/*
 * Greenshot - a free and open source screenshot tool
 * Copyright (C) 2007-2020 Thomas Braun, Jens Klingen, Robin Krom
 *
 * For more information see: http://getgreenshot.org/
 * The Greenshot project is hosted on GitHub https://github.com/greenshot/greenshot
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 1 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

using Greenshot.IniFile;
using Greenshot.Interop;
using Greenshot.Plugin;
using GreenshotPlugin.UnmanagedHelpers;
using log4net;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;
using System.Text;
using System.Text.RegularExpressions;
using System.Windows.Forms;

namespace GreenshotPlugin.Core {
    /// <summary>
	/// EnumWindows wrapper for .NET
	/// </summary>
	public class WindowsEnumerator {
		/// <summary>
		/// Returns the collection of windows returned by GetWindows
		/// </summary>
		public IList<WindowDetails> Items { get; private set; }

		/// <summary>
		/// Gets all top level windows on the system.
		/// </summary>
		public WindowsEnumerator GetWindows() {
			GetWindows(IntPtr.Zero, null);
			return this;
		}

		/// <summary>
		/// Gets all child windows of the specified window
		/// </summary>
		/// <param name="parent">Window Handle to get children for</param>
		public WindowsEnumerator GetWindows(WindowDetails parent)
		{
			GetWindows(parent?.Handle ?? IntPtr.Zero, null);
			return this;
		}

		/// <summary>
		/// Gets all child windows of the specified window
		/// </summary>
		/// <param name="hWndParent">Window Handle to get children for</param>
		/// <param name="classname">Window Classname to copy, use null to copy all</param>
		public WindowsEnumerator GetWindows(IntPtr hWndParent, string classname) {
			Items = new List<WindowDetails>();
			IList<WindowDetails> windows = new List<WindowDetails>();
			User32.EnumChildWindows(hWndParent, WindowEnum, IntPtr.Zero);

			bool hasParent = !IntPtr.Zero.Equals(hWndParent);
			string parentText = null;
			if (hasParent) {
				var title = new StringBuilder(260, 260);
				User32.GetWindowText(hWndParent, title, title.Capacity);
				parentText = title.ToString();
			}

			foreach (var window in Items) {
				if (hasParent) {
					window.Text = parentText;
					window.ParentHandle = hWndParent;
				}
				if (classname == null || window.ClassName.Equals(classname)) {
					windows.Add(window);
				}
			}
			Items = windows;
			return this;
		}

        /// <summary>
		/// The enum Windows callback.
		/// </summary>
		/// <param name="hWnd">Window Handle</param>
		/// <param name="lParam">Application defined value</param>
		/// <returns>1 to continue enumeration, 0 to stop</returns>
		private int WindowEnum(IntPtr hWnd, int lParam)
		{
			if (OnWindowEnum(hWnd)) {
				return 1;
			}
			return 0;
		}

        /// <summary>
		/// Called whenever a new window is about to be added
		/// by the Window enumeration called from GetWindows.
		/// If overriding this function, return true to continue
		/// enumeration or false to stop.  If you do not call
		/// the base implementation the Items collection will
		/// be empty.
		/// </summary>
		/// <param name="hWnd">Window handle to add</param>
		/// <returns>True to continue enumeration, False to stop</returns>
		protected virtual bool OnWindowEnum(IntPtr hWnd) {
			if (!WindowDetails.IsIgnoreHandle(hWnd)) {
				Items.Add(new WindowDetails(hWnd));
			}
			return true;
		}
	}

    /// <summary>
	/// Code for handling with "windows"
	/// Main code is taken from vbAccelerator, location:
	/// http://www.vbaccelerator.com/home/NET/Code/Libraries/Windows/Enumerating_Windows/article.asp
	/// but a LOT of changes/enhancements were made to adapt it for Greenshot.
	///
	/// Provides details about a Window returned by the  enumeration
	/// </summary>
	public class WindowDetails : IEquatable<WindowDetails>{
		private const string MetroWindowsClass = "Windows.UI.Core.CoreWindow"; //Used for Windows 8(.1)
		private const string FramedAppClass = "ApplicationFrameWindow"; // Windows 10 uses ApplicationFrameWindow
		private const string MetroApplauncherClass = "ImmersiveLauncher";
		private const string MetroGutterClass = "ImmersiveGutter";
		private static readonly IList<string> IgnoreClasses = new List<string>(new[] { "Progman", "Button", "Dwm" }); //"MS-SDIa"

		private static readonly ILog Log = LogManager.GetLogger(typeof(WindowDetails));
		private static readonly CoreConfiguration Conf = IniConfig.GetIniSection<CoreConfiguration>();
		private static readonly IList<IntPtr> IgnoreHandles = new List<IntPtr>();
		private static readonly IList<string> ExcludeProcessesFromFreeze = new List<string>();
		private static readonly IAppVisibility AppVisibility;

		static WindowDetails() {
			try
			{
				// Only try to instantiate when Windows 8 or later.
				if (Environment.OSVersion.Version.Major >= 6 && Environment.OSVersion.Version.Minor >= 2)
				{
					AppVisibility = COMWrapper.CreateInstance<IAppVisibility>();
				}
			}
			catch (Exception ex)
			{
				Log.WarnFormat("Couldn't create instance of IAppVisibility: {0}", ex.Message);
			}
		}

		public static void AddProcessToExcludeFromFreeze(string processname) {
			if (!ExcludeProcessesFromFreeze.Contains(processname)) {
				ExcludeProcessesFromFreeze.Add(processname);
			}
		}

		internal static bool IsIgnoreHandle(IntPtr handle) {
			return IgnoreHandles.Contains(handle);
		}

		private IList<WindowDetails> _childWindows;
		private IntPtr _parentHandle = IntPtr.Zero;
		private WindowDetails _parent;
		private bool _frozen;

		/// <summary>
		/// This checks if the window is a Windows 8 App
		/// For Windows 10 most normal code works, as it's hosted inside "ApplicationFrameWindow"
		/// </summary>
		public bool IsApp => MetroWindowsClass.Equals(ClassName);

		/// <summary>
		/// This checks if the window is a Windows 10 App
		/// For Windows 10 apps are hosted inside "ApplicationFrameWindow"
		/// </summary>
		public bool IsWin10App => FramedAppClass.Equals(ClassName);

		/// <summary>
		/// Check if the window is the metro gutter (sizeable separator)
		/// </summary>
		public bool IsGutter => MetroGutterClass.Equals(ClassName);

		/// <summary>
		/// Test if this window is for the App-Launcher
		/// </summary>
		public bool IsAppLauncher => MetroApplauncherClass.Equals(ClassName);

		/// <summary>
		/// Check if this window is the window of a metro app
		/// </summary>
		public bool IsMetroApp => IsAppLauncher || IsApp;

		/// <summary>
		/// To allow items to be compared, the hash code
		/// is set to the Window handle, so two EnumWindowsItem
		/// objects for the same Window will be equal.
		/// </summary>
		/// <returns>The Window Handle for this window</returns>
		public override int GetHashCode() {
			return Handle.ToInt32();
		}

		public override bool Equals(object right) {
			return Equals(right as WindowDetails);
		}

		/// <summary>
		/// Compare two windows details
		/// </summary>
		/// <param name="other"></param>
		/// <returns></returns>
		public bool Equals(WindowDetails other) {
			if (other is null) {
				return false;
			}

			if (ReferenceEquals(this, other)) {
				return true;
			}

			if (GetType() != other.GetType()){
				return false;
			}
			return other.Handle == Handle;
		}

		/// <summary>
		/// Check if the window has children
		/// </summary>
		public bool HasChildren => (_childWindows != null) && (_childWindows.Count > 0);

		/// <summary>
		/// Freeze information updates
		/// </summary>
		public void FreezeDetails() {
			_frozen = true;
		}

		/// <summary>
		/// Make the information update again.
		/// </summary>
		public void UnfreezeDetails() {
			_frozen = false;
		}

		/// <summary>
		/// Get the file path to the exe for the process which owns this window
		/// </summary>
		public string ProcessPath {
			get {
				if (Handle == IntPtr.Zero) {
					// not a valid window handle
					return string.Empty;
				}
				// Get the process id
                User32.GetWindowThreadProcessId(Handle, out var processid);
				return Kernel32.GetProcessPath(processid);
			}
		}


		/// <summary>
		/// Get the icon belonging to the process
		/// </summary>
		public Image DisplayIcon {
			get {
				try
                {
                    using var appIcon = GetAppIcon(Handle);
                    if (appIcon != null) {
                        return appIcon.ToBitmap();
                    }
                } catch (Exception ex) {
					Log.WarnFormat("Couldn't get icon for window {0} due to: {1}", Text, ex.Message);
					Log.Warn(ex);
				}
				if (IsMetroApp) {
					// No method yet to get the metro icon
					return null;
				}
				try {
					return PluginUtils.GetCachedExeIcon(ProcessPath, 0);
				} catch (Exception ex) {
					Log.WarnFormat("Couldn't get icon for window {0} due to: {1}", Text, ex.Message);
					Log.Warn(ex);
				}
				return null;
			}
		}

		/// <summary>
		/// Get the icon for a hWnd
		/// </summary>
		/// <param name="hwnd"></param>
		/// <returns></returns>
		private static Icon GetAppIcon(IntPtr hwnd) {
			IntPtr iconSmall = IntPtr.Zero;
			IntPtr iconBig = new IntPtr(1);
			IntPtr iconSmall2 = new IntPtr(2);

			IntPtr iconHandle;
			if (Conf.UseLargeIcons) {
				iconHandle = User32.SendMessage(hwnd, (int)WindowsMessages.WM_GETICON, iconBig, IntPtr.Zero);
				if (iconHandle == IntPtr.Zero) {
					iconHandle = User32.GetClassLongWrapper(hwnd, (int)ClassLongIndex.GCL_HICON);
				}
			} else {
				iconHandle = User32.SendMessage(hwnd, (int)WindowsMessages.WM_GETICON, iconSmall2, IntPtr.Zero);
			}
			if (iconHandle == IntPtr.Zero) {
				iconHandle = User32.SendMessage(hwnd, (int)WindowsMessages.WM_GETICON, iconSmall, IntPtr.Zero);
			}
			if (iconHandle == IntPtr.Zero) {
				iconHandle = User32.GetClassLongWrapper(hwnd, (int)ClassLongIndex.GCL_HICONSM);
			}
			if (iconHandle == IntPtr.Zero) {
				iconHandle = User32.SendMessage(hwnd, (int)WindowsMessages.WM_GETICON, iconBig, IntPtr.Zero);
			}
			if (iconHandle == IntPtr.Zero) {
				iconHandle = User32.GetClassLongWrapper(hwnd, (int)ClassLongIndex.GCL_HICON);
			}

			if (iconHandle == IntPtr.Zero) {
				return null;
			}

			Icon icon = Icon.FromHandle(iconHandle);

			return icon;
		}

		/// <summary>
		/// Use this to make remove internal windows, like the mainform and the captureforms, invisible
		/// </summary>
		/// <param name="ignoreHandle"></param>
		public static void RegisterIgnoreHandle(IntPtr ignoreHandle) {
			IgnoreHandles.Add(ignoreHandle);
		}

		/// <summary>
		/// Use this to remove the with RegisterIgnoreHandle registered handle
		/// </summary>
		/// <param name="ignoreHandle"></param>
		public static void UnregisterIgnoreHandle(IntPtr ignoreHandle) {
			IgnoreHandles.Remove(ignoreHandle);
		}

		public IList<WindowDetails> Children {
			get {
				if (_childWindows == null) {
					 GetChildren();
				}
				return _childWindows;
			}
		}

		/// <summary>
		/// Retrieve all windows with a certain title or classname
		/// </summary>
		/// <param name="windows"></param>
		/// <param name="titlePattern">The regexp to look for in the title</param>
		/// <param name="classnamePattern">The regexp to look for in the classname</param>
		/// <returns>List WindowDetails with all the found windows</returns>
		private static IEnumerable<WindowDetails> FindWindow(IList<WindowDetails> windows, string titlePattern, string classnamePattern) {
			Regex titleRegexp = null;
			Regex classnameRegexp = null;

			if (titlePattern != null && titlePattern.Trim().Length > 0) {
				titleRegexp = new Regex(titlePattern);
			}
			if (classnamePattern != null && classnamePattern.Trim().Length > 0) {
				classnameRegexp = new Regex(classnamePattern);
			}

			foreach(WindowDetails window in windows) {
				if (titleRegexp != null && titleRegexp.IsMatch(window.Text)) {
					yield return window;
				} else if (classnameRegexp != null && classnameRegexp.IsMatch(window.ClassName)) {
					yield return window;
				}
			}
		}

		/// <summary>
		/// Retrieve the child with matching classname
		/// </summary>
		public WindowDetails GetChild(string childClassname) {
			foreach(WindowDetails child in Children) {
				if (childClassname.Equals(child.ClassName)) {
					return child;
				}
			}
			return null;
		}

		/// <summary>
		/// Retrieve the children with matching classname
		/// </summary>
		public IEnumerable<WindowDetails> GetChilden(string childClassname) {
			foreach (WindowDetails child in Children) {
				if (childClassname.Equals(child.ClassName)) {
					yield return child;
				}
			}
		}

		public IntPtr ParentHandle {
			get {
				if (_parentHandle == IntPtr.Zero) {
					_parentHandle = User32.GetParent(Handle);
					_parent = null;
				}
				return _parentHandle;
			}
			set {
				if (_parentHandle != value) {
					_parentHandle = value;
					_parent = null;
				}
			}
		}
		/// <summary>
		/// Get the parent of the current window
		/// </summary>
		/// <returns>WindowDetails of the parent, or null if none</returns>
		public WindowDetails GetParent() {
			if (_parent == null) {
				if (_parentHandle == IntPtr.Zero) {
					_parentHandle = User32.GetParent(Handle);
				}
				if (_parentHandle != IntPtr.Zero) {
					_parent = new WindowDetails(_parentHandle);
				}
			}
			return _parent;
		}

		/// <summary>
		/// Retrieve all the children, this only stores the children internally.
		/// One should normally use the getter "Children"
		/// </summary>
		public IList<WindowDetails> GetChildren() {
			if (_childWindows == null) {
				return GetChildren(0);
			}
			return _childWindows;
		}

		/// <summary>
		/// Retrieve all the children, this only stores the children internally, use the "Children" property for the value
		/// </summary>
		/// <param name="levelsToGo">Specify how many levels we go in</param>
		public IList<WindowDetails> GetChildren(int levelsToGo) {
			if (_childWindows != null)
			{
				return _childWindows;
			}
			_childWindows = new WindowsEnumerator().GetWindows(Handle, null).Items;
			foreach(var childWindow in _childWindows) {
				if (levelsToGo > 0) {
					childWindow.GetChildren(levelsToGo-1);
				}
			}
			return _childWindows;
		}

		/// <summary>
		/// Retrieve children with a certain title or classname
		/// </summary>
		/// <param name="titlePattern">The regexp to look for in the title</param>
		/// <param name="classnamePattern">The regexp to look for in the classname</param>
		/// <returns>List WindowDetails with all the found windows, or an empty list</returns>
		public IEnumerable<WindowDetails> FindChildren(string titlePattern, string classnamePattern) {
			return FindWindow(Children, titlePattern, classnamePattern);
		}

		/// <summary>
		/// Recursing helper method for the FindPath
		/// </summary>
		/// <param name="classnames">List string with classnames</param>
		/// <param name="index">The index in the list to look for</param>
		/// <returns>WindowDetails if a match was found</returns>
		private WindowDetails FindPath(IList<string> classnames, int index) {
			if (index == classnames.Count - 1) {
				foreach (var foundWindow in FindChildren(null, classnames[index]))
				{
					return foundWindow;
				}
			} else {
				foreach(var foundWindow in FindChildren(null, classnames[index]))
				{
					var resultWindow = foundWindow.FindPath(classnames, index+1);
					if (resultWindow != null)
					{
						return resultWindow;
					}
				}
			}
			return null;
		}

		/// <summary>
		/// This method will find the child window according to a path of classnames.
		/// Usually used for finding a certain "content" window like for the IE Browser
		/// </summary>
		/// <param name="classnames">List of string with classname "path"</param>
		/// <param name="allowSkip">true allows the search to skip a classname of the path</param>
		/// <returns>WindowDetails if found</returns>
		public WindowDetails FindPath(IList<string> classnames, bool allowSkip) {
			int index = 0;
			var resultWindow = FindPath(classnames, index++);
			if (resultWindow == null && allowSkip) {
				while(resultWindow == null && index < classnames.Count) {
					resultWindow = FindPath(classnames, index);
				}
			}
			return resultWindow;
		}

		/// <summary>
		/// Deep scan for a certain classname pattern
		/// </summary>
		/// <param name="windowDetails">Window to scan into</param>
		/// <param name="classnamePattern">Classname regexp pattern</param>
		/// <returns>The first WindowDetails found</returns>
		public static WindowDetails DeepScan(WindowDetails windowDetails, Regex classnamePattern) {
			if (classnamePattern.IsMatch(windowDetails.ClassName)) {
				return windowDetails;
			}
			// First loop through this level
			foreach(var child in windowDetails.Children) {
				if (classnamePattern.IsMatch(child.ClassName)) {
					return child;
				}
			}
			// Go into all children
			foreach(var child in windowDetails.Children) {
				var deepWindow = DeepScan(child, classnamePattern);
				if (deepWindow != null) {
					return deepWindow;
				}
			}
			return null;
		}

		/// <summary>
		/// GetWindow
		/// </summary>
		/// <param name="gwCommand">The GetWindowCommand to use</param>
		/// <returns>null if nothing found, otherwise the WindowDetails instance of the "child"</returns>
		public WindowDetails GetWindow(GetWindowCommand gwCommand) {
			var tmphWnd = User32.GetWindow(Handle, gwCommand);
			if (IntPtr.Zero == tmphWnd) {
				return null;
			}
			var windowDetails = new WindowDetails(tmphWnd)
			{
				_parent = this
			};
			return windowDetails;
		}

		/// <summary>
		/// Gets the window's handle
		/// </summary>
		public IntPtr Handle { get; }

		private string _text;
		/// <summary>
		/// Gets the window's title (caption)
		/// </summary>
		public string Text {
			set {
				_text = value;
			}
			get {
				if (_text == null) {
					var title = new StringBuilder(260, 260);
					User32.GetWindowText(Handle, title, title.Capacity);
					_text = title.ToString();
				}
				return _text;
			}
		}

		private string _className;
		/// <summary>
		/// Gets the window's class name.
		/// </summary>
		public string ClassName => _className ?? (_className = GetClassName(Handle));

		/// <summary>
		/// Gets/Sets whether the window is iconic (mimimized) or not.
		/// </summary>
		public bool Iconic {
			get {
				if (IsMetroApp) {
					return !Visible;
				}
				return User32.IsIconic(Handle) || Location.X <= -32000;
			}
			set {
				if (value) {
					User32.SendMessage(Handle,  (int)WindowsMessages.WM_SYSCOMMAND, (IntPtr)User32.SC_MINIMIZE, IntPtr.Zero);
				} else {
					User32.SendMessage(Handle,  (int)WindowsMessages.WM_SYSCOMMAND, (IntPtr)User32.SC_RESTORE, IntPtr.Zero);
				}
			}
		}

		/// <summary>
		/// Gets/Sets whether the window is maximised or not.
		/// </summary>
		public bool Maximised {
			get {
				if (IsApp)
				{
					if (Visible) {
						Rectangle windowRectangle = WindowRectangle;
						foreach (var screen in Screen.AllScreens) {
							if (screen.Bounds.Contains(windowRectangle)) {
								if (windowRectangle.Equals(screen.Bounds)) {
									return true;
								}
							}
						}
					}
					return false;
				}
				return User32.IsZoomed(Handle);
			}
			set {
				if (value) {
					User32.SendMessage(Handle, (int)WindowsMessages.WM_SYSCOMMAND, (IntPtr)User32.SC_MAXIMIZE, IntPtr.Zero);
				} else {
					User32.SendMessage(Handle, (int)WindowsMessages.WM_SYSCOMMAND, (IntPtr)User32.SC_MINIMIZE, IntPtr.Zero);
				}
			}
		}

		/// <summary>
		/// This doesn't work as good as is should, but does move the App out of the way...
		/// </summary>
		public void HideApp() {
			User32.ShowWindow(Handle, ShowWindowCommand.Hide);
		}

		/// <summary>
		/// Gets whether the window is visible.
		/// </summary>
		public bool Visible {
			get {
				if (IsApp) {
					Rectangle windowRectangle = WindowRectangle;
					foreach (Screen screen in Screen.AllScreens) {
						if (screen.Bounds.Contains(windowRectangle)) {
							if (windowRectangle.Equals(screen.Bounds)) {
								// Fullscreen, it's "visible" when AppVisibilityOnMonitor says yes
								// Although it might be the other App, this is not "very" important
								RECT rect = new RECT(screen.Bounds);
								IntPtr monitor = User32.MonitorFromRect(ref rect, User32.MONITOR_DEFAULTTONULL);
								if (monitor != IntPtr.Zero) {
									MONITOR_APP_VISIBILITY? monitorAppVisibility = AppVisibility?.GetAppVisibilityOnMonitor(monitor);
									//LOG.DebugFormat("App {0} visible: {1} on {2}", Text, monitorAppVisibility, screen.Bounds);
									if (monitorAppVisibility == MONITOR_APP_VISIBILITY.MAV_APP_VISIBLE) {
										return true;
									}
								}
							} else {
								// Is only partly on the screen, when this happens the app is always visible!
								return true;
							}
						}
					}
					return false;
				}
				if (IsGutter) {
					// gutter is only made available when it's visible
					return true;
				}
				if (IsAppLauncher) {
					return IsAppLauncherVisible;
				}
				return User32.IsWindowVisible(Handle);
			}
		}

		public bool HasParent {
			get {
				GetParent();
				return _parentHandle != IntPtr.Zero;
			}
		}

		public int ProcessId {
			get {
                User32.GetWindowThreadProcessId(Handle, out var processId);
				return processId;
			}
		}

		public Process Process {
			get {
				try {
                    User32.GetWindowThreadProcessId(Handle, out var processId);
					return Process.GetProcessById(processId);
				} catch (Exception ex) {
					Log.Warn(ex);
				}
				return null;
			}
		}

		/// <summary>
		/// Make sure the next call of a cached value is guaranteed the real value
		/// </summary>
		public void Reset() {
			_previousWindowRectangle = Rectangle.Empty;
		}

		private Rectangle _previousWindowRectangle = Rectangle.Empty;
		private long _lastWindowRectangleRetrieveTime;
		private const long CacheTime = TimeSpan.TicksPerSecond * 2;

		/// <summary>
		/// Gets the bounding rectangle of the window
		/// </summary>
		public Rectangle WindowRectangle {
			get {
				// Try to return a cached value
				long now = DateTime.Now.Ticks;
				if (_previousWindowRectangle.IsEmpty || !_frozen) {
					if (_previousWindowRectangle.IsEmpty || now - _lastWindowRectangleRetrieveTime > CacheTime) {
						Rectangle windowRect = Rectangle.Empty;
						if (DWM.IsDwmEnabled())
						{
							bool gotFrameBounds = GetExtendedFrameBounds(out windowRect);
							if (IsApp)
							{
								// Pre-Cache for Maximised call, this is only on Windows 8 apps (full screen)
								if (gotFrameBounds)
								{
									_previousWindowRectangle = windowRect;
									_lastWindowRectangleRetrieveTime = now;
								}
							}
							if (gotFrameBounds && WindowsVersion.IsWindows10OrLater && !Maximised)
							{
								// Somehow DWM doesn't calculate it corectly, there is a 1 pixel border around the capture
								// Remove this border, currently it's fixed but TODO: Make it depend on the OS?
								windowRect.Inflate(Conf.Win10BorderCrop);
								_previousWindowRectangle = windowRect;
								_lastWindowRectangleRetrieveTime = now;
								return windowRect;
							}
						}

						if (windowRect.IsEmpty) {
							if (!GetWindowRect(out windowRect))
							{
								Win32Error error = Win32.GetLastErrorCode();
								Log.WarnFormat("Couldn't retrieve the windows rectangle: {0}", Win32.GetMessage(error));
							}
						}

						// Correction for maximized windows, only if it's not an app
						if (!HasParent && !IsApp && Maximised) {
                            // Only if the border size can be retrieved
							if (GetBorderSize(out var size))
							{
								windowRect = new Rectangle(windowRect.X + size.Width, windowRect.Y + size.Height, windowRect.Width - (2 * size.Width), windowRect.Height - (2 * size.Height));
							}
						}
						_lastWindowRectangleRetrieveTime = now;
						// Try to return something valid, by getting returning the previous size if the window doesn't have a Rectangle anymore
						if (windowRect.IsEmpty) {
							return _previousWindowRectangle;
						}
						_previousWindowRectangle = windowRect;
						return windowRect;
					}
				}
				return _previousWindowRectangle;
			}
		}

		/// <summary>
		/// Gets the location of the window relative to the screen.
		/// </summary>
		public Point Location {
			get {
				Rectangle tmpRectangle = WindowRectangle;
				return new Point(tmpRectangle.Left, tmpRectangle.Top);
			}
		}

		/// <summary>
		/// Gets the size of the window.
		/// </summary>
		public Size Size {
			get {
				Rectangle tmpRectangle = WindowRectangle;
				return new Size(tmpRectangle.Right - tmpRectangle.Left, tmpRectangle.Bottom - tmpRectangle.Top);
			}
		}

		/// <summary>
		/// Get the client rectangle, this is the part of the window inside the borders (drawable area)
		/// </summary>
		public Rectangle ClientRectangle {
			get {
                if (!GetClientRect(out var clientRect))
				{
					Win32Error error = Win32.GetLastErrorCode();
					Log.WarnFormat("Couldn't retrieve the client rectangle for {0}, error: {1}", Text, Win32.GetMessage(error));
				}
				return clientRect;
			}
		}

		/// <summary>
		/// Check if the supplied point lies in the window
		/// </summary>
		/// <param name="p">Point with the coordinates to check</param>
		/// <returns>true if the point lies within</returns>
		public bool Contains(Point p) {
			return WindowRectangle.Contains(p);
		}

		/// <summary>
		/// Restores and Brings the window to the front,
		/// assuming it is a visible application window.
		/// </summary>
		public void Restore() {
			if (Iconic) {
				User32.SendMessage(Handle, (int)WindowsMessages.WM_SYSCOMMAND, (IntPtr)User32.SC_RESTORE, IntPtr.Zero);
			}
			User32.BringWindowToTop(Handle);
			User32.SetForegroundWindow(Handle);
			// Make sure windows has time to perform the action
			// TODO: this is BAD practice!
			while(Iconic) {
				Application.DoEvents();
			}
		}

		/// <summary>
		/// Get / Set the WindowStyle
		/// </summary>
		public WindowStyleFlags WindowStyle {
			get {
				return (WindowStyleFlags)User32.GetWindowLongWrapper(Handle, (int)WindowLongIndex.GWL_STYLE);
			}
			set {
				User32.SetWindowLongWrapper(Handle, (int)WindowLongIndex.GWL_STYLE, new IntPtr((long)value));
			}
		}

		/// <summary>
		/// Get/Set the WindowPlacement
		/// </summary>
		public WindowPlacement WindowPlacement {
			get {
				var placement = WindowPlacement.Default;
				User32.GetWindowPlacement(Handle, ref placement);
				return placement;
			}
			set {
				User32.SetWindowPlacement(Handle, ref value);
			}
		}

		/// <summary>
		/// Get/Set the Extended WindowStyle
		/// </summary>
		public ExtendedWindowStyleFlags ExtendedWindowStyle {
			get {
				return (ExtendedWindowStyleFlags)User32.GetWindowLongWrapper(Handle, (int)WindowLongIndex.GWL_EXSTYLE);
			}
			set {
				User32.SetWindowLongWrapper(Handle, (int)WindowLongIndex.GWL_EXSTYLE, new IntPtr((uint)value));
			}
		}

		/// <summary>
		/// Capture Window with GDI+
		/// </summary>
		/// <param name="capture">The capture to fill</param>
		/// <returns>ICapture</returns>
		public ICapture CaptureGdiWindow(ICapture capture) {
			Image capturedImage = PrintWindow();
			if (capturedImage != null) {
				capture.Image = capturedImage;
				capture.Location = Location;
				return capture;
			}
			return null;
		}

		/// <summary>
		/// Capture DWM Window
		/// </summary>
		/// <param name="capture">Capture to fill</param>
		/// <param name="windowCaptureMode">Wanted WindowCaptureMode</param>
		/// <param name="autoMode">True if auto modus is used</param>
		/// <returns>ICapture with the capture</returns>
		public ICapture CaptureDwmWindow(ICapture capture, WindowCaptureMode windowCaptureMode, bool autoMode) {
			IntPtr thumbnailHandle = IntPtr.Zero;
			Form tempForm = null;
			bool tempFormShown = false;
			try {
				tempForm = new Form
				{
					ShowInTaskbar = false,
					FormBorderStyle = FormBorderStyle.None,
					TopMost = true
				};

				// Register the Thumbnail
				DWM.DwmRegisterThumbnail(tempForm.Handle, Handle, out thumbnailHandle);

				// Get the original size
                DWM.DwmQueryThumbnailSourceSize(thumbnailHandle, out var sourceSize);

				if (sourceSize.Width <= 0 || sourceSize.Height <= 0) {
					return null;
				}

				// Calculate the location of the temp form
				Rectangle windowRectangle = WindowRectangle;
				Point formLocation = windowRectangle.Location;
				Size borderSize = new Size();
				bool doesCaptureFit = false;
				if (!Maximised) {
					// Assume using it's own location
					formLocation = windowRectangle.Location;
                    using Region workingArea = new Region(Screen.PrimaryScreen.Bounds);
                    // Find the screen where the window is and check if it fits
                    foreach (Screen screen in Screen.AllScreens) {
                        if (!Equals(screen, Screen.PrimaryScreen)) {
                            workingArea.Union(screen.Bounds);
                        }
                    }

                    // If the formLocation is not inside the visible area
                    if (!workingArea.AreRectangleCornersVisisble(windowRectangle)) {
                        // If none found we find the biggest screen
                        foreach (Screen screen in Screen.AllScreens) {
                            Rectangle newWindowRectangle = new Rectangle(screen.WorkingArea.Location, windowRectangle.Size);
                            if (workingArea.AreRectangleCornersVisisble(newWindowRectangle)) {
                                formLocation = screen.Bounds.Location;
                                doesCaptureFit = true;
                                break;
                            }
                        }
                    } else {
                        doesCaptureFit = true;
                    }
                } else if (!WindowsVersion.IsWindows8OrLater) {
					//GetClientRect(out windowRectangle);
					GetBorderSize(out borderSize);
					formLocation = new Point(windowRectangle.X - borderSize.Width, windowRectangle.Y - borderSize.Height);
				}

				tempForm.Location = formLocation;
				tempForm.Size = sourceSize.ToSize();

				// Prepare rectangle to capture from the screen.
				Rectangle captureRectangle = new Rectangle(formLocation.X, formLocation.Y, sourceSize.Width, sourceSize.Height);
				if (Maximised) {
					// Correct capture size for maximized window by offsetting the X,Y with the border size
					// and subtracting the border from the size (2 times, as we move right/down for the capture without resizing)
					captureRectangle.Inflate(borderSize.Width, borderSize.Height);
				} else {
					// TODO: Also 8.x?
					if (WindowsVersion.IsWindows10OrLater)
					{
						captureRectangle.Inflate(Conf.Win10BorderCrop);
					}

					if (autoMode) {
						// check if the capture fits
						if (!doesCaptureFit)
                        {
                            // if GDI is allowed.. (a screenshot won't be better than we comes if we continue)
                            using Process thisWindowProcess = Process;
                            if (!IsMetroApp && WindowCapture.IsGdiAllowed(thisWindowProcess)) {
                                // we return null which causes the capturing code to try another method.
                                return null;
                            }
                        }
					}
				}
				// Prepare the displaying of the Thumbnail
				DWM_THUMBNAIL_PROPERTIES props = new DWM_THUMBNAIL_PROPERTIES
				{
					Opacity = 255,
					Visible = true,
					Destination = new RECT(0, 0, sourceSize.Width, sourceSize.Height)
				};
				DWM.DwmUpdateThumbnailProperties(thumbnailHandle, ref props);
				tempForm.Show();
				tempFormShown = true;

				// Intersect with screen
				captureRectangle.Intersect(capture.ScreenBounds);

				// Destination bitmap for the capture
				Bitmap capturedBitmap = null;
				bool frozen = false;
				try {
					// Check if we make a transparent capture
					if (windowCaptureMode == WindowCaptureMode.AeroTransparent) {
						frozen = FreezeWindow();
						// Use white, later black to capture transparent
						tempForm.BackColor = Color.White;
						// Make sure everything is visible
						tempForm.Refresh();
						Application.DoEvents();

						try
                        {
                            using Bitmap whiteBitmap = WindowCapture.CaptureRectangle(captureRectangle);
                            // Apply a white color
                            tempForm.BackColor = Color.Black;
                            // Make sure everything is visible
                            tempForm.Refresh();
                            if (!IsMetroApp) {
                                // Make sure the application window is active, so the colors & buttons are right
                                ToForeground();
                            }
                            // Make sure all changes are processed and visible
                            Application.DoEvents();
                            using Bitmap blackBitmap = WindowCapture.CaptureRectangle(captureRectangle);
                            capturedBitmap = ApplyTransparency(blackBitmap, whiteBitmap);
                        } catch (Exception e) {
							Log.Debug("Exception: ", e);
							// Some problem occurred, cleanup and make a normal capture
							if (capturedBitmap != null) {
								capturedBitmap.Dispose();
								capturedBitmap = null;
							}
						}
					}
					// If no capture up till now, create a normal capture.
					if (capturedBitmap == null) {
						// Remove transparency, this will break the capturing
						if (!autoMode) {
							tempForm.BackColor = Color.FromArgb(255, Conf.DWMBackgroundColor.R, Conf.DWMBackgroundColor.G, Conf.DWMBackgroundColor.B);
						} else {
							Color colorizationColor = DWM.ColorizationColor;
							// Modify by losing the transparency and increasing the intensity (as if the background color is white)
							colorizationColor = Color.FromArgb(255, (colorizationColor.R + 255) >> 1, (colorizationColor.G + 255) >> 1, (colorizationColor.B + 255) >> 1);
							tempForm.BackColor = colorizationColor;
						}
						// Make sure everything is visible
						tempForm.Refresh();
						if (!IsMetroApp) {
							// Make sure the application window is active, so the colors & buttons are right
							ToForeground();
						}
						// Make sure all changes are processed and visible
						Application.DoEvents();
						// Capture from the screen
						capturedBitmap = WindowCapture.CaptureRectangle(captureRectangle);
					}
					if (capturedBitmap != null) {
						// Not needed for Windows 8
						if (!WindowsVersion.IsWindows8OrLater) {
							// Only if the Inivalue is set, not maximized and it's not a tool window.
							if (Conf.WindowCaptureRemoveCorners && !Maximised && (ExtendedWindowStyle & ExtendedWindowStyleFlags.WS_EX_TOOLWINDOW) == 0) {
								// Remove corners
								if (!Image.IsAlphaPixelFormat(capturedBitmap.PixelFormat)) {
									Log.Debug("Changing pixelformat to Alpha for the RemoveCorners");
									Bitmap tmpBitmap = ImageHelper.Clone(capturedBitmap, PixelFormat.Format32bppArgb);
									capturedBitmap.Dispose();
									capturedBitmap = tmpBitmap;
								}
								RemoveCorners(capturedBitmap);
							}
						}
					}
				} finally {
					// Make sure to ALWAYS unfreeze!!
					if (frozen) {
						UnfreezeWindow();
					}
				}

				capture.Image = capturedBitmap;
				// Make sure the capture location is the location of the window, not the copy
				capture.Location = Location;
			} finally {
				if (thumbnailHandle != IntPtr.Zero) {
					// Unregister (cleanup), as we are finished we don't need the form or the thumbnail anymore
					DWM.DwmUnregisterThumbnail(thumbnailHandle);
				}
				if (tempForm != null) {
					if (tempFormShown) {
						tempForm.Close();
					}
					tempForm.Dispose();
					tempForm = null;
				}
			}

			return capture;
		}

		/// <summary>
		/// Helper method to remove the corners from a DMW capture
		/// </summary>
		/// <param name="image">The bitmap to remove the corners from.</param>
		private void RemoveCorners(Bitmap image)
        {
            using IFastBitmap fastBitmap = FastBitmap.Create(image);
            for (int y = 0; y < Conf.WindowCornerCutShape.Count; y++) {
                for (int x = 0; x < Conf.WindowCornerCutShape[y]; x++) {
                    fastBitmap.SetColorAt(x, y, Color.Transparent);
                    fastBitmap.SetColorAt(image.Width-1-x, y, Color.Transparent);
                    fastBitmap.SetColorAt(image.Width-1-x, image.Height-1-y, Color.Transparent);
                    fastBitmap.SetColorAt(x, image.Height-1-y, Color.Transparent);
                }
            }
        }

		/// <summary>
		/// Apply transparency by comparing a transparent capture with a black and white background
		/// A "Math.min" makes sure there is no overflow, but this could cause the picture to have shifted colors.
		/// The pictures should have been taken without differency, except for the colors.
		/// </summary>
		/// <param name="blackBitmap">Bitmap with the black image</param>
		/// <param name="whiteBitmap">Bitmap with the black image</param>
		/// <returns>Bitmap with transparency</returns>
		private Bitmap ApplyTransparency(Bitmap blackBitmap, Bitmap whiteBitmap)
        {
            using IFastBitmap targetBuffer = FastBitmap.CreateEmpty(blackBitmap.Size, PixelFormat.Format32bppArgb, Color.Transparent);
            targetBuffer.SetResolution(blackBitmap.HorizontalResolution, blackBitmap.VerticalResolution);
            using (IFastBitmap blackBuffer = FastBitmap.Create(blackBitmap))
            {
                using IFastBitmap whiteBuffer = FastBitmap.Create(whiteBitmap);
                for (int y = 0; y < blackBuffer.Height; y++) {
                    for (int x = 0; x < blackBuffer.Width; x++) {
                        Color c0 = blackBuffer.GetColorAt(x, y);
                        Color c1 = whiteBuffer.GetColorAt(x, y);
                        // Calculate alpha as double in range 0-1
                        int alpha = c0.R - c1.R + 255;
                        if (alpha == 255) {
                            // Alpha == 255 means no change!
                            targetBuffer.SetColorAt(x, y, c0);
                        } else if (alpha == 0) {
                            // Complete transparency, use transparent pixel
                            targetBuffer.SetColorAt(x, y, Color.Transparent);
                        } else {
                            // Calculate original color
                            byte originalAlpha = (byte)Math.Min(255, alpha);
                            var alphaFactor = alpha/255d;
                            //LOG.DebugFormat("Alpha {0} & c0 {1} & c1 {2}", alpha, c0, c1);
                            byte originalRed = (byte)Math.Min(255, c0.R / alphaFactor);
                            byte originalGreen = (byte)Math.Min(255, c0.G / alphaFactor);
                            byte originalBlue = (byte)Math.Min(255, c0.B / alphaFactor);
                            Color originalColor = Color.FromArgb(originalAlpha, originalRed, originalGreen, originalBlue);
                            //Color originalColor = Color.FromArgb(originalAlpha, originalRed, c0.G, c0.B);
                            targetBuffer.SetColorAt(x, y, originalColor);
                        }
                    }
                }
            }
            return targetBuffer.UnlockAndReturnBitmap();
        }

		/// <summary>
		/// Helper method to get the window size for DWM Windows
		/// </summary>
		/// <param name="rectangle">out Rectangle</param>
		/// <returns>bool true if it worked</returns>
		private bool GetExtendedFrameBounds(out Rectangle rectangle) {
            int result = DWM.DwmGetWindowAttribute(Handle, (int)DWMWINDOWATTRIBUTE.DWMWA_EXTENDED_FRAME_BOUNDS, out var rect, Marshal.SizeOf(typeof(RECT)));
			if (result >= 0) {
				rectangle = rect.ToRectangle();
				return true;
			}
			rectangle = Rectangle.Empty;
			return false;
		}

		/// <summary>
		/// Helper method to get the window size for GDI Windows
		/// </summary>
		/// <param name="rectangle">out Rectangle</param>
		/// <returns>bool true if it worked</returns>
		private bool GetClientRect(out Rectangle rectangle) {
			var windowInfo = new WindowInfo();
			// Get the Window Info for this window
			bool result = User32.GetWindowInfo(Handle, ref windowInfo);
			rectangle = result ? windowInfo.rcClient.ToRectangle() : Rectangle.Empty;
			return result;
		}

		/// <summary>
		/// Helper method to get the window size for GDI Windows
		/// </summary>
		/// <param name="rectangle">out Rectangle</param>
		/// <returns>bool true if it worked</returns>
		private bool GetWindowRect(out Rectangle rectangle) {
			var windowInfo = new WindowInfo();
			// Get the Window Info for this window
			bool result = User32.GetWindowInfo(Handle, ref windowInfo);
			rectangle = result ? windowInfo.rcWindow.ToRectangle() : Rectangle.Empty;
			return result;
		}

		/// <summary>
		/// Helper method to get the Border size for GDI Windows
		/// </summary>
		/// <param name="size">out Size</param>
		/// <returns>bool true if it worked</returns>
		private bool GetBorderSize(out Size size) {
			var windowInfo = new WindowInfo();
			// Get the Window Info for this window
			bool result = User32.GetWindowInfo(Handle, ref windowInfo);
			size = result ? new Size((int)windowInfo.cxWindowBorders, (int)windowInfo.cyWindowBorders) : Size.Empty;
			return result;
		}

		/// <summary>
		/// Set the window as foreground window
		/// </summary>
		/// <param name="handle">hWnd of the window to bring to the foreground</param>
		/// <param name="workaround">bool with true to use a trick to really bring the window to the foreground</param>
		public static void ToForeground(IntPtr handle, bool workaround = true)
		{
			var window = new WindowDetails(handle);
			// Nothing we can do if it's not visible!
			if (!window.Visible)
			{
				return;
			}
			if (window.Iconic)
			{
				window.Iconic = false;
				while (window.Iconic)
				{
					Application.DoEvents();
				}
			}
			// See https://msdn.microsoft.com/en-us/library/windows/desktop/ms633539(v=vs.85).aspx
			if (workaround)
			{
				const byte alt = 0xA4;
				const int extendedkey = 0x1;
				const int keyup = 0x2;
				// Simulate an "ALT" key press.
				User32.keybd_event(alt, 0x45, extendedkey | 0, 0);
				// Simulate an "ALT" key release.
				User32.keybd_event(alt, 0x45, extendedkey | keyup, 0);
			}
			// Show window in forground.
			User32.BringWindowToTop(handle);
			User32.SetForegroundWindow(handle);
		}

		/// <summary>
		/// Set the window as foreground window
		/// </summary>
		/// <param name="workaround">true to use a workaround, otherwise the window might only flash</param>
		public void ToForeground(bool workaround = true) {
			ToForeground(Handle, workaround);
		}

		/// <summary>
		/// Get the region for a window
		/// </summary>
		private Region GetRegion() {
			using (SafeRegionHandle region = GDI32.CreateRectRgn(0, 0, 0, 0)) {
				if (!region.IsInvalid) {
					RegionResult result = User32.GetWindowRgn(Handle, region);
					if (result != RegionResult.REGION_ERROR && result != RegionResult.REGION_NULLREGION) {
						return Region.FromHrgn(region.DangerousGetHandle());
					}
				}
			}
			return null;
		}

		private bool CanFreezeOrUnfreeze(string titleOrProcessname) {
			if (string.IsNullOrEmpty(titleOrProcessname)) {
				return false;
			}
			if (titleOrProcessname.ToLower().Contains("greenshot")) {
				return false;
			}

			foreach (string excludeProcess in ExcludeProcessesFromFreeze) {
				if (titleOrProcessname.ToLower().Contains(excludeProcess)) {
					return false;
				}
			}
			return true;
		}

		/// <summary>
		/// Freezes the process belonging to the window
		/// Warning: Use only if no other way!!
		/// </summary>
		private bool FreezeWindow() {
			bool frozen = false;
			using (Process proc = Process.GetProcessById(ProcessId)) {
				string processName = proc.ProcessName;
				if (!CanFreezeOrUnfreeze(processName)) {
					Log.DebugFormat("Not freezing {0}", processName);
					return false;
				}
				if (!CanFreezeOrUnfreeze(Text)) {
					Log.DebugFormat("Not freezing {0}", processName);
					return false;
				}
				Log.DebugFormat("Freezing process: {0}", processName);


				foreach (ProcessThread pT in proc.Threads) {
					IntPtr pOpenThread = Kernel32.OpenThread(ThreadAccess.SUSPEND_RESUME, false, (uint)pT.Id);

					if (pOpenThread == IntPtr.Zero) {
						break;
					}
					frozen = true;
					Kernel32.SuspendThread(pOpenThread);
					pT.Dispose();
				}
			}
			return frozen;
		}

		/// <summary>
		/// Unfreeze the process belonging to the window
		/// </summary>
		public void UnfreezeWindow()
        {
            using Process proc = Process.GetProcessById(ProcessId);
            string processName = proc.ProcessName;
            if (!CanFreezeOrUnfreeze(processName)) {
                Log.DebugFormat("Not unfreezing {0}", processName);
                return;
            }
            if (!CanFreezeOrUnfreeze(Text)) {
                Log.DebugFormat("Not unfreezing {0}", processName);
                return;
            }
            Log.DebugFormat("Unfreezing process: {0}", processName);

            foreach (ProcessThread pT in proc.Threads) {
                IntPtr pOpenThread = Kernel32.OpenThread(ThreadAccess.SUSPEND_RESUME, false, (uint)pT.Id);

                if (pOpenThread == IntPtr.Zero) {
                    break;
                }

                Kernel32.ResumeThread(pOpenThread);
            }
        }

		/// <summary>
		/// Return an Image representing the Window!
		/// As GDI+ draws it, it will be without Aero borders!
		/// </summary>
		public Image PrintWindow() {
			Rectangle windowRect = WindowRectangle;
			// Start the capture
			Exception exceptionOccured = null;
			Image returnImage;
			using (Region region = GetRegion()) {
				PixelFormat pixelFormat = PixelFormat.Format24bppRgb;
				// Only use 32 bpp ARGB when the window has a region
				if (region != null) {
					pixelFormat = PixelFormat.Format32bppArgb;
				}
				returnImage = new Bitmap(windowRect.Width, windowRect.Height, pixelFormat);
                using Graphics graphics = Graphics.FromImage(returnImage);
                using (SafeDeviceContextHandle graphicsDc = graphics.GetSafeDeviceContext()) {
                    bool printSucceeded = User32.PrintWindow(Handle, graphicsDc.DangerousGetHandle(), 0x0);
                    if (!printSucceeded) {
                        // something went wrong, most likely a "0x80004005" (Acess Denied) when using UAC
                        exceptionOccured = User32.CreateWin32Exception("PrintWindow");
                    }
                }

                // Apply the region "transparency"
                if (region != null && !region.IsEmpty(graphics)) {
                    graphics.ExcludeClip(region);
                    graphics.Clear(Color.Transparent);
                }

                graphics.Flush();
            }

			// Return null if error
			if (exceptionOccured != null) {
				Log.ErrorFormat("Error calling print window: {0}", exceptionOccured.Message);
				returnImage.Dispose();
				return null;
			}
			if (!HasParent && Maximised) {
				Log.Debug("Correcting for maximalization");
                GetBorderSize(out var borderSize);
				Rectangle borderRectangle = new Rectangle(borderSize.Width, borderSize.Height, windowRect.Width - (2 * borderSize.Width), windowRect.Height - (2 * borderSize.Height));
				ImageHelper.Crop(ref returnImage, ref borderRectangle);
			}
			return returnImage;
		}

		/// <summary>
		///  Constructs a new instance of this class for
		///  the specified Window Handle.
		/// </summary>
		/// <param name="hWnd">The Window Handle</param>
		public WindowDetails(IntPtr hWnd) {
			Handle = hWnd;
		}

		/// <summary>
		/// Gets an instance of the current active foreground window
		/// </summary>
		/// <returns>WindowDetails of the current window</returns>
		public static WindowDetails GetActiveWindow() {
			IntPtr hWnd = User32.GetForegroundWindow();
			if (hWnd != IntPtr.Zero) {
				if (IgnoreHandles.Contains(hWnd)) {
					return GetDesktopWindow();
				}

				WindowDetails activeWindow = new WindowDetails(hWnd);
				// Invisible Windows should not be active
				if (!activeWindow.Visible) {
					return GetDesktopWindow();
				}
				return activeWindow;
			}
			return null;
		}

		/// <summary>
		/// Check if this window is Greenshot
		/// </summary>
		public bool IsGreenshot {
			get {
				try {
					if (!IsMetroApp)
                    {
                        using Process thisWindowProcess = Process;
                        return "Greenshot".Equals(thisWindowProcess.MainModule.FileVersionInfo.ProductName);
                    }
				} catch (Exception ex) {
					Log.Warn(ex);
				}
				return false;
			}
		}

		/// <summary>
		/// Gets the Desktop window
		/// </summary>
		/// <returns>WindowDetails for the desktop window</returns>
		public static WindowDetails GetDesktopWindow() {
			return new WindowDetails(User32.GetDesktopWindow());
		}

		/// <summary>
		/// Get all the top level windows
		/// </summary>
		/// <returns>List of WindowDetails with all the top level windows</returns>
		public static IList<WindowDetails> GetAllWindows() {
			return GetAllWindows(null);
		}

		/// <summary>
		/// Get all the top level windows, with matching classname
		/// </summary>
		/// <returns>List WindowDetails with all the top level windows</returns>
		public static IList<WindowDetails> GetAllWindows(string classname) {
			return new WindowsEnumerator().GetWindows(IntPtr.Zero, classname).Items;
		}

		/// <summary>
		/// Recursive "find children which"
		/// </summary>
		/// <param name="point">point to check for</param>
		/// <returns></returns>
		public WindowDetails FindChildUnderPoint(Point point) {
			if (!Contains(point)) {
				return null;
			}
			var rect = WindowRectangle;
			// If the mouse it at the edge, take the whole window
			if (rect.X == point.X || rect.Y == point.Y || rect.Right == point.X || rect.Bottom == point.Y)
			{
				return this;
			}
			// Look into the child windows
			foreach(var childWindow in Children) {
				if (childWindow.Contains(point)) {
					return childWindow.FindChildUnderPoint(point);
				}
			}
			return this;
		}

		/// <summary>
		/// Retrieves the classname for a hWnd
		/// </summary>
		/// <param name="hWnd">IntPtr with the windows handle</param>
		/// <returns>String with ClassName</returns>
		public static string GetClassName(IntPtr hWnd) {
			var classNameBuilder = new StringBuilder(260, 260);
			User32.GetClassName(hWnd, classNameBuilder, classNameBuilder.Capacity);
			return classNameBuilder.ToString();
		}

		/// <summary>
		/// Helper method to decide if a top level window is visible
		/// </summary>
		/// <param name="window"></param>
		/// <param name="screenBounds"></param>
		/// <returns></returns>
		private static bool IsVisible(WindowDetails window, Rectangle screenBounds)
		{
			// Ignore invisible
			if (!window.Visible)
			{
				return false;
			}
			// Ignore minizied
			if (window.Iconic)
			{
				return false;
			}
			if (IgnoreClasses.Contains(window.ClassName))
			{
				return false;
			}
			// On windows which are visible on the screen
			var windowRect = window.WindowRectangle;
			windowRect.Intersect(screenBounds);
			if (windowRect.IsEmpty)
			{
				return false;
			}
			// Skip everything which is not rendered "normally", trying to fix BUG-2017
			var exWindowStyle = window.ExtendedWindowStyle;
			if (!window.IsApp && !window.IsWin10App && (exWindowStyle & ExtendedWindowStyleFlags.WS_EX_NOREDIRECTIONBITMAP) != 0)
			{
				return false;
			}

			return true;
		}

		/// <summary>
		/// Get all the visible top level windows
		/// </summary>
		/// <returns>List WindowDetails with all the visible top level windows</returns>
		public static IEnumerable<WindowDetails> GetVisibleWindows() {
			Rectangle screenBounds = WindowCapture.GetScreenBounds();
			foreach(var window in GetMetroApps()) {
				if (IsVisible(window, screenBounds))
				{
					yield return window;
				}
			}
			foreach (var window in GetAllWindows())
			{
				if (IsVisible(window, screenBounds))
				{
					yield return window;
				}
			}
		}

		/// <summary>
		/// Get the WindowDetails for all Metro Apps
		/// These are all Windows with Classname "Windows.UI.Core.CoreWindow"
		/// </summary>
		/// <returns>List WindowDetails with visible metro apps</returns>
		public static IEnumerable<WindowDetails> GetMetroApps() {
			// if the appVisibility != null we have Windows 8.
			if (AppVisibility == null)
			{
				yield break;
			}
			//string[] wcs = {"ImmersiveGutter", "Snapped Desktop", "ImmersiveBackgroundWindow","ImmersiveLauncher","Windows.UI.Core.CoreWindow","ApplicationManager_ImmersiveShellWindow","SearchPane","MetroGhostWindow","EdgeUiInputWndClass", "NativeHWNDHost", "Shell_CharmWindow"};
			//List<WindowDetails> specials = new List<WindowDetails>();
			//foreach(string wc in wcs) {
			//	IntPtr wcHandle = User32.FindWindow(null, null);
			//	while (wcHandle != IntPtr.Zero) {
			//		WindowDetails special = new WindowDetails(wcHandle);
			//		if (special.WindowRectangle.Left >= 1920 && special.WindowRectangle.Size != Size.Empty) {
			//			specials.Add(special);
			//			LOG.DebugFormat("Found special {0} : {1} at {2} visible: {3} {4} {5}", special.ClassName, special.Text, special.WindowRectangle, special.Visible, special.ExtendedWindowStyle, special.WindowStyle);
			//		}
			//		wcHandle = User32.FindWindowEx(IntPtr.Zero, wcHandle, null, null);
			//	};
			//}
			IntPtr nextHandle = User32.FindWindow(MetroWindowsClass, null);
			while (nextHandle != IntPtr.Zero) {
				var metroApp = new WindowDetails(nextHandle);
				yield return metroApp;
				// Check if we have a gutter!
				if (metroApp.Visible && !metroApp.Maximised) {
					var gutterHandle = User32.FindWindow(MetroGutterClass, null);
					if (gutterHandle != IntPtr.Zero) {
						yield return new WindowDetails(gutterHandle);
					}
				}
				nextHandle = User32.FindWindowEx(IntPtr.Zero, nextHandle, MetroWindowsClass, null);
			}
		}

		/// <summary>
		/// Check if the window is a top level
		/// </summary>
		/// <param name="window">WindowDetails</param>
		/// <returns>bool</returns>
		private static bool IsTopLevel(WindowDetails window)
		{
			// Ignore windows without title
			if (window.Text.Length == 0)
			{
				return false;
			}
			if (IgnoreClasses.Contains(window.ClassName))
			{
				return false;
			}
			// Windows without size
			if (window.WindowRectangle.Size.IsEmpty)
			{
				return false;
			}
			if (window.HasParent)
			{
				return false;
			}
			var exWindowStyle = window.ExtendedWindowStyle;
			if ((exWindowStyle & ExtendedWindowStyleFlags.WS_EX_TOOLWINDOW) != 0)
			{
				return false;
			}
			// Skip everything which is not rendered "normally", trying to fix BUG-2017
			if (!window.IsApp && !window.IsWin10App && (exWindowStyle & ExtendedWindowStyleFlags.WS_EX_NOREDIRECTIONBITMAP) != 0)
			{
				return false;
			}
			// Skip preview windows, like the one from Firefox
			if ((window.WindowStyle & WindowStyleFlags.WS_VISIBLE) == 0)
			{
				return false;
			}
			return window.Visible || window.Iconic;
		}

		/// <summary>
		/// Get all the top level windows
		/// </summary>
		/// <returns>List WindowDetails with all the top level windows</returns>
		public static IEnumerable<WindowDetails> GetTopLevelWindows() {
			foreach (var possibleTopLevel in GetMetroApps())
			{
				if (IsTopLevel(possibleTopLevel))
				{
					yield return possibleTopLevel;
				}
			}

			foreach (var possibleTopLevel in GetAllWindows())
			{
				if (IsTopLevel(possibleTopLevel))
				{
					yield return possibleTopLevel;
				}
			}
		}

		/// <summary>
		/// Find a window belonging to the same process as the supplied window.
		/// </summary>
		/// <param name="windowToLinkTo"></param>
		/// <returns></returns>
		public static WindowDetails GetLinkedWindow(WindowDetails windowToLinkTo) {
			int processIdSelectedWindow = windowToLinkTo.ProcessId;
			foreach(var window in GetAllWindows()) {
				// Ignore windows without title
				if (window.Text.Length == 0) {
					continue;
				}
				// Ignore invisible
				if (!window.Visible) {
					continue;
				}
				if (window.Handle == windowToLinkTo.Handle) {
					continue;
				}
				if (window.Iconic) {
					continue;
				}

				// Windows without size
				Size windowSize = window.WindowRectangle.Size;
				if (windowSize.Width == 0 ||  windowSize.Height == 0) {
					continue;
				}

				if (window.ProcessId == processIdSelectedWindow) {
					Log.InfoFormat("Found window {0} belonging to same process as the window {1}", window.Text, windowToLinkTo.Text);
					return window;
				}
			}
			return null;
		}

		/// <summary>
		/// Helper method to "active" all windows that are not in the supplied list.
		/// One should preferably call "GetVisibleWindows" for the oldWindows.
		/// </summary>
		/// <param name="oldWindows">List WindowDetails with old windows</param>
		public static void ActiveNewerWindows(IEnumerable<WindowDetails> oldWindows)
		{
			var oldWindowsList = new List<WindowDetails>(oldWindows);
			foreach(var window in GetVisibleWindows()) {
				if (!oldWindowsList.Contains(window)) {
					window.ToForeground();
				}
			}
		}

		/// <summary>
		/// Get the AppLauncher
		/// </summary>
		/// <returns></returns>
		public static WindowDetails GetAppLauncher() {
			// Only if Windows 8 (or higher)
			if (AppVisibility == null) {
				return null;
			}
			IntPtr appLauncher = User32.FindWindow(MetroApplauncherClass, null);
			if (appLauncher != IntPtr.Zero) {
				return new WindowDetails (appLauncher);
			}
			return null;
		}

		/// <summary>
		/// Return true if the metro-app-launcher is visible
		/// </summary>
		/// <returns></returns>
		public static bool IsAppLauncherVisible {
			get {
				if (AppVisibility != null) {
					return AppVisibility.IsLauncherVisible;
				}
				return false;
			}
		}
	}
}