using System;
using System.Diagnostics;
using System.IO;
using System.Runtime.InteropServices;

namespace DesktopNotifications.Windows
{
    public class WindowsApplicationContext : ApplicationContext
    {
        private WindowsApplicationContext(string name, string appUserModelId) : base(name)
        {
            AppUserModelId = appUserModelId;
        }

        public string AppUserModelId { get; }

        [DllImport("shell32.dll", SetLastError = true)]
        private static extern void SetCurrentProcessExplicitAppUserModelID(
            [MarshalAs(UnmanagedType.LPWStr)] string appId);

        public static WindowsApplicationContext FromCurrentProcess(
            string? customName = null,
            string? appUserModelId = null)
        {
            var mainModule = Process.GetCurrentProcess().MainModule;

            if (mainModule?.FileName == null)
            {
                throw new InvalidOperationException("No valid process module found.");
            }

            var appName = customName ?? Path.GetFileNameWithoutExtension(mainModule.FileName);
            var aumid = appUserModelId ?? appName; //TODO: Add seeded bits to avoid collisions?

            SetCurrentProcessExplicitAppUserModelID(aumid);

            return new WindowsApplicationContext(appName, aumid);
        }
    }
}