Program.cs

namespace WPUService;

internal static class Program
{
    private const string AppTitle = "Workstation Presence Utility";

    [STAThread]
    private static int Main(string[] args)
    {
        Application.SetUnhandledExceptionMode(UnhandledExceptionMode.CatchException);
        Application.ThreadException += (_, e) => HandleCrash("UI thread", e.Exception);
        AppDomain.CurrentDomain.UnhandledException += (_, e) => HandleCrash("background thread", e.ExceptionObject as Exception);

        try { Installer.EnsureAumidRegistration(); } catch { }
        try { NativeMethods.SetCurrentProcessExplicitAppUserModelID(AppIdentity.Aumid); } catch { }
        ApplicationConfiguration.Initialize();

        if (args.Length > 0)
        {
            var cmd = args[0].TrimStart('/', '-').ToLowerInvariant();
            if (cmd is "install")
            {
                var ok = Installer.Install();
                MessageBox.Show(
                    ok ? $"{AppTitle} installed.\n\nIt is now running in your system tray and will start automatically with Windows."
                       : $"{AppTitle} could not be installed.",
                    AppTitle,
                    MessageBoxButtons.OK,
                    ok ? MessageBoxIcon.Information : MessageBoxIcon.Error);
                return ok ? 0 : 1;
            }
            if (cmd is "uninstall")
            {
                var ok = Installer.Uninstall();
                MessageBox.Show(
                    ok ? $"{AppTitle} has been removed from this computer."
                       : $"{AppTitle} could not be fully removed.",
                    AppTitle,
                    MessageBoxButtons.OK,
                    ok ? MessageBoxIcon.Information : MessageBoxIcon.Error);
                return ok ? 0 : 1;
            }
        }

        if (!Installer.IsRunningFromInstallLocation())
        {
            var choice = MessageBox.Show(
                $"Install {AppTitle} to your user profile so it starts with Windows?" +
                "\n\nYes  – Install and start" +
                "\nNo   – Run once from the current location" +
                "\nCancel – Exit",
                AppTitle,
                MessageBoxButtons.YesNoCancel,
                MessageBoxIcon.Question);

            if (choice == DialogResult.Cancel) return 0;
            if (choice == DialogResult.Yes)
            {
                var ok = Installer.Install();
                MessageBox.Show(
                    ok ? $"{AppTitle} installed and started in your system tray."
                       : $"{AppTitle} could not be installed.",
                    AppTitle,
                    MessageBoxButtons.OK,
                    ok ? MessageBoxIcon.Information : MessageBoxIcon.Error);
                return ok ? 0 : 1;
            }
        }

        using var mutex = new Mutex(initiallyOwned: true, name: @"Global\WPUService.SingleInstance", out bool createdNew);
        if (!createdNew) return 0;

        Application.Run(new TrayContext());
        return 0;
    }

    internal static void LogException(string source, Exception? ex)
    {
        var details = ex?.ToString() ?? "(no exception object)";
        try
        {
            var dir = Path.Combine(
                Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData),
                "WPUService");
            Directory.CreateDirectory(dir);
            var line = $"[{DateTime.Now:yyyy-MM-dd HH:mm:ss}] {source}: {details}{Environment.NewLine}{Environment.NewLine}";
            File.AppendAllText(Path.Combine(dir, "error.log"), line);
        }
        catch { }
    }

    private static void HandleCrash(string source, Exception? ex)
    {
        LogException(source, ex);
        try
        {
            MessageBox.Show(
                $"{AppTitle} hit an unexpected error and the details were written to error.log in your WPUService AppData folder.\n\n{ex?.GetType().Name}: {ex?.Message}",
                AppTitle,
                MessageBoxButtons.OK,
                MessageBoxIcon.Error);
        }
        catch { }
    }
}