// -----------------------------------------------------------------------
// <copyright file="Util.cs">
// TODO: Update copyright text.
// </copyright>
// -----------------------------------------------------------------------

namespace WPFCustomMessageBox
{
    using System;
    using System.Drawing;
    using System.Runtime.InteropServices;
    using System.Windows;
    using System.Windows.Interop;
    using System.Windows.Media;
    using System.Windows.Media.Imaging;

    /// <summary>
    /// TODO: Update summary.
    /// </summary>
    internal static class Util
    {
        [DllImport("user32.dll")]
        static extern int GetWindowLong(IntPtr hwnd, int index);

        [DllImport("user32.dll")]
        static extern int SetWindowLong(IntPtr hwnd, int index, int newStyle);

        [DllImport("user32.dll")]
        static extern bool SetWindowPos(IntPtr hwnd, IntPtr hwndInsertAfter, int x, int y, int width, int height, uint flags);

        [DllImport("user32.dll")]
        static extern IntPtr SendMessage(IntPtr hwnd, uint msg, IntPtr wParam, IntPtr lParam);

        const int GWL_EXSTYLE = -20;
        const int WS_EX_DLGMODALFRAME = 0x0001;
        const int SWP_NOSIZE = 0x0001;
        const int SWP_NOMOVE = 0x0002;
        const int SWP_NOZORDER = 0x0004;
        const int SWP_FRAMECHANGED = 0x0020;
        //const uint WM_SETICON = 0x0080;


        internal static ImageSource ToImageSource(this Icon icon)
        {
            ImageSource imageSource = Imaging.CreateBitmapSourceFromHIcon(
                icon.Handle,
                Int32Rect.Empty,
                BitmapSizeOptions.FromEmptyOptions());

            return imageSource;
        }

        /// <summary>
        /// Keyboard Accellerators are used in Windows to allow easy shortcuts to controls like Buttons and 
        /// MenuItems. These allow users to press the Alt key, and a shortcut key will be highlighted on the 
        /// control. If the user presses that key, that control will be activated.
        /// This method checks a string if it contains a keyboard accellerator. If it doesn't, it adds one to the
        /// beginning of the string. If there are two strings with the same accellerator, Windows handles it.
        /// The keyboard accellerator character for WPF is underscore (_). It will not be visible.
        /// </summary>
        /// <param name="input"></param>
        /// <returns></returns>
        internal static string? TryAddKeyboardAccellerator(this string? input)
        {
            if (input == null)
                return input;

            const string accellerator = "_";            // This is the default WPF accellerator symbol - used to be & in WinForms

            // If it already contains an accellerator, do nothing
            if (input.Contains(accellerator)) return input;

            return accellerator + input;
        }

        /// <summary>
        /// Removes the icon from the given window.
        /// See https://stackoverflow.com/a/18581096
        /// </summary>
        /// <param name="window">The window to remove the icon from.</param>
        internal static void RemoveIcon(Window window)
        {
            // Get this window's handle
            IntPtr hwnd = new WindowInteropHelper(window).Handle;
            // Change the extended window style to not show a window icon
            int extendedStyle = GetWindowLong(hwnd, GWL_EXSTYLE);
            _ = SetWindowLong(hwnd, GWL_EXSTYLE, extendedStyle | WS_EX_DLGMODALFRAME);
            // Update the window's non-client area to reflect the changes
            SetWindowPos(hwnd, IntPtr.Zero, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER | SWP_FRAMECHANGED);
        }
    }
}