Program.cs

using System.Drawing.Imaging;
using System.Runtime.InteropServices;
using Timer = System.Windows.Forms.Timer;

namespace AwayBuster;

internal static class Program
{
 /// <summary>
 /// The interval in seconds between idle checks
 /// </summary>
 private const int TIMER_INTERVAL_SECONDS = 60;

 /// <summary>
 /// The maximum allowed idle time in seconds before triggering mouse movement
 /// </summary>
 private const int MAX_IDLE_SECONDS = 120;

 /// <summary>
 /// Retrieves the time elapsed since the last user input
 /// </summary>
 /// <returns>A TimeSpan representing the duration since the last user input</returns>
 private static TimeSpan RetrieveIdleTime()
 {
 var lastInputInfo = new LastInputInfo { cbSize = (uint)LastInputInfo.SizeOf };
 if (!Interop.GetLastInputInfo(ref lastInputInfo))
 {
 Console.WriteLine("GetLastInputInfo failed");
 return TimeSpan.Zero;
 }

 var elapsedTicks = Environment.TickCount - (int)lastInputInfo.dwTime;

 return elapsedTicks > 0 ? new TimeSpan(0, 0, 0, 0, elapsedTicks) : TimeSpan.Zero;
 }

 /// <summary>
 /// Simulates mouse movement to prevent system idle state
 /// by moving the cursor right and then left by 1 pixel
 /// </summary>
 private static void BustIdle()
 {
 var inputs = new Input[2];

 inputs[0].type = Interop.INPUT_MOUSE;
 inputs[0].U.mi.dx = 1;
 inputs[0].U.mi.dy = 0;
 inputs[0].U.mi.mouseData = 0;
 inputs[0].U.mi.dwFlags = Interop.MOUSEEVENTF_MOVE;
 inputs[0].U.mi.time = 0;
 inputs[0].U.mi.dwExtraInfo = UIntPtr.Zero;

 inputs[1].type = Interop.INPUT_MOUSE;
 inputs[1].U.mi.dx = -1;
 inputs[1].U.mi.dy = 0;
 inputs[1].U.mi.mouseData = 0;
 inputs[1].U.mi.dwFlags = Interop.MOUSEEVENTF_MOVE;
 inputs[1].U.mi.time = 0;
 inputs[1].U.mi.dwExtraInfo = UIntPtr.Zero;

 var numberOfInputsSent = Interop.SendInput((uint)inputs.Length, inputs, Marshal.SizeOf<Input>());
 if (numberOfInputsSent != inputs.Length) Console.WriteLine("SendInput failed: {0}", Marshal.GetLastWin32Error());
 }

 /// <summary>
 /// Creates a red-tinted version of the icon
 /// </summary>
 /// <param name="originalIcon">The original icon to tint</param>
 /// <returns>A red-tinted copy of the original icon</returns>
 private static Icon CreateRedTintedIcon(Icon originalIcon)
 {
 using var bitmap = new Bitmap(originalIcon.ToBitmap());
 using var graphics = Graphics.FromImage(bitmap);

 // Create a red color matrix
 var colorMatrix = new ColorMatrix([
 [1, 0, 0, 0, 0],
 [0, 0.5f, 0, 0, 0],
 [0, 0, 0.5f, 0, 0],
 [0, 0, 0, 1, 0],
 [0.5f, 0, 0, 0, 1]
 ]);

 using var imageAttributes = new ImageAttributes();
 imageAttributes.SetColorMatrix(colorMatrix);

 graphics.DrawImage(bitmap, new Rectangle(0, 0, bitmap.Width, bitmap.Height), 0, 0, bitmap.Width, bitmap.Height, GraphicsUnit.Pixel, imageAttributes);

 return Icon.FromHandle(bitmap.GetHicon());
 }

 /// <summary>
 /// Main entry point of the application. Sets up a system tray icon with a context menu
 /// and initializes a timer to check for system idle state.
 /// </summary>
 [STAThread]
 private static void Main()
 {
 // Initialize timer for periodic idle checks
 var timer = new Timer();
 timer.Interval = TIMER_INTERVAL_SECONDS * 1000;
 timer.Tick += (_, _) =>
 {
 var idleTime = RetrieveIdleTime();
 if (idleTime.TotalSeconds > MAX_IDLE_SECONDS)
 BustIdle();
 };

 var icon = Icon.ExtractAssociatedIcon(Application.ExecutablePath) ?? SystemIcons.Application;
 var redTintedIcon = CreateRedTintedIcon(icon);

 // Set up system tray icon
 var trayIcon = new NotifyIcon
 {
 Icon = icon,
 Text = "AwayBuster",
 Visible = true
 };

 // Create context menu with Enable/Disable and Exit options
 var menu = new ContextMenuStrip();
 var enableOption = new ToolStripMenuItem("Enable") { CheckOnClick = true, Checked = true };
 enableOption.CheckedChanged += (_, _) =>
 {
 trayIcon.Icon = enableOption.Checked ? icon : redTintedIcon;
 timer.Enabled = enableOption.Checked;
 };
 menu.Items.Add(enableOption);
 menu.Items.Add("Exit", null, (_, _) =>
 {
 trayIcon.Visible = false;
 Application.Exit();
 });
 trayIcon.ContextMenuStrip = menu;

 // Start the timer and run the winforms application
 timer.Start();
 Application.Run();
 }
}