//############################################################
//      quote:SmileWei.EmbeddedApp
//      https://github.com/yuzhengyang
//      author:yuzhengyang
//############################################################
using System;
using System.ComponentModel;
using System.Windows.Forms;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.IO;

namespace Y.Skin.YoPanel
{
    public partial class EmbedArticlePanel : Panel
    {

        /// <summary>
        /// Track if the application has been created
        /// </summary>
        bool created = false;

        /// <summary>
        /// Handle to the application Window
        /// </summary>
        IntPtr appWin;

        /// <summary>
        /// The name of the exe to launch
        /// </summary>
        private string exeName = "";

        /// <summary>
        /// Get/Set if we draw the tick marks
        /// </summary>
        [
        Category("Data"),
        Description("Name of the executable to launch"),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)
        ]
        public string ExeName
        {
            get
            {
                return exeName;
            }
            set
            {
                exeName = value;
            }
        }


        /// <summary>
        /// Constructor
        /// </summary>
        public EmbedArticlePanel()
        {
        }


        [DllImport("user32.dll", EntryPoint = "GetWindowThreadProcessId", SetLastError = true,
             CharSet = CharSet.Unicode, ExactSpelling = true,
             CallingConvention = CallingConvention.StdCall)]
        private static extern long GetWindowThreadProcessId(long hWnd, long lpdwProcessId);

        [DllImport("user32.dll", SetLastError = true)]
        private static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

        [DllImport("user32.dll", SetLastError = true)]
        private static extern long SetParent(IntPtr hWndChild, IntPtr hWndNewParent);

        [DllImport("user32.dll", EntryPoint = "GetWindowLongA", SetLastError = true)]
        private static extern long GetWindowLong(IntPtr hwnd, int nIndex);

        [DllImport("user32.dll", EntryPoint = "SetWindowLongA", SetLastError = true)]
        private static extern long SetWindowLong(IntPtr hwnd, int nIndex, long dwNewLong);

        [DllImport("user32.dll", SetLastError = true)]
        private static extern long SetWindowPos(IntPtr hwnd, long hWndInsertAfter, long x, long y, long cx, long cy, long wFlags);

        [DllImport("user32.dll", SetLastError = true)]
        private static extern bool MoveWindow(IntPtr hwnd, int x, int y, int cx, int cy, bool repaint);

        [DllImport("user32.dll", EntryPoint = "PostMessageA", SetLastError = true)]
        private static extern bool PostMessage(IntPtr hwnd, uint Msg, long wParam, long lParam);

        private const int SWP_NOOWNERZORDER = 0x200;
        private const int SWP_NOREDRAW = 0x8;
        private const int SWP_NOZORDER = 0x4;
        private const int SWP_SHOWWINDOW = 0x0040;
        private const int WS_EX_MDICHILD = 0x40;
        private const int SWP_FRAMECHANGED = 0x20;
        private const int SWP_NOACTIVATE = 0x10;
        private const int SWP_ASYNCWINDOWPOS = 0x4000;
        private const int SWP_NOMOVE = 0x2;
        private const int SWP_NOSIZE = 0x1;
        private const int GWL_STYLE = (-16);
        private const int WS_VISIBLE = 0x10000000;
        private const int WM_CLOSE = 0x10;
        private const int WS_CHILD = 0x40000000;

        /// <summary>
        /// Force redraw of control when size changes
        /// </summary>
        /// <param name="e">Not used</param>
        protected override void OnSizeChanged(EventArgs e)
        {
            this.Invalidate();
            base.OnSizeChanged(e);
        }


        /// <summary>
        /// Creeate control when visibility changes
        /// </summary>
        /// <param name="e">Not used</param>
        protected override void OnVisibleChanged(EventArgs e)
        {

            // If control needs to be initialized/created
            if (created == false)
            {

                // Mark that control is created
                created = true;

                // Initialize handle value to invalid
                appWin = IntPtr.Zero;

                // Start the remote application
                Process p = null;
                try
                {

                    // Start the process
                    p = System.Diagnostics.Process.Start(this.exeName);

                    // Wait for process to be created and enter idle condition
                    p.WaitForInputIdle();

                    // Get the main handle
                    appWin = p.MainWindowHandle;
                }
                catch (Exception ex)
                {
                    MessageBox.Show(this, ex.Message, "Error");
                }
                // Put it into this form
                SetParent(appWin, this.Handle);

                // Remove border and whatnot
                SetWindowLong(appWin, GWL_STYLE, WS_VISIBLE);

                // Move the window to overlay it on this window
                MoveWindow(appWin, 0, 0, this.Width, this.Height, true);
            }

            base.OnVisibleChanged(e);
        }


        /// <summary>
        /// 
        /// </summary>
        /// <param name="e"></param>
        protected override void OnHandleDestroyed(EventArgs e)
        {
            // Stop the application
            if (appWin != IntPtr.Zero)
            {

                // Post a colse message
                PostMessage(appWin, WM_CLOSE, 0, 0);

                // Delay for it to get the message
                System.Threading.Thread.Sleep(1000);

                // Clear internal handle
                appWin = IntPtr.Zero;

            }

            base.OnHandleDestroyed(e);
        }


        /// <summary>
        /// Update display of the executable
        /// </summary>
        /// <param name="e">Not used</param>
        protected override void OnResize(EventArgs e)
        {
            if (this.appWin != IntPtr.Zero)
            {
                MoveWindow(appWin, 0, 0, this.Width, this.Height, true);
            }
            base.OnResize(e);
        }

    }
}