using System;
using System.Runtime.InteropServices;

public static class NvmlWrapper
{
    [DllImport("nvml.dll", EntryPoint = "nvmlInit_v2")]
    public static extern int NvmlInit();

    [DllImport("nvml.dll", EntryPoint = "nvmlShutdown")]
    public static extern int NvmlShutdown();

    // Get device count
    [DllImport("nvml.dll", CallingConvention = CallingConvention.Cdecl)]
    private static extern int nvmlDeviceGetCount_v2(ref uint deviceCount);

    public static int NvmlDeviceGetCount(ref uint deviceCount)
    {
        return nvmlDeviceGetCount_v2(ref deviceCount);
    }

    [DllImport("nvml.dll", EntryPoint = "nvmlDeviceGetHandleByIndex_v2")]
    public static extern int NvmlDeviceGetHandleByIndex(int index, out IntPtr device);

    [DllImport("nvml.dll", EntryPoint = "nvmlDeviceGetUtilizationRates")]
    public static extern int NvmlDeviceGetUtilizationRates(IntPtr device, out NvmlUtilization utilization);

    [DllImport("nvml.dll", EntryPoint = "nvmlDeviceGetTemperature")]
    public static extern int NvmlDeviceGetTemperature(IntPtr device, uint sensorType, out uint temp);

    [DllImport("nvml.dll", EntryPoint = "nvmlDeviceGetFanSpeed")]
    public static extern int NvmlDeviceGetFanSpeed(IntPtr device, out uint speed);

    [StructLayout(LayoutKind.Sequential)]
    public struct NvmlUtilization
    {
        public uint Gpu;
        public uint Memory;
    }
}