;

            for (int i = 0; i < bitLength / 8; i++)
            {
                value |= (ulong)data[byteOffset + i] << (8 * i);
            }

            return value;
        }
    }
}