using System.IO;
using System.Runtime.InteropServices;
using System.Runtime.InteropServices.ComTypes;

namespace EmbyToolbox.Interop;

internal static class ToastShortcutRegistration
{
    private const int StgmReadwrite = 0x00000002;

    private static readonly PropertyKey AppUserModelIdKey = new(
        new Guid("9F4C2855-9F79-4B39-A8D0-E1D42DE1D5F3"),
        5);

    public static string? LastDiagnostics { get; private set; }

    public static bool TryEnsureStartMenuShortcut(string appUserModelId)
    {
        LastDiagnostics = null;

        if (!OperatingSystem.IsWindowsVersionAtLeast(10, 0, 10240))
        {
            LastDiagnostics = "требуется Windows 10 (10240) или новее.";
            return false;
        }

        try
        {
            var exePath = Environment.ProcessPath;
            if (string.IsNullOrWhiteSpace(exePath) || !File.Exists(exePath))
            {
                LastDiagnostics = "не удалось определить путь к exe.";
                return false;
            }

            var programs = Environment.GetFolderPath(Environment.SpecialFolder.StartMenu);
            var shortcutPath = Path.Combine(programs, "Programs", "Emby Toolbox.lnk");
            Directory.CreateDirectory(Path.GetDirectoryName(shortcutPath)!);

            var shellLinkObject = (object)new CShellLink();
            var shellLink = (IShellLinkW)shellLinkObject;
            shellLink.SetPath(exePath);
            shellLink.SetArguments(string.Empty);
            shellLink.SetWorkingDirectory(Path.GetDirectoryName(exePath) ?? AppContext.BaseDirectory);
            shellLink.SetDescription("Emby Toolbox");

            if (File.Exists(Path.Combine(AppContext.BaseDirectory, "Resources", "AppIcon.ico")))
            {
                shellLink.SetIconLocation(Path.Combine(AppContext.BaseDirectory, "Resources", "AppIcon.ico"), 0);
            }
            else
            {
                shellLink.SetIconLocation(exePath, 0);
            }

            using var appId = PropVariant.FromString(appUserModelId);
            var propertyStore = (IPropertyStore)shellLink;
            propertyStore.SetValue(AppUserModelIdKey, appId);
            propertyStore.Commit();

            var persistFile = (IPersistFile)shellLink;
            persistFile.Save(shortcutPath, true);
            return true;
        }
        catch (Exception ex)
        {
            LastDiagnostics = $"{ex.GetType().Name}: {ex.Message}";
            return false;
        }
    }

    [ComImport]
    [Guid("00021401-0000-0000-C000-000000000046")]
    private sealed class CShellLink
    {
    }

    [ComImport]
    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    [Guid("000214F9-0000-0000-C000-000000000046")]
    private interface IShellLinkW
    {
        void GetPath(IntPtr pszFile, int cchMaxPath, IntPtr pfd, uint fFlags);
        void GetIDList(out IntPtr ppidl);
        void SetIDList(IntPtr pidl);
        void GetDescription(IntPtr pszName, int cchMaxName);
        void SetDescription([MarshalAs(UnmanagedType.LPWStr)] string pszName);
        void GetWorkingDirectory(IntPtr pszDir, int cchMaxPath);
        void SetWorkingDirectory([MarshalAs(UnmanagedType.LPWStr)] string pszDir);
        void GetArguments(IntPtr pszArgs, int cchMaxPath);
        void SetArguments([MarshalAs(UnmanagedType.LPWStr)] string pszArgs);
        void GetHotkey(out short pwHotkey);
        void SetHotkey(short wHotkey);
        void GetShowCmd(out int piShowCmd);
        void SetShowCmd(int iShowCmd);
        void GetIconLocation(IntPtr pszIconPath, int cchIconPath, out int piIcon);
        void SetIconLocation([MarshalAs(UnmanagedType.LPWStr)] string pszIconPath, int iIcon);
        void SetRelativePath([MarshalAs(UnmanagedType.LPWStr)] string pszPathRel, uint dwReserved);
        void Resolve(IntPtr hwnd, uint fFlags);
        void SetPath([MarshalAs(UnmanagedType.LPWStr)] string pszFile);
    }

    [ComImport]
    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    [Guid("00000138-0000-0000-C000-000000000046")]
    private interface IPropertyStore
    {
        void GetCount(out uint cProps);
        void GetAt(uint iProp, out PropertyKey pkey);
        void GetValue(ref PropertyKey key, out PropVariant pv);
        void SetValue(in PropertyKey key, in PropVariant pv);
        void Commit();
    }

    [StructLayout(LayoutKind.Sequential, Pack = 4)]
    private readonly struct PropertyKey(Guid formatId, int propertyId)
    {
        private readonly Guid _formatId = formatId;
        private readonly int _propertyId = propertyId;
    }

    [StructLayout(LayoutKind.Sequential)]
    private sealed class PropVariant : IDisposable
    {
        private ushort _valueType;
        private ushort _reserved1;
        private ushort _reserved2;
        private ushort _reserved3;
        private IntPtr _value;
        private IntPtr _reserved4;

        public static PropVariant FromString(string value)
        {
            return new PropVariant
            {
                _valueType = 31, // VT_LPWSTR
                _value = Marshal.StringToCoTaskMemUni(value)
            };
        }

        public void Dispose()
        {
            PropVariantClear(this);
            GC.SuppressFinalize(this);
        }

        ~PropVariant()
        {
            PropVariantClear(this);
        }

        [DllImport("ole32.dll")]
        private static extern int PropVariantClear([In, Out] PropVariant pvar);
    }
}