PowerPlayToggle/PowerPlayToggle/Services/WMIService.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Management;

#pragma warning disable CA1416
namespace PowerPlayToggle.Services
{
    public interface IWMIService : IDisposable
    {
        void WatchForProcess(string processName, Action processStarted, Action processEnded);
    }

    public class WMIService : IWMIService
    {
        private readonly ManagementEventWatcher startWatcher;
        private readonly ManagementEventWatcher endWatcher;

        public WMIService()
        {
            startWatcher = new ManagementEventWatcher();
            endWatcher = new ManagementEventWatcher();
        }

        public void WatchForProcess(string processName, Action processStarted, Action processEnded)
        {
            var filter = $"TargetInstance ISA 'Win32_Process' AND TargetInstance.Name = '{processName}'";
            startWatcher.Query = new WqlEventQuery("__InstanceCreationEvent", new TimeSpan(0,0,1), filter);

            startWatcher.EventArrived += (sender, e) =>
            {
                processStarted.Invoke();
            };
            startWatcher.Start();

            endWatcher.Query = new WqlEventQuery("__InstanceDeletionEvent", new TimeSpan(0, 0, 1), filter);
            endWatcher.EventArrived += (sender, e) =>
            {
                processEnded.Invoke();
            };
            endWatcher.Start();
        }

        public void Dispose()
        {
            startWatcher.Stop();
            endWatcher.Stop();
        }
    }
}