using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using KGIS.Framework.Utils;

namespace Kingo.Plugin.EngineEditor.Common
{
    public class GetAllDesktopWindows
    {
        private delegate bool WNDENUMPROC(IntPtr hWnd, int lParam);

        //用来遍历所有窗口 
        [DllImport("user32.dll")]
        private static extern bool EnumWindows(WNDENUMPROC lpEnumFunc, int lParam);

        //获取窗口Text 
        [DllImport("user32.dll")]
        private static extern int GetWindowTextW(IntPtr hWnd, [MarshalAs(UnmanagedType.LPWStr)]StringBuilder lpString, int nMaxCount);

        //获取窗口类名 
        [DllImport("user32.dll")]
        private static extern int GetClassNameW(IntPtr hWnd, [MarshalAs(UnmanagedType.LPWStr)]StringBuilder lpString, int nMaxCount);

        [DllImport("user32.dll", EntryPoint = "IsWindow")]
        public static extern bool IsWindow(IntPtr hWnd);

        /// <summary>
        /// 自定义一个类，用来保存句柄信息，在遍历的时候，随便也用空上句柄来获取些信息
        /// </summary>
        public struct WindowInfo
        {
            public IntPtr hWnd;
            public string szWindowName;
            public string szClassName;
        }

        public List<WindowInfo> ToGetAllDesktopWindows()
        {
            //用来保存窗口对象 列表
            List<WindowInfo> wndList = new List<WindowInfo>();
            List<WindowInfo> wndList_IsWindows = new List<WindowInfo>();
            try
            {
                //enum all desktop windows 
                EnumWindows(delegate (IntPtr hWnd, int lParam)
                {
                    WindowInfo wnd = new WindowInfo();
                    StringBuilder sb = new StringBuilder(256);

                    //get hwnd 
                    wnd.hWnd = hWnd;

                    //get window name  
                    GetWindowTextW(hWnd, sb, sb.Capacity);
                    wnd.szWindowName = sb.ToString();

                    //get window class 
                    GetClassNameW(hWnd, sb, sb.Capacity);
                    wnd.szClassName = sb.ToString();

                    //add it into list 
                    wndList.Add(wnd);
                    return true;
                }, 0);

                if (wndList != null && wndList.Count() > 0)
                {
                    for (int u = 0; u < wndList.Count(); u++)
                    {
                        if (wndList[u].hWnd != IntPtr.Zero && IsWindow(wndList[u].hWnd) == true)//不为空且是窗口
                        {
                            if (string.IsNullOrWhiteSpace(wndList[u].szWindowName) == false)
                            {
                                wndList_IsWindows.Add(wndList[u]);
                            }
                            else
                            {
                                continue;
                            }
                        }
                        else
                        {
                            continue;
                        }
                    }
                }
                return wndList_IsWindows;
            }
            catch (Exception ex)
            {
                LogAPI.Debug("获取所有窗口句柄时失败，异常原因: " + ex + " ; ");
                return null;
            }
            finally
            {
                if (wndList != null && wndList.Count() > 0)
                {
                    wndList = null;
                }
                if (wndList_IsWindows != null && wndList_IsWindows.Count() > 0)
                {
                    wndList_IsWindows = null;
                }
            }
        }
    }
}