using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Interop;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Threading;

namespace Tango.Editors
{
    /// <exclude/>
    /// <summary>
    /// Contains some helper methods for UI interaction.
    /// </summary>
    internal static class UIHelper
    {
        #region Native Classes
        [StructLayout(LayoutKind.Sequential)]
        internal struct RECT
        {
            private int _Left;
            private int _Top;
            private int _Right;
            private int _Bottom;

            public RECT(RECT Rectangle)
                : this(Rectangle.Left, Rectangle.Top, Rectangle.Right, Rectangle.Bottom)
            {
            }
            public RECT(int Left, int Top, int Right, int Bottom)
            {
                _Left = Left;
                _Top = Top;
                _Right = Right;
                _Bottom = Bottom;
            }

            public int X
            {
                get { return _Left; }
                set { _Left = value; }
            }
            public int Y
            {
                get { return _Top; }
                set { _Top = value; }
            }
            public int Left
            {
                get { return _Left; }
                set { _Left = value; }
            }
            public int Top
            {
                get { return _Top; }
                set { _Top = value; }
            }
            public int Right
            {
                get { return _Right; }
                set { _Right = value; }
            }
            public int Bottom
            {
                get { return _Bottom; }
                set { _Bottom = value; }
            }
            public int Height
            {
                get { return _Bottom - _Top; }
                set { _Bottom = value + _Top; }
            }
            public int Width
            {
                get { return _Right - _Left; }
                set { _Right = value + _Left; }
            }
            public System.Drawing.Point Location
            {
                get { return new System.Drawing.Point(Left, Top); }
                set
                {
                    _Left = value.X;
                    _Top = value.Y;
                }
            }
            public System.Drawing.Size Size
            {
                get { return new System.Drawing.Size(Width, Height); }
                set
                {
                    _Right = value.Width + _Left;
                    _Bottom = value.Height + _Top;
                }
            }

            public static implicit operator System.Drawing.Rectangle(RECT Rectangle)
            {
                return new System.Drawing.Rectangle(Rectangle.Left, Rectangle.Top, Rectangle.Width, Rectangle.Height);
            }
            public static implicit operator RECT(System.Drawing.Rectangle Rectangle)
            {
                return new RECT(Rectangle.Left, Rectangle.Top, Rectangle.Right, Rectangle.Bottom);
            }
            public static bool operator ==(RECT Rectangle1, RECT Rectangle2)
            {
                return Rectangle1.Equals(Rectangle2);
            }
            public static bool operator !=(RECT Rectangle1, RECT Rectangle2)
            {
                return !Rectangle1.Equals(Rectangle2);
            }

            public override string ToString()
            {
                return "{Left: " + _Left + "; " + "Top: " + _Top + "; Right: " + _Right + "; Bottom: " + _Bottom + "}";
            }

            public override int GetHashCode()
            {
                return ToString().GetHashCode();
            }

            public bool Equals(RECT Rectangle)
            {
                return Rectangle.Left == _Left && Rectangle.Top == _Top && Rectangle.Right == _Right && Rectangle.Bottom == _Bottom;
            }

            public override bool Equals(object Object)
            {
                if (Object is RECT)
                {
                    return Equals((RECT)Object);
                }
                else if (Object is System.Drawing.Rectangle)
                {
                    return Equals(new RECT((System.Drawing.Rectangle)Object));
                }

                return false;
            }
        }

        #endregion

        [DllImport("user32.dll")]
        internal static extern bool GetWindowRect(IntPtr hWnd, out RECT lpRect);
        [DllImport("user32.dll")]
        internal static extern bool PrintWindow(IntPtr hWnd, IntPtr hdcBlt, int nFlags);
        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        internal static extern IntPtr GetCapture();

        internal static void InvokeUI(Action action)
        {
            EnsureDispatcher();


            try
            {
                Application.Current.Dispatcher.BeginInvoke(action);
            }
            catch { }
        }

        internal static void InvokeUIUrgent(Action action)
        {
            EnsureDispatcher();
            Application.Current.Dispatcher.Invoke(action, DispatcherPriority.Send);
        }

        internal static void EnsureDispatcher()
        {
            try
            {
                if (System.Windows.Application.Current == null) //Using this to enable processing outside a WPF application.
                {
                    new System.Windows.Application { ShutdownMode = ShutdownMode.OnExplicitShutdown };
                }
            }
            catch { }
        }

        internal static void DoEvents()
        {
            Application.Current.Dispatcher.Invoke(DispatcherPriority.Background,
                                                  new Action(delegate { }));
        }

        internal static void ReleaseMouseCapture()
        {
            IntPtr capturingHandle = GetCapture();
            for (int i = 0; i < Application.Current.Windows.Count; i++)
            {
                if (new WindowInteropHelper(Application.Current.Windows[i]).Handle == capturingHandle)
                {
                    Mouse.Capture(Application.Current.Windows[i], CaptureMode.Element);
                    Application.Current.Windows[i].ReleaseMouseCapture();
                    break;
                }
            }
        }

        internal static void RemoveChild(DependencyObject parent, UIElement child)
        {
            var panel = parent as Panel;
            if (panel != null)
            {
                panel.Children.Remove(child);
                return;
            }

            var decorator = parent as Decorator;
            if (decorator != null)
            {
                if (decorator.Child == child)
                {
                    decorator.Child = null;
                }
                return;
            }

            var contentPresenter = parent as ContentPresenter;
            if (contentPresenter != null)
            {
                if (contentPresenter.Content == child)
                {
                    contentPresenter.Content = null;
                }
                return;
            }

            var contentControl = parent as ContentControl;
            if (contentControl != null)
            {
                if (contentControl.Content == child)
                {
                    contentControl.Content = null;
                }
                return;
            }
        }

        internal static void AddChild(DependencyObject parent, UIElement child)
        {
            var panel = parent as Panel;
            if (panel != null)
            {
                panel.Children.Add(child);
                return;
            }

            var decorator = parent as Decorator;
            if (decorator != null)
            {
                decorator.Child = child;
                return;
            }

            var contentPresenter = parent as ContentPresenter;
            if (contentPresenter != null)
            {
                contentPresenter.Content = child;
                return;
            }

            var contentControl = parent as ContentControl;
            if (contentControl != null)
            {
                contentControl.Content = child;
                return;
            }
        }

        public static RenderTargetBitmap TakeSnapshot(Visual oVisual, Size oSize)
        {

            int nWidth = (int)Math.Ceiling(oSize.Width);
            int nHeight = (int)Math.Ceiling(oSize.Height);

            RenderTargetBitmap oTargetBitmap = new RenderTargetBitmap(
                nWidth,
                nHeight,
                96,
                96,
                PixelFormats.Pbgra32
            );

            DrawingVisual oDrawingVisual = new DrawingVisual();

            using (DrawingContext oDrawingContext = oDrawingVisual.RenderOpen())
            {
                VisualBrush oVisualBrush = new VisualBrush(oVisual) { Stretch = Stretch.Fill };

                oDrawingContext.DrawRectangle(
                    oVisualBrush,
                    null,
                    new Rect(
                        new Point(),
                        new Size(nWidth, nHeight)
                    )
                );

                oDrawingContext.Close();
                oTargetBitmap.Render(oDrawingVisual);
            }

            oTargetBitmap.Freeze();

            return oTargetBitmap;
        }

        public static RenderTargetBitmap TakeSnapshot(FrameworkElement element)
        {

            int nWidth = (int)Math.Ceiling(element.ActualWidth);
            int nHeight = (int)Math.Ceiling(element.ActualHeight);

            RenderTargetBitmap oTargetBitmap = new RenderTargetBitmap(
                nWidth,
                nHeight,
                96,
                96,
                PixelFormats.Pbgra32
            );

            DrawingVisual oDrawingVisual = new DrawingVisual();

            using (DrawingContext oDrawingContext = oDrawingVisual.RenderOpen())
            {
                VisualBrush oVisualBrush = new VisualBrush(element) { Stretch = Stretch.Fill };

                oDrawingContext.DrawRectangle(
                    oVisualBrush,
                    null,
                    new Rect(
                        new Point(),
                        new Size(nWidth, nHeight)
                    )
                );

                oDrawingContext.Close();
                oTargetBitmap.Render(oDrawingVisual);
            }

            return oTargetBitmap;
        }

        public static System.Drawing.Bitmap TakeSnapshot(Window window)
        {

            var handle = new WindowInteropHelper(window).Handle;
            RECT rc;
            GetWindowRect(handle, out rc);

            System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(rc.Width, rc.Height, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
            var gfxBmp = System.Drawing.Graphics.FromImage(bmp);
            IntPtr hdcBitmap = gfxBmp.GetHdc();

            PrintWindow(handle, hdcBitmap, 0);

            gfxBmp.ReleaseHdc(hdcBitmap);
            gfxBmp.Dispose();

            return bmp;
        }

        internal static Stream GetApplicationResource(String resourcePath)
        {
            String callingAssembly = Assembly.GetCallingAssembly().GetName().Name;
            Uri uri = new Uri("/" + callingAssembly + ";component/" + resourcePath, UriKind.Relative);
            System.Windows.Resources.StreamResourceInfo info = Application.GetResourceStream(uri);
            return info.Stream;
        }

        internal static BitmapSource GetImageFromApplicationResource(String resourcePath)
        {
            String callingAssembly = Assembly.GetCallingAssembly().GetName().Name;
            Uri uri = new Uri("/" + callingAssembly + ";component/" + resourcePath, UriKind.Relative);
            System.Windows.Resources.StreamResourceInfo info = Application.GetResourceStream(uri);

            var bitmapImage = new BitmapImage();
            bitmapImage.BeginInit();
            bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
            bitmapImage.StreamSource = info.Stream;
            bitmapImage.EndInit();
            return bitmapImage;
        }

        internal static String GetStartupPath()
        {
            return System.AppDomain.CurrentDomain.BaseDirectory;
        }

        internal static String GetRandomAnimationName()
        {
            return "ani" + Guid.NewGuid().ToString().Replace("-", "");
        }
    }
}