LANCommander/LANCommander.Launcher.Services/SystemService.cs

using System.Diagnostics;
using Microsoft.Win32;

namespace LANCommander.Launcher.Services;

public static class SystemService
{
    /// <summary>
    /// Registers custom lancommander:/ scheme with the system to have quick start of games
    /// </summary>
    public static void RegisterCustomScheme()
    {
        var scheme = "lancommander";
        
        if (CustomSchemeIsRegistered(scheme))
            return;
        
        var appPath = Environment.ProcessPath
                      ?? Process.GetCurrentProcess().MainModule?.FileName
                      ?? throw new InvalidOperationException("Unable to determine application path.");

        var baseKeyPath = $"Software\\Classes\\{scheme}";
        
        using var baseKey = Registry.CurrentUser.CreateSubKey(baseKeyPath, writable: true);
        
        baseKey.SetValue(null, $"URL:{scheme}", RegistryValueKind.String);
        baseKey.SetValue("URL Protocol", String.Empty, RegistryValueKind.String);

        using (var iconKey = baseKey.CreateSubKey("DefaultIcon", writable: true))
        {
            iconKey?.SetValue(null, $"{Quote(appPath)},0", RegistryValueKind.String);
        }

        var command = $"{Quote(appPath)} \"%1\"";

        using (var commandKey = baseKey.CreateSubKey("shell\\open\\command", writable: true))
        {
            commandKey?.SetValue(null, command, RegistryValueKind.String);
        }
    }

    private static bool CustomSchemeIsRegistered(string scheme)
    {
        using var k = Registry.CurrentUser.OpenSubKey($"Software\\Classes\\{scheme}", writable: true);
        return k is not null;
    }
    
    private static string Quote(string path) =>
        path.Contains(' ') || path.Contains('\t') || path.Contains('"')
            ? $"\"{path.Replace("\"", "\\\"")}\""
            : path;
}